CHAPTER 7. ENERGY CONSUMPTION OF FURNACES AND BOILERS

TABLE OF CONTENTS

7.1 INTRODUCTION ..................................................... 7-1

7.2 VIRTUAL FURNACE MODELS ......................................... 7-2

7.2.1 Actual Basic Furnace Models ...................................... 7-3

7.2.2 Input Capacity and Maximum Airflow ............................... 7-3

7.2.2.1 Non-Weatherized Gas Furnaces .............................. 7-3

7.2.2.2 Other Product Classes ...................................... 7-4

7.2.3 Blower Size .................................................... 7-5

7.2.4 Motor Size ..................................................... 7-6

7.2.5 Supply-Air Outlet Area ........................................... 7-6

7.2.6 Power Consumption of Draft Inducer ................................ 7-9

7.2.7 Delay and Ignitor Times ......................................... 7-10

7.3 HOUSING SAMPLE .................................................. 7-10

7.4 ASSIGNING FURNACES TO SAMPLE HOUSES .......................... 7-12

7.4.1 Furnace Input Capacity .......................................... 7-12

7.4.2 Airflow Capacity ............................................... 7-12

7.4.3 Efficiency ..................................................... 7-13

7.4.4 Electricity Consumption of the Furnace Blower ....................... 7-14

7.5 FURNACE BLOWER ELECTRICITY CONSUMPTION .................... 7-14

7.5.1 System Curves ................................................. 7-15

7.5.2 Furnace Fan Curves ............................................. 7-16

7.5.3 Fan Power .................................................... 7-18

7.5.4 Overall Air-Moving Efficiency .................................... 7-20

7.6 ANNUAL HEATING LOADS IN SAMPLE HOUSING UNITS ............... 7-21

7.7 ENERGY CONSUMPTION ............................................ 7-22

7.7.1 Fuel Consumption .............................................. 7-22

7.7.2 Electricity Consumption ......................................... 7-23

7.8 RESULTS .......................................................... 7-24

LIST OF TABLES

Table 7.2.1 Characteristics of Basic Furnace Models .............................. 7-3

Table 7.2.2 Virtual Model Furnaces: Capacity and Airflow ........................ 7-4

Table 7.2.3 Relevant Sizes of Virtual Models for Non-Weatherized and

Weatherized Gas Furnaces ......................................... 7-4

Table 7.2.4 Relevant Sizes of Virtual Models for Mobile Home Furnaces ............. 7-5

Table 7.2.5 Relevant Sizes of Virtual Models for Oil-Fired Furnaces ................. 7-5

Table 7.2.6 Relevant Sizes of Virtual Models for Gas Boilers ...................... 7-5

Table 7.2.7 Relevant Sizes of Virtual Models for Oil Boilers .. 7-5

Table 7.2.8 Assigned Blower Size by Airflow Capacity ........................... 7-6

7-i

 EE-RM/STD-01-350 COMMENT 164

CHAPTER 7. ENERGY CONSUMPTION OF FURNACES AND BOILERS 

TABLE OF CONTENTS 

7.1 INTRODUCTION ..................................................... 7-1 

7.2 VIRTUAL FURNACE MODELS ......................................... 7-2 

7.2.1 Actual Basic Furnace Models ...................................... 7-3 

7.2.2 Input Capacity and Maximum Airflow ............................... 7-3 

7.2.2.1 Non-Weatherized Gas Furnaces .............................. 7-3 

7.2.2.2 Other Product Classes ...................................... 7-4 

7.2.3 Blower Size .................................................... 7-S 

7.2.4 Motor Size ..................................................... 7-6 

7.2.S Supply-Air Outlet Area ........................................... 7-6 

7.2.6 Power Consumption of Draft Inducer ................................ 7-9 

7.2.7 Delay and Ignitor Times ......................................... 7-10 

7.3 HOUSING SAMPLE .................................................. 7-10 

7.4 ASSIGNING FURNACES TO SAMPLE HOUSES .......................... 7-12 

7.4.1 Furnace Input Capacity .......................................... 7-12 

7.4.2 Airflow Capacity ............................................... 7-12 

7.4.3 Efficiency ..................................................... 7-13 

7.4.4 Electricity Consumption of the Furnace Blower ....................... 7-14 

7.S FURNACE BLOWER ELECTRICITY CONSUMPTION .................... 7-14 

7.S.1 System Curves ................................................. 7-1S 

7.S.2 Furnace Fan Curves ............................................. 7-16 

7.S.3 Fan Power .................................................... 7-18 

7.S.4 Overall Air-Moving Efficiency .................................... 7-20 

7.6 ANNUAL HEATING LOADS IN SAMPLE HOUSING UNITS ............... 7-21 

7.7 ENERGY CONSUMPTION ............................................ 7-22 

7.7.1 Fuel Consumption .............................................. 7-22 

7.7.2 Electricity Consumption ......................................... 7-23 

7.8 RESULTS .......................................................... 7-24 

Table 7.2.1 

Table 7.2.2 

Table 7.2.3 

Table 7.2.4 

Table 7.2.S 

Table 7.2.6 

Table 7.2.7 

Table 7.2.8 

LIST OF TABLES 

Characteristics of Basic Furnace Models .............................. 7-3 

Virtual Model Furnaces: Capacity and Airflow ........................ 7-4 

Relevant Sizes of Virtual Models for Non-Weatherized and 

Weatherized Gas Furnaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4 

Relevant Sizes of Virtual Models for Mobile Home Furnaces ............. 7-S 

Relevant Sizes of Virtual Models for Oil-Fired Furnaces ................. 7-S 

Relevant Sizes of Virtual Models for Gas Boilers ...................... 7-S 

Relevant Sizes of Virtual Models for Oil Boilers .. 7-S 

Assigned Blower Size by Airflow Capacity ........................... 7-6 

7-i 
Table 7.2.9 Assigned Motor Size by Airflow Capacity ............................ 7-6

Table 7.2.10 Supply-Air Outlet Area (in Square Feet) for Virtual Non-Condensing

Gas Furnace Models ............................................. 7-9

Table 7.2.11 Supply-Air Outlet Area ( in Square Feet) for Virtual Condensing

Gas Furnace Models ............................................. 7-9

Table 7.2.12 Values for Delay and Ignition Times ................................ 7-10

Table 7.3.1 Criteria for Selection of RECS Records by Product Class ............... 7-11

Table 7.5.1 Coefficients for CFM equation for PSC motors ....................... 7-17

Table 7.5.2 Coefficients for CFM equation for Two-Stage and Continuous

Modulating furnaces with brushless permanent magnet motors ........... 7-18

Table 7.5.3 Coefficients for W/CFM equation for PSC motors ..................... 7-19

Table 7.5.4 Coefficients for W/CFM equation for Two-Stage and Continuous

Modulating furnaces with ECM motors ............................. 7-20

Table 7.8.1 Non-Weatherized Gas Furnace Energy Use .......................... 7-24

Table 7.8.2 Weatherized Gas Furnace Energy Use (Low Cost Scenario) ............. 7-26

Table 7.8.3 Mobile Home Furnace Energy Use ................................. 7-28

Table 7.8.4 Oil-Fired Furnace Energy Use ..................................... 7-30

Table 7.8.5 Gas Boiler Energy Use (Low Cost Scenario) ......................... 7-32

Table 7.8.6 Oil-Fired Boiler Energy Use ...................................... 7-34

LIST OF FIGURES

Figure 7.2 .1 Supply-Air Outlet Area for Non-Condensing Natural Gas Furnaces ........ 7-7

Figure 7.2 .2 Supply-Air Outlet Area for Condensing Natural Gas Furnaces ............ 7-8

Figure 7.5 . 1 Sample of System Curves with a Typical Fan Curve ................... 7-16

Figure 7.8 . 1 Range of Annual Gas Use in MMBtu for Non-Weatherized Gas Furnaces . . 7-25

Figure 7.8 . 2 Range of Electricity Use in kWh for Non-Weatherized Gas Furnaces ...... 7-25

Figure 7.8 . 3 Range of Annual Gas Use in MMBtu for Weatherized Gas Furnaces

(Low Cost Scenario) ............................................ 7-27

Figure 7.8 .4 Range of Electricity Use in kWh for Weatherized Gas Furnaces

(Low Cost Scenario) ............................................ 7-27

Figure 7.8.5 Range of Annual Gas Use in MMBtu for Mobile Home Furnaces ......... 7-29

Figure 7.8 . 6 Range of Electricity Use in kWh for Mobile Home Furnaces ............. 7-29

Figure 7.8.7 Range of Annual Gas Use in MMBtu for Oil -Fired Furnaces ............. 7-31

Figure 7.8 . 8 Range of Electricity Use in kWh for Oil-Fired Furnaces ................ 7-31

Figure 7.8.9 Range of Annual Gas Use in MMBtu for Hot-Water Gas Boilers

(Low Cost Scenario) ............................................ 7-33

Figure 7.8 . 10 Range of Electricity Use in kWh for Hot-Water Gas Boilers

(Low Cost Scenario) ............................................ 7-33

Figure 7.8 . 11 Range of Annual Gas Use in MMBtu for Hot-Water Oil-Fired Boilers ..... 7-35

Figure 7.8 . 12 Range of Electricity Use in kWh for Hot-Water Oil-Fired Boilers ......... 7-35

7-ii

 EE-RM/STD-01-350 COMMENT 164

Table 7.2.9 

Table 7.2.10 

Table 7.2.11 

Table 7.2.12 

Table 7.3.1 

Table 7.5.1 

Table 7.5.2 

Table 7.5.3 

Table 7.5.4 

Table 7.8.1 

Table 7.8.2 

Table 7.8.3 

Table 7.8.4 

Table 7.8.5 

Table 7.8.6 

Figure 7.2.1 

Figure 7.2.2 

Figure 7.5.1 

Figure 7.8.1 

Figure 7.8.2 

Figure 7.8.3 

Figure 7.8.4 

Figure 7.8.5 

Figure 7.8.6 

Figure 7.8.7 

Figure 7.8.8 

Figure 7.8.9 

Figure 7.8.10 

Figure 7.8.11 

Figure 7.8.12 

Assigned Motor Size by Airflow Capacity ............................ 7-6 

Supply-Air Outlet Area (in Square Feet) for Virtual Non-Condensing 

Gas Furnace Models ............................................. 7-9 

Supply-Air Outlet Area (in Square Feet) for Virtual Condensing 

Gas Furnace Models ............................................. 7-9 

Values for Delay and Ignition Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10 

Criteria for Selection ofRECS Records by Product Class ............... 7-11 

Coefficients for CFM equation for PSC motors ....................... 7-17 

Coefficients for CFM equation for Two-Stage and Continuous 

Modulating furnaces with brushless permanent magnet motors ........... 7-18 

Coefficients for W /CFM equation for PSC motors ... . . . . . . . . . . . . . . . . . . 7-19 

Coefficients for W /CFM equation for Two-Stage and Continuous 

Modulating furnaces with ECM motors ............................. 7-20 

Non-Weatherized Gas Furnace Energy Use .......................... 7-24 

Weatherized Gas Furnace Energy Use (Low Cost Scenario) ............. 7-26 

Mobile Home Furnace Energy Use ................................. 7-28 

Oil-Fired Furnace Energy Use ..................................... 7-30 

Gas Boiler Energy Use (Low Cost Scenario) ......................... 7-32 

Oil-Fired Boiler Energy Use ...................................... 7-34 

LIST OF FIGURES 

Supply-Air Outlet Area for Non-Condensing Natural Gas Furnaces ........ 7-7 

Supply-Air Outlet Area for Condensing Natural Gas Furnaces ............ 7-8 

Sample of System Curves with a Typical Fan Curve ................... 7-16 

Range of Annual Gas Use in MMBtu for Non-Weatherized Gas Furnaces .. 7-25 

Range of Electricity Use in kWh for Non-Weatherized Gas Furnaces ...... 7-25 

Range of Annual Gas Use in MMBtu for Weatherized Gas Furnaces 

(Low Cost Scenario) ............................................ 7-27 

Range of Electricity Use in kWh for Weatherized Gas Furnaces 

(Low Cost Scenario) ............................................ 7-27 

Range of Annual Gas Use in MMBtu for Mobile Home Furnaces ......... 7-29 

Range of Electricity Use in kWh for Mobile Home Furnaces ............. 7-29 

Range of Annual Gas Use in MMBtu for Oil-Fired Furnaces ............. 7-31 

Range of Electricity Use in kWh for Oil-Fired Furnaces ................ 7-31 

Range of Annual Gas Use in MMBtu for Hot-Water Gas Boilers 

(Low Cost Scenario) ............................................ 7-33 

Range of Electricity Use in kWh for Hot-Water Gas Boilers 

(Low Cost Scenario) ............................................ 7-33 

Range of Annual Gas Use in MMBtu for Hot-Water Oil-Fired Boilers ..... 7-35 

Range of Electricity Use in kWh for Hot-Water Oil-Fired Boilers ......... 7-35 

7-ii 
CHAPTER 7. ENERGY CONSUMPTION OF FU RNACES AND BOILERS

7.1 INTRODUCTION

The furnace and boiler energy-efficiency standards rulemaking considers the change in

life-cycle cost (LCC) due to increased energy efficiency of furnaces and boilers. Energy

consumption is the key part of the operating-cost input of the LCC calculation. The energy

consumption of a furnace or boiler includes gas or oil and electricity.

In the engineering analysis, the Department calculated energy consumption of baseline

model-sized furnaces and boilers using the DOE test procedure for these types of equipment.

For the LCC analysis, DOE estimated energy consumption of furnaces and boilers in actual

housing units. To represent actual housing units likely to purchase and use furnaces and boilers

in 2015, DOE used a set of housing units from DOE's Energy Information Administration

(EIA)'s Residential Energy Consumption Survey of 2001 (RECS 2001).' For each housing unit,

RECS reports space-heating energy consumption, which is based on the existing heating

equipment. The Department calculated and adjusted the heating load of some of the RECS

sample housing units so that they better represent housing units in 2015. The Department then

calculated the energy consumption of alternative (more-efficient) equipment if it were purchased

and installed in each housing unit in place of the existing equipment.

The Department developed the method of calculation described in this chapter for nonweatherized gas furnaces, the most common in the US residential market among the six product

classes in the rulemaking analysis. The Department generalized the energy consumption

calculation for this product class to the other furnace product classes. Fuel consumption

calculations for boilers are similar to those for the furnace product classes. The electricity

calculations for boilers are simpler than for furnaces, because boilers do not provide thermal

distribution for space cooling as furnaces often do.

To begin the analysis, the Department developed representative conceptual furnace

models. These "virtual" models incorporated typical features of currently-marketed furnaces.

The Department based the virtual furnaces on models selected from the March 2005 Gas

Appliance Manufacturers Association (GAMA) Directory2 and product literature. The virtual

models capture the range of actual furnace sizes. The analysis assigned an appropriately sized

virtual furnace to each sample housing unit. As a way of modeling energy consumption of

alternative furnace designs, different design options were then applied to the virtual furnace.

Estimating the annual energy consumption of alternative furnaces in each housing unit

required DOE to estimate the heating loads of each housing unit. These loads represent the

amount of heating required to keep a housing unit comfortable during an entire year. The

Department estimated the heating loads from the heating energy consumption and the assumed

characteristics of the existing furnace and air conditioner in each sample housing unit. The

Department assigned the characteristics of the existing equipment to each sample housing unit,

depending on the size and climate zone of each housing unit and the age of the heating

7-1

 EE-RM/STD-01-350 COMMENT 164

CHAPTER 7. ENERGY CONSUMPTION OF FURNACES AND BOILERS 

7.1 INTRODUCTION 

The furnace and boiler energy-efficiency standards rulemaking considers the change in 

life-cycle cost (LCC) due to increased energy efficiency of furnaces and boilers. Energy 

consumption is the key part of the operating-cost input of the LCC calculation. The energy 

consumption of a furnace or boiler includes gas or oil and electricity. 

In the engineering analysis, the Department calculated energy consumption of baseline 

model-sized furnaces and boilers using the DOE test procedure for these types of equipment. 

For the LCC analysis, DOE estimated energy consumption of furnaces and boilers in actual 

housing units. To represent actual housing units likely to purchase and use furnaces and boilers 

in 2015, DOE used a set of housing units from DOE's Energy Information Administration 

(EIA)'s Residential Energy Consumption Survey of2001 (RECS 2001).1 For each housing unit, 

RECS reports space-heating energy consumption, which is based on the existing heating 

equipment. The Department calculated and adjusted the heating load of some of the RECS 

sample housing units so that they better represent housing units in 2015. The Department then 

calculated the energy consumption of alternative (more-efficient) equipment ifit were purchased 

and installed in each housing unit in place of the existing equipment. 

