NBS

PUBLICATIONS

NBSIR 84-2939

NATL INST. OF STAND & TECH

A111D7 3^10ED

Criteria for Mechanical Systems

in Multifamily Buildings for

Residential Weatherization

Options

Lawrence S. Galowin

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Equipment Division

Gaithersburg, MD 20899

September 1984

Sponsored by:

Department of Energy

BATIOIfJa OF ST.VTVPXM

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NBSIR 84-2939

// ^ CRITERIA FOR MECHANICAL SYSTEMS

IN MULTIFAMILY BUILDINGS FOR

RESIDENTIAL WEATHERIZATION

OPTIONS

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Lawrence S. Galowin

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Equipment Division

Gaithersburg, MD 20899

September 1984

Sponsored by:

Department of Energy

Office of Weatherization Assistance

Forrestal Building

Washington, DC 20585

U.S. DEPARTMENT OF COMMERCE. Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Ernest Ambler, Director

ABSTRACT

The National Bureau of Standards (NBS) prepared the original criteria and list

of eligible retrofit options adopted for energy conservation by the Department

of Energy (DoE) Weatherization Assistance Program (WAP) regulation under the

Energy Conservation in Existing Buildings Act of 1976. NBS was requested to

review, update, and expand the criteria and list of retrofits for 1984 amendments to the regulation. This report presents the criteria and reference

standards for retrofit options of mechanical equipment and systems in multifamily buildings.

Mechanical systems equipment, controls, energy management systems, burners,

and boiler/furnace tuneup/repairs were included. The options for retrofit

technologies for equipment replacement components include items such as burners,

burner controls, combustion chamber refractories, modifications with dampers,

turbulators, and waste heat recovery devices. The criteria developed did not

include economic factors and statutory constraints under the rulemaking procedures.

Key words: boiler/furnace performance upgrading; energy controls; energy

conservation; mechanical building equipment; replacement burners;

weatherization; tuneups and repairs for multifamily building

equipment

.

Disclaimer — Names of manufactured items do not indicate endorsement or evaluation of products; such identification illustrates representative

examples

.

iii
TABLE OF CONTENTS

Page

ABSTRACT iii

LIST OF TABLES v LIST OF FIGURES vi

i . INTRODUCTION 1 1.1 Background 1 1.2 Profile of Multifamily Buildings 2 1.3 Multifamily Buildings Energy Usage 2

2. ENERGY EQUIPMENT IN MULTIFAMILY RESIDENCES 17

2.1 Central Systems and Components 17

2.1.1 Steam Distribution Systems 18

2.1.2 Hot Water Heating System 20

2.1.3 Domestic Hot Water Systems 24

2.2 Functions of Boilers, Furnaces, Water Heaters 28

3. MECHANICAL RETROFITTING CRITERIA FOR MULTIFAMILY BUILDINGS 30

3.1 STANDARDS AND ORGANIZATIONS 38

3.1.1 Equipment Efficiency Improvements 41

3.1.2 Thermostatic Radiator Valves and Steam Traps 45

3.1.3 Hot Water Piping and Recirculation Systems 46

3.1.4 Training — Maintenance, Operation, Tuneups, Repair and

Modification 47

4. WEATHERI ZATI ON RETROFIT EXAMPLES 51

4.1 Various Sized Buildings 51

4.2 Central Powerhouse Replacement with Modular Boilers 52

4.3 High Efficiency Furnaces and Boilers 52

5. DISCUSSION OF MECHANICAL WEATHERI ZATI ON OPTIONS 54

6. CONCLUSIONS 56

REFERENCES 57

APPENDIX A - WEATHERI ZATI ON MATERIALS A-l

APPENDIX B - MODEL CODES B-l

APPENDIX C - BOILER RATINGS C-l

APPENDIX D - CODES, STANDARDS, ORGANIZATIONS, AND MARKINGS D-l

iv
LIST OF TABLES

Page

Table 3.1 Summary of Recommended Criteria 32

Table 3.2 Boiler Efficiency Improvement Seminar 49

Table 3.3 Association of Energy Engineers Seminars 50

Table B-l Model Codes Governing Installation of Residential Gas-Fueled

Heating Appliances B-2

Table B-2 Survey of Municipal Codes Regulating Installation of

Residential Gas Appliances B-3

v
LIST OF FIGURES

Page

Figure 1.1 Composition of the multifamily by building size (1978) 4

Figure 1.2 Growth of the multifamily housing stock 5

Figure 1.3 Household energy consumption, 1978-1979 6

Figure 1.4 Functional end-use by residential structure type 7

Figure 1.5 Percent of total Etu 8

Figure 1.6 Percent of rental apartment units using various heating

fuels, by region 9

Figure 1.7 Heating fuel by multifamily building size (percent of units

using various fuels for heating) 10

Figure 1 .8 Functional end-use of energy in apartments and fuel share

(1978) 11

Figure 1.9 Central heating systems by region and building size (1977) .. 12

Figure 1.10 Multifamily rental units by heating system type 14

Figure 1.11 Multifamily rental units by building size 15

Figure 1.12 Reported utility costs in apartment buildings (current

dollars) 16

Figure 2.1 Typical upfeed gravity one-pipe air vent system 19

Figure 2.2 Hot water system with one circuit having a direct return and

one circuit having a reversed return 21

Figure 2.3 Multizone hot water system with primary and secondary

pumping 22

Figure 2.4 Forced circulation of domestic hot water especially needed

in long, low buildings 25

Figure 2.5 Domestic hot water from a built-in tankless coil in a hot water

heating, boiler 26

Figure 2.6 Downfeed water distribution. Schematic section, part of the

water services of a 10 story building. Hot water circulation

is through the hot upfeed, in two directions at the hot water

heater and down to the tank through the two downfeed hot water

risers 27

vi
LIST OF FIGURES

Page

Figure 5.1 Estimated vs. actual energy savings (as a percentage of

initial consumption) from retrofitting 18 commercial

buildings . The data show no apparent correlation between

pre-retrofit predictions and actual results. Source: Ross

and Whalen, 1981 , 55

Figure C-l Net load recommendations for obsolete round cast-iron boilers . C-3

Figure C-2 Net load recommendations for obsolete square (sectional type)

cast iron boilers

vii

1 . INTRODUCTION

1 . 1 BACKGROUND

The Weatherization Assistance Program (WAP) was established under the Energy

Conservation in Existing Buildings Act of 1976, as amended, to provide assistance to low-income persons and to reduce national energy consumption.

Funds are allocated under the WAP to States, the District of Columbia and

Indian tribal organizations (under certain circumstances). Within those jurisdictions distributions of funds are made to local governments, nonprofit organizations and tribal groups to perform weatherization retrofits and activities.

Funds are allocated to the states using a formula which is based upon the

numbers of low-income households in each state, the annual heating and cooling

degree days, and the percentage of total residential energy used for space

heating and cooling.

In January 1984, the Department of Energy (DoE) adopted amendments to the

regulation for the program to improve its efficiency and effectiveness.

Among the changes adopted were an expanded list of eligible measures which now

encompasses options for mechanical equipment, including multifamily buildings*.

The definition of "Weatherization Materials" now includes several new products,

systems components, and materials. Further, appendix A of the regulation was

revised to incorporate a listing of applicable standards for additional adopted

measures

.

The National Bureau of Standards prepared the expanded criteria, to support the

revisions to the measures list and appendix A, adopted in the final rule published in the Federal Register, January 27, 1984. This report discusses the

retrofits applicable for multifamily building mechanical equipment. The

provisions tabulated in this report established recommended WAP criteria for

mechanical equipment and systems in the DoE update of the regulations. The new retrofit criteria published for materials used as "Architectural" options

and mechanical equipment options for single-family residences in are presented

in [2] and [3], respectively. As used here, the term retrofit means the

process whereby materials, components of systems, and products are permanently

added to single-family and multifamily residential dwelling units or homes in

order to reduce heating and cooling energy consumption. Also, certain modifications, repairs, tune-up adjustments, and component cleaning are included as measures for improving performance of existing equipment although no standards

or specifications prescribe the procedures, training, licensing, and experience

are required. The expanded categories for specific eligible weatherization

measures permit a comprehensive approach for energy savings beyond the earlier

"architectural" measures which functioned primarily to reduce air infiltration

through the building envelope and provide increased thermal insulation [I].

* Amendments to the proposed rules for public comment were announced in the

Federal Register, Vol. 48, No. 215, November 4, 1983. Final rule amending

the regulation was published in the Federal Register, Vol. 49, No. 19,

January 27, 1984.

1
1.2 PROFILE OF MULTIFAMILY BUILDINGS

The multifamily building sector in the United States residential housing stock

was reported in a study of the residential energy market sponsored by the Gas

Research Institute [4]. From that report, information has been summarized to

provide a background for multifamily building energy conservation opportunities.

The multifamily sector represents approximately 13 million rental units which

consume about one quad of energy per year (1 quad = 10^ Btu) . According to

the Annual Housing Survey of 1978, 82 percent of the apartments are renter

occupied. The multifamily buildings considered in the statistics [4] were

for five or more apartments. In ASHRAE Standard 100. 2P, "Energy Conservation

in Existing Buildings: High-Rise Residential," building classifications are subdivided into Low Level Residential not more than three stories in height,

and High-Rise Residential-more than three stories. The geographical distributions of apartment buildings are: Northeast Census Region contains about 30

percent. Southern Census Region about 26 percent, and the North Central and

Western Regions about 22 percent each.

In multifamily rental units, energy usage has become a major part of operating

cost. Building owners and managers have little incentive for investment

because of constraints from local conditions of rent control, taxes on improvements through higher assessments, and local building regulations that

require considerable overall systems upgrading when making any single component

retrofit. There is a trend toward individual metering for utility consumption

in each rental unit (31 states have considered banning master metering for gas

and electric services in new buildings).

The estimated national average for the number of apartments in buildings is 14

units per multifamily structure. In figure 1.1 the distributions of apartments

by size (based on the Census Regions) are shown. The non-uniform distributions

of apartment compositions for building sizes in different parts of the United

States are indicated. Construction of multifamily structures has had a strong

growth pattern since 1950. About two-thirds of existing apartment buildings were constructed since 1950 and one-half of existing apartment buildings are

less than 20 years old (an average single-family home is 27 years old). In

figure 1.2 the growth of the multifamily housing stock is shown for renteroccupied units since 1970. Small apartment buildings, those with fewer than

20 units, comprised 73 percent of the net addition of all apartment units from

1970 to 1978; buildings containing 5 to 9 units represented about one-half of

the total growth in the same period. Demand for multifamily rental and condominium units were attributed to: growth in the early family, individuals in

the under 35 year age group and the over 65 year age group; long-term social

patterns of declining birth rates leading to smaller average household sizes;

and continued increases in the costs of owning single-family homes.

1.3 MULTIFAMILY BUILDINGS ENERGY USAGE

The multifamily buildings sector is distinguished from other residential stock

by its composition, size, and geographical concentrations. Apartment units

2
and common areas used 930 trillion Btu’s of energy in 1978. A comparison of

household energy usage in residential buildings is shown in figure 1.3. The

average apartment annually consumes 43 percent less energy than the average

single-family detached home. This lower energy usage per unit is due, in

part, to the smaller size living units. The national average size for rentable

apartments is 850 square feet compared with about 1,500 square feet for singlefamily homes. Apartment units within a single building envelope (with lower

ratios of surface to volume ratios than single-family homes) benefit somewhat

from adjacent occupied apart ments in lowering energy losses. The correlations

between household income and energy use indicates that lower incomes would be

associated with lower energy consumption. For residential units on a squarefootage basis, single-family house use about 104,000 Btu/ft^/year and apartments

use about 96,000 Btu/ftVyear .

The pattern of energy load distributions in multifamily units differs from

those in single-family homes. In figure 1.4 the distributions for energy end- use are illustrated. For high-rise multifamily units 55 percent of the total

amount of energy is used for space heating and cooling while a single-family

detached house uses 70 percent of the total energy for the space conditioning.

A larger part of the energy budget in multifamily housing is expended for

heating water; the 30 percent level is twice that for single-family detached

units. The percentages of the various fuels used to meet the energy needs of

the residential sector are shown in figure 1.5. Following gas as the foremost

fuel, oil is the second most preferred fuel in the multifamily buildings. The

distribution of fuels used for heating rental apartments in the U.S. Census

Regions are shown in figure 1.6. Dependence on oil is dominant in the northeast

region whereas in other regions gas or electricity is the principal energy

source. Within multifamily buildings the variations of fuel types with building

size are shown in figure 1.7. For buildings with 20 units, the percentage of

oil usage is greatest while for buildings with up to 19 units gas is the most

commonly used fuel.

