A11107 3T0tjfl4

NBSIR 84-2869

Test Methods for the Direct

Measurement of Stack Energy

Loss During the Off-Period of

Space Heating Equipment

Esher Kweller

Robert A. Wise

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Equipment Division

Gaithersburg, MD 20899

August 1984

100

. U56

84-2369

1934

Sponsored by:

The Department of Energy

Office of Conservation and

Renewable Energy

Washington, DC 20585

NBSIR 84-2869

TEST METHODS FOR THE DIRECT

MEASUREMENT OF STACK ENERGY

LOSS DURING THE OFF-PERIOD OF

SPACE HEATING EQUIPMENT

Esher Kweller

Robert A. Wise

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Equipment Division

Gaithersburg, MD 20899

August 1984

Sponsored by:

The Department of Energy

Office of Conservation and

Renewable Energy

Washington, D.C. 20585

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

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director

FOREWORD

The subject of this report involves an alternative test method toward arriving

at a part-load or seasonal efficiency for vented space heating equipment

(furnaces and boilers). In order for the reader to better understand this

subject it would be desirable to first have an understanding of the existing

DoE test procedures for this equipment. It is therefore desirable that at

least some background review of references 1, 4, and 6 be attained. See

page 1_7_ for these references.

iii
ABSTRACT

Evaluations have been made of a possible alternative to the tracer gas test

method now being used to measure off-period energy loss of space heating

equipment with vent dampers.

This alternative method offers the potential of a direct measurement method

without the need for expensive tracer gas type instrumentation. The method

uses a controlled flow of gas to a small gas fueled burner to simulate normal

flue or stack temperatures previously measured during a cool-down test.

Energy metered though the gas burner during the simulation gives a direct

measurement of the thermal energy losses out of the stack. Results in comparison with the tracer gas method of test were lower for off-period energy loss

meaurements. A trend to better agreement between the two methods was noticeable

for test furnaces with greater fuel input rates. Further development testing

and evaluation will be required before the simulation can be considered as an acceptable alternative test method.

Keywords: boilers; fossil fueled heating systems; furnaces; household heating

equipment; part load efficiency; stack energy loss.

iv
NOMENCLATURE

Br L s OFF during simulated cool down test determined by a metered burner.

C

P Specific heat of air = 1.0 Kj/kg * °C (0.24 Btu/lb • °F).

Cf Concentration by volume of tracer gas in stack (ppm).

Cp

Concentration by volume of active tracer gas in a tracer gas supply

(ppm)

l i,off Off-cycle infiltration loss, in % of the fuel input rate.

li,on On-cycle infiltration loss, in % of the fuel input rate.

k. Latent heat loss, in % of the fuel input rate.

ls,off Off-cycle sensible heat loss, in % of the fuel input rate.

ls,on On-cycle sensible heat loss, in % of the fuel input rate.

ls,ss,a Sensible heat loss at steady-state operation, in % of the fuel input

rate

M Mass flow during an increment of time (1 minute) during off-period.

MLOS Summation of the mass flow M from the start of the cool down to each

time increment during cool down.

ms,off Mass flow rate through the stack during total off-period, kg/s

(lb/min)

Pb Barometer pressure KPa (inches of mercury).

Pf Ratio of Qp * Qin = pilot fraction.

Pv Partial pressure of water vapor in the combustion products of a known

fuel gas at a given excess air value (CO2 value known) in the flue gas

pvs The saturated partial pressure of water vapor in combustion products

of a known fuel gas at a given flue gas temperature.

Q Calculated energy during an increment of time KJ/min (Btu/min )dur ing

cool down period based on metered gas flow.

Qin Fuel energy input rate at steady-state operation (including any pilot

light input), in But/h. Qin, min a - minimum input, Q^ n max at maximum

input rate.

Qi Summation of the off-period infiltration heat loss through the stack

from the start of the cool-down KJ (BTU).

V
Qlos or

QS

Qout

Qp

tg

TG

toff

fc on

-oa

tRA

tS,OFF

%

p

s

4

>

Summation of the off-period sensible heat loss through the stack

from the start of the cool down to each time increment during the

cool down KJ (Btu).