The Department developed the method of calculation described in this chapter for nonweatherized gas furnaces, the most common in the US residential market among the six product 

classes in the rulemaking analysis. The Department generalized the energy consumption 

calculation for this product class to the other furnace product classes. Fuel consumption 

calculations for boilers are similar to those for the furnace product classes. The electricity 

calculations for boilers are simpler than for furnaces, because boilers do not provide thermal 

distribution for space cooling as furnaces often do. 

To begin the analysis, the Department developed representative conceptual furnace 

models. These "virtual" models incorporated typical features of currently-marketed furnaces. 

The Department based the virtual furnaces on models selected from the March 2005 Gas 

Appliance Manufacturers Association (GAMA) Directory2 and product literature. The virtual 

models capture the range of actual furnace sizes. The analysis assigned an appropriately sized 

virtual furnace to each sample housing unit. As a way of modeling energy consumption of 

alternative furnace designs, different design options were then applied to the virtual furnace. 

Estimating the annual energy consumption of alternative furnaces in each housing unit 

required DOE to estimate the heating loads of each housing unit. These loads represent the 

amount of heating required to keep a housing unit comfortable during an entire year. The 

Department estimated the heating loads from the heating energy consumption and the assumed 

characteristics of the existing furnace and air conditioner in each sample housing unit. The 

Department assigned the characteristics of the existing equipment to each sample housing unit, 

depending on the size and climate zone of each housing unit and the age of the heating 

7-1 
equipment. The estimation of heating loads also required calculation of the electricity

consumption of the furnace blower, since heat from the furnace blower contributes to heating of

the housing unit.

To complete the analysis, the Department calculated how much energy would be required

by furnaces with various design options to meet the heating load of each sample housing unit.

7.2 VIRTUAL FURNACE MODELS

To conduct the analysis, the Department developed conceptual furnace models. The

Department intended these virtual furnace models to represent typical furnaces with basic

features, but not to describe specific, existing furnaces. The Department derived the

characteristics of the virtual furnace models from existing "basic" furnace models, after

examining the March 2005 GAMA Directory2 and the product literature of existing furnaces.

See Appendix F, Reduced Set of Furnace Models Database, for more details.

As a starting point for choosing values of input capacity for the virtual furnace models,

the Department looked at the number of models listed by input capacity in the March 2005

GAMA Directory (see Chapter 3, Figure 3 . 2.1). The Department selected models that were nonweatherized gas furnaces, not designed for mobile homes, not single packaged unit (combination

of heating and cooling), and not discontinued. Using these selection criteria, DOE reduced the

6,833 non-weatherized gas furnace models in the GAMA Directory to 1,277 models. For virtual

furnaces, DOE selected twelve input capacities that were the most common and that spanned the

range on the market. The Department made these selections based on the assumption that the

sizes that have the most models are the most popular.

The Department defined airflow capacity as the nominal maximum airflow at 0.5 inches

water gauge (in.w.g.) external static pressure , as listed in the product literature for each models.

Manufacturers usually code this airflow capacity in the model number (see Appendix G on

Decoding of Manufacturer Model Numbers, for more details.) Most of the furnaces fit into four

airflow capacity sizes: 800 cubic feet per minute (cfm), 1200 cfm, 1600 cfm, and 2000 cfm.

These airflow capacities correspond to nominal air-conditioner sizes of two tons, three tons, four

tons, and five tons, respectively. The Department used the same set of airflow and capacity sizes

for both non-condensing and condensing furnaces.

Furnaces are capable of providing several levels of airflow . For heating and cooling operation the manufacturer default

airflow level is used. If the furnace provides airflow for an air conditioner during cooling operation , it is typically set

to provide a higher level of airflow than when heating operation is used.

7-2

 EE-RM/STD-01-350 COMMENT 164

equipment. The estimation of heating loads also required calculation of the electricity 

consumption of the furnace blower, since heat from the furnace blower contributes to heating of 

the housing unit. 

To complete the analysis, the Department calculated how much energy would be required 

by furnaces with various design options to meet the heating load of each sample housing unit. 

7.2 VIRTUAL FURNACE MODELS 

To conduct the analysis, the Department developed conceptual furnace models. The 

Department intended these virtual furnace models to represent typical furnaces with basic 

features, but not to describe specific, existing furnaces. The Department derived the 

characteristics of the virtual furnace models from existing "basic" furnace models, after 

examining the March 2005 GAMA Directory2 and the product literature of existing furnaces. 

See Appendix F, Reduced Set of Furnace Models Database, for more details. 

As a starting point for choosing values of input capacity for the virtual furnace models, 

the Department looked at the number of models listed by input capacity in the March 2005 

GAMA Directory (see Chapter 3, Figure 3.2.1). The Department selected models that were nonweatherized gas furnaces, not designed for mobile homes, not single packaged unit (combination 

of heating and cooling), and not discontinued. Using these selection criteria, DOE reduced the 

6,833 non-weatherized gas furnace models in the GAMA Directory to 1,277 models. For virtual 

furnaces, DOE selected twelve input capacities that were the most common and that spanned the 

range on the market. The Department made these selections based on the assumption that the 

sizes that have the most models are the most popular. 

The Department defined airflow capacity as the nominal maximum airflow at 0.5 inches 

water gauge (in.w.g.) external static pressure, as listed in the product literature for each model". 

Manufacturers usually code this airflow capacity in the model number (see Appendix G on 

Decoding of Manufacturer Model Numbers, for more details.) Most of the furnaces fit into four 

airflow capacity sizes: 800 cubic feet per minute (cfm), 1200 c:fm, 1600 cfm, and 2000 cfm. 

These airflow capacities correspond to nominal air-conditioner sizes of two tons, three tons, four 

tons, and five tons, respectively. The Department used the same set of airflow and capacity sizes 

for both non-condensing and condensing furnaces. 

a Furnaces are capable of providing several levels of airflow. For heating and cooling operation the manufacturer default 

airflow level is used. If the furnace provides airflow for an air conditioner during cooling operation, it is typically set 

to provide a higher level of airflow than when heating operation is used. 

7-2 
7.2.1 Actual Basic Furnace Models

The Department selected actual furnace models that represent the fundamental

characteristics of non-condensing and condensing non-weatherized gas furnaces with no special

features. The Department used the characteristics listed in Table 7.2.1 to select basic furnace

models. These characteristics are the most common among models on the market (see Appendix

H, Determination of Basic Models). The Department selected several dozen furnace models that

have these features. It looked in detail at these basic models to determine specific characteristics

to use for creating virtual furnaces.

Table 7.2.1 Characteristics of Basic Furnace Models

Non-Condensing Gas Furnace Condensing Gas Furnace

single-stage single-stage

80% AFUE 90-92% AFUE

permanent split capacitor (PSC) blower motor PSC blower motor

forward-curved impeller blades forward-curved impeller blades

up-flow or horizontal air-flow down-flow, up-flow, or horizontal air-flow

The basic furnace models are listed by brand and series in Appendix H, which contains

basic non-condensing and condensing model data.

7.2.2 Input Capacity and Maximum Airflow

7.2.2.1 Non-Weatherized Gas Furnaces

For virtual furnace models, DOE selected 25 combinations ("bins") of input capacity and

maximum airflow. The marked cells in Table 7.2.2 reflect the input capacity and nominal

maximum airflow for the virtual furnace models. The selection reflects the most common input

and nominal maximum airflow capacities of models in the March 2005 GAMA Directory,2 in

product literature, and listed on furnace manufacturer web sites. Most basic models on the

market fit into the 25 bins of input capacity and airflow capacity. Some models do not exactly

match the bins, but their values are close enough that DOE included them in one of the 25 bins.

For example, 40 kBtu/h and 45 kBtu/h models are grouped together into a single 45 kBtu/h bin.

Most bins have at least two actual models.

 EE-RM/STD-01-350 COMMENT 164

7.2.1 Actual Basic Furnace Models 

The Department selected actual furnace models that represent the fundamental 

characteristics of non-condensing and condensing non-weatherized gas furnaces with no special 

features. The Department used the characteristics listed in Table 7.2.1 to select basic furnace 

models. These characteristics are the most common among models on the market (see Appendix 

H, Determination of Basic Models). The Department selected several dozen furnace models that 

have these features. It looked in detail at these basic models to determine specific characteristics 

to use for creating virtual furnaces. 

Table 7 2 .. 1 Characteristics of Basic Furnace Models 

Non-Condensing Gas Furnace Condensing Gas Furnace 

single-stage single-stage 

80%AFUE 90-92% AFUE 

permanent split capacitor (PSC) blower motor PSC blower motor 

forward-curved impeller blades forward-curved impeller blades 

up-flow or horizontal air-flow down-flow, up-flow, or horizontal air-flow 

The basic furnace models are listed by brand and series in Appendix H, which contains 

basic non-condensing and condensing model data. 

7.2.2 Input Capacity and Maximum Airflow 

7.2.2.1 Non-Weatherized Gas Furnaces 

For virtual furnace models, DOE selected 25 combinations ("bins") of input capacity and 

maximum airflow. The marked cells in Table 7.2.2 reflect the input capacity and nominal 

maximum airflow for the virtual furnace models. The selection reflects the most common input 

and nominal maximum airflow capacities of models in the March 2005 GAMA Directory/ in 

product literature, and listed on furnace manufacturer web sites. Most basic models on the 

market fit into the 25 bins of input capacity and airflow capacity. Some models do not exactly 

match the bins, but their values are close enough that DOE included them in one of the 25 bins. 

For example, 40 kBtu/h and 45 kBtu/h models are grouped together into a single 45 kBtu/h bin. 

Most bins have at least two actual models. 

7-3 
Table 7.2.2 Virtual Model Furnaces: Capacity and Airflow

Input Capacity (kBtu/h)

45 50 60 70 75 80 90 100 115 120 125 140

800 cfm x x x

(2 tons)

1200 cfin x x x x x x x x

(3 tons)

1600 cfm x x x x x x x x

(4 tons)

2000 cfm

:I

x x x x x x

(5 tons)

- I

The Department created one virtual model to represent all the models assigned to each

bin. The Department used specifications from the actual models in each bin to determine the

specifications for the corresponding virtual model. These specifications include blower size,

motor size, supply-air outlet area, power consumption of the draft inducer and the igniter, and

several delay times. The specifications are described in the sections below.

7.2.2.2 Other Product Classes

In its analysis of weatherized gas furnaces, DOE used the same virtual models as it used

in the analysis of non-weatherized gas furnaces. Because of the limited number of sizes

available for mobile home gas furnaces, DOE selected a subset of the 25 input and airflow

capacity combinations to represent each product class. The selection of oil-fired furnaces

reflects the most common input and nominal maximum airflow capacities of models in the

March 2005 GAMA Directory. The selection of oil-fired and gas boilers reflects the most

common input capacities of models in the March 2005 GAMA Directory. Tables 7.2.3-7.2.7 list

the relevant sizes for non-weatherized and weatherized gas furnaces, mobile home furnaces, oilfired furnaces, gas boilers, and oil-fired boilers.

Table 7.2.3 Relevant Sizes of Virtual Models for Non-Weatherized and Weatherized Gas

Furnaces

Input Capacity (kBtu/h)

45 50 60 70 75 80 90 100 115 120 125 140

Max. 2 X X X

Airflow 3 X X X X X X X X

(tons) 4 X X X X X X X X

5 X X X X X X

7-4

 EE-RM/STD-01-350 COMMENT 164

Table 7.2.2 Virtual Model Furnaces: Capacity and Airflow 

Input Capacity (kBtu/h) 

45 50 60 70 75 80 90 100 115 120 125 140 

800 cfm x 

(2 tons) 

1200 dill x 

(3 tons) 

1600 cfm 

(4 tons) 

2000 cfm 

(5 tons) 

x x 

x x x x 

x x 

x x x 

x x x x x x 

x x x x x x 

The Department created one virtual model to represent all the models assigned to each 

bin. The Department used specifications from the actual models in each bin to determine the 

specifications for the corresponding virtual model. These specifications include blower size, 

motor size, supply-air outlet area, power consumption of the draft inducer and the igniter, and 

several delay times. The specifications are described in the sections below. 

7.2.2.2 Other Product Classes 

In its analysis of weatherized gas furnaces, DOE used the same virtual models as it used 

in the analysis of non-weatherized gas furnaces. Because of the limited number of sizes 

available for mobile home gas furnaces, DOE selected a subset of the 25 input and airflow 

capacity combinations to represent each product class. The selection of oil-fired furnaces 

reflects the most common input and nominal maximum airflow capacities of models in the 

March 2005 GAMA Directory. The selection of oil-fired and gas boilers reflects the most 

common input capacities of models in the March 2005 GAMA Directory. Tables 7.2.3-7.2.7 list 

the relevant sizes for non-weatherized and weatherized gas furnaces, mobile home furnaces, oilfired furnaces, gas boilers, and oil-fired boilers. 

Table 7.2.3 Relevant Sizes of Virtual Models for Non-Weatherized and Weatherized Gas 

Furnaces 

Input Capacity (kBtu/h) 

45 50 60 70 75 80 90 100 115 120 125 140 

Max. 2 X X X 

Airflow 3 X X X X X X X X 

(tons) 4 X X X X X X X X 

5 X X X X X X 

7-4 
Table 7.2.4 Relevant Sizes of Virtual Models for Mobile Home Furnaces

Input Capacity (kBtu/h)

Max.

Airflow

(tons)

60 70 1 75 1 80 1 90 1 100 1 115 1 120 1 125 1 140

X i I X I I X

X X X

X X X

X X X

Table 7.2.5 Relevant Sizes of Virtual Models for Oil-Fired Furnaces

Input Capacity (kBtu/h)

70 90 105 120 140 154 175 210

Max.

Airflow

2

(tons) 3 X X X

4 X X

5 X X X X X X

Table 7.2.6 Relevant Sizes of Virtual Models for Gas Boilers

Input Capacity (kBtu/h)

50 75 105 125 150 175 200

Table 7.2.7 Relevant Sizes of Virtual Models for Oil Boilers

Input Capacity (kBtu/h)

90 105

7.2.3 Blower Size

120 140 155 175 190

225

210

250

245

300

280

The Department selected a blower size (listed as nominal diameter in inches by nominal

width in inches) for each virtual furnace model (Table 7.2.8). The blower size is typical for the

basic furnace models in each bin. Blower size increases with airflow capacity, but not with input

capacity. The Department used four blower sizes-the same ones for condensing and noncondensing virtual furnace models. For the blower sizes of basic furnace models, see

Appendix H, Determination of Basic Models.

 EE-RM/STD-01-350 COMMENT 164

Table 7.2.4 Relevant Sizes of Virtual Models for Mobile Home Furnaces 

Input Capacity (kBtu/h) 

60 70 75 80 90 100 115 120 125 140 

Max. 2 X X X 

Airflow 3 X X X 

(tons) 4 X X X 

5 X X X 

Table 7.2.5 Relevant Sizes of Virtual Models for Oil-Fired Furnaces 

Input Capacity (kBtu/h) 

70 90 105 120 140 154 175 210 

Max. 2 

Airflow 

(tons) 3 X X X 

4 X X 

5 X X X X X X 

Table 7.2.6 Relevant Sizes of Virtual Models for Gas Boilers 

Input Capacity (kBtu/h) 

50 I 75 I 105 I 125 I 150 I 175 I 200 I 225 I 250 I 300 

Table 7.2.7 Relevant Sizes of Virtual Models for Oil Boilers 

Input Capacity (kBtu/h) 

90 I 105 I 120 I 140 I 155 I 175 I 190 I 210 I 245 I 280 

7.2.3 Blower Size 

The Department selected a blower size (listed as nominal diameter in inches by nominal 

width in inches) for each virtual furnace model (Table 7.2.8). The blower size is typical for the 

basic furnace models in each bin. Blower size increases with airflow capacity, but not with input 

capacity. The Department used four blower sizes-the same ones for condensing and noncondensing virtual furnace models. For the blower sizes of basic furnace models, see 

Appendix H, Determination of Basic Models. 

7-5 
Table 7.2.8 Assigned Blower Size b y Airflow Capacity

Airflow Capacity (cfm) Blower Size (inches)

2-ton models (800 cfm) 9 X 8

3-ton models (1200 cfm) 10 X 8

4-ton models (1600 cfm) 10 X 10

5-ton models (2000 cfm) 11 X 10

7.2.4 Motor Size

The motors for the basic furnace models are six-pole permanent split capacitor (PSC)

induction motors. The motors in the basic furnaces come with three to five taps that are used to

set the motor speed. The Department assumed that, at high speed, the motors operate with a

speed of 1075 revolutions per minute (rpm) to provide the nominal maximum airflow at 0.5

in.w.g.

The Department assigned motor size to virtual furnace models, as shown in Table 7.2.9,

to reflect typical-size motors of the basic furnace models. Motor sizes are the same for noncondensing and condensing furnaces. The larger the nominal maximum airflow, the larger the

motor size. For the blower motor size and number of taps on basic model furnaces, see

Appendix H, Determination of Basic Models, which lists the blower-motor sizes and number of

blower motor taps of basic furnace models.