Within multifamily buildings the different end use purposes for various fuels

vary as shown by the bar chart of figure 1.8. Of the total amount of energy

about 53 percent was used for space heating, 30 percent for water heating,

and the remainder for all other applications (the estimates for 1978 were

based on the DoE consumption model which dates back to 1974 and on survey data

for 1978 to 1979). Hot water requirements of occupants in any type residential

facility are similar; consequently with lower total energy usage in apartments

the portion of energy consumed for hot water would represent a larger fraction

(as seen is figure 1.4). Hot water energy consumption represents a target in

retrofit energy conservation measures, and these measures can be coupled with

water conservation techniques to further reduce energy usage.

Centrally heated multifamily units represent 44 percent of the national rental

units, the others are heated by individual systems.* Figure 1.9 shows the

* Equipment for retrofit within individual apartment systems would follow

recommendations and criteria cited by the WAP from for single-family

residences [3].

3
100 4

Figure

l.t.

Composition

of

the

multifamily

by

building

size

(1978)
10290

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Figure

1.2.

Growth

of

the

mill

1

f1

ami l

y

housing

stock
MILLION

BTU'S/HOUSEHOLD/YEAR

Figure 1.3. Household energy consumption, 1978-1979

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Figure

1.4.

Functional

end

by

residential

structure

type
8

2-4

UNIT

BUILDINGS

5+

UNITS

BUILDINGS
9

rtment

units

using

various

heating

fuels,

by

region
10

Figure

1.7.

Heating

fuel

by

multifamily

building

size

(percent

of

units

using

various

fuels

for

heating)
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11

Figure

1.8.

Functional

end-use

of

energy

In

apartments

and

fuel

share

(1978)
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CM

1 m

+

o

CM

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S1IND INBWiaVdV G31V3H AT1VH1N30 31V 30 %

12

Units

Units

Units

Units

Units

Units

Units

Units

NORTHEAST

NORTH

CENTRAL

SOUTH

WEST
distribution of central systems by region and building size. The northeast has

57 percent of the Nation’s apartment buildings; buildings with 20 or more units

comprise 58 percent of centrally heated buildings. The types of equipment

used for central and individual heating in multifamily rental units are shown

in figure 1.10. The central systems are primarily steam or hydronic systems

with 6 percent warm air furnaces older in smaller apartments. Warm air furnaces

represent 55 percent of the individual heating systems with 23 percent in the

form of electric resistance devices. The other types of individual unit systems

are wall or floor furnaces, room heaters, fireplaces, stoves, and portable

heaters. In figure 1.11 it is shown that central steam and hot water systems

are located primarily in larger apartment buildings. Warm air furnaces are

the most common in individual unit heating systems and also appear to be concentrated in smaller apartment buildings.

The utility bills for multifamily operations are more than one-quarter of the

total operating expenses. Figure 1.12 indicates the increased costs of heating

fuel from 1974 to 1979; gas, electric, and oil increased by 27, 14, and

13 percent, respectively.

13
14

Figure

1.10.

Multifamily

rental

units

by

heating

system

type
15

20-49

UNITS

50+

UNITS
COSTS

($/SF

Rentable

area

—

Current

dollars)

0.5 r

0.4

0.3

0.2

0.1

0.08

0.06

0.04

0.02

74 75 76 77 78 79

YEAR

Figure 1.12. Reported utility costs in apartment buildings (current dollars)

16
2. ENERGY EQUIPMENT IN MULTIFAMILY RESIDENCES

Energy usage patterns for occupants in multifamily dwelling units and

single-family residences are similar. The greatest amount of end-use energy

in multifamily dwellings is for space conditioning, at about 55 percent of the

total energy. The next most important energy end use is for water heating,

about 30 percent (that percentage is approximately twice that for single-family

residential energy usage). The total energy consumed in apartments with multifamily usage is less than for single-family buildings; consequently, water

heating becomes a larger fraction of all the energy used. That is because

water load patterns for occupants are not altered by the size of the building.

Other energy consumption is approximately 5 percent each for lighting, cooking,

and refrigeration (with clothes drying, garbage disposal, television, fans,

and other small appliances included as miscellaneous items).

The criteria for weatherization as discussed in other reports [1, 2, 3] are applicable and independent of the building size when individual apartment

units have installed unitary equipment comparable to those in single-family

residences. Those retrofits measures include windows, walls, caulking, and

appliances or other dwelling equipment (including special service rooms or basements equipped for laundry and drying).

In this weatherization study of multifamily buildings the requirements con- sidered were primarily for central systems used for space conditioning and

domestic hot water heating systems. Space conditioning and hot water systems

of multifamily buildings represent the largest energy usage (about 85 percent)

in apartment buildings. Descriptions of various types of installed equipment

are provided in the following sections.

2.1 CENTRAL SYSTEMS AND COMPONENTS

Central systems supply conditioned water, steam, or air through pipes and ducts

for heating and cooling of individual apartments from a large furnace, boiler,

chiller, or air-conditioner. Some systems employ large conditioned hot or cold

water storage holding tanks. The mechanical equipment is typically located

in the basement and high-rise buildings mechanical components may be located

in an equipment penthouse. Local building codes often prohibit central recirculating air systems in apartment buidings since It is considered undesirable

to mix return air from many occupied units (cooking odors, germs, smoking

products are of concern). Thermal exchange through heat emitters (radiators,

finned tube baseboards, etc.) at the point of use from the heat transport

media provides the energy within the occupied space. Steam, hot water, and/or

anti-freeze liquids are used to circulate the energy contained in the working

fluid. The ASHRAE Guide and Data Book* provide schematics and descriptions

Older volumes contain material appropriate to the times of construction and

installation of equipment in buildings that are probable condidates for

weatherization.

17
of various central systems, distribution methods, and various applications of

controls for safety and performance.

2.1.1 Steam Distribution Systems

Steam distribution systems for operation below 15 psig (pounds per square

inch, gauge) are classified as low pressure, and those for operation above

15 psig as high pressure.* Steam heating systems are identified as the gravity

circulation type when condensate returns under its own hydraulic head and the

mechanical circulation type when condensate water is returned by a pump.

Those systems are further specified as upfeed, when the supply main is below

the heat emitter and downfeed when the supply main is above the heat emitter.

Additional classification of steam systems are known as one-pipe or two-pipe

(or more) depending upon whether the steam and condensate are carried in the same pipe or separate pipes (additional numbers of pipes may appear when

chilled water is circulated).

The one-pipe system carries steam and condensate to and from the boiler and

through the radiator or baseboard element in the same pipe. The original

heating systems in many older buildings were of the single-pipe steam type. A

typical one-pipe air vent system is shown in figure 2.1 with a common air vent

in the return line. The individual radiators require a steam air vent (venting

to atmosphere) which may be controlled by a thermostatic element and a supply

radiator valve on each unit (and can be the same type of valve normally used

for two-pipe systems). Vacuum breaker air vents must be installed on risers of

the steam system.

Boiler operation is initiated by a sensor/controller in a representative

building or apartment zone, or by a timer. Steam is delivered by the piping

distribution system. The radiator air vent valve permits contained air to be

displaced (eliminated) while the steam enters. The thermostatic valve element

closes when sufficiently heated. As the steam cools in the radiator the con- densate forms and flows out of the radiator permitting more steam to enter.

The radiator fills with steam and remains hot when the air vent valve is closed

and latent heat is released from the condensing steam. During cooldown (or

off cycle — the boiler may be shutdown) the air vent valve permits air to

enter the radiator while the remaining condensate returns to the boiler.

Proper operation requires that the interior pressure (gauge) returns to zero during the off cycle. A controller on the return line assures that all the

steam is condensed when the pressure is essentially zero. Vacuum breakers or quick air vents open to atmosphere when there is no pressure in the system to

avoid suction pressures and pull back of steam upon resumption of operation.

Retrofits for steam systems with thermostatic valves require selection of

devices and installation based upon manufacturer specifications and procedures.

* Older equipment installations in buildings are the component and equipment

issues in this report; consequently specifications, displays of identification

markings and display tags will be shown in nonmetric units that would be

imprinted thereon.

18
Figure 2.1. Typical upfeed gravity one-pipe air vent system

19
Improperly cycled boiler operation will cause either excessive heat or lack of

heat depending on the time constant of the system. If the radiator is flooded

with water (from earlier cycle condensate) because return flow is prevented

by high velocity entry steam at the radiator inlet valve (due to undersizing)

no steam will enter and the radiator will remain cold. Flooded backed up

radiator conditions will cause new water makeup (additional water due to lowered

level) addition to the boiler and subsequently cause the boiler to flood.

Vacuum return systems are two-pipe systems in which a vacuum return pump creates

a low-pressure in a condensate receiver connected to the return line. At the

return pump the water and air are separated, with the water returned to the

boiler and air discharged to the atmosphere. Subatmospheric systems regulate

steam flow into the main by a supply throttle valve controlled by an automatic

thermostatic control, and maintains fixed vacuum differential between supply

and return lines by a differential controller. Condensate-pump systems use water pumps in place of vacuum return pumps; they are found in systems for

extended surface heating coils and in limited size distribution piping for

direct radiation (panels, surface coils).

2.1.2 Hot Water Heating Systems

Hot water heating systems or central hydronic systems have two-, three-, or four-pipe water distribution systems. These systems can include cooling and

heating for space conditioning (with appropriate boilers, chillers, controls,

and valves). One-pipe may mean either a loop or supply main, with heat emitters

in a series circuit, or the loop main with diverting fittings at branch takeoff

points. The two-pipe system has one common central supply pipe and one return

pipe for all apartment units. The three- and four-pipe systems are applied for

chilled water supply and hot water supply with either a common return pipe or separate (hot and chilled) water return lines. Examples of installed systems

are indicated in figures 2.2 and 2.3. In operation the hot water circulation

may be controlled by one or more pumps depending on the system design. Design

supply temperatures above 250°F are frequently designated as high temperature

hot water (HTHW) systems which are found in larger individual and central

system applications. Operating design supply temperatures up to 325°F are designed for operating pressures of 125 psig. The requirements* for equipment/

accessories installations of the heat generator (existing or replacement

boilers, furnaces) should be according to those originally certified by their

manufacturers (see later discussion of fuel types). Pressure vessel requirements and provisions for repair to maintain pressure integrity should be in

accordance with the American Society of Mechanical Engineers (ASME) Pressure

Vessel Code.

* Older building equipment installations were subject to practices, regulations,

and requirements which may be different from current local jurisdiction

building codes. Changes, replacement, or modifications may be locally

regulated to require that other mechanical systems/components be upgraded.

Such requirements and approvals for mechanical system changes should be

determined.

20
Figure 2.2. Hot water system with one circuit having a direct return and one circuit having a reversed return

21
Secondary Secondary Secondary

Secondary zone * zone 2 zone 3

Figure 2.3. Multizone hot water system with primary and secondary pumping
The series loop one-pipe system is commonly used in the smaller buildings and

in subcircuits of larger buildings. The hot water flows successively through

the heat emitting devices (usually baseboard or finned-tube units) which

serve as part of the circuit. All series heat extraction devices are affected

by the control or regulation of the hot water delivery. Parallel installations

of the heat extraction units, which permit individual radiator control in a system with a single-pipe main, require a diverting tee that cause a pressure

drop between supply and return runouts, thereby causing circulation through

the unit. Two-pipe systems are used as mains in larger installations, where

the subcircuits and/or zones may be either one-pipe or two-pipe systems.

Air must be eliminated from the system to reduce piping corrosion and noise

following repairs or retrofits. Venting may be manual or automatic, with the

air removal from the piping close to the outlet side of the heat source (furnace, boiler) where the air liberation is maximum. Low pressure systems may

have provision for air trapping in the expansion tank by a boiler fitting with

a dip-tube or other air-separating devices. Closed expansion tanks are used to

allow for the expansion and contraction of the system water with temperature

changes and to provide a controlled system pressure above the saturation

pressure (except for steam pressurized vessels maintained at the saturation

pressure)

.

Insulation of steam and hot water heating pipes with factory applied "jackets",

where the seams were sealed by adhesive materials, has been common practice.

In older buildings the deteriorated conditions of original insulation may

require replacement. Selection of replacement insulation materials should be

made consistent with the recommendations and criteria discussed in [2]. Boiler,

furnace insulation, and hot water storage tanks have had ceraentatious materials

(portland and asbestos cement) applied to the outer shells. Package (scotch

marine) boilers usually are furnished by the manufacturers with insulation

covered by a metal jacket. Local requirements regulating handling and removal

of asbestos containing materials, and personnel safety /health procedures

during retrofit /renovations or upgrading must be followed . Substitute materials

used to repair (patch) or replace thermal insulation materials subjected to

the conditions on and about combustion type heat generators should be selected

following referenced criteria in [2]. Warm air furnaces typically have metal

jacket exteriors with thermal insulation applied to the inside surfaces by the

manufacturer (additional external or internal insulation benefits requires more information to be developed).

Unitary space conditioning systems have increased in usage largely due to

requirements for individual energy metering. Such equipment or appliance

installations are similar to those in single-family dwellings, in some cases with modifications for mounting locations for installation (e.g., through the

wall, in mechanical equipment rooms, enclosure in soffits or dropped ceilings).