Fuel energy output rate - mj n

at minimum input rate, Qout max

at maximum input rate.

Fuel energy input rate to pilot light in Btu/h.

Ls OFF during simulated cool-down period determined using a tracer

gas test method.

Ls OFF during normal cool-down period determined using a tracer

gas method.

Off-time per cycle, in minutes.

On-time per cycle, in minutes.

Average outdoor air temperature applicable during the heating

season.

Laboratory room temperature, in °C (°F).

Stack temperature during the cool-down period °C (°F).

Part load efficiency in %

Density of stage gas Kg/m (lb/ft ).

Infiltration factor (dimensionless and assumed = 0.7).

vi
Table of Contents

Page

FOREWORD * .... ill

ABSTRACT * . iv

NOMENCLATURE v LIST OF TABLES lx

LIST OF FIGURES x

1 . INTRODUCTION 1

1.1 Background 1 1.2 Tracer Gas Test Metod for Measuring Off-Period Losses 2

1.2.1 Off-period Sensible Heat Loss 2

1.2.2 Off-period Infiltration Loss, Lj gFF 5

1.3 Objective of Alternative Method to Tracer Gas Testing ..... 5

2. DESCRIPTION OF THE ALTERNATIVE MEASUREMENT METHOD 7 2.1 Measurement of the Off-Period Sensible Heat Loss 7 2.2 Measurement of the Off-Period Infiltration Loss 8

3. TEST EQUIPMENT AND PROCEDURES USED 10

3.1 Equipment 10

3.1.1 Dampers Tested 10

3.1.2 Heating Equipment 10

3.1.3 Laboratory Equipment 11

3.1.4 Test Burners Used to Reproduce Cool-Down

Temperature Conditions 11

3.2 Test Procedures Used 11

3.2.1 Tests on the Room Heaters Having External Draft

Hoods 11

3.2.2 Tests on the Wall Furnaces and Forced Air Furnace

Equipped with Internal Diverter 12

3.2.3 Tests on the Hot Water Boiler, Equipped with

Draft Hood 12

4. TEST RESULTS 13

4.1 Off-Period Sensible Loss by Tracer Gas Measurements (Qg) .. 13

4.2 Off-Period Infiltration Loss (Qp) 13

4.3 Comparison of the Simulated Test Results with Normal CoolDown Test Results 13

4.3.1 Comparison of the Tracer Gas Test Results, Cool

Down Simulated with Bunsen Burner Versus Normal

Cool Down; (tg/TG) 13

4.3.2 Comparison of the Metered Burner Method with

Tracer Gas Method During the Simulated Cool-Down

Test, (Br/tg) 14

4.3.3 Comparison of the Metered Burner Method with Normal

Cool-Down Test Method Using Tracer Gas (Br/TG) 14

vii
Table of Contents (Continued)

Page

5. SUMMARY . 16

6. REFERENCES 17

Appendix A. Guidelines for Measuring Off-Period Mass Flow Using

the Tracer Gas Method 37

Appendix B. Computerized Calculation Procedure 40

Appendix C. Example of Computer Output Tracer Gas Test Results for

the 45K Btu/h Room Heater 45

viii
List of Tables

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

1. Off-Period Energy Losses for Three Household Heaters

2. Off-Period Energy Losses for Gas Furnace (20 Minute Cooldown

Period) .

3. Off-Period Energy Losses for Gas Furnace (13 Minute Cooldown

Period) . . . .

4. Off-Period Energy Losses for Gas Boiler (33 Minute Cooldown

Period)

5. Off-Period Energy Loss Ratios for Room Heater Rated 45K

Btu/h

6. Off-Period Energy Loss Ratios for 35K Btu/h Wall Furnace ...

7. Off-Period Energy Loss Ratios for Room Heaters Rated

35K Btu/h

8. Off-Period Energy Loss Ratios for an 80K Btu/h Hot Water

Boiler

9. Off-Period Energy Loss Ratios for a Gas Furnace (for 13

Minute and 20 Minute Cooldown Period)

10. Units Conversion Table: Sl/lnch-Pound/SI

ix

Page

18

19

20

21

22

23

24

25

26

27
List of Figures

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

1. Thermal flow paths of energy losses with vented space

heating equipment - stack loss and infiltration air flow . .