Table 7.2.9 Assigned Motor Size by Airflow Capacity

Airflow Capacity (cfm) Motor Size (HP)

2-ton models (800 cfm) 1/5

3-ton models (1200 cfm) 1/3

4-ton models (1600 cfm) 1/2

5-ton models (2000 cfm) 3/4

7.2.5 Supply-Air Outlet Area

The supply-air outlet area is the opening from the furnace to the supply duct. The

supply-air outlet area for basic furnace models increases with airflow capacity and input

capacity. To capture this trend, DOE constructed a multiple regression equation of the supplyair outlet area to input capacity and airflow capacity for condensing and non-condensing

furnaces (see Appendix H, Determination of Basic Models, for supply-air outlet areas of basic

furnace models). The Department used the following equations to determine the supply-air

outlet area of the non-condensing and condensing virtual model furnace models:

7-6

 EE-RM/STD-01-350 COMMENT 164

T a bi e 7 2 8 .. A· sSlgne d Bl ower S· lze b .y A· lr fl ow C apaclry ·t 

Airflow Capacity (cfm) Blower Size (inches) 

2-ton models (800 cfm) 9x8 

3-ton models (1200 cfm) 10 x 8 

4-ton models (1600 cfm) lOx 10 

5-ton models (2000 cfm) 11 x 10 

7.2.4 Motor Size 

The motors for the basic furnace models are six-pole permanent split capacitor (PSC) 

induction motors. The motors in the basic furnaces come with three to five taps that are used to 

set the motor speed. The Department assumed that, at high speed, the motors operate with a 

speed of 1075 revolutions per minute (rpm) to provide the nominal maximum airflow at 0.5 

m.w.g. 

The Department assigned motor size to virtual furnace models, as shown in Table 7.2.9, 

to reflect typical-size motors of the basic furnace models. Motor sizes are the same for noncondensing and condensing furnaces. The larger the nominal maximum airflow, the larger the 

motor size. For the blower motor size and number of taps on basic model furnaces, see 

Appendix H, Determination of Basic Models, which lists the blower-motor sizes and number of 

blower motor taps of basic furnace models. 

T a bi e 729 .. A· sSlgne d M o t or S· b A· fl C lZe 'y lr ow apacuy 

Airflow Capacity (cfm) Motor Size (HP) 

2-ton models (800 cfm) 1/5 

3-ton models (1200 cfm) 1/3 

4-ton models (1600 cfm) 1/2 

5-ton models (2000 cfm) 3/4 

7.2.5 Supply-Air Outlet Area 

The supply-air outlet area is the opening from the furnace to the supply duct. The 

supply-air outlet area for basic furnace models increases with airflow capacity and input 

capacity. To capture this trend, DOE constructed a multiple regression equation of the supplyair outlet area to input capacity and airflow capacity for condensing and non-condensing 

furnaces (see Appendix H, Determination of Basic Models, for supply-air outlet areas of basic 

furnace models). The Department used the following equations to determine the supply-air 

outlet area of the non-condensing and condensing virtual model furnace models: 

7-6 
SNC = 0.9498 + 0.5505 x (Q / 1000) + 0.0073 x (QIN) Eq.1

Sc = 0.7882 + 0.5006 x (Q / 1000) + 0.0087 x (QIN) Eq. 2

where:

= supply-air outlet area (sq. ft.) (non-condensing), and

= supply-air outlet area (sq. ft.) (condensing),

= nominal maximum airflow (cfm) at 0.5 in.w.g. static pressure, and

= input capacity (kBtu/h).

SNC

Sc

Q

QIN

Figures 7.2.1 and 7.2.2 show the data points for supply-air outlet area for basic furnace

models and the linear plane fit used to fit these points.

b

140 XJBG^

C&.^BOf^r(k?Lj

SNC = 0.9498 + 0.5505 * (Q/1000) + 0.0073 * AN)

R2 = .677

# -a

9 Data Points

Figure 7.2.1 Supply-Air Outlet Area for Non-Condensing Natural Gas Furnaces

7-7

 EE-RM/STD-01-350 COMMENT 164

SNC = 0.9498 + 0.5505 x CQ / 1000) + 0.0073 X CQIN) Eq. 1 

Sc = 0.7882 + 0.5006 x CQ / 1000) + 0.0087 X CQIN) Eq.2 

where: 

SNC = supply-air outlet area (sq. ft.) (non-condensing), and 

Sc = supply-air outlet area (sq. ft.) (condensing), 

Q = nominal maximum airflow (cfm) at 0.5 in.w.g. static pressure, and 

QIN = input capacity (kBtu/h). 

Figures 7.2.1 and 7.2.2 show the data points for supply-air outlet area for basic furnace 

models and the linear plane fit used to fit these points. 

60 100 

{r.p~tc ~ 

~ty(It13I(.J 

SNC = 0.9498 + 0.5505 * (Q/1000) + 0.0073 * (QIN) 

R2 = .677 

<;> Data Points 

Figure 7.2.1 Supply-Air Outlet Area for Non-Condensing Natural Gas Furnaces 

7-7 
Figure 7.2.2 Supply-Air Outlet Area for Condensing Natural Gas Furnaces

Tables 7.2.10 and 7 . 2.11 show the values DOE used for supply-air outlet areas for noncondensing and condensing virtual gas furnaces. The supply-air outlet area is larger for

condensing models. The larger opening compensates for the increased pressure drop due to the

secondary, condensing heat exchanger. This larger supply-air outlet area reduces the pressure

drop across the furnace , so that the pressure rise for condensing furnaces is the same as noncondensing model furnaces at the same airflow.

 EE-RM/STD-01-350 COMMENT 164

3.6 

3.4-

(I) 3.2 

.§ 3·0 

~ 2·8 ~ ... 2.6 C 

~ 2.4 

~ 2.2 

ii 

!!II 2.0 

~ 

c!fO 100 

iFDl.Jtc 120 

~/1);-(IcS7LJ 

Sc = 0.7882 + 0.5006 * (Q/1000) + 0.0087 * (QIN) 

R2 = .654 

:Iii"' u.: 

.lid.. 

lit 

.'E 

"'l" 

9 Data Points 

Figure 7.2.2 Supply-Air Outlet Area for Condensing Natural Gas Furnaces 

Tables 7.2.10 and 7.2.11 show the values DOE used for supply-air outlet areas for noncondensing and condensing virtual gas furnaces. The supply-air outlet area is larger for 

condensing models. The larger opening compensates for the increased pressure drop due to the 

secondary, condensing heat exchanger. This larger supply-air outlet area reduces the pressure 

drop across the furnace, so that the pressure rise for condensing furnaces is the same as noncondensing model furnaces at the same airflow. 

7-8 
Table 7.2.10 Supply-Air Outlet Area (in Square Feet) for Virtual Non-Condensing Gas

Furnace Models

Table 7.2.11 Supply-Air Outlet Area (in Square Feet) for Virtual Condensing Gas

Furnace Models

45

U O

O

O

00

0 0

N M

0 0

0 0

o V

50

1.72 1 1.76

1.94 1 1.98

60 1 70

1.83

2.05 1 2.13

2.35

75

2.16

2.39

Input Capacity (kBtu/h)

80

2.20

2.42

7.2.6 Power Consumption of Draft Inducer

90

2.27

2.50

2.06

100 1 115

2.35

2.57 1 2.68

2.79 2.90

120

2.72

2.94

125

2.75

2.97

140

3.08

A common value for the power consumption of the draft inducer, PE, for basic

non-condensing model furnaces is 75 watts, and the average value is about 75 W, so DOE

selected 75 W for all the non-condensing models. The Department found no correlation between

the PE and input capacity or between PE and airflow capacity. For condensing furnaces, the

Department used a PE of 90 W, which closely matches the mean for that group. See Appendix

H, Determination of Basic Models, for the power consumption of the draft inducer in the basic

models.

7-9

 EE-RM/STD-01-350 COMMENT 164

Table 7.2.10 Supply-Air Outlet Area (in Square Feet) for Virtual Non-Condensing Gas 

Furnace Models 

~ 

~ 

~ 

'" 

1.62 

0.. ~ ~---+----+---~~---

.~ " 

i/5 

v, 

o 

1;J 

1.78 1.82 2.00 2.04 

2.20 2.24 

Input Capacity (kBtu/h) 

2.08 2.17 

2.29 2.37 2.46 2.59 2.63 

2.57 2.66 2.79 2.83 2.88 3.01 

Table 7.2.11 Supply-Air Outlet Area (in Square Feet) for Virtual Condensing Gas 

Furnace Models 

Input Capacity (kBtu/h) 

cS~ 1.72 1.76 

~ o£ " " ON 

00 ~ 

" 0.. '" 

.~ 

E 1.94 1.98 2.13 2.16 2.20 2.27 CIl 

V, 

° 1;J 

:;: 2.35 2.39 2.42 2.50 2.57 2.68 2.72 0 

'E 

:.;;: 

s 

s '" ';< 2.06 2.79 2.90 2.94 2.97 3.08 

OJ 

::E 

7.2.6 Power Consumption of Draft Inducer 

A common value for the power consumption of the draft inducer, PE, for basic 

non-condensing model furnaces is 75 watts, and the average value is about 75 W, so DOE 

selected 75 W for all the non-condensing models. The Department found no correlation between 

the PE and input capacity or between PE and airflow capacity. For condensing furnaces, the 

Department used a PE of 90 W, which closely matches the mean for that group. See Appendix 

H, Determination of Basic Models, for the power consumption of the draft inducer in the basic 

models. 

7-9 
7.2.7 Delay and Ignitor Times

Pre-purge and post-purge times are the lengths of time the draft inducer operates before

and after a firing cycle. On-delay is the amount of time the blower waits to begin operating after

the burner starts firing. Off-delay is the time the blower keeps operating after the burner turns

off. Ignition time is the length of time the hot surface ignitor is on before gas is sent to the

burner.

Pre-purge, post-purge, on-delay, and off-delay times are not related to airflow or input

capacity. The Department selected common values for the delay and ignition times of

condensing and non-condensing virtual furnace models (Table 7.2.12). For these data on basic

furnace models, see Appendix H, Determination of Basic Models.

Table 7.2.12 Values for Delay and Ignition Times

Pre-Purge Post-Purge On-Delay Off-Delay ignition

15 seconds 5 seconds 30 seconds 120 seconds 37 seconds

7.3 HOUSING SAMPLE

The Department used a subset of records from the complete RECS 2001 data set that met

all of the following criteria:

1) Used central heating equipment,

2) Used a boiler or furnace as the main source of heat,

3) Used a heating fuel that is natural gas, liquefied petroleum gas (LPG), or fuel oil,

4) Heated only one housing unit, and,

5) Had energy consumption greater than zero.

The reason for the fourth criterion is that the Department assumed any furnaces or boilers

heating more than one unit would be larger than a residential furnace or boiler.

Of the 4822 housing units surveyed in RECS 2001, 2121 housing records (44.6 percent

of the total weighted sample) had central, forced-air furnaces and met the above criteria; 474

housing records (8.0 percent of the weighted sample) had boilers and met the above criteria. The

residential furnace and boiler subset thus represents 52.6 percent of the total housing units in the

United States. Appendix 0 presents a description of the subset.

The Department divided the RECS 2001 sample by product classes, using different

classification algorithms based on fuel type, home type, (the presence of) central air

conditioning, etc. (Table 7.3.1). The Department further divided the housing units with nonweatherized gas furnaces into those located in cold and mild climates.

The Department assembled the values for each sample housing unit for a number of

7-10

 EE-RM/STD-01-350 COMMENT 164

7.2.7 Delay and Ignitor Times 

Pre-purge and post-purge times are the lengths of time the draft inducer operates before 

and after a firing cycle. On-delay is the amount of time the blower waits to begin operating after 

the burner starts firing. Off-delay is the time the blower keeps operating after the burner turns 

off. Ignition time is the length of time the hot surface ignitor is on before gas is sent to the 

burner. 

Pre-purge, post-purge, on-delay, and off-delay times are not related to airflow or input 

capacity. The Department selected common values for the delay and ignition times of 

condensing and non-condensing virtual furnace models (Table 7.2.12). For these data on basic 

furnace models, see Appendix H, Determination of Basic Models. 

T a e hI 7212 .. V I a ues £ or D I e ayan dI 19m "t" IOn T" lmes 

Pre-Purge Post-Purge On-Delay Off-Delay Ignition 

15 seconds 5 seconds 30 seconds 120 seconds 37 seconds 

7.3 HOUSING SAMPLE 

The Department used a subset of records from the complete RECS 2001 data set that met 

all of the following criteria: 

1) Used central heating equipment, 

2) Used a boiler or furnace as the main source of heat, 

3) Used a heating fuel that is natural gas, liquefied petroleum gas (LPG), or fuel oil, 

4) Heated only one housing unit, and, 

5) Had energy consumption greater than zero. 

The reason for the fourth criterion is that the Department assumed any furnaces or boilers 

heating more than one unit would be larger than a residential furnace or boiler. 

Of the 4822 housing units surveyed in RECS 2001, 2121 housing records (44.6 percent 

of the total weighted sample) had central, forced-air furnaces and met the above criteria; 474 

housing records (8.0 percent of the weighted sample) had boilers and met the above criteria. The 

residential furnace and boiler subset thus represents 52.6 percent of the total housing units in the 

United States. Appendix 0 presents a description of the subset. 

The Department divided the RECS 2001 sample by product classes, using different 

classification algorithms based on fuel type, home type, (the presence of) central air 

conditioning, etc. (Table 7.3.1). The Department further divided the housing units with nonweatherized gas furnaces into those located in cold and mild climates. 

The Department assembled the values for each sample housing unit for a number of 

7-10 
variables concerning housing unit characteristics, equipment characteristics, household

characteristics, and energy use. Appendix 0 presents the variables included.

Table 7.3.1 Criteria for Selection of RIECS Records by Product Class

Product Class Algorithm # of # of US Households

Records Represented (million)

Non-Weatherized Gas Central heating equipment = furnace 1880 43.5

Furnace Heating fuel = gas

Home type = single or multi-family

Number of Housing Units Heated = 1

Weatherized* Gas Central heating equipment = furnace 373 8.4

Furnace Heating fuel = gas

Central air conditioning = yes (packaged unit)

Home type = single or multi-family

Number of Housing Units Heated = 1

Census Division = West or East South Central

Large State = California, Florida or Texas

Manufactured-Home Central heating equipment = furnace 72 1.5

Gas Furnace Heating fuel = gas

Home type = manufactured home

Number of Housing Units Heated = 1

House Vintage = after 1979**

Oil-Fired Furnace Central heating equipment = furnace 169 2.8

Heating fuel = oil

Home type = single or multi-family

Number of Housing Units Heated = 1

Fuel Oil Consumption >0

Gas Hot-Water Boilert Central heating equipment = boiler 266 5.3

Heating fuel = gas

Home type = single or multi-family

Number of Housing Units Heated = 1

Oil-Fired Hot-Water Central heating equipment = boiler 208 3.3

Boiler' Heating fuel = oil

Home type = single or multi-family

Number of Housing Units Heated = 1

Some of the same housing records are used for analyzing both weatherized and non-weatherized furnace product

classes, because equipment type is not given in RECS2001. To define weatherized furnaces, DOE looked at the

subset of housing records that had gas furnaces and central air conditioners, and were located in the West South

Central, East South Central Census divisions, or in the states of California, Florida, or Texas.

** Federal regulation regarding mobile housing construction changed the quality of the structures manufactured

after this year.

t Because RECS does not distinguish between steam and hot-water boilers, DOE assumed for the purposes of this

analysis that all boilers in RECS where the number of units heated equal one are hot-water boilers. Hot-water

boilers comprise 84 percent of gas boiler shipments and 88 percent of oil-fired boiler shipments.'

7-11

 EE-RM/STD-01-350 COMMENT 164

variables concerning housing unit characteristics, equipment characteristics, household 

characteristics, and energy use. Appendix 0 presents the variables included. 

T a e bi 731 o 0 C n °t ena 0 ~ or S I e ee f IOn 0 fRECSR eeor d b s )y Pdt ro lie CI ass 

Product Class Algorithm # of # of US Households 

Records Represented (million) 

Non-Weatherized Gas Central heating equipment = furnace 1880 43.5 

Furnace Heating fuel = gas 

Home type = single or multi-family 

Number of Housing Units Heated = 1 

Weatherizel Gas Central heating equipment furnace 373 8.4 

Furnace Heating fuel = gas 

Central air conditioning = yes (packaged unit) 

Home type = single or multi-family 

Number of Housing Units Heated = 1 

Census Division = West or East South Central 

Large State California, Florida or Texas 

Manufactured-Home Central heating equipment = furnace 72 1.5 

Gas Furnace Heating fuel gas 

Home type = manufactured home 

Number of Housing Units Heated = 1 

House Vintage after 1979** 

Oil-Fired Furnace Central heating equipment = furnace 169 2.8 

Heating filel = oil 

Home type = single or multi-family 

Number of Housing Units Heated = 1 

Fuel Oil Consumption >0 

Gas Hot-Water Boilert Central heating equipment boiler 266 5.3 

Heating fuel = gas 

Home type single or multi-family 

Number of Housing Units Heated = 1 

Oil-Fired Hot-Water Central heating equipment = boiler 208 3.3 

Boiler! Heating fuel = oil 

Home type = single or multi-family 

Number of Housing Units Heated = 1 

* Some ofthe same housmg records are used for analyzmg both weatherized and non-weathenzed furnace product 

classes, because equipment type is not given in RECS2001. To define weatherized filrnaces, DOE looked at the 

subset of housing records that had gas filrnaces and central air conditioners, and were located in the West South 

Central, East South Central Census divisions, or in the states of California, Florida, or Texas. 