The requirements for such individual residential equipment are discussed in

[3].

23
2.1.3 Domestic Hot Water Systems

The domestic hot water intended for residential, institutional, and commercial

building service, (other than for space heating) is supplied by a water heater.

The equipment, sometimes called a "domestic hot water boiler " indicates

a once-through unit as distinguished from a recirculating hot water boiler for

space heating. For domestic hot water service systems in large buildings, the

reheat of hot water by recirculating piping systems is a common practice. The

equipment, ratings, fuel type, method of heat addition (directly or indirectly

fired), types of controls and lining materials are usually indicated by the

manufacturer’s tag plate on the devices. Insulated storage tanks are normally

provided for hot water reserve; otherwise unusually large heaters would be

required for the peak demand period. Instantaneous (also known as tankless or continuous) water heaters which supply hot water for immediate use (without a storage tank) are designed to meet maximum temperature demands at peak draw.

Sizing procedures for instantaneous, semi-instantaneous, and indirect water

heating equipment and boilers in buildings, with the methods for determining

total demand are discussed elsewhere [5, 7]. Pipes and fittings for domestic

hot water should be insulated to conserve the energy used to heat the water

and to provide the design capacity at required temperature at the point of use. Small storage tanks and heaters are mostly manufactured with integral

insulation. On non-insulated heaters/storage tanks insulative coverings

should be provided. Several types of building installations are shown in

figures 2.4, 2.5, 2.6 (from [8]).

Water heaters are classified as direct fired when the heat is transferred

to the water from combustion gases or by an electric contact heater through

heating surfaces (coils, tubes, or shell) and indirect fired when the thermal

energy is absorbed and transmitted from a secondary source (steam or hot water).

The direct fired water heater is completely independent of the building heating

system. Storage tanks are usually installed to handle peak load demands with

both types of heat sources. The storage water heater combines the equipment

functions for heat transfer (direct or indirect) with the volumetric capacity

of the storage tank. Such configurations do not place a large instantaneous

demand on the fuel source, and in the case of indirect heating limits the

withdrawal of steam generated in a boiler.

For older buildings many "non-code" water heaters were manufactured, especially

for domestic use [9]

Those included the range boiler (with side-arm heater)

and the bucket-a-day heater. The range boiler (essentially a storage tank) was manufactured in accordance with "Simplified Practice Recommendations for

Ferrous Range Boilers, Expansion Tanks, and Solar Tanks," U.S. Department

of Commerce Standard R8-50.

As in current practice, casualty insurance carriers and State Board of Boiler

Rules and Regulations generally required hot water heaters to be constructed

in accordance with the ASME* Boiler and Pressure Vessel Code, Section IV — Low

* See abbreviations listing in appendix. Updated codes and standards may

replace the older equipment standards.

24
Cold water I I

• •

Figure 2.4. Forced circulation of domestic hot water especially

needed in long, low buildings

25
Figure 2.5. Domestic hot water from a built-in tankless coil in a hot water

heating boiler. This method, suitable for small, compact

installations, provides no circulation.

26
Roof Home tank

punt min a

* m or a|ti>

Figure 2.6 Downfeed water distribution. Schematic section, part of the

water services of a 10 story building. Hot water circulation

is through the hot upfeed, in two directions at the hot water

heater and down to the tank through the two downfeed hot water

risers •

27
Pressure Heating Boilers (up to 160 psig pressure or 250°F) ; unfired storage

tanks constructed in accordance with Section VIII — Unfired Pressure Vessels.

Electric water heaters were constructed, tested, and rated in accordance with

National Electrical Manufacturing Association (NEMA) Standard 45-105 — Electric

Water Heaters; storage electric water heaters followed NEMA Standard C72.1 —

Household Automatic Electric Storage Water Heaters. Gas-fired water heaters

required tests and ratings for quality of construction and compliance with

American Gas Association (AGA) Standard Z21.10, "Approval Requirements for Gas

Water Heaters." Indirect storage and tankless water heaters were tested and

rated for compliance using test procedures and rating codes of the Institute

of Boiler and Radiator Manufacturers (now superseded by the Hydronics Institute)

in tests conducted by independent laboratories. Current versions of the requirements should be reviewed for retrofit actions.

Additional information concerning the various types of water heaters can be

found in [9] as well as in other building equipment handbooks. Oil-burning,

gas-burning, and electric energy source heaters are described in manufacturer

specification brochures. Burners for replacement are available, over ranges of

design heat release rates, from equipment manufacturers. Replacement burners

must be selected within the furnace or boiler rating limits. Internal flues

and hot gas paths are designed to accommodate the combustion products over the

heat exchanger gas side surfaces for ranges of prescribed pressure drops to

transfer heat to the water. Modifications of the hot gas flow paths, e.g.,

with turbulators to raise heat transfer rates, or derating of boiler systems,

should be done under professional direction. Retrofit replacement burners

should be selected in accordance with manufacturer specifications within the

range of heat release limits originally provided. In retrofitting the hot

water system, compatible burner and draft controls for automated operation with

computerized energy management systems or individual manual operations must

be selected.

2.2 FUNCTIONS OF BOILERS, FURNACES, WATER HEATERS

The primary function of the heat generator (heat source) is to provide a means

for transferring the heat of combustion of a fuel (or electrical resistance

heat) to the water or steam. The rate of consumption of input fuel is

controlled by the type of fuel burning equipment, firing method for the types

of fuels and the capacity of the burners, or grate size with solid fuels.

Combustion chambers for some types of burners provide for containment of the

flames. The heat release rate and the maximum temperatures (accounting for

radiation) attained impose requirements on the construction. Excessive temperatures and particulates from the combustion process may cause erosion of

refractory materials and heat exchange surfaces. Depositions on heat exchange

surfaces (walls and tubes) can limit the effectiveness of the thermal energy

transfer; outer tube surface accumulations of soot (or other deposits) and

internal tube wall surface depositions (from minerals precipitated from the

water flow and other sludge precipitates) requires systematic inspection and

maintenance procedures to maintain the design performance levels. Increased

chimney gas temperatures will result from poor heat transfer and are an indicator of reduced thermal efficiency. Surface heat absorption problems are reduced through proper maintenance and operation procedures. Waterside surfaces

28
coated with scale, precipitates, and other sludge will tend to overheat and

burn out. Fireside surfaces are subject to deterioration from corrosion and

erosion, caustic embrittlement of materials, frequency (amount and rate) of

temperature changes in heating and cooling cycles, and expansion and contraction.

Combustion requires sufficient air for burning the fuel (ideally, the chemical

reaction goes to completion and the oxygen is consumed, i.e., the stoichiometric

condition). The flow of air and combustion products is caused by buoyancy of

the hot gases and the resulting pressure difference between the burner inlet

and the exhaust stack (chimney or flue). The driving draft can be induced by

the chimney effect (natural draft) or by mechanical means (blowers or power

burners). Beyond the theoretically predicted combustion air requirement,

excess air is necessary to supply additional oxygen for completion of fuel

combustion in regions where poor fuel/air mixing occurs (e.g., long grates

with solid fuels). The quantity of excess air significantly influences the

boiler or furnance temperature and the overall thermal efficiency. In very

large systems preheating of combustion air and feedwater with waste heat

recovery has been utilized to improve overall thermal efficiency (frequently

identified as economizers).

The temperature of the combustion gases entering the flue gas stack is limited

by the dewpoint; condensation of water vapor may occur when the exit temperatures are too low. Condensation conditions must be avoided to prevent corrosion particularly with fuels of high sulfur content. Heat recovery devices

for extraction of the latent heat from the water vapor in the combustion

products (e.g., condensing furnace) require materials that are capable of

withstanding the severe conditions. The discharge temperatures of the exhaust

gases from condensing furnaces are sufficiently low (further air dilution may

be unnecessary) that a flue vent discharge through a side wall, instead of a chimney, may be installed.

29
3. MECHANICAL RETROFITTING CRITERIA FOR MULTIFAMILY BUILDINGS

Mechanical equipment and product requirements for eligible options in the DoE

Weatherization Assistance Program for large buildings were reviewed. The

performance requirements, maintenance, operation, and control of mechanical

equipment and devices in multifamily building central systems for space con- ditioning and domestic hot water service were of primary concern. Generally,

such equipment is required to meet more detailed specifications and installation

practices which differ from those for individual residential buildings. Controls,

thermostatic regulators, energy, and duty cycle systems which can generally

be integrated with an automated (programmable) central management system were

included for large buildings since effective energy saving benefits can be

obtained. The concerns for the higher residential density are reflected in

many jurisdictions by regulations for multifamily buildings which require

building permits, licensed installers and inspection/approval procedures as well as adaptions to model codes that are specific to local conditions. The

criteria for eligible options applicable to both single-family dwellings and

multistory buildings include retrofit installations of thermal insulation,

caulking materials, sealants, windows, doors, and individual apartment utility

equipment (e.g., hot water appliances or devices and tanks, furnaces) as described by Rossiter [1, 2] and Kweller [3].

The criteria for performance, fire and health safety, and structural integrity

are usually prescribed for large buildings through local legal requirements

with reference to model codes. Product compliance, installation, and maintenance practices with inspector approvals are established in most local jurisdictions through the legislative process (see illustrative listing examples in

appendix B). In many jurisdictions a requirement for upgrading the entire

mechanical system installation may exist if any subset of the existing equipment

and devices is upgraded. It is essential that local groups conducting energy

upgrading establish the needs for compliance or exceptions in the locality.

For all items which meet the recommended acceptable DoE criteria their use is

allowed only if they do not violate applicable local building-related codes or variance approvals (exceptions) are in conformance with local regulations . Repairs, tuneups, and installations by licensed (or certified) service staff

may also be required.

Asbestos thermal insulation, often in combination with other cementatious

materials, was commonly applied to furnaces, boilers, storage tanks, and

piping in older installations. The recent concerns from investigations of

potential hazards of asbestos have resulted in local regulations for removal

and handling. In conducting energy retrofits it is essential that local re- quirements for handling or removal of asbestos materials be followed .

The expanded DoE Weatherization Assistance Program is intended to conserve

energy by including repair, component replacement (e.g., burners), and retrofit

of the installed mechanical equipment in multifamily buildings. The selection

and guidance for establishment of the recommended retrofit options was derived

from review of the literature specifically oriented to multifamily building

applications. Equipment and device standards and specifications were surveyed

for suitability as a basis of the criteria. Those included certification

30
programs by appropriate organizations and listing procedures to show compliance

with standards, (where such exist). The equipment and products considered

eligible for the DoE WAP and the criteria for determining their eligibility

are summarized in table 3.1. In cases where no applicable standards exist,

specifications established by reputable manufacturers and/or associations or adequate experience to confirm the performance effectiveness of the retrofit

elements or procedures should be acceptable. The use of those items should

not be hindered by requiring that new standards or specifications be written.

The list in table 3.1 contains reference to the primary measures that may be

considered for implementation in weatherization projects. A comprehensive

tabulation of many other potentially useful requirements, practices, methods,

standards, and many sponsoring organizations are provided in chapter 45 of the

1983 ASHRAE Equipment Handbook. Methods for evaluation of high-rise residential

buildings for determination of actual energy usage may be found in many publications and recent textbooks. ASHRAE Standard 100. 2P, "Energy Conservation in

Existing High-Rise Buildings," provides information and stated requirements

for retrofits, changes, additions, strategies, and maintenance procedures to

conserve energy.

The local jurisdictional requirements which regulate the acceptable practices and

installations are usually established by the mechanical, plumbing, and building

codes. In such documents, reference to or listing of standards will be found

which guides the approval authority. Beyond listed or referenced standards the

local building official may frequently provide approvals for equipment and/or

practices through submittal of necessary information, data, and other necessary

documentation, as part of provisions for exceptions and variances.

The Laboratories Certification Seal of the American Gas Association Laboratories

indicates compliance with applicable National standards for appliances and

accessories. Those are applicable for use only with the classes of fuel gases

and input ratings and the installation conditions described. The information

is usually provided by manufacturer's bulletins, specifications, and brochures.

Compliance with National standards for equipment and other fuel types can generally be obtained from equipment specifications and information published

by the manufacturers. The assistance of the National Oil Jobbers Council may

be obtained from their association representation for the oil-fired equipment

manufacturers. Other organizations that either conduct certification programs

or review performance test data to evaluate and provide approvals are listed

in section 3.1. The listing in table 3.1 also contains the title of referenced

standards indicated by letter and number designations .

Caution should be exercised in the examination of identification tags,

specification plates or printed brochures for laboratory certification, or approval symbols. For example, electrical components, motors, wiring, and

switch/relay components are usually listed by Underwriters Laboratories (U.L.)

when U.L. standards (or others, such as ANSI, ASTM, etc.) are met. The display

of the U.L. symbol may be applicable to only the electrical components and not

the entire device (where in some cases, such as for controls, standards have

not yet been developed). In other cases the approval listing indicates that

31
Table- 3.1 Summary of Recommended Criteria 1

Equipment or Product Recommended Criteria—Reference Standard,

Specification, Practice

Heat Exchangers

Heat Exchangers • ASME Pressure Code provisions, as

• applicable to pressure levels.