2. Typical part load losses of an in-space room heater without

stack damper . . .

3. A direct measurement method for the off-period sensible heat

losses (Lg ^ OFF )

*

3a . Normal cool-down (TG)

3b. Reproduced cool-down (tg and BR) ».

3c. Normal and reproduced cool-down temperature profile

4. Partial pressure of water vapor in combustion products of

natural gas (Pv ) vs. percent CO2 in flue gas and partial

pressure of water vapor at saturated conditions (Pvs ) vs. flue gas temperature °F

5. Test conditions of method used in obtaining test data for

80K Btu/h hot water boiler showing locations used to inject

and to sample tracer gas in the flue and stack

6. Equipment used in tests

6a. Simulated cool-down test of room heater. Bubble meter and

wet test meter shown on bench

6b. Forced air upflow gas furnace

6c. Hot water boiler set up for normal cool-down test showing

tracer gas injection and sampling tubes in stack

6d. Simulated cool-down test of boiler stack and draft hood.

Bunsen burner in place and tracer gas injection and sampling

tubes in stack

7. Description of test burner showing location of burner for

simulated cool-down of forced air furnace

7a. Forced air furnace showing position of test burner in

diverter section at exit of heat exchanger

7b. Test burner used for simulating cool-down temperature of

furnace

Page

28

28

29

29

29

29

30

31

32

32

32

32

32

33

33

33

x
List of Figures (Continued)

Page

Figure 7c. Exit of heat exchangers in diverter compartment 32

Figure 7d. Test burner in position with exit of heat exchangers

33

Figure 8 . Results of three methods used for measuring off-cycle

loss-comparison using ratio of values measured ........ 34

Figure 9. Ratio of off-cycle loss (Lg off) found by three methods

tests with data grouped by input rate and averaged for

of

each

35

Figure 10. Various test conditions used to heat-up for normal and for

the simulated cool-down testing of the 80K Btu/h warm air

36

39

Figure A-l. Equipment used for tracer gas measurement ........

41

Figure B“1 • Example of data sheet * 42

Figure 15“2 • Sample of computer input aata

42

Figure 15 —3 • Sample of computer output • • • 43

Figure B-4

Listing of Fortran computer program

xi

1 . INTRODUCTION

1.1 BACKGROUND

As a part of the Department of Energy's (DoE) energy conservation program for

consumer products, the National Bureau of Standards (NBS) developed test procedures for gas and oil-fired furnaces and household heaters [1]. The Department of Energy published their rules and regulations covering test procedures

for furnaces and vented heaters in the Federal Register on May 10, 1978 [2].

These procedures involve measuring values of flue gas temperature during a heat-up and cool-down test together with a thermal efficiency measurement by

the flue loss method at steady-state conditions. Either measured or assigned

draft stack factors (Dp, Dg, or Dp) which depend on the heater design are then used with the measured temperatures to calculate the part load utilization

efficiency (%)*.

Part load space heater efficiency requires the determination of five flue

losses. These are on-period sensible heat loss (l«g

s 0N)> latent heat loss (Ll),

on-period infiltration loss (Lj qn)> off-period infiltration loss (Li^Ff)* and

off-period sensible heat loss (Lg^opp). Measurement of the off-period losses is

the objective of this report.

On-period Sensible Heat Loss , (Lg qn^ ds sensible energy leaving the building

up the stack which represents energy required to raise the stack gas from room

temperature to stack temperature. This loss depends upon the heat exchanger

effectiveness and the amount of excess combustion air used.

Latent Loss , (Ll) is the energy loss involved in the formation of water due to

the combustion process. Hydrogen in the fuel combines with the combustion air

oxygen to form water vapor. This water vapor requires potentially available

heat if it does not condense (latent heat of vaporization). Latest DoE procedures now provide credit for the recovery of the latent heat of vaporization

for high efficiency condensing furnaces [4, 7].