** Federal regulation regarding mobile housing construction changed the quality of the structures manufactured 

after this year. 

t Because RECS does not distinguish between steam and hot-water boilers, DOE assumed for the purposes of this 

analysis that all boilers in RECS where the number of units heated equal one are hot-water boilers. Hot-water 

boilers comprise 84 percent of gas boiler shipments and 88 percent of oil-fired boiler shipments.3 

7-11 
7.4 ASSIGNING FURNACES TO SAMPLE HOUSES

To estimate the heating load of each sample housing unit, DOE represented the existing

furnace by assigning an input capacity , airflow capacity , and annual fuel utilization efficiency

(AFUE) to the furnace in the RECS sample housing units. The Department used the input

capacity and nominal maximum airflow capacity assigned to the existing furnace to choose a

specific virtual furnace model for the housing unit.

7.4.1 Furnace Input Capacity

The Department assigned an input capacity for the existing furnace of each housing unit based

on an algorithm that correlates the housing unit size with the distribution of input capacity of

new furnaces sold the year the furnace was installed. The following steps describe the

assignment process.

(1) The Department ranked all the RECS housing units in ascending order by size (square foot)

and calculated the percentile rank of each housing unit using the statistical weight of each of

the sample records.

(2) The Department constructed percentile tables by input capacity of furnaces sold each year

for 2003 and prior years, based on the historical shipment information for each year.'

(3) After selecting a housing unit from the RECS database during each Monte Carlo iteration,

DOE noted the size of the selected housing unit and determined the percentile rank from

Step 1.

(4) To avoid a one-to-one deterministic relation between the housing unit size and input

capacity, DOE added a random term to the percentile identified in Step 3 so that the

correlation was not perfect. The Department used a normal distribution to characterize the

random term. The random term has a mean of zero and a standard deviation of 8 percent.

(5) Using the percentile from Step 4, DOE looked up the input capacity from the input capacity

percentile table in Step 2 for the age of the equipment.

7.4.2 Airflow Capacity

The Department classified furnaces by nominal maximum airflow in cfm at 0.5 in.w.g. of

external static pressure. The Department assigned the airflow capacity of existing furnaces for

housing units that had air conditioners in a similar manner that it assigned furnace input capacity.

Larger air conditioners go to larger housing units, according to the distribution of sizes of air

conditioners sold the year the air conditioner was installed in that housing unit. The Department

used the air conditioner nominal size of two, three, four, or five tons to set the airflow capacity

with a ratio of 400 cfm per ton of cooling . The steps were:

(1) Based on historical shipment information of residential central air conditioners by capacity,

DOE constructed the airflow capacity percentiles tables for air conditioners sold in 2001

and prior years. The Department restricted the airflow sizes to two, three, four, or five

tons-the equivalent of 800, 1200, 1600, or 2000 cfm at 0.5 in. w.g. static pressure. Most

of the annual sales of residential central air conditioners from 1976 to 1994 are in these

7-12

 EE-RM/STD-01-350 COMMENT 164

7.4 ASSIGNING FURNACES TO SAMPLE HOUSES 

To estimate the heating load of each sample housing unit, DOE represented the existing 

furnace by assigning an input capacity, airflow capacity, and annual fuel utilization efficiency 

(AFUE) to the furnace in the RECS sample housing units. The Department used the input 

capacity and nominal maximum airflow capacity assigned to the existing furnace to choose a 

specific virtual furnace model for the housing unit. 

7.4.1 Furnace Input Capacity 

The Department assigned an input capacity for the existing furnace of each housing unit based 

on an algorithm that correlates the housing unit size with the distribution of input capacity of 

new furnaces sold the year the furnace was installed. The following steps describe the 

assignment process. 

(1) The Department ranked all the RECS housing units in ascending order by size (square foot) 

and calculated the percentile rank of each housing unit using the statistical weight of each of 

the sample records. 

(2) The Department constructed percentile tables by input capacity of furnaces sold each year 

for 2003 and prior years, based on the historical shipment information for each year. 3 

(3) After selecting a housing unit from the RECS database during each Monte Carlo iteration, 

DOE noted the size of the selected housing unit and determined the percentile rank from 

Step 1. 

(4) To avoid a one-to-one deterministic relation between the housing unit size and input 

capacity, DOE added a random term to the percentile identified in Step 3 so that the 

correlation was not perfect. The Department used a normal distribution to characterize the 

random term. The random term has a mean of zero and a standard deviation of 8 percent. 

(5) Using the percentile from Step 4, DOE looked up the input capacity from the input capacity 

percentile table in Step 2 for the age of the equipment. 

7.4.2 Airflow Capacity 

The Department classified furnaces by nominal maximum airflow in cfm at 0.5 in.w.g. of 

external static pressure. The Department assigned the airflow capacity of existing furnaces for 

housing units that had air conditioners in a similar manner that it assigned furnace input capacity. 

Larger air conditioners go to larger housing units, according to the distribution of sizes of air 

conditioners sold the year the air conditioner was installed in that housing unit. The Department 

used the air conditioner nominal size of two, three, four, or five tons to set the airflow capacity 

with a ratio of 400 cfm per ton of cooling. The steps were: 

(1) Based on historical shipment information of residential central air conditioners by capacity, 

DOE constructed the airflow capacity percentiles tables for air conditioners sold in 2001 

and prior years. The Department restricted the airflow sizes to two, three, four, or five 

tons-the equivalent of 800, 1200, 1600, or 2000 cfm at 0.5 in. w.g. static pressure. Most 

of the annual sales of residential central air conditioners from 1976 to 1994 are in these 

7-12 
airflow sizes. The variation of the distribution of the four airflow sizes over the years is

small.

(2) Since there are no available shipment data on the airflow capacity of furnaces, the

Department used the airflow capacity of residential central air conditioners as a proxy.

Using the adjusted percentile of housing unit size from Step (4) in the Input Capacity

section, DOE determined the airflow capacity by looking up the percentile in the

corresponding distribution of nominal air conditioner size for the age of the cooling

equipment. The Department selected a virtual model with the identified airflow capacity. If

no virtual model with the identified airflow capacity was available, the Department selected

the virtual model with the same input capacity and the closest airflow capacity as a

substitute.

(3) If the RECS record indicated that the housing unit did not have an air conditioner, DOE still

used the procedure from step (2) to determine the airflow capacity. In this case, DOE used

the age of the housing unit (or 30 years if the housing unit was older than 30 years) as a

substitute for the age of the cooling equipment.

7.4.3 Efficiency

GAMA shipments data indicate that housing units in colder regions receive more-efficient

furnaces.3 Therefore, DOE correlated the AFUE of existing furnaces with the heating degree

days (HDD) to base 65°F associated with each sample housing unit. The following steps

describe this process:

(1) The Department sorted the RECS housing units in ascending order of HDDs, and calculated

the percentile rank of each housing unit by HDD using the statistical weight of each sample

housing unit.

(2) Based on the historical furnace shipment information sorted by AFUE, DOE constructed

percentile tables by AFUE shipments of furnaces for 2001 and prior years.

(3) After DOE selected a housing unit from the RECS database during each Monte Carlo

iteration, it noted the HDD of the selected housing unit. The Department looked up the

percentile rank of that housing unit from the HDD percentile table developed in Step (1).

(4) The Department added a random uncertainty term to the HDD percentile found in Step (3)

to account for variability within the sample. The Department used a normal distribution to

characterize the uncertainty term. The distribution of values of the uncertainty term has a

mean of zero and a standard deviation of 8 percent.

(5) Using the adjusted HDD percentile from Step (4), DOE determined the AFUE by looking it

up from the AFUE percentile table from Step (2) corresponding to the age of the existing

equipment in the housing unit.

7.4.4 Electricity Consumption of the Furnace Blower

Most furnaces manufactured since about 1980 use forward-curved impellers driven directly

by a PSC motor. Some models, which utilize modulating design options, use forward-curved

impellers driven directly by an ECM motor. Currently, there are no models using backward7-13

 EE-RM/STD-01-350 COMMENT 164

airflow sizes. The variation of the distribution of the four airflow sizes over the years is 

small. 

(2) Since there are no available shipment data on the airflow capacity of furnaces, the 

Department used the airflow capacity of residential central air conditioners as a proxy. 

Using the adjusted percentile of housing unit size from Step (4) in the Input Capacity 

section, DOE determined the airflow capacity by looking up the percentile in the 

corresponding distribution of nominal air conditioner size for the age of the cooling 

equipment. The Department selected a virtual model with the identified airflow capacity. If 

no virtual model with the identified airflow capacity was available, the Department selected 

the virtual model with the same input capacity and the closest airflow capacity as a 

substitute. 

(3) If the RECS record indicated that the housing unit did not have an air conditioner, DOE still 

used the procedure from step (2) to determine the airflow capacity. In this case, DOE used 

the age of the housing unit (or 30 years if the housing unit was older than 30 years) as a 

substitute for the age of the cooling equipment. 

7.4.3 Efficiency 

GAMA shipments data indicate that housing units in colder regions receive more-efficient 

furnaces. 3 Therefore, DOE correlated the AFUE of existing furnaces with the heating degree 

days (HDD) to base 65°F associated with each sample housing unit. The following steps 

describe this process: 

(1) The Department sorted the RECS housing units in ascending order ofHDDs, and calculated 

the percentile rank of each housing unit by HDD using the statistical weight of each sample 

housing unit. 

(2) Based on the historical furnace shipment information sorted by AFUE, DOE constructed 

percentile tables by AFUE shipments of furnaces for 2001 and prior years. 

(3) After DOE selected a housing unit from the RECS database during each Monte Carlo 

iteration, it noted the HDD of the selected housing unit. The Department looked up the 

percentile rank of that housing unit from the HDD percentile table developed in Step (1). 

(4) The Department added a random uncertainty term to the HDD percentile found in Step (3) 

to account for variability within the sample. The Department used a normal distribution to 

characterize the uncertainty term. The distribution of values of the uncertainty term has a 

mean of zero and a standard deviation of 8 percent. 

(5) Using the adjusted HDD percentile from Step (4), DOE determined the AFUE by looking it 

up from the AFUE percentile table from Step (2) corresponding to the age of the existing 

equipment in the housing unit. 

7.4.4 Electricity Consumption of the Furnace Blower 

Most furnaces manufactured since about 1980 use forward-curved impellers driven directly 

by a PSC motor. Some models, which utilize modulating design options, use forward-curved 

impellers driven directly by an ECM motor. Currently, there are no models using backward7-13 
curved impellers. Thus, most existing furnaces have a blower and blower motor similar to those

in the virtual furnace modelsb . Therefore, in assigning the electricity consumption of the existing

furnace blower for each housing unit , DOE assumed that the electricity use of the existing

furnace was equivalent to the electricity use of the virtual furnace model described in section 7.2.

The Department calculated electricity use by the existing furnace from the fan curves,

watts/CFM curves, and time delays of the virtual furnace model of the same input capacity and

airflow capacity.

7.5 FURNACE BLOWER ELECTRICITY CONSUMPTION

The electricity consumption (and overall efficiency) of a blower motor depends on the speed

at which the motor operates, the external static pressure difference across the blower, and the

airflow through the blower . To calculate blower-motor electricity consumption, DOE

determined the operating conditions (the pressure and airflow) at which a particular furnace in a

particular housing unit will operate . These operating conditions can be graphically displayed as

the intersection of a system curve of the ducts in the housing unit (which plots the airflow across

the supply and return air ducts as a function of static pressure) with the fan curve of the furnace

(which plots the airflow through the furnace as a function of static pressure). The intersection of

these two curves is the airflow and the static pressure at which the furnace will operate in that

housing unit.

Furnace fan curves, reported as tables of airflow rise versus static pressure through the

furnace, are available from manufacturers in the product literature for each furnace . Some of the

manufacturers also supply blower-motor input power as a function of static pressure across the

furnace.

Air power is calculated from the air speed through the furnace and the pressure rise across the

furnace. The overall air-moving efficiency is air power divided by the electric power to the

blower motor . All the electric power of the blower motor eventually is converted to heat that

contributes to meeting the building heating load. See Appendix K for more information about

air handler efficiency.

7.5.1 System Curves

The system curve of the air-distribution system is a graphical representation of the airflow

through the supply and return ducts in a house for different static pressure. The airflow and

pressure drop at which the furnace will operate can be determined by the intersection of the

b A very small share of existing furnaces use belt-drive blowers with shaded-pole motors. That arrangement was less

efficient than direct-driven PSC motors, but the airflow from these old model furnaces was less, so electricity

consumption was not significantly reduced when this technology became obsolete."

7-14

 EE-RM/STD-01-350 COMMENT 164

curved impellers. Thus, most existing furnaces have a blower and blower motor similar to those 

in the virtual furnace modelsb

• Therefore, in assigning the electricity consumption of the existing 

furnace blower for each housing unit, DOE assumed that the electricity use of the existing 

furnace was equivalent to the electricity use of the virtual furnace model described in section 7.2. 

The Department calculated electricity use by the existing furnace from the fan curves, 

watts/CFM curves, and time delays of the virtual furnace model of the same input capacity and 

airflow capacity. 

7.5 FURNACE BLOWER ELECTRICITY CONSUMPTION 

The electricity consumption (and overall efficiency) of a blower motor depends on the speed 

at which the motor operates, the external static pressure difference across the blower, and the 

airflow through the blower. To calculate blower-motor electricity consumption, DOE 

determined the operating conditions (the pressure and airflow) at which a particular furnace in a 

particular housing unit will operate. These operating conditions can be graphically displayed as 

the intersection of a system curve of the ducts in the housing unit (which plots the airflow across 

the supply and return air ducts as a function of static pressure) with the fan curve of the furnace 

(which plots the airflow through the furnace as a function of static pressure). The intersection of 

these two curves is the airflow and the static pressure at which the furnace will operate in that 

housing unit. 

Furnace fan curves, reported as tables of airflow rise versus static pressure through the 

furnace, are available from manufacturers in the product literature for each furnace. Some of the 

manufacturers also supply blower-motor input power as a function of static pressure across the 

furnace. 

Air power is calculated from the air speed through the furnace and the pressure rise across the 

furnace. The overall air-moving efficiency is air power divided by the electric power to the 

blower motor. All the electric power of the blower motor eventually is converted to heat that 

contributes to meeting the building heating load. See Appendix K for more information about 

air handler efficiency. 

7.5.1 System Curves 

The system curve of the air-distribution system is a graphical representation of the airflow 

through the supply and return ducts in a house for different static pressure. The airflow and 

pressure drop at which the furnace will operate can be determined by the intersection of the 

b A very small share of existing furnaces use belt-drive blowers with shaded-pole motors. That arrangement was less 

efficient than direct-driven PSC motors, but the airflow from these old model furnaces was less, so electricity 

consumption was not significantly reduced when this technology became obsolete.4 

7-14 
system curve of the house and the fan curve of the furnace circulating air blower.'

The Department modeled system curves as quadratic curves, which is standard in heating,

ventilation, and air conditioning (HVAC) design and fan selection handbooks.' The curves are

based on Bernoulli's equations for fluid flow and are expressed as the following equation:

where:

Q = airflow (cfm),

P = static pressure (in.w.g.), and

a = a constant coefficient.

The Department selected the coefficient in the system curve equation for each housing unit. It

randomly sampled a coefficient from one of four distributions, depending on the nominal

maximum airflow of the virtual model furnace selected for that housing unit. The Department

designed each distribution so that 10 percent of samples would have static pressures below 0.5

in.w.g., and 1 percent of the samples would have static pressures greater than 1 in.w.g at the

nominal maximum airflow. This is in line with several field studies.' To keep the system curves

from clumping at the higher pressures, the Department used a log-normal distribution of values

of the coefficient. See Figure 7.5.1 for an example of a plot of system curves intersecting a

furnace fan curve.

 EE-RM/STD-01-350 COMMENT 164

system curve of the house and the fan curve of the furnace circulating air blower. 5 

The Department modeled system curves as quadratic curves, which is standard in heating, 

ventilation, and air conditioning (HVAC) design and fan selection handbooks. 6 The curves are 

based on Bernoulli's equations for fluid flow and are expressed as the following equation: 

where: 

Q = airflow (cfm), 

P = static pressure (in.w.g.), and 

ex = a constant coefficient. 