Commercially available.

Standards of Tubular Exchanger

Manufacturers Association (last edition

with 1983 Addenda, TEMA).

With Gas-Fired Appliances* AGA Requirement 70-1 for Gas-Fueled

’ Equipment.

ANSI Z-21 (standards, as appropriate,

of committee for domestic and

commercial types of equipment).

• AGA Laboratories Certification Seal.^

* The heat reclaimer is for installation in a section of the vent connector

from appliances equipped with draft hoods or appliances equipped with powered

burners or induced draft and not equipped with a draft hood.

Thermostat and Control Systems

Automatic Setback Thermostats

Line Voltage or Low Voltage Room

Thermostats

Automatic Gas Ignition Systems

Energy Management Systems

Hydronic Boiler Control

Listed by Underwriters Laboratories

(U.L. symbol).

Conformance to NEMA DC 15-1979.

NEMA DC 3-1978.

Conformance to ANSI Z21.21.

AGA Laboratories Certification.

Listed by Underwriters Laboratories

(U.L. symbol).

Commercial Availability.

Commercial Availability.

Microcomputer Burner Control Commercial Availability.

I All items are to be Installed in accordance with manufacturers recommendations

and/or as required in existing and applicable building and mechanical-related

code. Revisions of specifications and updated standards should be reviewed

for applications in Weatherization Assistance Programs. Whenever determined,

latest revisions should be included where applicable.

^ See description and discussion of AGA Certified Appliances and Accessories.

32
Table 3.1 Summary of Recommended Criteria (Continued)

Equipment or Product Recommended Criteria—Reference Standard,

Specification, Practice

Water Heater Modifications

Insulate Tank and Distribution Piping (See Insulation Standards [2])

Install Heat Traps on Inlet and

Outlet Piping

Applicable Local Plumbing Code.

Hot Water Pipe Heater Strips Listed by Underwriters Laboratories

(U.L. symbol).

Reduce Thermostat Settings State or Local Recommendations

.

Install Stack Damper, Gas-Fueled ANSI Z21.68,

ANSI Z21.67, including addendas A and B,

ANSI Z223. 1-1980.

Install Stack Damper, Oil-Fueled UL-17

,

NFPA 31-19833

,

Waste Heat Recovery Devices

Desuperheater/Water Heaters Conformance to ARI 470-80^.

Conformance to ARI 1060-80.

Condensing Heat Exchangers Commercially available components and

in new heating furnace systems to

manufacturer specifications.

Condensing Heat Exchangers

(Commercial, Multistory Building,

and Institutional)

Commercially available with teflon lined

tubes to manufacturer specifications.

Energy Recovery Equipment Energy Recovery Equipment and Systems

Air-to-Air (1978) Sheet Metal and

Air Conditioning Contractor's National

Association ( SMACNA)

.

J NFPA indicates National Fire Protection Association.

4 ART indicates Air Conditioning and Refrigeration Institute.

33
Table 3.1 Summary of Recommended Criteria (Continued)

Equipment or Product Recommended Criteria—Reference Standard,

Specification, Practice

Boiler and Furnace Repairs and Modifications/Efficiency Improvements

Installation of Gas Conversion Power In conformance with, or latest, ANSI

Burners (for Gas- or Oil-Fired

Systems Replacements)

Z2I.8a, ANSI Z21.17 and Installation

ANSI Z223. 1-1980 (or latest National

Fuel Gas Code).

AGA Laboratories Certification Seal.

Replacement Oil Burner

\

t

ANSI Z96.2 (UL 296).

ANSI Z91.2.

NFP A 31-1983.

Power Burners (Oil/Gas) Conformance to ANSI Z223.1, National

Fuel Gas Code; ANSI Z83.1 Gas

Installations; NFPA 31 Oil Equipment.

Furnaces, Oil Installation of 011-Burning Equipment,

NFPA 31-1976.

Furnaces, Gas Gas-Fired Central Furnaces, ANSI

Z21. 47-1978.

Readjustment Boiler Water

Temperature or Installation of

Automatic Boiler Temperature

Reset Control

ANST/ASME CSD. 1-1982, and applicable

section of ANSI Z223. 1-1980 and

NFPA 31-1983.

A

Boilers Boiler and Pressure Vessel Code

(eleven sections) ASME 1980 or latest.

Testing and Ratings Hydronics Institute

( HYDI)

Clean Heat Exchangers, Adjust

Burner Air Shutter(s), Check

Smoke No. on Oil-Fueled

Equipment. Check Operation

of Pump(s) and Replace

F liters

Per Manufacturer's Instructions.

Combustion Chambers Refractory linings may be required for

conversions.

Heat Exchangers, Tubes Protection from flame contact with

conversion burners by refractory

shield.

Thermostatic Radiator Valves Commercially available. One-pipe

steam systems require steam air

vents on each radiator, see manufacturer requirements. 0

Boiler Duty Cycle Control System Commercially available. National

Electrical Code (NEC) and local

electrical codes provisions for

wiring

34
Table 3.1 Summary of Recommended Criteria (Continued)

Equipment or Product Recommended Criteria—Reference Standard,

Specification, Practice

Heating and Cooling System

Repairs and Tuneups/Ef f iciency Improvements

Burners

Training and/or Experience

Duct Insulation

Reduced Input of Burner, Derating

Gas-Fueled*

See power burners, gas, oil.

Comparable to courses of Boiler

Efficiency Institute, World Energy

Engineering Congress Seminars, Trade

schools or equipment manufacturer’s

courses. Local jurisdictional

licensing and practitioner requirements

may be prescribed.

In accordance with FS HH-1-558B

(See [3] Insulation Sections).

Training and experience.

In accordance with local utility

company procedures, if applicable,

for gas-fueled furnaces and

Appendix H of NFPA 54

ANSI Z223.1.

Oil-Fired

Replacement Combustion Chamber,

in Oil-Fired Furnace, Boiler

Clean Heat Exchanger and Adjust

Burner:

Adjust Air Shutter

and Check CO 2 and Stack

Temperature

Clean or Replace Air Filter on Forced Air Furnace

Gas-Fueled Heating Systems, Vent

Dampers

In accordance with NFPA 31-1983,

Standard for the Installation of

Oil-Burning Equipment.

In accordance with NFPA 31-1983.

See ANSI Z223.1, Appendix H.

In accordance with applicable sections,

National Fuel Gas Code Z223.1

including Appendices H, I, J, and K.

ANSI Z21. 66-1977 and Addenda A and B for Electrically Operated Dampers.

ANSI Z21. 68-1978 and Appendices A

and B for Thermally Activated Vent

Dampers

.

ANSI Z21 .67—1978 and Appendices A and

B for mechanically actuated vent

dampers

.

* This may be prohibited by local jurisdiction — it may also void the

manufacturer's warranty. The National Fuel Gas Code does not specifically

endorse this.

35
Table 3.1 Summary of Recommended Criteria (Continued)

Equipment or Product Recommended Criteria—Reference Standard,

Specification, Practice

Oil-Fueled Systems, Vent Dampers In accordance with applicable sections

of NFPA 31-1983 for installation and

in conformance with UL 17.

Reduce Excess Dilution Air:

a) Reduction of Vent Connector

Size of Gas-Fueled Appliances

See Part 9 of ANSI Z223. 1-1980 and

Appendices G and H.

b) Adjustment of Barometric Draft

Regulator for Oil-Fuels

NFPA 31-1980 for Air Fueled and per

manufacturer's (furnace or burner)

instructions

Replacement of constant burning

pilot with electric ignition

device on gas-fueled furnaces

or boilers

ANSI Z21. 71-1981.

Readjustment of Fan Switch on Forced Air Gas- or Oil-Fueled

Furnaces 1

In accordance with applicable sections;

ANSI Z223. 1-1980.

Appendix H for Gas Furnaces and

NFPA 31-1983 for Oil Furnaces.

Forced Air Systems:

Duct Furnaces (Gas) ANSI Z223. 1-1980, National Fuel Gas

Code

Heat Pumps Listed by Underwriters Laboratories

(U.L.), ANSI/UL 559-1976.

Outlets, Inlets, Air Flow^ Methods of Testing for Rating the

Air Flow of Performance of Outlets

and Inlets, ASHRAE 70-72.

Warm Air Heating Ducts^ Installation of Warm Air Heating and

Air Conditioning Systems, NFPA 90B.

Air Ducts and Connectors Factory Made Air Ducts and Connectors

(1981), UL 181.

6 Applies also to forced air systems category.

7 Follow practices as a guideline for existing building installations.

36
the product performance tests have been performed (and determined to be) in

accordance with the pertinent standard(s).

In the retrofit of older boilers and furnaces it is advisable to refer to the

manufacturer for rating data. A list of references (from [9]) is reproduced in

appendix C that provides information for determining the ratings of older

boilers and furnaces. With power conversion burners and reduced excess air

(and with changes of fuels) increased heat release, higher temperatures, and

greater flame lengths can occur as part of the process to improve thermal

efficiency. Selection of burners to assure equipment compatibility is necessary in order to prevent rapid deterioration of combustion chambers, refractory

lining materials, and heat transfer tubes. Flame baffles of refractory materials

may be necessary to protect against flame impingement on other components.

The requirement for limiting retrofits to rated capacity permits the maximum

extraction of the usable energy (from the combustion products and/or radiation)

that should result in: (a) flue gas temperatures which are within the upper

temperature limits of chimney materials, and (b) prevention of condensation at

the lower temperature limits (leading to rapid materials deterioration) except

for heat exchangers specially designed for condensing-latent heat extraction.

Power conversion burners sold by manufacturers are usually supplied as complete

fuel burning systems. Units are generally factory tested, assembled, and wired

with the control panel as an integral part of the unit. The burner and forced

draft blower sizes will be listed according to the heat release rates (for gas)

and consumption rates (for oil) which are offered with insurance approvals

appropriate to the size. The packaged units provide simplified installation

for most types of boilers by bolting to the front of the boiler. Firing-burner

head designs for mixing results in short, clean flames, complete combustion,

and fuel savings (according to manufacturer’s brochures). The need for specially

shaped refractory combustion chambers is claimed to be unnecessary to assist

or obtain efficient combustion in newer boilers.

For fuel conversion or burner replacement, burner mounting can be made through

the fire door of older boilers at a safe distance below the crown sheet. Such

installation is intended to permit greater heat transfer. In older boiler

systems (grate fuel retainers) the base or ash pit or chamber area can be

filled with sand or refractory rubble with oil- or gas-fueled burners. The

effects of complete combustion with well-regulated flame patterns (as compared

with older less efficient and high excess air burners) must be considered

since higher gas temperatures can lead to thermal stresses and flame impingement on cold surfaces that can deteriorate equipment or cause failures.

Specific examples of energy savings from retrofit options in multifamily

buildings generally result from site specific combinations of measures. Average annual energy savings of 39 percent for eight buildings due to the

combined weatherization measures (boiler changes, thermal insulation improvement, thermostatic radiator valve installation, etc.), were reported [10]

and are discussed in section 4. Only one retrofit measure, the installation

of energy efficient modular pulsed combustion gas-air boilers, was made; those

replaced a central powerhouse boiler room and underground pumped hot w.it'T

piping distribution system for heating in a complex of 19 buildings.

37
Priorities for selection of available options in residential single-family or small buildings have been developed from predictive models and field experience [13-20] , some without complete validation. The capability of determining

an ordered set of priorities for weatherization actions for multifamily buildings

has not been developed (relations among the parameters may be site dependent).

The lack of available evaluations and assessments with predictive models to

correlate actual energy savings from various combinations of measures and

strategies for existing multistory commercial buildings (which have analogies

with multistory residential buildings) was shown in [12]. The results reported

for large buildings had demonstrated energy savings up to 45 percent but there was no correlation between predicted and actual energy savings. Advantages

from mechanical system retrofits for the heating systems in residential homes

(only) were calculated to show that those steps provide the most significant

cost/benefit options [12]. For retrofits in some steam heated multifamily

buildings, the actual modifications to the mechanical system were also indicated to provide more energy savings than other possible building weatherization

techniques [10], even though combinations of installed retrofits were actually

made. The proceudres that were implemented in examples of mechanical systems

retrofits, modifications, and intallation practices are discussed in section 4.

3.1 STANDARDS AND ORGANIZATIONS

The titles of standards listed in table 3.1 and several other useful references

are presented below. The organizations which sponsor standards, and their

publications that may be sources of information, are provided.

1. ADC - Air Diffusion Council

435 North Michigan Avenue

Chcago, Illinois 60611

- ADC 1062 R4 (1977) - Certification, Rating, and Test Manual

2. AGA - America Gas Association

1515 Wilson Boulevard

Arlington, Virginia 22209

- AGA 80-1 - AGA Requirements for Heat Reclaimer Devices for Use with

Gas-Fired Appliances, June 1, 1980.