On-period Infiltration Loss , (Lj

} on) applies to heaters installed indoors

and using indoor air for combustion and draft dilution. The energy loss is

equivalent to the amount of energy used to heat air from the average heating

season outdoor temperature of 6°C (42°F) to the indoor temperatures assumed

to be 21°C (70°F)

* Part load efficiency (nu) is defined as:

nu

= 100 - LL

- — ( lS,0N + lS,0FF + lI,0N + l i,off)

fc on + PF x t 0ff

where the part load losses are described above, t on and t 0 ff are the burner

on- and off-periods and PF is the pilot fractional input of the total input

rate

1
Off-period Infiltration Loss , (Lj OFF^ represents the amount of energy needed

to heat the air which leaves the building up the stack while the burner is

off. This loss is now determined in the DoE test procedure using an equation

that predicts the mass flow during the cool-down test.

The various flow paths are shown in figure 1. A typical set of these part

load losses for a vented room heater tested in the NBS combustion equipment

laboratory is shown in figure 2. Depending upon the type of heater used, and

its firing rate, these part load losses can vary significantly as will be

shown by the range of values found in tests. (See reference 3 for details.)

The calculation of Lg qff in the DoE test procedure is based on a relationship

of assigned factors including flue and stack mass flow ratio with the burner on

and off and uses measured flue temperatures during a cool-down test from steadystate conditions. These data and assigned values are used to calculate stack

energy loss (Lg off) during the cool-down period from the time the burner

shuts down through the time t 0 ff. References [1, 5, and 6] include background

and discussion of the equations involved.

The DoE procedure with assigned draft factors (Dg and S/F) was applicable

for electrically operated dampers but was inappropriate for determining part

load efficiency for heaters equipped with thermally activated dampers because

the thermal dampers typically have higher off-period leakage rates and the

leakage rate is temperature dependent.

In an effort to update the test procedures, DoE requested NBS to develop a method of testing which could be used to compare the annual performance of

vented heaters with and without thermally activated vent dampers. NBS investigated the use of a tracer gas method and recommended that method to DoE for

testing equipment with thermal stack dampers [3]. DoE published proposed test

procedures in the Federal Register on June 17, 1983, for both furnaces and

household vented heaters equipped with thermal stack dampers [4]. Those test

procedures specify that a tracer gas test method be used to determine the offperiod energy losses. DoE also proposed [4] that this tracer gas procedure be an option for all types of stack dampers and that it be the only procedure

allowed after a two year period for all types of stack dampers.

1.2 TRACER GAS TEST METHOD FOR MEASURING OFF-PERIOD LOSSES

1.2.1 Off-period Sensible Heat Loss

This method involves measuring mass flow and temperature in the stack during

a cool-down period. The product of stack mass flow, specific heat of air,

and temperature rise above room temperature when integrated over the burner

off-cycle period is equivalent to the off-cycle energy loss:

100 x (C

p

) toff

lS,0FF =

1 mS,0FF ( tS,0FF “ tra) dt (2)

(Qin) fc on 0

2
where

Ls OFF is the off-cycle loss expressed as a percentage of the input rate,

Qin is the burner input rate expressed in KJ/sec (Btu/sec),

t on and t 0 ff are the assigned burner cycling times on and off (min),

Mg OFF is the stack mass flow rate, kg/s (lb/min),

TS off and Tra are the stack temperature and room temperature at time t during

the cool-down test expressed in °C (°F), and

Cp is the specific heat of air = 1.0 kJ/kg*°C (0.24 Btu/lb • °F).

100 converts the fraction to a percentage.

The method of test used to measure Lg qfF ^- s to measure of the mass flow

and temperature continuously during a cool-down period immediately after the

heater has been operating at steady-state conditions. A tracer gas measurement

using the guidelines described in appendix A was used in these tests to determine

mass flow rate. The procedure used to obtain the data was as follows:

1. The unit was turned on and allowed to heat up to steady-state conditions.

For heaters equipped with step modulating thermostats, the heater is set

to the minimum heat input setting. For heaters with two stage thermostats

two tests were run, one at minimum and one at maximum heat input setting.

For furnaces equipped with a single stage thermostat the unit was operated

at the maximum input rate.