The Department selected the coefficient in the system curve equation for each housing unit. It 

randomly sampled a coefficient from one of four distributions, depending on the nominal 

maximum airflow of the virtual model furnace selected for that housing unit. The Department 

designed each distribution so that 10 percent of samples would have static pressures below 0.5 

in.w.g., and 1 percent of the samples would have static pressures greater than 1 in.w.g at the 

nominal maximum airflow. This is in line with several field studies. 7 To keep the system curves 

from clumping at the higher pressures, the Department used a log-normal distribution of values 

of the coefficient. See Figure 7.5.1 for an example of a plot of system curves intersecting a 

furnace fan curve. 

7-15 
1600

1200

U0_

3 800

0

400

0-

0.00 0.25 1.00

- - 1200 CFM Generic Single-Stage

Furnace Model (Heating Tap

0.50

External Static Pressure ( in. w.g.)

T

0.75

Figure 7.5.1 Sample of System Curves with a Typical Fan Curve

7.5.2 Furnace Fan Curves

Depending on the resistance (measured as static pressure) of the supply and return air ducts, a

furnace will move more or less air. When these airflow values are plotted graphically against

pressure, they are referred to as fan curves.

The Department developed fan curves for the single-stage virtual furnace models by fitting

the manufacturer airflow and pressure data points from the basic model furnaces8' 9, 10, 11, 12, 13, 14 to

a fourth-order polynomial. The Department did this separately for each of the four nominal air

handlers sizes for both non-condensing and condensing furnaces. The CFM for PSC blower

motors is given by the following equation:

CFM= m0+ m1 X (P) + m2

X (P2) + m3 X (P3) + m4 X (P4)

where,

CFM

m0123, , and 4

P

Eq. 3

airflow in CFM reported by manufacturer,

coefficients derived from 4th degree polynomial approximation (see

Table 7.5.1 for actual coefficient values), and

external static pressure (in. w.g.).

7-16

 EE-RM/STD-01-350 COMMENT 164

i' 

u.. 

!2. 

3: 

0 

'E 

« 

1600,------------,------------,------------r----~D_--_, 

1200 

.... .. 800 .. ~~~~--"--~ .. - ~~ -

.. 

400 

I II Highest 1 %~~m~__ _____ ' 

t---tlHIf------+---------+-___ , -<>--median I 

l

' -4-Lowest 10% , 

- - 1200 CFM Generic Single-StageJ 

Furnace Model (Heating T~ 

O __ --------+----------~---~--~==-··-~I ---------~ 

0.00 0.25 0.50 0.75 1.00 

External Static Pressure (in. w.g.) 

Figure 7.5.1 Sample of System Curves with a Typical Fan Curve 

7.5.2 Furnace Fan Curves 

Depending on the resistance (measured as static pressure) of the supply and return air ducts, a 

furnace will move more or less air. When these airflow values are plotted graphically against 

pressure, they are referred to as fan curves. 

The Department developed fan curves for the single-stage virtual furnace models by fitting 

the manufacturer airflow and pressure data points from the basic model furnaces 8

,9, 10, II, 12, 13, 14 to 

a fourth-order polynomial. The Department did this separately for each of the four nominal air 

handlers sizes for both non-condensing and condensing furnaces. The CFM for PSC blower 

motors is given by the following equation: 

where, 

CFM 

rnO),2,3, and 4 

p 

Eq.3 

airflow in CFM reported by manufacturer, 

coefficients derived from 4th degree polynomial approximation (see 

Table 7.5.1 for actual coefficient values), and 

external static pressure (in. w.g.). 

7-16 
Table 7.5. 1 Coefficients for CFM equation for PSC motors

2-ton

3-ton

4-ton

5-ton

2-ton

3-ton

4-ton

5-ton

m0 M, mz m3 m4

891.0 -590.8 564.6 -552.2 0.0

1280.6 -279.8 194.4 -456.3 0.0

1585.1 32.8 -575.7 -78.4 12.3

1998.1 260.9 -93.2 -359.8 115.9

840.4 70.0 -908.4 294.3 56.4

1169.5 -226.1 -272.6 -95.7 137.0

1541.2 -110.3 -777.3 419.0 0.0

1915.1 -198.0 -594.5 -277.8 8.3

Data on the basic models that were used to develop these fan curves and the resulting fan

curves for non-condensing and condensing single-stage furnaces are shown in Appendix I,

Furnace Fan Curves.

The two-stage and continuous modulating design options in this analysis use brushless

permanent magnet motors (or sometimes referred as Electronically Commutated Motors (ECM)).

Unlike PSC motors, these motors are electronically commutated and the speed they operate at

can be varied across a wide range. These motors are controlled to operate the blower fans at a

wide variety of air flows and static pressures . In the furnaces with these motors currently on the

market, the controls are designed to provide a nearly constant air flow across the entire range of

pressures at which they operate.

Because of the versatility of the motors , manufacturers only offer furnaces with blowers

nominally designed for operation with five-ton and three -ton air conditioners. The

manufacturers provide control options to decrease the airflow for installations that use smaller

air conditioners.

To develop fan curves for furnaces with permanent magnet brushless motors, the Department

fit quadratic curves through the air flow and pressure data points reported by manufacturers.'s, 16,

17, 18, 19, 20 , 21 DOE did this separately for high-fire and low-fire operation for both noncondensing and condensing furnaces. The CFM for ECM blower motors is given by the

following equation:

CFM = mo+m1

where,

(P) + m2 x (P2) Eq. 4

CFM = airflow in CFM reported by manufacturer,

mo,I, and2 = coefficients derived from 2n' degree polynomial approximation (see

Table 7.5.2 for actual coefficient values), and

P = external static pressure (in. w.g.).

7-17

 EE-RM/STD-01-350 COMMENT 164

T a e hI 7 5 1 C .. oe ffi' IClen t s ~ or CFM equa t" IOn ~ or PSC mo t ors 

mo mj m2 mJ m4 

bJ) 2-ton 891.0 -590.8 564.6 -552.2 0.0 .5 

= '" 

Q) 3-ton 1280.6 -279.8 194.4 -456.3 0.0 

'1:l 

= c 4-ton 1585.1 32.8 -575.7 -78.4 12.3 U I 

= c 5-ton 1998.1 260.9 -93.2 -359.8 115.9 

Z 

bJ) 2-ton 840.4 70.0 -908.4 294.3 56.4 

.5 3-ton 1169.5 -226.1 -272.6 -95.7 137.0 

= '" 

Q) 

'1:l 4-ton 1541.2 -llO.3 -777.3 419.0 0.0 c = 

U 5-ton 1915.1 -198.0 -594.5 -277.8 8.3 

Data on the basic models that were used to develop these fan curves and the resulting fan 

curves for non-condensing and condensing single-stage furnaces are shown in Appendix I, 

Furnace Fan Curves. 

The two-stage and continuous modulating design options in this analysis use brushless 

permanent magnet motors (or sometimes referred as Electronically Commutated Motors (ECM)). 

Unlike PSC motors, these motors are electronically commutated and the speed they operate at 

can be varied across a wide range. These motors are controlled to operate the blower fans at a 

wide variety of air flows and static pressures. In the furnaces with these motors currently on the 

market, the controls are designed to provide a nearly constant air flow across the entire range of 

pressures at which they operate. 

Because of the versatility of the motors, manufacturers only offer furnaces with blowers 

nominally designed for operation with five-ton and three-ton air conditioners. The 

manufacturers provide control options to decrease the airflow for installations that use smaller 

air conditioners. 

To develop fan curves for furnaces with permanent magnet brushless motors, the Department 

fit quadratic curves through the air flow and pressure data points reported by manufacturers. 15, 16, 

17,18,19,20,21 DOE did this separately for high-fire and low-fire operation for both noncondensing and condensing furnaces. The CFM for ECM blower motors is given by the 

following equation: 

where, 

CFM 

mO,I, and 2 

p 

Eq. 4 

airflow in CFM reported by manufacturer, 

coefficients derived from 2nd degree polynomial approximation (see 

Table 7.5.2 for actual coefficient values), and 

external static pressure (in. w.g.). 

7-17 
Table 7.5.2 Coefficients for CFM equation for Two-Stage and Continuous Modulating

2-ton

3-ton

4-ton

5-ton

2-ton

3-ton

4-ton

5-ton

furnaces with brushless permanent magnet motors

High Fire Low Fire

ma m2 m, MI m2

857.5 62.0 0.0 634.7 37.5 0.0

1091.1 37.4 0.0 831.7 6.4 0.0

1324.8 12.9 0.0 1028.7 -24.7 0.0

1558.5 -11.7 0.0 1225.7 -55.8 0.0

714.0 -16.4 -13.8 489.4 -50.2 0.0

1003.0 -27.4 0.0 680.2 -31.5 0.0

1291.9 -38.4 13.8 870.9 -12.9 0.0

1580.9 -49.5 27.6 1061.6 5.8 0.0

Data on the basic models that were used to develop these fan curves, the methodology used,

and the resulting fan curves for non-condensing and condensing single-stage furnaces are shown

in Appendix I, Furnace Fan Curves.

7.5.3 Fan Power

For furnaces with air handlers with PSC blower motors, one manufacturer reports watts across

a range of pressures." 9, 10, 11, 12, 13, 14 The Department divided watts at these pressures by air flow

in CFM at these same pressures. These values of watts/CFM across a range of pressures were fit

to a fourth order polynomial for the basic furnace models made by the manufacturer. The

Department did this separately for each of the four nominal air handlers sizes for both noncondensing and condensing furnaces. The Watts/CFM for PSC blower motors is given by the

following equation:

Watts

CFM= mp+m1x(P)+m2X (P2)+m3X(P3)+m4X (P4) Eq. 5

where,

Watts/CFM = blower electricity consumption in watts reported by manufacturer

divided by the airflow in CFM at the same static pressure,

mo r z 3, a„ d4 = coefficients derived from 4" degree polynomial approximation (see

Table 7.5.3 for actual coefficient values), and

P = external static pressure (in. w.g.).

7-18

 EE-RM/STD-01-350 COMMENT 164

Table 7.5.2 Coefficients for CFM equation for Two-Stage and Continuous Modulating 

f urnaces WI 'th b rus hI ess permanent magnet motors 

High Fire Low Fire 

mil mJ m2 ma mJ m2 

~ 2-ton 857.5 62.0 0.0 634.7 37.5 0.0 .S 

'" = Q.l 3-ton 1091.l 37.4 0.0 831.7 6.4 0.0 "0 

0 = 

U 4-ton 1324.8 12.9 0.0 lO28.7 -24.7 0.0 I 

= 5-ton 1558.5 -11.7 0.0 1225.7 -55.8 0.0 0 

Z 

~ 

2-ton 714.0 -16.4 -13.8 489.4 -50.2 0.0 

.5 3-ton 1003.0 -27.4 0.0 680.2 -31.5 0.0 '" = Q.l 

"0 4-ton 1291.9 -38.4 13.8 870.9 -12.9 0.0 0 = 

U 5-ton 1580.9 -49.5 27.6 106l.6 5.8 0.0 

Data on the basic models that were used to develop these fan curves, the methodology used, 

and the resulting fan curves for non-condensing and condensing single-stage furnaces are shown 

in Appendix I, Furnace Fan Curves. 

7.5.3 Fan Power 

For furnaces with air handlers with PSC blower motors, one manufacturer reports watts across 

a range of pressures. 8,9,10,11,12,13,14 The Department divided watts at these pressures by air flow 

in CFM at these same pressures. These values ofwatts/CFM across a range of pressures were fit 

to a fourth order polynomial for the basic furnace models made by the manufacturer. The 

Department did this separately for each of the four nominal air handlers sizes for both noncondensing and condensing furnaces. The Watts/CFM for PSC blower motors is given by the 

following equation: 

where, 

Watts/CFM 

rn O,l.2,3, and 4 

p 

blower electricity consumption in watts reported by manufacturer 

divided by the airflow in CFM at the same static pressure, 

coefficients derived from 4th degree polynomial approximation (see 

Table 7.5.3 for actual coefficient values), and 

external static pressure (in. w.g.). 

7-18 
Table 7.5.3 Coefficients for W/CFM equation for PSC motors

2-ton

3-ton

4-ton

5-ton

2-ton

3-ton

4-ton

5-ton

m0 mz mj m4

0.39 -0.01 -0.11 0.22 0.03

0.43 -0.15 0.09 0.02 0.06

0.41 -0.16 0.14 -0.07 0.08

0.44 -0.08 0.01 0.05 0.01

0.40 -0.19 0.41 -0.50 0.31

0.45 -0.24 0.19 0.02 -0.04

0.41 -0.12 -0.10 0.20 -0.02

0.47 -0.19 0.30 -0.32 0.17

Data from the models that were used to develop these fan curves and the fit curves of

Watts/CFM for pressures from 0 in.w.g. to 1.0 in.w.g. is shown in Appendix J.

For the two-stage and continuous modulating furnaces with ECM motors, the Department

calculated watts per CFM equations using data from basic models of several manufacturers.'s, 16,

17, 18, 19, 20, 21 These data are in the reduced set of furnace models database.

This was done for basic model furnaces nominally designed for use with 5 ton and 3 ton air

conditioners. The watts per CFM data points these basic models were fit to straight lines using

Equation 2. This was done separately for high fire and low fire for both non-condensing and

condensing models. Table 7.5.4 shows the coefficients for two-stage and continuous

modulating furnaces with brushless permanent magnet motors using Eq. 6. Data from the

models that were used to develop these fan curves and the fit curves of Watts/CFM for pressures

from 0 in.w.g. to 1.0 in.w.g. is shown in Appendix J.

Watts

CFM = mo + ml x (P) Eq. 6

where,

Watts/CFM = blower electricity consumption in watts reported by manufacturer

divided by the airflow in CFM at the same static pressure,

mo,] = coefficients derived from linear approximation (see Table 7.5.4 for

actual coefficient values), and

P = external static pressure (in. w.g.).

To be consistent with other analyses, the Department calculated the slope and intercept for the

w/CFM curves for furnaces intended to operate with 4 ton and 2 ton air conditioner using the

same techniques it used to develop the fan curves of these furnaces.

7-19

 EE-RM/STD-01-350 COMMENT 164

T a bi e 753 C oe ffi· lelen t s £ or W/CFM equa f IOn £ or PSC mo t ors 

mo ml m2 m3 m4 ell 2-ton 0.39 -0.01 -0.11 0.22 0.03 .5 

'" = Cl.l 3-ton 0.43 -0.15 0.09 0.02 0.06 "0 

0 = 4-ton 0.41 -0.16 0.14 -0.07 0.08 U I 

= 0 5-ton 0.44 -0.08 0.01 0.05 0.01 

Z 

ell 2-ton 0.40 -0.19 0.41 -0.50 0.31 

.5 3-ton 0.45 -0.24 0.19 0.02 -0.04 '" = Cl.l 

"0 4-ton 0.41 -0.12 -0.10 0.20 -0.02 

= 0 

U 5-ton 0.47 -0.19 0.30 -0.32 0.17 

Data from the models that were used to develop these fan curves and the fit curves of 

Watts/CFM for pressures from 0 in.w.g. to 1.0 in.w.g. is shown in Appendix J. 

F or the two-stage and continuous modulating furnaces with ECM motors, the Department 

calculated watts per CFM equations using data from basic models of several manufacturers. IS, 16, 

17,18,19,20,21 These data are in the reduced set of furnace models database. 

This was done for basic model furnaces nominally designed for use with 5 ton and 3 ton air 

conditioners. The watts per CFM data points these basic models were fit to straight lines using 

Equation 2. This was done separately for high fire and low fire for both non-condensing and 

condensing models. Table 7.5.4 shows the coefficients for two-stage and continuous 

modulating furnaces with brushless permanent magnet motors using Eq. 6. Data from the 

models that were used to develop these fan curves and the fit curves ofWatts/CFM for pressures 

from 0 in.w.g. to 1.0 in.w.g. is shown in Appendix J. 

where, 

Watts/CFM 

p 

Watts 

CFM = mo + m1 x (P) Eq. 6 

blower electricity consumption in watts reported by manufacturer 

divided by the airflow in CFM at the same static pressure, 

coefficients derived from linear approximation (see Table 7.5.4 for 

actual coefficient values), and 

external static pressure (in. w.g.). 

To be consistent with other analyses, the Department calculated the slope and intercept for the 

w/CFM curves for furnaces intended to operate with 4 ton and 2 ton air conditioner using the 

same techniques it used to develop the fan curves of these furnaces. 