3. ANSI - American National Standards Institute, Inc.

1430 Broadway

New York, New York 10018

- ANSI /AGA Z 2 1.8-7

- Installation of Domestic Gas Conversion Burners.

- ANSI/AGA Z21.17b-74 - Domestic Gas Conversion Burners (Addendas A&B)

- ANSI Z21. 21-74 - Automatic Valves for Gas Appliances (Addendas A&B)

38
- ANSI Z21. 47-83 - Gas-Fired Central Furnaces (Except Direct Vent and

Separated Combustion System Central Furnaces)

- ANSI/AGA Z21. 66-77 - Electrically Operated Automatic Vent Damper Devices

for Use with Gas-Fired Appliances (Addenda A and B)

- ANSI/AGA Z21. 67-78 - Mechanically Actuated Automatic Vent Damper Devices

for Use with Gas-Fired Appliances (Addenda A and B)

- ANSI/AGA Z21. 68-78 - Thermally Actuated Automatic Vent Damper Devices for

Use with Gas-Fired Appliances (Addenda A and B)

- ANSI/AGA Z21. 71-81 - Automatic Intermittent Pilot Ignition Systems for

Field Installation

- ANSI Z91.2-76 - Performance Requirements for Automatic Pressure Atomizing

Oil Burners of the Mechanical Draft Type

- ANSI/NFPA Z223.1-80 - National Fuel Gas Code

- ANSI/UL 559 - Heat Pumps; February 8, 1983

4. ARI - Air Conditioning and Refrigeration Institute

1815 North Fort Myer Drive

Arlington, Virginia 22209

Conducts equipment performance certification program.

- ARI 470-80 - Standard for Desuperheater/Water Heaters

- ARI 1060-80 - Standard for Air-to-Air Heat Recovery Equipment

- ARI Rating Certification Program

5. ASHRAE - The American Society of Heating,

Refrigerating, and Air-Conditioning Engineers, Inc.

1791 Tullie Circle, N.E.

Atlanta, Georgia 30329

- ASHRAE 70-72 - Method of Testing for Rating the Air Flow Performance of

Outlets and Inlets

- ASHRAE 100.2 - Energy Conservation in Existing Buildings High-Rise

Residential

~ ASHRAE 103-1982 (ANSI) - Method of Testing for Heating Seasonal Efficiency

of Central Furnaces and Boilers

6. ASME - American Society of Mechanical Engineers

345 East 47th Street

New York, New York 10017

39
- ASME CSD.1-82 - Controls and Safety Devices for Automatically Fired Boilers

- ASME 1980 Boiler Pressure Vessel Code (selected sections)

7. EPA - Environmental Protection Agency

EPA Office of Research and Development

Industrial Environmental Research Laboratory

Research Triangle Park, North Carolia 27711

- EPA 600/Z-75-069-9 - Guidelines for Residential Oil Burner Adjustments

8. GAMA - Gas Appliance Manufacturers Association, Inc.

1901 North Fort Myer Drive

Arlington, Virginia 22209

Conducts furnace and boiler efficiency certification program.

9. HYDI - The Hydronics Institute

35 Russo Place

Berkeley Heights, New Jersey 07922

Formerly: National Boiler and Radiator Manufacturers Association and

Institute of Boilers and Radiators.

Conducts cast iron and steel boilers finned-tube radiation, baseboard radiation

testing program for rating and use of I = B = R and SBI approval emblems.

10. NEMA - National Electrical Manufacturers Association

2101 L Street N.W.

Washington, DC 20037

- NEMA DC 3-1978 - Low-Voltage Room Thermostats

- NEMA DC 15-1979 - Line-Voltage Room Thermostats

11. NFPA - National Fire Protection Association, Inc.

Batterymarch Park

Quincy, Massachusetts 02269

- NFPA 31 - Installation of Oil-Burning Equipment 1983

- ANSl/NFPA 70 - National Electrical Code (NEC)

- NFPA 90B - Standard for the Installation of Warm Air Heating and Air . Conditioning Systems 1980

12. SMACNA - Sheet Metal and Air Conditioning Contractor’s National Association

P.0. Box 70

Merrifield, Virginia 22116

- SMACNA 1978 Energy Recovery Equipment and Systems Air-to-Air

A0
- SMACNA 1974-3 Thermoplastic Duct (PVC) Construction Manual

13. TEMA - Tubular Exchanger Manufacturers Association

331 Madison Avenue

New York, New York 10017

- TEMA (1983 Addenda) Standards of Tubular Exchanger Manufacturers Association

14. UL - Underwriters Laboratories Inc.

333 Pfingsten Road

Northbrook, Illinois 60062

- UL 17 - Vent or Chimney Connector Dampers for Oil-Fired Appliances

- UL 181 ~ Factory Made Air Ducts and Connectors; September 16, 1981

- UL 296-80 - Oil Burners; December 3, 1982

3.1.1 Equipment Efficiency Improvements

Improvements in thermal efficiency of boilers and furnaces can be obtained

through retrofitting, replacement of burners, installation of control devices,

and also by performing systematic tuneups and maintenance procedures. Many of

the techniques can be applied to existing units, but consideration should be

given to the structural integrity, status, and lifetime expectancy; further

evaluations may indicate that it is more economical to install a modern, efficient new unit (that may particularly apply when extensive furnace/boiler

derating is required). The methods described here are intended to provide only

brief descriptions. Specific information based upon manuals, training or experience, and recommended installation practices for materials and products

should be consulted. Conformance with local jurisdictional building requirements may be necessary and gas emissions regulations may require tests for

conformance to air quality requirements. Instruction materials consolidated

from several sources of information [22] are presented, with brief descriptions

of technical modifications and practices (e.g., adjustment of fuel/air

ratio, heat recovery devices, and combustion controls) that can be applied In

multifamily buildings. Other sources of information on advanced methods (under

investigation) for improvements that may be applicable in the WAP are discussed

in [23, 24, 25]. Examples of modifications that can be made are provided in

the following:

Turbulators

Firetube turbulators are baffles inserted in tube bundles that project Into

the combustion gas flow paths to induce turbulence in the hot gas stream in

order to increase the heat transfer to the tube surfaces. The increased gain

of energy in the water or steam increases the thermal efficiency which results

in reduced exhaust gas (chimney) temperature over a range of firing rates.

The application is frequently made with reductions in the excess air levels of

the burner/draft air. Installation of turbulators alters the combustion ^ns

flow resistance so that they can also be utilized to balance or redistribute

41
the hot gas flow. Readjustment of burner controls following installation of

turbulators may be necessary, particularly when reductions of excess air are also accomplished. Such adjustments can be determined by a post installation

efficiency check (for stack temperatures, measurements of O 2 and CO2 ) which

should be performed to verify the degree of complete combustion.

Combustion Systems Control and Instrumentation

The quantity of fuel and air flows, duty cycles, setback or nonoperational

periods are regulated by elements of the combustion control system and/or

energy management systems. The combustion control arrangement can range

from manual control to advanced computerized methods. Instrumentation

provisions consist of sensing elements that provide the current conditions of

operation and performance. The determination of the difference between the

desired set point and the measured signal provides output for control action

to adjust the operating levels. To detect deviations automatically from

desired operation unless an interface with an energy management system is

required. Input signals are supplied to operator displays, or with automated

systems, for corrective actions. Increased concerns for environmental pollution

control may require special instrumentation for monitoring stack emissions of

gaseous pollutants.

Oil and Gas Burners and Supply Systems

Oil and gas burner retrofit actions have a range of options for upgrading.

These actions vary from relatively simple maintenance cleaning and tuneups,

orifice replacements or installation replacements with new conversion power

burners. Reduction of the excess air levels while maintaining complete combustion with increases the thermal efficiency. The new combustion systems have

improved fuel atomization and/or air/fuel mixing to achieve extremely low

excess air operating levels. In equipment for large building the firing rate

variations require capabilities of regulation and modulation ranges for control

of off-peak firing rate operation. Appliance type equipment for small buildings

may not utilize variable output burners and therefore cannot be modulated.

High efficiency pulse combustion burner systems have been developed for appliances and have been applied in weatherization projects as reported in [11, 23].

The changes in flame shape and length, with higher temperature levels from

improved combustion can require modifications to the combustion chambers.

Refractory, high temperature resistant baffles may be required to prevent

impingement of the flame on tubes and interior furnace walls. Pattern changes

of interior combustion gas flows that result from internal alterations by

burner modifications, turbulators, draft flow reductions, etc., do not appear

to have been evaluated. For older installed mechanical equipment the ratings

for replacement burners provided in manufacturer specifications should be

compatible with the original capacity of the furnace or boiler (or for derating

practices with lower heat release rates).

42
Derating

Reductions of energy losses by energy conservation measures such as increased

building thermal insulation, storm windows, reduction of air infiltration,

and piping insulation, result in decreased thermal energy demand loads. When

changes with sufficiently large energy savings occur, the rated capacity

of the existing system may be substantially beyond that required. Selection

of smaller burners, changes of hot water or steam flow rates, and modifications

of controlled duty cycle load management procedures can be optional procedures

for reduction of the thermal energy output requirements from the source, so- called derating techniques. Fuel savings and higher annual energy performance

efficiency can result from derating of existing installed equipment. Derating

results in lowered stack temperatures (which are related to increased thermodynamic efficiency) ; however, caution must be exercised since there is a concern

for material deterioration due to water vapor condensation that can occur in

the flue and sufficient draft to transort combustion products must be maintained.

The fuel burning periods can often be increased at lowered fuel flow rates

thereby decreasing the on-off cycles; in such cases the number of cycles for

reheating the thermal mass of the boiler/furnace is reduced and improved dynamic

thermal performance efficiency is obtained.

Energy Management Systems and Controls

Energy management systems (EMS) and controls provide effective methods and

techniques for energy conservation. Wide ranges of capabilities and features

for implementation of strategies are available from commercially available

devices with manufacturer descriptions for applications. In commercial buildings

the potentials for energy savings through the use of computerized energy management systems have been estimated to vary from 15 to 40 percent [26]. Building

automation systems manage the energy use through time and event programming,

load cycling, duty operation (burner operation and circulation pumps), boiler

optimization (particularly with modular units), and setback (timer) operation,

and also perform diagnostic procedures. To interface with control components,

signal sensor devices (primarily thermostats, burner/ignition control elements,

and water level instruments) are required as inputs to determine and optimize

performance levels. Zone controls can be implemented (for separate regions of

the building) which provide only the heat required within those parts. Zone

controls are applicable only for piping or air flow distribution systems

which can be sectioned off for the different building regions. Analysis of

the system to determine whether zone control is possible will require services

by experienced professionals. The zone controls will probably be less costly

than individual room control (e.g., individual radiator controls) according to

[27].

Many boiler systems heat water to a fixed temperature, independent of the

outdoor temperature. Hydronic heat systems usually set the design discharge

water temperature sufficiently high to provide for the coldest outdoor temperature anticipated. Energy waste can occur during milder weather due to

overheating. Manufacturer claims for energy savings with outdoor reset controlvary from 15 to 20 percent (which may be based upon the inclusion of unoccuplo!

time periods with shutdowns and use of a timer programmer for setback control).

43
Resetting boiler water temperature downward usually reduces stack losses,

indicating an improved thermal efficiency for a fixed firing rate.

Use of computer energy management control systems requires high reliability,

low downtime, and local availability of immediate service with trained support

personnel [28]. Much of the building energy savings has been attributed to

conventional time clock controlled functions and improved temperature controls

[29]. The simplest manual needs for remote stop/start operations to accomplish

the clock set functions were indicated to be achievable with only a control

panel (with switch/ relay and toggle switch inputs) to attain comparable automated energy savings (reliance on the operator may be a concern). The benefits

for control of mechanical equipment through an EMS provides greater flexibility, can improve labor efficiency, reduce maintenance costs, and extend equipment

life, although such measures have been less quantifiable [26].

Heat Recovery Devices and Air Preheaters

Heat exchangers of conventional design for waste thermal energy reclamation

are available from many manufacturers in shell and tube, multishell, and plate

and frame design. Those units installed in process industries, commercial

buildings, and large residential buildings provide savings in boiler fuel,

reduced steam use, and lowered boiler horsepower consumption. Heat recovery

boosts system heating capacity, extends boiler life, and contributes to reductions of gas emissions (which reduces pollutants). Examples of other heat

recovery devices are the rotary heat wheel, and heat pipe exchangers (unpowered

and no moving parts except for auxiliary dampers). The recovered thermal

energy from combustion stack exhaust gases, discharged heated air, and return

steam or condensate can be utilized for various purposes. Heat exchange to

incoming air for space conditioning results in energy savings through reduced

loads on existing space conditioning equipment. Heating of incoming cold

water supply for boiler makeup water or domestic hot water service is an energy

conservation opportunity.