2. When steady-state temperature was achieved, tracer gas was fed at a constant

metered rate into the stack at the draft relief opening using guidelines

described in appendix A.

3. The burner was shut off and the stack tracer gas concentration and

temperature, and room temperature was measured continuously. These values

were recorded at the midpoint of each one minute interval during the cooldown period. Sampling delay time was considered in these measurements.

Sample delay time is determined as described in appendix A.

4. Barometric pressure was recorded.

After the above data was collected, the calculation of the product of mass flow and temperature could be determined using the summation of the incremental

values as described in equation (2).

3
ZMS OFF (TS OFF “ is t^ie summation of 20 values* of the quantity

Ms OFF CTS OFF “ T^) measured at midpoint of each one minute interval following burner shut down. Tj^ is the room ambient temperature entering the

draft relief opening (averaged during the test) and Tg OFF *- s an individual

reading of the stack temperature.

When a pure tracer gas (a single component gas) is used Mg qff calculated

from:

100 - C

MS,0FF = '—c7~“ Ps

When a mixture of tracer gas component with inert gas is used as the tracer

gas, Mg^QFF i s calculated from:

V " CT

• mS, 0FF = —- VT Ps ( 4 )

where

Ms ,0FF = mass flow kg/s (lb/min),

V,j = flow rate of tracer gas through the stack in m

J /s (ft'Vmin),

Ct = concentration by volume of tracer gas present in the stack gas

sample in percent,

Ct* = concentration by volume of the active tracer gas fed into

the draft relief opening, and

ps = the density the stack gas would have at the temperature in

kg/m^ (lb/ft^). It may be approximated by the equation:

p s = 1.325 ( Tt + 460r)

where

(5)

Tt = absolute temperature of tracer gas entering flow meter °F, and

Pg = barometric pressure during the test in inches of mercury (kPa).

* Twenty values were taken for the test of the vented heaters and furnaces. A

33 minute cool down period (34 readings) was used when testing the hot water

boiler since that is considered its normal off—period in DoE Test Procedures

for Boilers.

4
1.2.2 Off-period Infiltration Loss, Lj^Qpp

The measured mass flow rate through the stack used in determining the Lg^pp

is also used In determining the Lp 0FF* The quantity of energy involved

is found from the product of stack’mass flow specific heat of air and temperature differences between indoor and outdoor temperatures (i.e., 70-TqA)*

The same data for stack mass flow measured for Lg qn during the cool-down period

is used for this calculation. The off-period infiltration loss is calculated

from:

lI,OFF

“ (1.3) 100 C

p

<<>)

(Qin) c on

(70-T0A)

where:

MS,0FF dt ( 6 )

In addition to units previously defined above in equations (2) and (3):

Tqa = the average outdoor temperature in the cycling mode, °C (°F),

this is taken to be 42 °F for furnaces and boilers and 45 °F

for household heaters as per the DoE test procedures,

<J> = infiltration parameter, dimensionless, assumed equal to 0.7,

(70 percent of the infiltration air is charged to the furnace flow),

70 = assumed indoor average room temperature, 21 °C (°F),

100 = conversion factor for percentage,

1.3 = a dimensionless factor for converting laboratory measured stack

flow to typical field conditions.

1.3 OBJECTIVE OF ALTERNATIVE METHOD TO TRACER GAS TESTING

Although the tracer gas method is a precise method and applicable to all vented

heating equipment, it requires special equipment (as described in appendix A),

which typically may not be part of a small manufacturers laboratory facility.

Any alternative to the tracer gas test method must be one that offers both

direct measurement rather than an analytical approach and be consistent with

the tracer gas method in its results. In order to be considered as a substitute to tracer gas measurement an alternate method should offer an advantage

over the tracer gas method with respect to the cost of instrumentation required

for its use.

The objectives of the following possible alternate method, as with the tracer

gas direct measurement method, are:

1. To offer a test method of measurement of the off-cycle loss of equipment

with stack dampers for which an analytical approach is not feasible.