7-19 
Table 7.5.4 Coefficients for W/CFM equation for Two-Stage and Continuous

Modulating furnaces with ECM motors

2-ton

3-ton

4-ton

5-ton

2-ton

3-ton

4-ton

5-ton

High Fire Low Fire

m0, m, m0 m,

0.13 0.24 0.06 0.25

0.14 0.24 0.08 0.25

0.15 0.24 0.09 0.25

0.16 0.24 0.11 0.24

0.12 0.23 0.10 0.24

0.14 0.24 0.10 0.25

0.17 0.25 0.11 0.26

0.20 0.26 0.11 0.27

Once the operating point of air flow and static pressure is determined by finding the

intersection of the fan curve and the system curve, the watts per CFM are determined using the

equations above. The fan power at this operating condition, BE, is calculated by multiplying the

Watts/CFM by the CFM at the operating point:

- Watts BE CFM)

X Q

where,

BE = circulating air fan electrical energy consumption (watts),

Watts/CFM = determined by equation 1 or equation 2 in section 7.5.3, and

Q = airflow (cfm).

7.5.4 Overall Air-Moving Efficiency

The overall air-moving efficiency is a ratio of the air power divided by the electric

power used by the blower motor:

AHP

?,overall = BE

where:

rl overall

AHP

BE

overall air-moving efficiency,

air horsepower (watts), and

circulating air fan electrical energy consumption (watts).

7-20

 EE-RM/STD-01-350 COMMENT 164

Table 7.5.4 Coefficients for W/CFM equation for Two-Stage and Continuous 

M d 0 u a Iff mg urnaces WI ·th ECM mo t ors 

High Fire Low Fire 

mo mJ mo mJ 

OJ) 2-ton 0.13 0.24 0.06 0.25 .5 

= '" 

ClJ 3-ton 0.14 0.24 0.08 0.25 '0 

c = 

U 4-ton 0.15 0.24 0.09 0.25 I 

= 0 5-ton 0.16 0.24 0.11 0.24 Z 

OJ) 2-ton 0.12 0.23 0.10 0.24 

.5 3-ton 0.14 0.24 0.10 0.25 '" 

ClJ = 

'0 

= 4-ton 0.17 0.25 0.11 0.26 0 

U 5-ton 0.20 0.26 0.11 0.27 

Once the operating point of air flow and static pressure is determined by finding the 

intersection of the fan curve and the system curve, the watts per CFM are determined using the 

equations above. The fan power at this operating condition, BE, is calculated by multiplying the 

Watts/CFM by the CFM at the operating point: 

where, 

BE 

Watts/CFM 

Q 

circulating air fan electrical energy consumption (watts), 

determined by equation 1 or equation 2 in section 7.5.3, and 

airflow (cfm). 

7.5.4 Overall Air-Moving Efficiency 

The overall air-moving efficiency is a ratio of the air power divided by the electric 

power used by the blower motor: 

where: 

170veraU 

AHP 

BE 

AHP 

n a;erall = -- '/ BE 

overall air-moving efficiency, 

air horsepower (watts), and 

circulating air fan electrical energy consumption (watts). 

7-20 
Air power is the power embodied in the air due to its motion and pressure increase. Air

power at any operating condition can be calculated for any furnace from pressure, airflow, and

supply air outlet area, as explained in Appendix K. See Appendix K for overall air-moving

efficiency derivation and curves.

7.6 ANNUAL HEATING LOADS IN SAMPLE HOUSING UNITS

The annual house-heating load (HHL) is the total amount of heat output from the furnace

that the house needs during the heating season. This includes heat from the burner and heat from

the blower and the blower motor.

The Department determined HHL for each sampled housing unit, based on the BOH and

the characteristics of the assigned existing furnace, using the following calculations:

HHL = QyR,recs x AFUEeX + 3.412 xBE x

where:

BOHex + N x HLH x t+ t3600

QPR,recs = annual fuel consumption for heating the housing unit, from RECS

2001 (kBtu/yr),

AFUEeX = AFUE of existing furnace (see section 7.4.3 to see how this was

assigned for each household),

3.412 = constant to convert kW to kBtu/hr,

BEex = power consumption of the blower motor of existing furnace (kW),

BOHe, = as defined below (hr/yr),

N = number of cycles per hour (set equal to 5 for furnaces and 2 for

boilers),

HLH = heating load hours (hr) (see Appendix M for the derivation),

t + = offdelay (seconds) (see section 7.2.7 for values used), and

on delay (seconds) (see section 7.2.7 for values used),

Burner operating hours (BOHex), the number of hours the existing furnace burner is on

during a year, is a key variable in the calculation of HHL. The Department calculated BOH for

the existing furnace as:

BOH =

ex QIN, ex

where:

BOH,, burner operating hours of existing household (hrs/yr),

QYR, recs

7-21

 EE-RM/STD-01-350 COMMENT 164

Air power is the power embodied in the air due to its motion and pressure increase. Air 

power at any operating condition can be calculated for any furnace from pressure, airflow, and 

supply air outlet area, as explained in Appendix K. See Appendix K for overall air-moving 

efficiency derivation and curves. 

7.6 ANNUAL HEATING LOADS IN SAMPLE HOUSING UNITS 

The annual house-heating load (HHL) is the total amount of heat output from the furnace 

that the house needs during the heating season. This includes heat from the burner and heat from 

the blower and the blower motor. 

The Department determined HHL for each sampled housing unit, based on the BOH and 

the characteristics of the assigned existing furnace, using the following calculations: 

where: 

HHL = QYR recs x AFUEex + 3.412 xBE x [BOHex + N x HLH X (t+ -r)] , 3600 

QYR,recs 

AFUEex 

3.412 

BEex 

BOHex 

N 

t 

annual fuel consumption for heating the housing unit, from RECS 

2001 (kBtu/yr), 

AFUE of existing furnace (see section 7.4.3 to see how this was 

assigned for each household), 

constant to convert kW to kBtu/hr, 

power consumption of the blower motor of existing furnace (kW), 

as defined below (hr/yr), 

number of cycles per hour (set equal to 5 for furnaces and 2 for 

boilers), 

heating load hours (hr) (see Appendix M for the derivation), 

off delay (seconds) (see section 7.2.7 for values used), and 

on delay (seconds) (see section 7.2.7 for values used), 

Burner operating hours (BOHex), the number of hours the existing furnace burner is on 

during a year, is a key variable in the calculation of HHL. The Department calculated BOH for 

the existing furnace as: 

where: 

BOH 

ex 

QYR, rees 

QIN,ex 

burner operating hours of existing household (hrs/yr), 

7-21 
QYR,recs

QIN, ex

as defined above (kBtu/yr),

input capacity of the existing furnace (see section 7.4.1 to see how

this was assigned for each household) (kBtu/hr).

The power consumption of the blower motor depends on the steady-state operating

conditions (the pressure and airflow) for the furnace. This calculation is explained in section 7.5,

Calculating Furnace Blower Electricity Consumption.

The Department made adjustments to reflect the expectation that newly-built housing

units in 2015 will have a somewhat different heating load than the housing units in the RECS

2001 new construction sub-sample. The adjustment involves multiplying the calculated HHL for

each RECS 2001 housing unit in the new construction sub-sample by two factors. The first

factor, building thermal efficiency, accounts for the estimated improvement in home insulation

and other thermal efficiency practices between 2001 and 2015. The value used is 0.97, which

means that the average new home in 2015 requires less heat energy to maintain indoor comfort.

The second factor, house floor area, accounts for the estimated increase in average new house

floor area between 2001 and 2015. The value used is 1.053, which means that the average new

home in 2015 is projected to be larger than in 2001. DOE derived both of these values from the

NEMS simulation done for EIA's Annual Energy Outlook 2005. The net effect is that the

estimated HHL for homes built in 2015 is 2.1 percent larger than the HHL of the homes in the

RECS 2001 new construction sub-sample.

7.7 ENERGY CONSUMPTION

Once the heating load of each sample housing unit is known, it is possible to estimate

what the energy consumption would be if more-efficient equipment, rather than the baseline

equipment, were used in each housing unit.

7.7.1 Fuel Consumption

The Department calculated the fuel consumption (Fuel Use) for each furnace and boiler

using the following formulas from the current proposed revision to the American Society of

Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) test procedure SPC 103-

1993R22 section C:

Fuel Use = BOHss x QIN ^c,d for single-stage furnace or boiler,

where:

` For natural draft equipment this formula is modified to include the pilot light consumption. See Appendix L.

d For modulating equipment this formula includes parameters for the operation at full, modulating, and reduced load.

See Appendix L.

7-22

 EE-RM/STD-01-350 COMMENT 164

QYR,recs 

QIN,ex 

as defined above (kBtu/yr), 

input capacity of the existing furnace (see section 7.4.1 to see how 

this was assigned for each household) (kBtu/hr). 

The power consumption of the blower motor depends on the steady-state operating 

conditions (the pressure and airflow) for the furnace. This calculation is explained in section 7.5, 

Calculating Furnace Blower Electricity Consumption. 

The Department made adjustments to reflect the expectation that newly-built housing 

units in 2015 will have a somewhat different heating load than the housing units in the RECS 

2001 new construction sub-sample. The adjustment involves multiplying the calculated HHL for 

each RECS 2001 housing unit in the new construction sub-sample by two factors. The first 

factor, building thermal efficiency, accounts for the estimated improvement in home insulation 

and other thermal efficiency practices between 2001 and 2015. The value used is 0.97, which 

means that the average new home in 2015 requires less heat energy to maintain indoor comfort. 

The second factor, house floor area, accounts for the estimated increase in average new house 

floor area between 2001 and 2015. The value used is 1.053, which means that the average new 

home in 2015 is projected to be larger than in 2001. DOE derived both of these values from the 

NEMS simulation done for EIA's Annual Energy Outlook 2005. The net effect is that the 

estimated HHL for homes built in 2015 is 2.1 percent larger than the HHL of the homes in the 

RECS 2001 new construction sub-sample. 

7.7 ENERGY CONSUMPTION 

Once the heating load of each sample housing unit is known, it is possible to estimate 

what the energy consumption would be if more-efficient equipment, rather than the baseline 

equipment, were used in each housing unit. 

7.7.1 Fuel Consumption 

The Department calculated the fuel consumption (FueIUse) for each furnace and boiler 

using the following formulas from the current proposed revision to the American Society of 

Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) test procedure SPC 103-

1993R22 section C: 

FuelUse = BOHss x QIN ,c,d for single-stage furnace or boiler, 

where: 

C For nahlral draft equipment this fOlIDula is modified to include the pilot light consumption. See Appendix L. 

d For modulating equipment this fonnula includes parameters for the operation at full, modulating, and reduced load. 

See Appendix L. 

7-22 
BOHSS = steady-state burner operating hours (hr),

Qi„ = input capacity of existing furnace (kBtu/hr),

The details for calculating energy consumption appear in Appendix L, Determination of

Furnace and Boiler Energy Use.

7.7.2 Electricity Consumption

The Department calculated furnace electricity consumption for the blower, the draft

inducer, and the ignitere. The blower moves heated air through the house whenever the furnace

burner is on (adjusted for delay times between burner and blower operation). It also operates in

the cooling season (summer) if the house is air-conditioned, but the Dept only considered use

during the heating season. The Department calculated the electricity consumption as:

Elec Use = BOHSS x (y x BE + yp x PE + ytg x PE,g) ,f for single-stage furnace or boiler,

where:

BOHss = as defined above,

y = ratio ofblower on-time to burner on-time,

BE = power consumption of the blower or circulating pump motor (kW),

,1P = ratio ofinduced-draft blower on-time to burner on-time,

PE = power consumption of the draft-inducer blower-motor (kW),

yrc = ratio ofignitor on-time to burner on-time, and

PEIG = power consumption of the ignitor (kW).

The ratio of blower on-time to burner on-time and the ratio of induced draft blower ontime to burner on-time are from the current proposed revision to the ASHRAE test procedure

SPC 103-19938222 using delay times for the virtual model furnaces. The ratio of ignitor on-time

to burner on-time comes from the DOE test procedure23 and the ignition time of the virtual model

furnaces.5

The details for calculating electricity consumption appear in Appendix L, Determination

of Furnace and Boiler Energy Use.

The DOE and ASHRAE test procedures do not count the electricity used by controls when the furnace is not firing.

f For modulating equipment this formula includes parameters for the operation at full, modulating , and reduced load.

See Appendix L.

8 The ASHRAE test procedure does not deal with ignitor energy consumption.

7-23

 EE-RM/STD-01-350 COMMENT 164

BOHss 

Qil1 

steady-state burner operating hours (hr), 

input capacity of existing furnace (kBtu/hr), 

The details for calculating energy consumption appear in Appendix L, Determination of 

Furnace and Boiler Energy Use. 

7.7.2 Electricity Consumption 

The Department calculated furnace electricity consumption for the blower, the draft 

inducer, and the ignitere. The blower moves heated air through the house whenever the furnace 

burner is on (adjusted for delay times between burner and blower operation). It also operates in 

the cooling season (summer) if the house is air-conditioned, but the Dept only considered use 

during the heating season. The Department calculated the electricity consumption as: 

ElecUse = BOHss x (y x BE + yp x PE + yig x PEig) / for single-stage furnace or boiler, 

where: 

BOHss 

y 

BE 

yP 

PE 

yIG 

PEIG 

as defined above, 

ratio of blower on-time to burner on-time, 

power consumption of the blower or circulating pump motor (kW), 

ratio of induced-draft blower on-time to burner on-time, 

power consumption of the draft-inducer blower-motor (kW), 

ratio of ignitor on-time to burner on-time, and 

power consumption of the ignitor (kW). 

The ratio of blower on-time to burner on-time and the ratio of induced draft blower ontime to burner on-time are from the current proposed revision to the ASHRAE test procedure 

SPC 103-1993R22 using delay times for the virtual model furnaces. The ratio of ignitor on-time 

to burner on-time comes from the DOE test procedure23 and the ignition time of the virtual model 

fumaces. g 

The details for calculating electricity consumption appear in Appendix L, Determination 

of Fumace and Boiler Energy Use. 

e The DOE and ASHRAE test procedures do not count the electricity used by controls when the furnace is not firing. 

f For modulating equipment this fornmla includes parameters for the operation at full, modulating, and reduced load. 

See Appendix L. 

g The ASHRAE test procedure does not deal with ignitor energy consumption. 

7-23 
7.8 RESULTS

This section presents annual gas or oil consumption and winter electricity consumption

for the considered design options in each product class. The average annual energy use for each

design option is shown in Tables 7.8.1 through 7.8.6 for each product class. The range of annual

gas or oil use and winter electricity consumption for each design option is shown in Figures 7.8.1

through 7.8.12.

7.8.2.

Energy use for non-weatherized gas furnaces shown in Table 7.8.1 and Figures 7.8.1 and

Table 7.8.1 Non-Weatherized Gas Furnace Energy Use

Design Option

by AFUE

Average Annual Gas Use

(MmBtu)

Average Electricity Use

(kWh)

78% 56.6 496

80% 55.2 484

80% - Modulation (Two-Stage) 56.0 304

81% 54.6 479

81 % - Modulation (Two-Stage) 55.3 300

90% 49.4 417

92% 48.3 409

92% - Modulation (Two-Stage) 48.9 257

92% - Modulation (Continuous) 48.3 416

96% - Modulation (Continuous) 46.4 400

 EE-RM/STD-01-350 COMMENT 164

7.8 RESULTS 

This section presents annual gas or oil consumption and winter electricity consumption 

for the considered design options in each product class. The average annual energy use for each 

design option is shown in Tables 7.8.1 through 7.8.6 for each product class. The range of annual 

gas or oil use and winter electricity consumption for each design option is shown in Figures 7.8.1 

through 7.8.12. 

Energy use for non-weatherized gas furnaces shown in Table 7.8.1 and Figures 7.8.1 and 

7.8.2. 

T a e hI 7 8 1 N W .. on- ea th enze . d G F as urnace E nergy U se 

Design Option Average Annual Gas Use Average Electricity Use 

by AFUE (MMBtu) (kWh) 

78% 56.6 496 

80% 55.2 484 

80% - Modulation (Two-Stage) 56.0 304 

81% 54.6 479 

81 % - Modulation (Two-Stage) 55.3 300 

90% 49.4 417 

92% 48.3 409 

92% - Modulation (Two-Stage) 48.9 257 

92% - Modulation (Continuous) 48.3 416 

96% - Modulation (Continuous) 46.4 400 

7-24 
Annual Gas Vse ROWS e^ Design Option

140

-- hletl Ian

120 a.g4117_.. ... ..