The lowered temperature impact on gas emission products from the chimney must

be considered where air pollution regulations are applicable since concentrations of N0X , CO may be changed. Moisture condensation on heat transfer

surfaces, flues, and chimneys at lowered exhaust stack temperatures could lead

to increased corrosive conditions. Materials capable of withstanding such

environments are required for the heat recovery equipment. Existing interfaces,

ducts/flues and chimneys should be able to tolerate the changed conditions.

At sufficiently low gas discharge temperatures, plastic exhaust flues/outlets

have been recommended with small appliances which, however, may not be applicable to large building systems due to local fire/safety regulations.

Flue gas recovery systems based upon latent heat extraction from the combustion

gas water vapor with condensing heat exchangers are available with packaged

furnaces and as an add-on retrofit equipment. The open loop recovery system

discharges the condensate into a building plumbing drain. Local jurisdictions

may be required to reach a decision on the acceptability of the possibly corrosive discharged water for collection in the plumbing drain piping. Neutralizing

44
the small amount of condensate by running the flow over a limestone block

prior to collection in the drain appears to be practical*.

A closed loop system recirculates and sprays water to absorb the heat from the

hot exhaust gases. The heated water supplies the recovered thermal energy

through a heat exchanger to preheat incoming air or water. Cooled flue gases,

which have given up the waste heat, at a sufficiently low temperature can be

vented outdoors through a plastic flue pipe (according to the manufacturer's

brochure). For existing furnace installations in large buildings, with heat

input rates varying between 200,000 to 1,500,000 Btu/hr, and an assumption of

60 percent average efficiency, the provisions for condensing closed loop

systems were claimed to have payback from fuel savings in less than 2 years

for both oil and gas (based upon a set of required heating condition) with a 30 percent fuel savings**).

A well established function for waste heat recovery is the use of an economizer

in large plants, which is an air preheater for transfer of heat energy from

the stack exhaust gases to the incoming combustion air supply. The boiler

thermal efficiency is improved as a result of the reduced stack gas temperatures. The benefit from combustion air preheating permits the burner to

operate with lower excess air level (LEA), an effect similar to that provided

with power burner conversions.

3.1.2 Thermostatic Radiator Valves and Steam Traps

The installation of non-electric thermostatic radiator valves (TRV) proves a cost-effective small capital investment heating retrofit for upgrading existing

hot water and steam heating systems. The installation of nonelectric thermostatic radiator control valves provides short payback periods.

Individual thermostatic radiator controls for one- and two-pipe radiators,

baseboard and heat convector units provide individual room thermostat settings

for the amount of heat needed within a living unit. The self-contained thermostatic head is nonpowered. Piping rework for retrofit installation is kept to

a minimum. Individual radiator controls come in two types depending on the

piping system. The one-pipe system requires steam air vent relief (vacuum

relief valves) to the atmosphere on each radiation unit. A radiator thermostatic valve should not be applied within a zone control sector if the boiler

is cycled from a zoned thermostat. If the steam system does not have vacuum

breakers on the risers they must be installed. The two pipe steam (or hot

water) systems require the thermostatic valves to be installed in the supply

pipe. Manufacturer equipment specifications should be reviewed for availability

* Private communication from Brookhaven Laboratory on industrial process

heat recovery techniques.

** Heat Extractor Corporation brochure — a supplier of industrial and

residential equipment for flue gas recovery systems.

45
of an insert which permits upgrading older types of hand valve bodies. The use of an insert eliminates the requirement to remove the old valve body,

thereby reducing the cost of installation.

The two-pipe steam system carries the condensate away from the radiator in

the return line. In order to prevent the escape of steam through the radiator

steam traps are installed at each radiator return connection. The device

closes when contacted by steam and causes the steam condensation to take place

within the radiator. By means of those airtight devices the steam can be

generated and circulated at low temperature and partial vacuum [8]. The steam

carrying pipes should be kept free of condensate by installation of thermostatic

steam traps at the base of all risers, the lead ends of the steam mains, and at

low points in the steam distribution systems.

3.1.3 Hot Water Piping and Recirculation Systems

In buildings with hot water circulating systems the design provides for instantaneous delivery of hot water supply with circulating pumps — the horsepower

required is dependent upon the height of the building and the piping distribution

system parameters (fitting losses, pipe wall roughness, corrosion on inner pipe

surfaces, etc.). Heat losses in long exposed hot water pipes can be reduced

with pipe thermal insulation or eliminated by providing strip heaters on the

pipes

Development of a self-regulating, semiconductive polymer material as the core

of an electrically powered strip heater has provided new capabilities. The

functions of sensing and responding to the localized temperature status,

providing heat proportional to the local requirement (control) of electric

current along the electrical conductive paths) and on-off switch control have

been established based upon the material properties and variable electrical

resistance [30, 31]. No electromechanical sensors or controls are required

since those functions are intrinsic to the polymeric material. Pipe insulation

is required around and over the pipe and heater strip to prevent the heat

loss. The installation of such a self-regulating heater strip maintains the

hot water temperature. Any heat loss is replaced only at those locations

where the hot water temperature has decreased. There is no need for return

circulation piping, balancing valves, circulation pumps, and controls. The

energy savings result from the elimination of heat loss throughout the usual

circulating pipe loop(s) that must be made up at the central heat source. Pumping power is eliminated since no circulation is required. Lower water

temperatures leaving the water heater can be set, since the hot water temperature in the piping can be maintained. The application of this type of strip

heater can be made to exposed hot water pipes; the greatest benefits would

become available when complete building renovations are undertaken in order

to permit "in-the-wall" retrofits.

46
indicated* Acceptance in National codes was * for temperature maintenance by

the self-regulating powered strip heater by, the following organizations:

• U.L. Systems Listing (File No. E58016)

• BOCA Building Code and BOCA Research Report No. 82 (Building

Officials and Code Administration International, Inc.)

• Southern Building Code Congress, Compliance Report No. 8270

• Material Standard Plumbing Code

3.1.4 Training — Maintenance, Operation, Tuneups, Repair and Modification

The information regarding adjustments, modifications, controls, and maintenance

of mechanical equipment is described in many publications. For example, in

[22] over 100 reference sources are listed for (all) the chapters in that book

which deal with boilers. The text presents discussions of simple adjustments

from fuel/air ratio (several percentage points in fuel savings) through the

installation of complex auxiliary equipment (for major savings with large

capital outlays). The techniques described include monitoring and testing

performance, installing combustion controls, reducing heat losses, adjusting

combustion conditions, and removing pollutants from stack emissions the information was from studies conducted for the Federal Energy Administration, the

U.S. Department of Energy, and the U.S. Environmental Protection Agency. The

chapter titles, reproduced below, indicate the scope of the practices and

techniques which are required by trained (often times Certified) personnel to

upgrade mechanical systems. For large boiler systems combined maintenance and

equipment upgrading efficiency improvements and fuel reductions were claimed

to yield up to 30 percent.

Chapter Subject Headings:

1. Overview of Boiler Efficiency and Controlling Factors

2. Combustion in Boiler Systems

3. Combustion in Natural Gas and Fuel Oil Burners

* Raychem Corporation Process Division, Redwood City, California information.

• U.L. Systems Listing (File No. E58016)

• BOCA Building Code and BOCA Research Report No. 82 (Building

Officials and Code Administration International, Inc.)

• Southern Building Code Congress, Compliance Report No. 8270

• Material Standard Plumbing Code

47
4. Boiler Testing

5. Reduction of NOx and Other Impurities

6. Operational Procedures and Modifications

7. Efficiency Improvement Equipment

8. Boiler Maintenance Practices

9. Determination of Combustion Efficiency

10. Calculation of Boiler Efficiency (Based on site measurements)

11. Economics Evaluation

Programs sponsored by State energy offices and industrial organizations provide

practical training courses. One example is the Boiler Efficiency Improvement

(2 day) seminar, which has been attended by more than 20,000 personnel* in many

states and Staff of the Department of Energy. In table 3.2, many of the topics

listed as states and Staff of the Department of Energy. In table 3.2, many of

the topics states and Staff of the Department of Energy. In table 3.2, many

of the topics seminar subjects are applicable to the WAP for mechanical improvement options in multistory buildings. The course leaders indicate a 6 percent

average improvement in efficiency, without further capital expenditure beyond

the training, and larger savings with small investments in equipment are econom- ically justified.

Table 3.3 shows the 1 day training seminar courses available on the subjects

of Waste Heat Recovery, Energy Management Systems and Boiler Efficiency (among

others) provided by the Association of Energy Engineers that are given

concurrently with the annual World Energy Engineering Congress.** Such courses provide specific problem solutions and present new skills and techniques.

Local jurisdictional requirements for licensing of skilled and trained service

staff are not normally replaced by training programs, and local regulations

must be determined.

* Brochure announcement — Boiler Efficiency Institute, University Station,

P.0. Box 18430-A, Baton Rouge, Louisiana 70893.

** Association of Energy Engineers, 4025 Pleasantdale Road, Suite 340,

Atlanta, Georgia 30340

48
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4. WEATHERIZATION RETROFIT EXAMPLES

The measures described in [10, 11, 33] emphasized the importance of mechanical

system retrofits in multifamily buildings. Different measures were applied

which illustrate the range of options available to conduct weatherization

energy conservation projects. Those examples indicate, that for each site,

conditions exist for which one or more retrofit actions may be applicable

under the criteria.

4.1 VARIOUS SIZED BUILDINGS

In Chicago, eight buildings achieved an average 39 percent annual energy savings

(without providing the basis of determination). The following building size

apartment units were:

Five of the buildings had coal fired heating plants. All had single-pipe

steam systems with original radiators. Some storm windows were installed and

R-40 thermal insulation was blown into spaces between the roof and topmost

ceiling (common "attic" construction practice in multiunit buildings in the

early 1900 ’s in Chicago). Building temperature controls installed were air

temperature sensing burner controls with programmable setback functions, high

limit outdoor thermostats, and thermostatic radiator valves. The interior

building thermostat was placed in the apartment furthest from the boilers;

the system was balanced to minimize overheating in other apartments. The

largest building had a steam cycle controller added to proportion the boiler

firing in relation to the outdoor temperature.

Gas-fuel power burner replacements were used for conversion and the boilers

were derated and tuned. Conversions from original coal-fired systems result

in oversized heating plants, and with other energy saving measures which reduce

building heat losses boilers were found to be even more oversized. The derating

involved reductions of fuel and combustion air flow rates. The three smaller

buildings had flue dampers installed; the larger boilers had brick flues that

were too short to accommodate the dampers. One large boiler had a motor operated

damper installed on the primary air intake for the burner and the combustion

hatch was sealed, resulting in a sealed combustion system. Piping and boiler

thermal insulation was installed. Turbulators were installed in four of the

boilers but were found to limit the derating process and were removed. Turbulators, which transfer more heat from the combustion gases and lower 9tack

temperature mostly affect the combustion (heat recovery) efficiency. The

derating benefits were greater for improving total system seasonal efficiency

and the stack temperatures were also lowered. Domestic hot water system

No. of Buildings Apartments

12

1

1

11

4

6

7 13

19

25

51
improvements were made by adding thermal insulation jackets and thermal dampers.

Balancing of the buildings was noted to require lengthy data compilation and

feedback on conditions for the heating performance in each apartment. High

costs for contracting such services were noted to possibly not be cost effective, whereas, trained building owners or staff could make compiling the

required data cost effective.

4.2 CENTRAL POWERHOUSE REPLACEMENT WITH MODULAR BOILERS

An apartment complex of 19 buildings with two central gas-fired boilers for

hot water supply in a circulation system and domestic hot water had the system

replaced with 52 modular gas-fired boilers. Two to seven modular boilers were

located in each building. The sealed pulse-combustion fired modules (commercially available units) achieve over 90 percent combustion efficiency. The

two central boilers were capable of producing 16 million Btu/hr and with the

system redesign the total input was reduced to 5 million Btu/hr. The individual

modules were rated at 100,000 Btu/hr rating. The central powerhouse boiler

room had to pump hot water through 2 miles of piping, which required electrical

pump power and often required repair of leaks in the piping system. The modular

boilers have low vented exhaust temperatures with discharge through plastic

pipe flues, so that no additional expenses for chimneys (which would have had

to be built) were required.

The hot water is piped through existing fan-coil units in each apartment unit

for heating. Each apartment retained an individual thermostat temperature

control. The modular feature provides operation only on an as-needed basis and

proportional to the demand load; the modular operation eliminated the "all-on"

or "all-off" function of the large boiler, previously in use.

Comparisons during comparable 3 month periods early in 1982 and 1983 (it was unknown if degree-day adjusted values were used) indicated reduction of about

23,000 therms. Additionally, with the removal of electrical powered circulating pumps in the underground piping about 31,000 kW were saved. With the

claimed gas-fuel savings of 26.6 percent and electric power reduction of 9.5

percent the overall decrease in energy consumption was 36 percent.