5
2 . To provide an alternative method of test in order to reduce the number of

waivers from testing because either the equipment or furnace involved is

unique in such a way that the current test procedures do not apply, or the assigned factor of stack to flue flow ratios (Dg) is not believed

to apply to specific manufacturer's equipment*.

* The analytical approach which uses assigned draft factors of mass flow rate,

Dp and Dg remains in the DoE procedures for conventional equipment.
2 . DESCRIPTION OF THE ALTERNATIVE MEASUREMENT METHOD

2.1 MEASUREMENT OF THE OFF-PERIOD SENSIBLE HEAT LOSS

This method uses a controlled flow of gas to a small flame holder (bunsen

burner) in order to duplicate normal stack temperatures that would exit during

a cool-down test from steady-state conditions. The amount of energy metered

to the burner during this test is equivalent to the normal stack heat lost

from residual heat stored in the heat exchanger and lost out the flue during

the off-perod (Lg OFF)* The method is applicable to furnaces and heaters

using thermal vent dampers and as such is a potential alternative to the direct

though more complex requirements of a tracer gas measurement method required

by the proposed DoE procedures in reference [4]

This procedure involves the following steps (refer to figure 3):

1. Determine the stack temperatures vs. time during a normal cool-down period

after operating at steady-state (figure 3a).

2. Reheat the unit to steady-state by using either the burner of the heater

or furnace or by using a separate burner such as a Bunsen burner positioned

at the entrance to the draft hood (figure 3b).

3. Block the heat exchanger exit prior to a second simulated cool-down

period.

4. Reproduce the stack cool-down temperature profile originally found

(figure 3). This is done by substituting the heat that would have exited

the stack with a controlled gas flame placed at the draft hood relief

opening. The volume of gas used is metered during this second cool down

period and the amount used during each one minute period of cool down is

recorded. With the heating value of the gas known, the total volume used

is converted to Btu's which gives a direct measure of thermal energy loss

through the stack (Lg

} QFF)»

In calculating the thermal energy loss, the net heating value of the fuel is

used*. The measured higher heating value of the fuel was reduced by approximately 10 percent in those tests to arrive at a net heating value of the natural

gas used for testing. This net heating value is dependent upon the fuel gas

composition and will vary with the local source of fuel and type used (i.e.,

natural gas, propane, or butane). Net heating value is used because some of

the heat from the fuel is given up to vaporize water formed due to oxidation

of hydrogen in the fuel. This latent heat is not available unless there is

condensation of water vapor in the stack and it was found that condensation of

water vapor did not occur. This was determined by knowing the stack gas

* Net heating value, also called lower heating value, is equal to the higher

heating value of the fuel minus the latent heat of evaporation of the water

vapor formed by combustion of the fuel.

7
combustion products i.e., CO 2 in the stack gas. If the partial pressure of

water vapor in the combustion products (Pv) is less than the saturated partial

pressure of water (Pvs) in the flue gas (or stack gas) then relative humidity

will be less than 100 percent and condensation will not occur. Figure 4 was prepared to evaluate whether Pv, determined from a known CO 2 value in combustion products would be greater or less than Pvs at the temperature of the

combustion products during a test. Data for Pvs and the calculations of Pv

used in development of figure 4 may be found in reference [7], In these

tests CO2 values did not exceed 0.5 percent. Therefore, Pvs was always

greater than Pv. Flue temperatures during the cool-down tests are listed for

each test in appendix C for one of the heaters tested.

During the early stages of the development of this method the controlled heat

source used to reproduce the stack temperature was an electric resistance

heating element. A 220 volt power supply connected to an electric clothes dryer

heating element was controlled by a variable transformer. The thermal mass of

the electric heater limited the response time needed to track rapid changes in

temperature during the early stages of cool down. It also required correcting

the test results for the energy stored in the heating element at the beginning

and the end of the test. A simple gas Bunsen burner with needle valve control

was found to eliminate the problem of stored energy and allowed for instantaneous control of heat output. The Bunsen burner was sufficient for those units

with external draft hoods but a special burner configuration was designed for

the test units with internal draft diverter.