-r- T

80

r..... ,. .... ^._ Yom' 1...^ ^' i

Q

s

a u

I

€

1 3 ._.._ e 73

41) .. .. ..

r F a

I

20

L-r I

0

'D co lo m lo

1 1^6 1

1 Cs E 'E

N G C

®

p

m 06 m

m

Figure 7.8.1 Range of Annual Gas Use in MMBtu for NonWeatherized Gas Furnaces

1 200

1000

R00

600

400

200

0

co00fElectricity use Ranges By' Design Option

Figure 7.8.2 Range of Electricity Use in kWh for Non-Weatherized

Gas Furnaces

7-25

 EE-RM/STD-01-350 COMMENT 164

Mnual Gas Use Ran~es ey DesIgn option 

IF '" ", <U 0 lfI '" 0 ~ ~ I!! c E c:> ~ c:> II) :2 :I 0 ::::i: :::> ::2 

.... ...: < C1 < Q c 

~ II> ~ .., ~ CD :::> ::l 

Gl .,. ... ~ .5 

'" '" is "E ..: 1;6 ts ~ c:> 0 

E N u N .., ,{, S 2- g .E 

"# "# "* # "# ~ .., I:) El 05, N Q 0 co 1ii N a> :E ~ '" a> 

~ ~ N ell 

'" C>I 

Figure 7.8.1 Range of Annual Gas Use in MMBtu for NonWeatherized Gas Furnaces 

1200.-------~--.---c---~------~--,,--~--_r--~--_o--_, 

l;! <U 0 <I> 0 IF '" ", qr 'i:O' <X> E <> E <> I:) I!! 0 ::2 ::s .... "I( :2 "I( :2 '" ~ :I a c 

~ CD 

~ .., ~ '" ::2 2 CR .,. i' ~ . '" '" ... ~ ....: 11! ..: ~ c: 0 I:> £ N u N .s s cJ. 8- ~ -.,. ~ "* # 

~ "# ,., ,., I:) In N a c I:) co 1ii co t:;1 ~ E 

~ ~ n !Q 01 a> 

Figure 7.8.2 Range of Electricity Use in kWh for Non-Weatherized 

Gas Furnaces 

7-25 
7.8.4.

Energy use for weatherized gas furnaces shown in Table 7.8.2 and Figures 7.8.3 and

Table 7.8.2 Weatherized Gas Furnace Energy Use (Low Cost Scenario

Design Option

by AFUE

Average Annual Gas Use

(MMBtu)

Average Electricity Use

(kWh)

78% 33.0 293

80% 32.2 286

81% 31.8 283

82% 31.4 279

83% 31.0 276

 EE-RM/STD-01-350 COMMENT 164

Energy use for weatherized gas furnaces shown in Table 7.8.2 and Figures 7.8.3 and 

7.8.4. 

Table 7.8.2 Weatherized Gas Furnace Ener2Y Use (Low Cost Scenario) 

Design Option Average Annual Gas Use Average Electricity Use 

by AFUE (MMBtu) (kWb) 

78% 33.0 293 

80% 32.2 286 

81% 31.8 283 

82% 31.4 279 

83% 31.0 276 

7-26 
Figure 7.8.3 Range of Annual Gas Use in MMBtu for Weatherized

Gas Furnaces (Low Cost Scenario)

Figure 7.8.4 Range of Electricity Use in kWh for Weatherized Gas

Furnaces (Low Cost Scenario)

7-27

 EE-RM/STD-01-350 COMMENT 164

M nu81 G as Use Ranges IJY DesIgn OpUon 

80r-----~----~------~----~------~----~----~----~ 

aD 

7fi 

so 

10 

-M~dlan 

lJ M~~n 

• • • ;. • • 0· • • 

o~----~~----~----~------~---~-----~---------~ II> "' m '" . ", 

.5 I!? 2! I!:' I!:' iii ~ ..: ..:: ..:: .. ~ . f f ... 

ID 

~ .. .. .... .... ... . .... .., ~ 

"" ..5 ..5 .5 .5 .... /Po ~ III ~ c:) ,... ..... M 

"" a:I II:) II:) 

Figure 7.8.3 Range of Annual Gas Use in MMBtu for Weatherized 

Gas Furnaces (Low Cost Scenario) 

Eleetrlel1'1 Use Ranges BY DesIgn oPtion 

700 r-----_.._---~------.._---_.._--__.------..___----__._---__, 

SOD 

600 

400 

300 

:JOO 

1DO 

--Me~lan r '- .. _(_.. - r .•.•.... . ri •.. ""9l~ ........ ..... ~ ................. ........ " ..... j ....... ........ j ................ .... .......... ; .. . 

~ ~ { 1 

·l t ! 

! 

... ··· .. ··· .. : .. ··· · .. F4 · .... [J···+· ·· r±l :::~ : . ~:::; ........ ' .. ; .. ····l ~ r·t nJ. [] L.:~ .. J · [J I .. · .. · .. ··· .. ·· ..

<" .. iJ i- ·l ~l II ·· 

! t. .... ... __ '!~_ \ I I , i -:--' .. . '.-.- --1_" -J- =+= o~---~------~---~--------------------~----~----~ .., "' m cs c: ! I!! I!! ! "' ~ q:. ..: q: q: ~1' 

~ . ~ ~ OJ 

m .. .. b; ' .. tI! .. .. .. II:) ..5 ..5 .5 ..5 .... llI. /Po llI. llI. o · . ... M ' 

"" "" "" 

Figure 7.8.4 Range of Electricity Use in kWh for Weatherized Gas 

Furnaces (Low Cost Scenario) 

7-27 
Energy use for mobile home furnaces shown in Table 7.8.3 and Figures 7.8.5 and 7.8.6.

Table 7.8.3 Mobile Home Furnace Energy Use

Design Option

by AFUE

Average Annual Gas Use

(MMBtu)

Average Electricity Use

(kWh)

75% 44.3 392

80% 39.0 381

80% - Modulation (Two-Stage) 39.6 253

81% 38.6 376

81 % - Modulation (Two-Stage) 39.1 251

82% 38.1 372

82% - Modulation (Two-Stage) 38.6 248

90% 34.9 332

 EE-RM/STD-01-350 COMMENT 164

Energy use for mobile home furnaces shown in Table 7.8.3 and Figures 7.8.5 and 7.8.6. 

T a bl e 7 .. 83M 0 bi! e H orne F urnace E nere;y U se 

Design Option Average Annual Gas Use Average Electricity Use 

by AFUE (MMBtu) (kWh) 

75% 44.3 392 

80% 39.0 381 

80% - Modulation (Two-Stage) 39.6 253 

81% 38.6 376 

81 % - Modulation (Two-Stage) 39.1 251 

82% 38.1 372 

82% - Modulation (Two-Stage) 38.6 248 

90% 34.9 332 

7-28 
Figure 7.8.5 Range of Annual Gas Use in MMBtu for Mobile

Home Furnaces

1 0 0

MI

sou

700

.11

son

400

300

200

1011

0

EI trlef+Use Ranges Btq Design Onion

Figure 7.8.6 Range of Electricity Use in kWh for Mobile Home

Furnaces

7-29

 EE-RM/STD-01-350 COMMENT 164

70 

60 

50 

40 

30 

20 

10 

Annual GIiIS use: RlilngeS BY Design oPtion 

o~--~----~----------------~----~--~----~--~--~ 

"" ." '0 ." .., ." -g ,§ ~ '" 0:. ~ -a 2! I: 

81 0( :::Ii 0( ::II "( ::II "w. I: 

~ (I) ~ 41 ~ 4f II> <II ..,. ... ... ., 1%1 "" CII CII 

E q; ~ 0;;- <:i 0;; I: 

~ D 

N <'1. ..G: N (.} 

tt til If. ~ !:II !fl *' c c .- .... N n <=> tI> Q) a> ""- "" 1%1 "" 

Figure 7.8.5 Range of Annual Gas Use in MMBtu for Mobile 

Home Furnaces 

EIMtrlCItp' USB Ranlles ~ 08sliln OP1on 

1000r-------~--~--------~--,_--_,--------~--~--~ 

eOD 

700 

600 

SOD 

0400 

30n 

200 

100 

-""sellan -

il fljeari _0..;..:. 

- • • ~ _w " •• , • • ~i' , 

D ~ __ ~ ____ ~ __ ~ ____ ~ __ ~ ____ ~ __ ~ ____ L-__ ~ ____ ~ __ -J 

II) 111' -c: 1'$ -c: n: -c: D _5 ~ I) ~ I) ~ I) c: Ii ..;C :E ..;C :E ..;C :E -m ... :¥ ID 

~ ID I» co :¥ II) n: D D III >al '1lI III .... no .... 35 ... 35 .... 35 c: 

*- .., .., ..., I) 

..... .5 N .5 N .5 N 00 ..... *- # .,. ~ #! # ~ 

= 00 «i 0:; <"V N 0 co co 00 co CI) 

Figure 7.8.6 Range of Electricity Use in kWh for Mobile Home 

Furnaces 

7-29 
Energy use for oil-fired furnaces shown in Table 7.8.4 and Figures 7.8.7 and 7.8.8.

Table 7.8.4 Oil-Fired Furnace Energy Use

Design Option

by AFUE

Average Annual Oil Use

(MMBtu)

Average Electricity Use

(kWh)

78% 73.2 789

80% 71.4 770

81% 70.6 761

81% - Interrupted Ignition 71.3 589

81% - Atomized Burner w/ TwoStage

72.2 388

82% 69.8 752

82% - Interrupted Ignition 70.5 582

82% - Atomized Burner w/ TwoStage

71.3 383

83% 69.0 743

83% - Interrupted Ignition 69.7 575

83% - Atomized Burner w/ TwoStage

70.5 379

84% 68.2 735

84% - Interrupted Ignition 68.9 569

84% - Atomized Burner w/ TwoStage

69.6 375

85% 67.4 727

85% - Interrupted Ignition 68.1 562

85% - Atomized Burner w/ TwoStage

68.8 371

 EE-RM/STD-01-350 COMMENT 164

Energy use for oil-fired furnaces shown in Table 7.8.4 and Figures 7.8.7 and 7.8.8. 

T a e bI 7 . . 8 4 01 I -F" Ire d F urn ace E ner2Y U se 

Design Option Average Annual Oil Use Average Electricity Use 

by AFUE (MMBtu) (kWh) 

78% 73.2 789 

80% 71.4 770 

81% 70.6 761 

81 % - Interrupted Ignition 71.3 589 

81 % - Atomized Burner wi Two- 72.2 388 

Stage 

82% 69.8 752 

82% - Interrupted Ignition 70.5 582 

82% - Atomized Burner wi Two- 71.3 383 

Stage 

83% 69.0 743 

83% - Interrupted Ignition 69.7 575 

83% - Atomized Burner wi Two- 70.5 379 

Stage 

84% 68.2 735 

84% - Interrupted Ignition 68.9 569 

84% - Atomized Burner wi Two- 69.6 375 

Stage 

85% 67.4 727 

85% - Interrupted Ignition 68.1 562 

85% - Atomized Burner wi Two- 68.8 371 

Stage 

7-30 
713% Baseline 1

80% Inc r HK Area

81 %1nc r HX Area

8196 Interrupted Ignition

81 %AtomBurner2-rude Mod

82% Incr HE Area

62% Interrupted I gnI[Ion

82%AtomBumer2- loge Mod

83% Incr HJ{ Area

8395 Interrupted Ignition

83%AtomAurner1 geMod

84% IncI HX Area

849fi Interrupted Ignition

84%AM mBurner2- 92de Mod

85% Incr HX Area

85% Interrupted ignition

81 %At rnBumer2• atage Mod

4 4 Q CM G

0 o a o 0 0

OQ O O 

70% Baseline

_.....

80% IncrHX Area T 

81 % Incr HE Area

01% Interrupted Ignition

81 %AtamBurner2- E ge Mod. ._.--.l----

82% Incr HE Area

1.__.... _ . -

82% Interrupted IUnition

IT

82% Atom Burner 2- dage Mod 

83% Incr HE Area

83% Interrupted Ignition I 

83°.6At3mBurner2- dageMud 4--^ 

84% IncrHXArea

84% Interrupted ignition

84% Atom Burner 2- stage Mud

85% Incr Hai Area

.... :.,.T 

85% Interrupted Ignition -- ^ ® 

81-'AtomBurner 7-eta eMad

^

Q.) '" .. 0:::: .." <II c: .." .. 0:::: .." 'I> 0:::: .." 'I> 0:::: .." sc OJ g D OJ D OJ .2 D Q.) g D g Q <- < 2' :E < 50 :E < § :E ."< :E § :E X ;:t; II> ;:t; II> ;:t; II> X II> X OJ <Xl "" "" "" "" til ED :I: :I: i :r: i :I: i ::L i :I: '- .gj ::; y '" y s y s u CD -u <D :s s; Q. ..... .s "'- ..... s; "'- ..... sc Q. ..... sc <>. ....... 

#- ';f. ::3 ';f. :: .. ';f. ::l .. #- :: lD #- 2 .:.. :ii m II> II> m m GI 0 a:; E N E E .... E It) <:: CD E '" CD :e '" s' '" Ell E '" <D $ :; tr: m .". m .". m .". m .". m E N E M E .... E '" E <D «> (IQ QO QO 

IS IS iI 

..... n M ... ... «> QO «> QO CD 

Figure 7.8.7 Range of Annual Gas Use in MMBtu for Oil-Fired 

Furnaces 

EI ectrlclb' U is!! Ranges BY oe sign 0 pUC n 

II> .. (10 <:: p .. 0:::: -g 'I> C .." (10 <:: g ! 0:::: "CJ ,5 CD 0 2! .2 D Q Q . D 

i < <: '2: ..: '2 :E < :E ...:: .J2 <- :E x x E- '" ;:t; II> X E' GI X ." '" X II> ,. "" .... ZII "" .... m :I: :I: ]j til :I: i ::L "IS :I: -u til :I: .,. ;:; y E ;:; ID· ;:; AI U i 

QQ SC .s: <L .-:.. .s; ... ..... SC 11- ..... .s: Q. ..... :s ... n 

...... #- 2 '- '# :::> .. #- 2 .. ::I .... '# 2 .. iii CD 53 II> iii GI j . CD liS g a; E N C fT) E ... E £; ::> '" CD :s :; CD :E '" CD E ::> CD E '" lfI m tr: m If! m m tr: m 

... E ".... E M E ... E It) E 

CD <D !XI al <D 

If< 

,... n ..... "'" eo 00 CD QO OQ 

Figure 7.8.8 Range of Electricity Use in kWh for Oil-Fired 

Furnaces 

7-31 
Energy use for gas boilers shown in Table 7.8.5 and Figures 7.8.9 and 7.8.10.

Table 7.8.5 Gas Boiler Ener Use (Low Cost Scenario

Design Option

by AFUE

Average Annual Gas Use

(MMBtu)

Average Electricity Use

(kWh)

80% 79.4 135

81% 75.7 149

81% - Modulation (Two-Stage) 75.5 189

82% 74.8 147

82% - Modulation (Two-Stage) 74.6 187

83% 73.9 145

83% - Modulation (Two-Stage) 73.7 185

84% 73.0 143

84% - Modulation (Two-Stage) 72.9 183

85% 72.2 142

85% - Modulation (Two-Stage) 72.0 181

86% 71.3 140

91% 67.5 132

99% 62.0 122

 EE-RM/STD-01-350 COMMENT 164

Energy use for gas boilers shown in Table 7.8.5 and Figures 7.8.9 and 7.8.10. 

Table 7.8.5 Gas Boiler Energ~ Use (Low Cost Scenario) 

Design Option Average Annual Gas Use Average Electricity Use 

by AFUE (MMBtu) (kWb) 

80% 79.4 135 

81% 75.7 149 

81% - Modulation (Two-Stage) 75.5 189 

82% 74.8 147 

82% - Modulation (Two-Stage) 74.6 187 

83% 73.9 145 

83% - Modulation (Two-Stage) 73.7 185 

84% 73.0 143 

84% - Modulation (Two-Stage) 72.9 183 

85% 72.2 142 

85% - Modulation (Two-Stage) 72.0 181 

86% 71.3 140 

91% 67.5 132 

99% 62.0 122 

7-32 
1 BO

160

140

120

100

BO

ii0

40

20

0 du

a,

Ql

ca

m

a' m

Figure 7.8.9 Range of Annual Gas Use in MMBtu for Hot-Water

Gas Boilers (Low Cost Scenario)

Figure 7.8.10 Range of Electricity Use in kWh for Hot-Water Gas

Boilers (Low Cost Scenario)

7-33

 EE-RM/STD-01-350 COMMENT 164

Mnuel Gas Use Armges ~ DeSign QPtion 

OJ ~ 0::: ~ 0:: ~ C ~ 1! r:: ~ 0:: ~ ~ ~ E l! 2! !! ~ .... '" <"'> .... ..., '" .... IT.I CD 0 00 Cl 00 a a;. 0 00 Cl <XI "" '" '" ... ... .. "" .. .. "C "C T.l tJ "C CD .5 .5 .5 .5 .5 ~ .. t- t- .. t- oO ... ". fl '0 CD -g 0 Q 0 

::s; ::s; !E E E II) II> OJ 0» III 

"" C1 0\ QI C1 

~ ~ ~ {! -m N ('of "" .,:; .,;, 

~ III III ~ ~ ... n !:"1 1J!; '" CD. 00 <XI 00 

Figure 7.8.9 Range of Annual Gas Use in MMBtu for Hot-Water 

Gas Boilers (Low Cost Scenario) 

OJ ~ .0::: ~ 0:: III 0:: ~ ~ ~ 0:: ~ Ifl ~ .!: ... E '" !! M 2! .... ~ '" I! <D .... en Ai CD 0 00 0 00 a CD 0 00 Cl CD "" '" '" ... u OJ ... ... ~ '0 "C T.l '" "C 

.5 .5 .6 .5 .5 ~ .. .. t- .. t- -:::I ... ". ..., ... CD -g 0 Q a 0 

::s; E !E E ~ II) III OJ !II II> 

"" "" 0\ 0::0 C1 

~ ~ fI {! -m ". ('of M N .,;, 

~ III ~ ~ III ... n <"'> .... "" CD 00 <XI 00 00 

Figure 7.8.10 Range of Electricity Use in kWh for Hot-Water Gas 

Boilers (Low Cost Scenario) 

7-33 
Energy use for oil-fired boilers shown in Table 7.8.6 and Figures 7.8.11 and 7.8.12.