4.3 HIGH EFFICIENCY FURNACES AND BOILERS

Multifamily building retrofit weatherization measures undertaken by the

Philadelphia Housing Authority were described in [33]. Individual residential

high efficiency pulse combustion furnaces were installed in multifamily buildings where no equipment rooms or closest spaces (to "hide" the appliance) were

available. With costs of about $1,100 per furnace and 30 percent gain in

efficiency (over older installed equipment) the payback period is expected

to be about 3 years. The funding was provided from HUD for the energy conser- vation measures which also included insulation, siding, and thermally efficient

windows. In another project the central boiler plant was evaluated to be

inefficient and had a deteriorating underground feed distribution system. The

modifications to be made will have mini-boiler rooms with four pulse combustion

boilers for the hot water system for heating which are to be installed with

modular configuration for proportioning the loads. Monitoring of the system

52
performance and identification of needs for service repairs will be provided

by a computer-based system. A 14 story citizens apartment building modification

was reported underway where each floor will house its own boiler room with

pulse combustion boilers.

53
5. DISCUSSION OF MECHANICAL WEATHERIZATION OPTIONS

The problems in implementing weatherization energy savings measures in

multifamily housing are complex due to the diversity of the housing stock

and the complexity of the systems. There is a lack of technical knowledge

about how multifamily buildings can be retrofitted with predictable results . In single-family buildings the impacts of mechanical system modifications upon

overall energy benefits have been integrated with heat loss reductions asso- ciated with the building shell for predictive models. Reasonable capabilities

have been developed to evaluate various energy conservation steps to determine

retrofit performance, and thereby provide guidelines and prioritization for

energy audits and the recommendations derived therefrom.

The estimation of savings for residential multifamily energy retrofits for

buildings is similar in accuracy of the state-of-the-art for commercial buildings. In [12] the investigators showed comparisons of actual energy savings

with the predictions made during the pre-retrofit energy audits. From that

study, figure 5.1 is reproduced, and shows " there is virtually no corre- lation between predicted and actual energy savings. Nor is it clear as yet

why some retrofit projects performed much worse than predicted and others

much better."

Many conventional steps for energy retrofit may be of small consequence in

large residential buildings. With masonry construction and noncavity walls,

improvements of thermal installation may not be feasible. Conventional storm

windows may not be applicable, whereas replacement double-glazed windows may

be required at higher costs. Heating systems in multifamily buildings are more complicated, probably less well maintained and require balancing to prevent

overheating some apartments and allowing other units to be cold. When the

building envelope can be retrofitted, the heating plant can become oversized

thereby leading to inefficient on-off cycling of the system. Burner conversions

for improved combustion efficiency with lowered excess air can alter hot gas flow

distributions within boilers and furnaces that were designed, in some cases,

for other fuels under different conditions (e.g., radiation at different peak

temperatures, pressure drops across baffled sections designed for different

flow rates, other hot gas to water heat transfer rates in fire tube bundles

and combustion chamber refractory linings sized for combustion control by long

flames). The presence of elevator shafts, light shafts, and stairways increases

the "stack" effect on air movement and infiltration. Air infiltration paths and

general ventilation in common areas and stairwells have been studied to some extent by dynamic mass/heat flow analyses. The example of replacing radiator

valves with thermostatic radiator control valves (recognized as a low-cost

improvement for retrofit) can effectively control room temperatures. However,

if steam traps are not at the same time replaced or brought to a satisfactory

performance condition, a considerable amount of energy in the steam can be

wasted in the return piping to the boiler. The assembly of data, with empirical adjustments for modeling the aforementioned elements, for determination of

the building performance with mechanical equipment operations does not appear

to be available to provide guidelines for a systematic or on a step-by-step

basis. The technical knowledge from multifamily building performance retrofit

savings has to be systematically developed [32].

54
50 r

CO

0

z

>

<

CO

o

LU

CO

LU

45 -

40

35 h

30

25

20

15

10

• /

/

X •

5 • / " /

1 1

10 15 20 25 30 35 40

ACTUAL SAVINGS (%)

45 50 55

Figure 5.1 Estimated vs. actual energy savings (as a percentage of initial

consumption) from retrofitting 18 commercial buildings. The data

show no apparent correlation between pre-retrofit predictions an i actual results. Source: Ross and Whalen, 1981.

55
Estimation procedures for decisions on tuneups and/or replacement can be made

for furnaces and boilers from currently established procedures. These steps

include:

® Measurement of stack (chimney) gas temperature.

® Condition of burner, orifices, and pilot (type and operation).

® Flame, combustion analysis.

® Refractories and thermal insulation on boiler/furnace and piping.

® Buildups on heat exchange surfaces which decrease heat transfer.

The ability to accurately predict energy savings is essential to set priorities

on the investment of resources to achieve effective weatherization retrofits.

The mechanical equipment measures, previously described, provide energy savings

and their selection requires that evaluations for major equipment upgrading

be made through on-site inspection.

It is essential to develop initial evaluations to determine priorities of

retrofit measures. The assessment techniques necessary for initial preparation

of recommendations must be based upon thorough inspections. Such services can

be provided by contractors and professional practitioners. As part of the

mechanical system analysis the evaluation of waste heat recovery should be made

The proposed utilization and applications of thermal energy made available from

heat recovery needs to be evaluated prior to the installation of such equipment

6. CONCLUSIONS

This report provides the product and equipment recommendations for the DoE

Weatherization Assistance Program in Table 3.1, "Summary of Recommended

Criteria". The measures for energy conservation performance upgrading recom- mended inclusion of training for maintenance operation and tuneups under the

program. Mechanical systems equipment, controls, energy management systems,

burners, and boiler/furnace tuneup/repairs were discussed. The options for

retrofit technologies indicate compliance with reference standards such as burners, burner controls, combustion chamber refractories, modifications

with dampers, turbulators, and waste heat recovery devices.

The criteria developed did not include economic factors and statutory con- straints under the rulemaking procedures. The need for developing predictive

monetary capabilities and establishment of cost/benefit priority selection

was indicated.

56
REFERENCES

1. Rossiter, W. J., Jr. and Mathey, R. G., "Criteria for Retrofit Materials

and Products for Weatherization of Residences," NBS Tech Note 982,

September 1978.

2. Rossiter, W. J., Jr. and Mathey, R. G., "Weatherization of Residences:

Criteria for Retrofit Materials and Products, NBSIR 84-2870; February 1984.

3. Kweller, E. and Silberstein, S., "Performance and Selection Criteria for

Mechanical Energy Savings Retrofit Options for Single-Family Residences,"

NBSIR 84-2870, December 1983.

4. Ackerman, P. D. and Jacobsen, A. S., Efficient Gas Utilization in Multifamily Dwellings," Final Report Booz-Allen and Hamilton, Inc., Bethesda,

MD, October 1981 (for Gas Research Institute).

5. ASHRAE Guide and Data Book, American Society of Heating, Refrigerating

and Air-Conditioning Engineers, Atlanta, GA.

6. ASME Pressure Vessel Code, American Society of Mechanical Engineers,

New York.

7. ASPE Data Book Vol. 1, Fundamentals of Plumbing Design, American Society

of Plumbing Engineers, Sherman Oaks, CA, 1980.

8. McGuinness, W. J. and Stein, B., "Mechanical and Electrical Equipment for

Buildings," John Wiley and Sons, Inc. 1971, New York.

9. Shields, C. D., "Boilers — Types, Characteristics, and Functions,"

McGraw-Hill Book Company, New york, 1961.

10. Frantz, J. P., "Retrofits to Heat Delivery Systems," Air Conditioning and

Refrigeration News , September 26, 1983, p. 15.

11. "Boilers Saving 30 percent on Apartment Heating Costs," Contractor , November 15, 1983, p. 25.

12. Deringer, J., Ross, H., and Harris, J., "Opportunities for Saving Energy

in Commercial Buildings," Proceedings of the 1980 Summer Study, Improving

Energy Efficiency in Buildings, held at University of California, Santa

Cruz, August 1980, pp. 3.1.1-3.1.73.

13. Petersen, Stephen R., "Retrofitting Existing Housing for Energy

Conservation: An Economic Analysis," National Bureau of Standards (U.S.),

Bldg. Sci. Ser. 64, 76 pages, December 1974.

14. "In the Bank . . . Or Up the Chimney? A Dollar and Cents Guide to EnergySaving Home Improvements," U.S. Department of Housing and Urban Development , April 1975, Available from the Superintendent of Documents.

57
15. Pilati, David A., "The Energy Conservation Potential of Winter Thermostat

Reductions and Night Setback," Oak Ridge National Labortaory Report.

16. Nelson, Lome W. , "Reducing Fuel Consumption with Night Setback,"

ASHRAE Journal, August 1973, pp. 41-49.

17. Burch, D. M. and Hunt, C.M., "Retrofitting and Existing Wood Frame

Residence for Energy Conservation — an Experimental Study," National

Bureau of Standards Report NBSIR 77-1274, 157 pages, July 1977.

18. "Retrofitting Homes for Energy Conservation, A Business Guide," NAHB

Research Foundation, Inc., Rockville, MD, March 1975.

19. "Insulation Manual — Home /Apartments , " NAHB Research Foundation, Inc.,

Rockville, MD , September 1971.

20. Hastings, S. Robert, Crenshaw, Richard W. , "Window Design Strategies

to Conserve Energy," Nat. Bur. Stand. (U.S.) Bldg. Sci. Ser. 104,

209 pages, June 1977.

21. Gathers, W. , Recommendations for Improving the Effectiveness of Federal

Low Income Weatherizat ion and Energy Assistance Programs, Alliance to

Save Energy, Washington, DC, May 1983.

22. Yaverbaum, L. H. (Editor), Energy Saving by Increasing Boiler Efficiency,

Noyes Data Corporation, Park Ridge, NJ , 1979.

23. Locklin, D. W. and Hazard, D. W. , Technology for the Development of

High-Efficiency Oil-Fired Residential Heating Equipment BNL 51325 UC-95d,

Brookhaven National Laboratory, Upton, NY, June 1980.

24. Woodworth, L. M. , and Denneby, G., Space Conditioning Equipment

Technology — A Progress Report on the Brookhaven National Laboratory Program,

BNL 51403 UC-95d , Brookhaven National Laboratory, Upton, NY, March 1981.

25. Putnam, A. A., Talbert, S. G., et al., Survey of Available Technology for

the Improvement of Gas-Fired Residential Heating Equipment, BNL 51067,

Brookhaven National Laboratory, Upton, NY, August 1979.

26. Caffrey, R. J., Using Energy Management Systems, ASHRAE Journal,

June 1983, pp. 33-34.

27. Energy Conservation for Housing: A Workbook, Office of Policy Development

and Research, HUD, May 1982 (A Component of the Evaluation of the Physical

Condition of Public Housing Stock — by Perkins and Will with the Ehrenkrantz

Group) May 1982.

28. McNall , P. and Cleary, P., Building Control Systems, Improving Energy

Efficiency in Buildings: Progress and Problems — Proceedings. University

of California, Santa Cruz, August 1980, pp. 3.5.1 to 3.5.7.

58
29. Gunterraan, A. E., Energy Management Systems: Are They Cost Effective?,

Heating/Piping/Air Conditioning, Vol. 54, No. 9, September 1982,

pp. 102-116.

30. Steele, A., Strip Heating Concept Researched, Plumbing Engineer,

January/February 1983, Construction Industry Press, Inc., pp. 36-39.

31. McGraw, J., An Alternative Method to Hot Water Circulation Systems,

ASSE Refresher Course Program, October 1981.

32. Bleviss, D. L., Retrofitting Multifaraily Housing, Proceedings, University

of California, Santa Cruz, August 1980, pp. 1.3.1 to 1.3.16.

33. Schwed , B., High Cost Heating for Low Income Housing, Contracting Business,

Vol. 41, No. 2, February 1984, pp. 45-46.

59

APPENDIX A - WEATHERIZATION MATERIALS

The proposed rules for public comment published in the Federal Register

Vol. 48, No. 215, November 4, 1983, p. 51076 lists the following "Weatherization

Materials "

(1) Caulking and weatherstripping of doors and windows;

(2) Furnace efficiency modifications, limited to:

(i) Replacement burners designed to substantially increase the

energy efficiency of the heating system;

(ii) Devices for modifying flue openings which will increase the

energy efficiency of the heating system; and

(iii) Electrical or mechanical furnace ignition systems which

replace standing gas pilot lights;

(3) Clock thermostats;

(4) Ceiling, attic, wall, floor, and duct insulation;

(5) Water heater insulation;

(6) Storm windows and doors, multiglazed windows and doors, heatabsorbing or heat-reflective window and door materials; and

(7) The following insulating or energy conserving devices or technologies:

(i) Skirting;

(ii) Items to improve attic ventilation;

(iii) Vapor barriers;

(iv) Materials used as a patch to reduce infiltration through the

building envelope;

(v) Water flow controllers;

(vi) Movable insulation systems for windows;

(vii) Materials to construct vestibules;

(viii) Pipe and boiler insulation;

(ix) Heat exchangers;

(x) Thermostat control systems;

A1
(xi) Replacement windows and doors;

(xii) Materials used for water heater modifications which will result

in improved energy efficiency;

(xiii) Hot water heat pumps;

(xiv) Waste heat recovery devices;

(xv) Materials used for water heater modifications which will

result in improved energy efficiency;

(xvi) Materials used for boiler repair and modifications which will

result in improved energy efficiency.