2.2 MEASUREMENT OF THE OFF-PERIOD INFILTRATION LOSS

In order to measure off-period infiltration loss that would result in a home,

it is necessary to calculate mass flow through the stack during the cool-down

test. Knowing the Btu's of energy flow over a period of time and the average

temperature above room temperature during that period of time, the mass flow

may be calculated from:

M = 2 (7 (Cp) ( AT) W

where

M is mass flow in an interval of time during the cool-down test,

Cp is the specific heat of air,

Q is energy flow through the stack in an interval of time during the

cool-down test, and

AT is average temperature above room temperature of the stack or flue

gas during the interval of time.

Substituting the metered gas flow converted to Q in Btu into the above equation,

the increment of M is determined. In evaluating this alternate test method, the

increment of time used was one minute during the first five minutes of cool-down.

8
The method requires taking a gas meter reading at the end of each minute but

when temperature is not falling rapidly, i.e., after five minutes, this increment

may be increased to every three, four, or five minutes. The total mass flow

during cooldown is obtained by summing the incremental calculated mass flows.

Off-period infiltration loss is then calculated using equation (6) where the

*- 0 ! f

value of \ Mso ff is the sum of the incremental readings. In order to obtain

0

the average temperature during each increment it is necessary to have made a continuous recording of the stack temperature during the simulated cool-down

test

9
3. TEST EQUIPMENT AND PROCEDURES USED 3.1

3.1.1EQUIPMENT

Dampers Tested

Three different models of thermally activated vent dampers approved for use with

gas fueled heaters were used in these tests. Damper B had a bimetal coil with

linkage that moved a damper plate. Dampers A and C use bimetal which serves as both the sensor and damper restriction surface. With either type the principal

of operation is the same. When the burner is operating, the hot stack gases

impinge upon the bimetal sensor. The resulting movement of the bimetal opens

the stack damper. When the burner shuts off the bimetal cools and moves the

restriction back to its normally closed position; the damper then remains in

the closed position until the burner is again operating. A 102 mm (4 in)

diameter and a 127 mm (5 in) diameter model of each type damper was tested.

In each case the dampers were installed within one foot of the draft hood

outlet.

3.1.2

Heating Equipment

Three gas fueled vented heaters, one furnace, and one boiler described below

were used in these tests:

1. A forced convection counter flow room heater rated 13,188 W (45,000 Btu/h)

maximum input. This heater was equipped with a hydraulic type thermostat

control (step-modulating type control). No combustion air adjustment is

provided with this type control other than a manually adjustable primary

air shutter on the atmospheric type burner. The unit had a 127 mm (5 in)

diameter stack and an external draft hood.

2. A natural convection type (parallel flow) room heater rated 10,255 W

(35,000 Btu/h) maximum input. This heater was also equipped with a hydraulic type thermostat control (step-modulating). The stack diameter

of this heater was 102 mm (4 in). This heater also had an external draft

hood.

3. A forced convection type (counter flow) wall furnace rated 10,255 W

(35,000 Btu/h). The draft diverter was internal.

4. A forced air central furnace upflow type (shown in figure 6) rated 120,000

Btu/h. This unit was also operated at 80,000 Btu/h by derating the input

in order to increase the test data base and to include input rates consistent with residential equipment. The unit had a five section heat exchanger

(5 burners).

5. A hot water boiler (shown in figure 6c) rated 80,000 Btu/h, single burner

and an external draft hood.

10
3.1.3 Laboratory Equipment

Aooendix A Includes a description of equipment used in tracer gas measurements.

In addition to the equipment described In appendix A, a precision liquid manometer was connected to the static pressure leg of a pitot tube to measure stack

draft.

A drv test (diaphragm type) and a wet test gas meter 0.1 cu ft per revolution

of the dial were usS to meter natural gas during the simulated cool-down test.

The dry test meter was needed for very low flow rates due to the inability o

the wet test meter to turn uniformly at extremely low rates (less than 100 Btu/h)

3.1.4 Test Burners Used to Reproduce Cool Down Temperature Conditions

A Bunsen burner was used to reproduce the cool-down temper,ature profile

the two heaters with external draft hood and the boiler during the simulated

cool-down tests. A small burner having a needle valve fuel flow control was mounted on a bracket and positioned within the internal draft diverter compartment of the wall furnace. A special burner was designed for use with the

forced air furnace. The burner and its positioning in the draft diverter

compartment is shown in figure 7. This particular design was chosen in order

to uniformly distribute the heat across the width of the heat exchanger to

simulate the flow of heat as it would normally occur during the cool down.