Table 7.8.6 Oil-Fired Boiler Energy Use

Design Option

by AFUE

Average Annual Oil Use

(MMBtu)

Average Electricity Use

(kWh)

80% 82.7 297

81% 81.7 294

81 % - Interrupted Ignition 82.0 235

82% 80.7 290

82% - Interrupted Ignition 81.0 232

82% - Atomized Burner w/ TwoStage

80.7 311

83% 79.8 287

83% - Interrupted Ignition 80.0 230

83% - Atomized Burner w/ TwoStage

79.7 307

84% 78.9 284

84% - Interrupted Ignition 79.1 227

84% - Atomized Burner w/ TwoStage

78.8 304

85% 77.9 280

85% - Interrupted Ignition 78.2 224

85% - Atomized Burner w/ TwoStage

77.9 301

86% 77.0 277

86% - Interrupted Ignition 77.3 222

86% - Atomized Burner w/ TwoStage

77.0 297

90% 73.9 212

95% 70.0 201

 EE-RM/STD-01-350 COMMENT 164

Energy use for oil-fired boilers shown in Table 7.8.6 and Figures 7.8.11 and 7.8.12. 

T bl 7 8 6 0"1 F O 

a e o 0 I - Ire d B 01 01 er E U nergy se 

Design Option Average Annual Oil Use Average Electricity Use 

by AFUE (MMBtu) (kWh) 

80% 82.7 297 

81% 81.7 294 

81 % - Interrupted Ignition 82.0 235 

82% 80.7 290 

82% - Interrupted Ignition 81.0 232 

82% - Atomized Burner wi Two- 80.7 311 

Stage 

83% 79.8 287 

83% - Interrupted Ignition 80.0 230 

83% - Atomized Burner wi Two- 79.7 307 

Stage 

84% 78.9 284 

84% - Interrupted Ignition 79.1 227 

84% - Atomized Burner wi Two- 78.8 304 

Stage 

85% 77.9 280 

85% - Interrupted Ignition 78.2 224 

85% - Atomized Burner wi Two- 77.9 301 

Stage 

86% 77.0 277 

86% - Interrupted Ignition 77.3 222 

86% - Atomized Burner wi Two- 77.0 297 

Stage 

90% 73 .9 212 

95% 70.0 201 

7-34 
150

140

120

100

BO

50

40

20

AnnUal411VseRUNS 'Design4pUon

Figure 7.8.11 Range of Annual Gas Use in MMBtu for Hot-Water

Oil-Fired Boilers

Figure 7.8.12 Range of Electricity Use in kWh for Hot-Water OilFired Boilers

7-35

 EE-RM/STD-01-350 COMMENT 164

MnUiill 011 use Ranges Etf Design OI)1lDn 

., ~ c: tl 0:: ., ~ c: 11> ~ c: CD #. .0:: ., ~ c: 11> <fI. c: 0:: .,. o:n ... ? "" .,. .,. z:n z:n ? "" .,. 0; 'L: i ,.., -It ... :ell "" -Ill u::;. -It CI 'L: 3i '" ... CD "- ttl ... '" .. '" ... 01 CD ., ~ $! ., CD ., ... sa :s "" o:lo .5 ~ :s o:lo :E o:lo 5 III i!Il l!fI E i!Il E 1!!1 E l!fI E i!Il E 1!!1 l!fI ,.... n ~ "'" ~ 'IT 

~ '" ~ 0::> ~ '"" Q 00 (Il 00 .1;1) (Il 00 1;1) (Il 

!11 l!/l i!Il l!fI ~ 

'"" 1;'1 g '" 0::> 1;1) 00 (Il 00 

Figure 7.8.11 Range of Annual Gas Use in MMBtu for Hot-Water 

Oil-Fired Boilers 

Elettrlelt,' Use RangeS BY Des!!.," ClDllan 

; 

., ~ c: #. 0:: ., ~ c: 11> 

~ c: '" #. 0:: ., ~ ~ 11> g; c: 0:: ? o:n .,. .,. m .,. .,. z:n o:n m .,. ~ 0; N .:: i 'L: -iii z:: ill In -Ill u::;. -iii ... <: '" IX> ttl '" ... IX> "- Of 1,11 $ .. ~ ., .$ CD ., ... .5 :E "" ~ 5 ~ E oA :E n 5 III E E E E E ;,II i!Il ;,II i!Il 1!!1 ;,II i!Il 1!!1 ,... n ~ M ~ 'IT ~ '" ~ 0::> ~ '"" Q 00 (Il 00 1;1) (Il 00 1;1) (Il 

III ~ ~ !tI ~ 

'" M ~ '" <0 1;1) ()O (Il 00 

Figure 7.8.12 Range of Electricity Use in kWh for Hot-Water OilFired Boilers 

7-35 
REFERENCES

1. U.S. Department of Energy - Energy Information Administration, Residential Energy

Consumption Survey: Household Energy Consumption and Expenditures 2001, 2001.

(Lastaccessed May 18, 2005.)

<http://www.eia.doe.gov/emeu/recs/recs200l/publicuse2OOl.html>

2. Gas Appliance Manufacturers Association (GAMA), GAMA Directory March 2005, 2005.

(Lastaccessed March, 2005.)

<http://www. gamanet. org/gama/inforesources.nsf/vAllDocs/Product+Directories?OpenDo

cument>

3. Gas Appliance Manufacturers Association (GAMA), Updated Shipment Data for

Residential Furnaces and Boilers,personal communication. April 25, 2005.

4. Phillips, E., Blower Efficiency in Domestic Heating Systems, June, 1995. UNIES Ltd.

Winnipeg, Manitoba. Report No. CEA 9202 U 921.

5. Lindeburg, M. R., Fans and Ductwork, Chapter 20. In Mechanical Engineering Reference

Manual for the PE Exam, Michael R. Lindeburg PE, Editor. Tenth ed. 1997. Professional

Publications, Inc.: Belmont, CA. p. 20-23

6. American Society of Heating Refrigeration and Air-Conditioning Engineers, ASHRAE

1997 Handbook - Fundamentals. 1997.: Atlanta, GA.p. 3.12.

7. Proctor, J. and D. Parker, Hidden Power Drains: Residential Heating and Cooling Fan

Power Demand. In ACEEE 2000 Summer Study on Energy Efficiency in Buildings. 2000.

Asilomar, CA, August 20-25 . American Council for an Energy-Efficient Economy. 1: pp.

225-234.

8. Lennox Industries Inc., Lennox Engineering Data: G40DF (Merit Series

Upflow/Horizontal Gas Furnace), 2003 . Lennox Industries, Inc. 2003.)

<http ://pirl.lennox. com/C03e7ol4l/76EOZC21u/ehb_g40df 0307.pdf>

9. Lennox Industries Inc., Lennox Engineering Data: G40UH (Merit Series

Upflow/Horizontal Gas Furnace), 2004. Lennox Industries, Inc.

<http ://pirl.lennox . com/C03e7ol4l/76EOZC21u/ehb_g4Ouh0407.pdf>

10. Lennox Industries Inc., Lennox Engineering Data: G41 UF (Merit Series Downflow Gas

Furnace), 2004. Lennox Industries, Inc.

<http ://pirl.lennox. com/C03e7ol41/76EOZC21u/ehb_g4luf 0402.pdf>

7-36

 EE-RM/STD-01-350 COMMENT 164

REFERENCES 

1. U.S. Department of Energy - Energy Information Administration, Residential Energy 

Consumption Survey: Household Energy Consumption and Expenditures 2001,2001. 

(Lastaccessed May 18,2005.) 

<http://www.eia.doe.gov/emeulrecs/recs200 I/publicuse200 l.html> 

2. Gas Appliance Manufacturers Association (GAMA), GAMA Directory March 2005, 2005. 

(Lastaccessed March, 2005.) 

<http://www.gamanet.org/ gama/inforesources.nsf/v AllDocs/Product+ Directories?OpenDo 

cument> 

3. Gas Appliance Manufacturers Association (GAMA), Updated Shipment Data for 

Residential Furnaces and Boilers,personal communication. Apri125, 2005. 

4. Phillips, E., Blower Efficiency in Domestic Heating Systems, June, 1995. UNIES Ltd. 

Winnipeg, Manitoba. Report No. CEA 9202 U 921. 

5. Lindeburg, M. R., Fans and Ductwork, Chapter 20. In Mechanical Engineering Reference 

Manualfor the PE Exam, Michael R. Lindeburg PE, Editor. Tenth ed. 1997. Professional 

Publications, Inc.: Belmont, CA. p. 20-23 

6. American Society of Heating Refrigeration and Air-Conditioning Engineers, ASHRAE 

1997 Handbook - Fundamentals. 1997.: Atlanta, GA.p. 3.12. 

7. Proctor, J. and D. Parker, Hidden Power Drains: Residential Heating and Cooling Fan 

Power Demand. In ACEEE 2000 Summer Study on Energy Efficiency in Buildings. 2000. 

Asilomar, CA, August 20-25. American Council for an Energy-Efficient Economy.l: pp. 

225-234. 

8. Lennox Industries Inc., Lennox Engineering Data: G40DF (Merit Series 

UpjlowlHorizontal Gas Furnace), 2003. Lennox Industries, Inc. 2003.) 

<http://pirl.lennox.com/C03e7014lI76EOZC21u1ehb_g40dC0307.pdf> 

9. Lennox Industries Inc., Lennox Engineering Data: G40UH (Merit Series 

UpjlowlHorizontal Gas Furnace), 2004. Lennox Industries, Inc. 

<http://pirl.lennox.com/C03e7 0 14l176EOZC21 ulehb _g40uh _ 0407.pdf> 

10. Lennox Industries Inc., Lennox Engineering Data: G41 UF (Merit Series Downjlow Gas 

Furnace), 2004. Lennox Industries, Inc. 

<http://pirl.lennox.com/C03e7014lI76EOZC21u1ehb_g41uC0402.pdf> 

7-36 
11. Lennox Industries Inc., Lennox Engineering Data: G43 UF (Merit Series Upflow Gas

Furnace), 2004. Lennox Industries, Inc.

<http://pirl.lennox.com/C03e7ol41/76EOZC21u/ehb_g43uf 0412.pdf>

12. Lennox Industries Inc., Lennox Engineering Data: G50DF (Elite Series Downflow Gas

Furnace), 2003. Lennox Industries, Inc.

<http://pirl.lennox.com/C03e7ol4l/76EOZC21u/ehb_g5Odf 0307.pdf>

13. Lennox Industries Inc., Lennox Engineering Data. G50UH (Elite Series

Upflow/Horizontal Gas Furnace), 2003 . Lennox Industries, Inc.

<http://pirl.lennox . com/C03e7ol4l/76EOZC2 lu/ehb_g50uh_03 07.pdf>

14. Lennox Industries Inc., Lennox Engineering Data. G51MP (Elite Series Multi-Position

Gas Furnace), 2004. Lennox Industries, Inc.

<http://pirl.lennox.com/C03e7ol4l/76EOZC2 lu/ehb_g51 mp_0412.pdf>

15. Carrier Corporation, Carrier Product Data: 58CVA/CVX(Infinity 80 Series MultiPoise

Furnace), 2004. Carrier Co.

<http ://www.xpedio . carrier. com/idc/groups/public/documents/techlit/5 8cv-3pd.pdf>

16. Carrier Co., Carrier Product Data: 58MVP (Infinity 96 Deluxe 4-Way Multipoise

Furnace), 2004. Carrier Co.

<http://www.xpedio.carrier.com/idc/groups/public/documents/techlit/58mvp-11 pd.pdf>

17. Lennox Industries Inc., Lennox Engineering Data: G61MPV (Multi-Position - Variable

Speed Blower - Two-Stage Heat - Direct Vent/Non-Direct Vent). 2004, Lennox Industries,

Inc.

18. Lennox Industries Inc., Lennox Engineering Data. G60UHV (Up-Flow/Horizontal - Two

Stage Heat - Variable SpeedBlower). 2003 , Lennox Industries, Inc.

19. Lennox Industries Inc., Lennox Engineering Data: G60DFV (Down flow - Variable Speed

Blower - Two-Stage Heat). 2004, Lennox Industries, Inc.

20. Trane Co., Trane Product Data: XV 80, 2004. Trane Co.

21. Trane Co., Trane Product Data: XV 90, 2004. Trane Co.

22. American Society of Heating Refrigerating and Air-Conditioning Engineers Inc., Method

of Testing for Annual Fuel Utilization Efficiency of Residential Central Furnaces and

Boilers, October, 2003 . Atlanta, GA. Report No. BSR/ASHRAE Standard 103-1993R.

First Public Review.

23. Title 10, Code ofFederal Regulations, Part 430- Energy Conservation Program for

Consumer Products, Appendix N to Subpart B of Part 430-Uniform Test Method for

7-37

 EE-RM/STD-01-350 COMMENT 164

11. Lennox Industries Inc., Lennox Engineering Data: G43 UF (Merit Series Upjlow Gas 

Furnace), 2004. Lennox Industries, Inc. 

<http://pirl.1ennox.com/C03e70141/76EOZC21u/ehb_g43uC0412.pdf> 

12. Lennox Industries Inc., Lennox Engineering Data: G50DF (Elite Series Downjlow Gas 

Furnace), 2003. Lennox Industries, Inc. 

<http://pirl.1ennox.com/C03e70141/76EOZC21u1ehb_gSOdC0307.pdf> 

13. Lennox Industries Inc., Lennox Engineering Data: G50UH (Elite Series 

Upjlow/Horizontal Gas Furnace), 2003. Lennox Industries, Inc. 

<http://pirl.1ennox.com/C03e70141/76EOZC21u1ehb_gSOuh_0307.pdf> 

14. Lennox Industries Inc., Lennox Engineering Data: G 51 MP (Elite Series Multi-Position 

Gas Furnace), 2004. Lennox Industries, Inc. 

<http://pirl.1ennox.com/C03e70141/76EOZC21u1ehb_gSlmp_0412.pdf> 

IS. Carrier Corporation, Carrier Product Data: 58CVA/CVX(Infinity 80 Series MultiPoise 

Furnace}, 2004. Carrier Co. 

<http://www.xpedio.carrier.com/idc/groups/public/documents/techlitlS8cv-3pd.pdf> 

16. Carrier Co., Carrier Product Data: 58MVP (Infinity 96 Deluxe 4-Way Multipoise 

Furnace), 2004. Carrier Co. 

<http://www.xpedio.carrier.com/idc/groups/public/documents/techlitlS8mvp-ll pd. pdf> 

17. Lennox Industries Inc., Lennox Engineering Data: G61MPV (Multi-Position - Variable 

Speed Blower - Two-Stage Heat - Direct Vent/Non-Direct Vent). 2004, Lennox Industries, 

Inc. 

18. Lennox Industries Inc., Lennox Engineering Data: G60UHV (Up-Flow/Horizontal - Two 

Stage Heat - Variable Speed Blower). 2003, Lennox Industries, Inc. 

19. Lennox Industries Inc., Lennox Engineering Data: G60DFV (Down-jlow - Variable Speed 

Blower - Two-Stage Heat). 2004, Lennox Industries, Inc. 

20. Trane Co., Trane Product Data: XV 80, 2004. Trane Co. 

21. Trane Co., Trane Product Data: XV 90, 2004. Trane Co . 

. 22. American Society of Heating Refrigerating and Air-Conditioning Engineers Inc., Method 

o/Testing/or Annual Fuel Utilization Efficiency o/Residential Central Furnaces and 

Boilers, October, 2003. Atlanta, GA. Report No. BSRlASHRAE Standard 103-1993R. 

First Public Review. 

23. Title 10, Code o/Federal Regulations, Part 430- Energy Conservation Program/or 

Consumer Products, Appendix N to Subpart B 0/ Part 430-Uniform Test Method/or 

7-37 
Measuring the Energy Consumption of Furnaces and Boilers, January 1, 1999. Chapter II.

 EE-RM/STD-01-350 COMMENT 164

Measuring the Energy Consumption a/Furnaces and Boilers, January 1,1999. Chapter II. 

7-38