The listing included the proposed expansion from the prior regulations which

did not provide for mechanical and selected "architectural options in single

and multifamily residential buildings." These measures were adopted as part

of the final rule published in the Federal Register, January 27, 1984.
APPENDIX B - MODEL CODES

As mentioned in the body of this report, the acceptance and installation of new mechanical equipment (upgrading for partial retrofit or replacement) in buildings

is specified in various nationally recognized building model codes. All or parts of code documents may be incorporated into a municipal code. In [25] a list of residential gas-fueled heating appliances was presented as those most

likely to be applicable; the table B-l is reproduced as an example. Local

jursidiction requirements for compliance are to be determined, since differences and modifications may locally exist in the code documents as adopted.

One example of differences cited was that appliance derating for altitudes

higher than 2000 feet above sea level is specified in the National Fuel Gas

Code whereas the Dwelling Code specifies an air pressure test of the installation inspection without a derating provision. Other examples of differences

were noted in [ 25]

.

Municipalities that regulate the installation of gas appliances in residences

generally adopt one of the model codes with or without modification. Indications of those choices are illustrated in table B-2, (reproduced from [25]).

The listing emphasizes the need to determine the appropriate locally accepted

practice

.

B-l
Table 8-1. Model Codes Governing Installation of Residential Gas-Fueled Heating Appliances

Code

laaulng

Agency^*' Comment

One and Two Family Dwelling Code AIA A composite of provisions drawn from

BOCA other model codes and applied

IC30 specifically to one and two family

SBCC dwellings

Basic (Building, Mechanical, Plumbing] Code^) BOCA

National [Building, Plumbing, Electrical] Code AIA

Code for the Installation of Heat Producing

Appliances ^ c ^ AIA

Standard [Building, Gas, Plumbing] Code SBCC

Uniform [Building, Mechanical, Plumbing] ICBO

National Fuel Gas Code ANS Also known as ANS Z223.1 or as NFPA No. 54

NFPA Standards

No. 54 National Fuel Gas Code

No. 70 National Electrical Code

No. 70A Dwelling Electrical Code

No. 85 Single Burner Boiler-Furnaces

No. 89M Heat Producing Appliance Clearances

No. 90B Warm Air Heating and Air

Conditioning Systems

No. 211 Chimneys, Fireplaces, and Vents

NFPA Pocketbook editions

Footnotes for Table B—

(a) Acronyms

A.G.A. —

AIA —

ANS --

AS ME -- BOCA —

American Gas Association

American Insurance Association

American National Standards

American Society of Mechanical Engineers

Building Officials and Code Administrators

International, Inc.

ICBO — International Conference of Building Officials

NFPA — National Fire Protection Association

SBCC — Southern Building Code Congress International

(b) Separate codes are Issued for each item In the brackets.

This Is the analog for a National Mechanical Code.

B-2
Table B-2. Survey of

Gas Appli

Municipal Codes Regulating Installation of Residential

ances

State Municipality^ 3 ^ Code Remarks

AL Birmingham

AZ Phoenix Uniform Mechanical Code ( ICBO)

AR Little Rock

CA Los Angeles Uniform Mechanical Code (ICBO)

San Diego Uniform Mechanical Code (ICBO)

San Francisco

Santa Monica

CO Denver

CT Hartford Basic Mechanical Code (BOCA)

DE Wilmington

FL Mi ami National Fuel Gas Code (NFPA 54)

GA Atlanta National Fuel Gas Code (NFPA 54)

ID Boise

IL Chicago National Fuel Gas Code (NFPA 54)

Evanston

IN Hammond

KS Wichita

KY Louisville

LA New Orleans National Fuel Gas Code (NFPA 54)

ME Portland

MD Baltimore

MA Boston Massachusetts Fuel Gas Code Adaptation of National

Fuel Gas Code (NFPA 54)

MI Detroit

Flint

MN Minneapolis Minnesota Mechanical Code

MS Jackson

MO Kansas City Uniform Mechanical Code (ICBO)

St. Louis Basic Mechanical Code (BOCA)

MT Butte

NE Omaha

NV Las Vegas

B-3
Table B-2. Survey of Municipal Codes Regulating Installation of Residential

Gas Appliances (Continued)

State Municipality^ 3 ) Code^k) Remarks

NH Nashua

NJ Newark

NM Albuquerque

NY Buffalo National Fuel Gas Code (NFPA 54)

New York City National Fuel Gas Code (NFPA 54)

Syracuse

NC Charlotte

ND Minot

OH Cincinnati National Fuel Gas Code (NFPA 54)

Cleveland Uniform Mechanical Code (ICBO)

Columbus

OK Oklahoma City

OR Portland Uniform Mechanical Code (ICBO)

PA Philadelphia National Fuel Gas Code (NFPA 54) 1969 version of NFPA

54 (i.e., ANSI Z21.30)

Pittsburgh National Fue Gas Code (NFPA 54)

RI Providence

SC Columbia

SD Rapid Center

TN Memphis Basic Mechanical Code (BOCA)

TX Dallas Uniform Mechanical Code (ICBO)

Houston Uniform Mechanical Code (ICBO)

UT Salt Lake City Uniform Mechanical Code (ICBO)

VT Burlington

VA Alexandria

WA Seattle Uniform Mechanical Code (ICBO)

WV Charleston

WI Milwaukee

WY Casper

( a ) For each state in the contiguous U.S. at least one municipality is listed having

a high number of residential gas "househeating" customers (relative to other

localities in the state) to indicate potential replacement/ retrof it markets for

advanced technology equipment.

(b) Entries appear only for municipalities surveyed.

B-4
APPENDIX C - BOILER RATINGS

The determination of ratings of older boilers may not be readily obtained due

to the loss of identification tags or coverings that prevent determination of

surface markings. For some equipment the manufacturers may no longer be in

business and therefore other sources of data are required. Prior to development

of modern testing and rating codes, such as those of the Institute for Boiler

Ratings (IBR), uniform nomenclature and units did not exist [9]. Referenced

sources of information are provided below (reproduced from Chapter 28 — Boiler

Ratings)

.

American Boiler Manufacturers Association, Industry Standards and Engineering

Information—Steam Generating Equipment (1958); Technical Committee of

Packaged Firetube Branch, Packaged Firetube Boiler Ratings (1959).

American Gas Association Laboratories, Directory of Approved Appliances and

Listed Accessories (semiannual).

American Society of Heating, Refrigerating, and Air Conditioning Engineers,

Guide (annual).

American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel

Code; Power Test Codes .

American Standards Association Approval Requirements, ASA Z21.10 Gas Water

Heaters; ASA Z21.13.1 Central Heating Gas Appliances (Steam and Hot Water

Boilers , V. 1); ASA C72.1 Household Electric Storage Type Water Heaters .

Beacon Boiler Reference Book , Heating Publishers, Inc.

deLorenzi, 0., Combustion Engineering . Combustion Engineering, Inc. (1947).

Fuel Oil News Boiler Rating Handbook , Oildom Publishing Co.

Hartford Steam Boiler Insurance and Inspection Co. literature.

Hunter, L. N. "Most Heating Boilers Selected on the Basis of Their Net

Ratings," Heating, Piping, and Air Conditioning, February 1956.

Institute of Boiler and Radiator Manufacturers, IBR Testing and Rating Code

for Low Pressure Heating Boilers; IBR Ratings for Cast-Iron Boilers; IWH

Testing and Rating Code for Indirect Storage and Tankless Water Heaters,

External Type, Tested in Tank; IWH Testing and Rating Code for Indirect TankU -s - Water Heaters, Tested with Boilers.

Kent, R. T. , Kent's Mechanical Engineers' Handbook , John Wiley & Sons, New York..

Marks, L. S. Mechanical Engineers' Handbook, McGraw-Hill, New York.

C-l
Mechanical Contractors Association of America, "Net Load Recommendations for

Heating Boilers" and "Testing and Rating Code for Boiler-Burner Units,"

Engineering Standards, Part II (annual); Private Communications.

Pape-Swift Boiler Reference Books , Color-Art Printing and Stationery Co.,

Kirkwood, Mo.

Steel Boiler Institute, SBI Rating Code for Steel Boilers ; Private

Communications.

Stoker Manufacturers Association, Uniform Stoker Ratings .

Titusville Iron WOrks Division, Struthers Wells Corp., trade literature.

U.S. Department of Commerce, Simplified Practice Recommendations for Steel

Firebox Boilers and Steel Heating Boilers (R 157-50).

The reference [9] suggests that the Beacon Boiler Reference Book, Fuel Oil NewsBoiler Rating Handbook, and Pape-Switft Boiler Reference Books may be useful.

Although many of the applications were in equipment sizes appropriate to utility

installations the lower levels of performance rating values could apply to

building system plants. The "Guide" of the American Society of Heating,

Refrigeration, and Air Conditioning Engineers also provides a recommendation

for boiler heating surface and steam generation in units of equivalent square,

foot of steam radiation (usually denoted as EDR). Other sources are the

American Boiler Manufacturers Association (ABMA) and the Steel Boiler Institute

(SBI). The Mechanical Constractors Association (MCA) formerly the Heating,

Piping, and Air Conditioning Contractors National Association, had the two codes

for:

1. MCA Testing and Rating Code for Residential and Small Commercial

Package Boiler Units — for testing and rating small and intermediate

sizes of heating boilers with integral burner units fired with fuel

oil

2. MCA Testing and Rating Code for Commercial Package Boiler Units — for

rating commercial sizes of steel heating boilers fired with oil- or gas-fuel

The figures C-l and C-2 (from [9]) indicate the type of boiler net-load

information of older equipment.

C-2
|Qj

tnd

»no

poo|

t*N

Figure C-l . Net load recommendations for obsolete round cast iron b'>i l«“i based on 13,000 Btu per lb of hand-fired coal. In 7"°K

(Prom MCA, "Net Load Recommendations for Heating Boilers. )

C-3

Number

of

tartloni

b*N»««n

flrapo*

ond

do»r>«
Figure C-2 . Net load recommendations for obsolete square (sectional type)

cast-iron boilers

Individual curves are for grate widths from 22 to 79 in.; load recommendations

based on 13,000 Btu per lb of hand-fired coal, in 70°F ambient. (From MCA,

"Net Load Recommendations for Heating Boilers.")

C-4
APPENDIX D - CODES, STANDARDS, ORGANIZATIONS, AND MARKINGS

D.l NAMEPLATES, SYMBOLS, AND IDENTIFICATION MARKINGS

Larger scale mechanical equipment has been, and continues to be, guided by

standardization and regulation through various interests for construction and

inspection. Many nameplates or markings are used with identifying symbols

or stampings to show that requirements have been met, often to indicate a seal

of approval.

For example, gas appliances and accessories may be entitled to bear the

Laboratories Certification Seal of the American Gas Association. The symbol

provides the manufacturer’s representation that the unit is constructed according

to the design certified by the American Gas Association Laboratories and found

to comply with generally accepted national standards. Jurisdictions may require

installed appliances to comply with American National Standards and may accept

AGA certification as evidence of such compliance.

D-l
NBS-114A (REV. 2-80

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 84-2939

2. Performing Organ. Report No. 3. Publication Date

4.

TITLE AND SUBTITLE

CRITERIA FOR MECHANICAL SYSTEMS IN MULTIFAMILY BUILDINGS FOR RESIDENTIAL

WEATHERIZATION OPTIONS

5.

AUTHOR(S)

Lawrence S . Galowin

6.

PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8 . Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

Department of Energy

Office of Weatherization Assistance

Forrestal Building

Washington, D.C.

10.

SUPPLEMENTARY NOTES

] Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bl iography or literature survey, mention it here) The National Bureau of Standards (NBS) prepared the original criteria and list of

eligible retrofit options adopted for energy conservation by the Department of Energy

Conservation in Existing Buildings Act of 1976. NBS was requested to review, update,

and expand the criteria and list of retrofits for 1984 ammendments to the regulation.

This report presents the criteria and reference standards for retrofit options of

mechanical equipment and systems in multifamily buildings.

Mechanical systems equipment, controls, energy management systems, burners, and boiler/

furnace tuneups/repairs were included. The options for retrofit technologies for equipment replacement components include items such as burners, burner controls, combustion

chamber refractories, modifications with dampers, turbulators, and waste heat recovery

devices. The criteria developed did not include economic factors and statutory con- straints under the rulemaking procedures.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) boiler/furnace performance upgrading; energy controls; energy conservation; mechanical

building equipment; replacement burners; weatherization; tuneups and repairs for multifamily building equipment.

13. AVAILABILITY

Uni i mi ted

| | For Official Distribution. Do Not Release to NTIS

~H Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

“ 20402 .

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

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15. Price

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