The higher heating value of the natural gas fuel pipeline supplied from the

local utility company, was continuously measured onsite with a recording

calorimeter.

3.2 TEST PROCEDURES USED

Each of the heaters was run with each type of vent damper and without any

damper. For each test without a vent damper, the currently prescribed DoE

test procedure [2] was used to measure flue and stack temperatures during heat

up and cool-down tests. Flue and stack temperatures and C0 2 concentration

were measured at the steady-state condition. Each heater was run as if equipped

with a single stage thermostat (maximum input) and as though equipped with a step-modulating control (both maximum and reduced input rates).

Tests were run with both a 1.5 m (5 ft) stack installed as per the DoE test

procedure and with a 5.2 m (17 ft) stack to stimulate field equivalent condi

tions (figure 1). Additional details of these field vs. lab tests are described

under Test Results (section 4).

3.2.1 Tests on the Room Heaters Having External Draft Hoods

The design of this heater allowed easy placement of a small Bunsen burner at

the draft hood relief opening (see figure 6a).

11
3.2.2 Tests on the Wall Furnace and Forced Air Furnace Equipped with Internal

Diverter

Burners used for these test units were described previously (section 3.1).

Several burner locations and other test conditions were investigated with the

forced air furnace. These are described in table 9 and shown in figure 10.

3.2.3 Tests on the Hot Water Boiler, Equipped with Draft Hood

It was impractical to position the burner inside the flue of this unit since

the burner could not be seen and could block the normal flow of air through the

flue passage, Instead, the simulated test was run with the stack, draft hood,

and flue connector pipe erected above a laboratory bench and tested after the

normal cool-down test was run with these parts on the boiler.

The test setups for the normal cool down and for the simulated test of the

boiler are shown in figures 5, 6c, and 6d. Various test parameters involving

the location for introducing the tracer gas and sampling the diluted tracer

gas were investigated. Also the effect of stack draft was investigated.

Attempts were made to duplicate the stack draft that existed at the start of

the normal cool-down conditions at the start of the simulated test. In order

to do this, the length of test stack above the draft hood was varied by

+ 2 ft to - 2 ft. At the start of the simulated cool down test, the Bunsen

burner flame length was believed to be affecting or possibly igniting the

tracer gas (carbon monoxide/nitrogen mixture) introduced into the lower section

at point B in figure 5. In order to reduce flame length, a screen was positioned above the burner and a radiation shield (aluminum foil) was placed

around the burner and screen.

12
4. TEST RESULTS

4 .

OFF-PERIOD SENSIBLE LOSS BY TRACER GAS MEASUREMENTS ( Qg )_

The calculation procedure in computerized format is described in appendix B.

An example of each of the tracer gas test results for one of the heaters tested

is listed in appendix C. Measured test results are shown in the columns of

tracer gas concentration (CONC) and average stack gas temperature (TEMP),

column labelled "M" is the calculated mass flow during the increment of time

(one minute in these tests); "MLOS" is the summation of the mass flow from the

start to each time; "Q" is the calculated stack loss in Btu during the time

increment of one minute; and "QLOS" is the summation of stack loss from the

start to each time increment.

Each test result of normal cool down for each test condition of appendix C

is followed by the results found under the simulated direct measurement test

for the same heater and test condition.

The last result (last line) of each test under the column "QLOS" at the end of

the 20 minute cool-down period is the result which is listed in table 1 (under

Qc) for the 45K Btu/h room heater. The computer program, written in FORTRAN,

used to calculate these data is included in appendix B. Appendix B also shows

a data sheet used to enter test data into the computer. Table 1 also shows

results for two other household heaters tested. Tables 2 and 3 list the

off-period losses for a gas furnace tested at 80K Btu/h and at 121K Btu/h

input for two cool-down periods (20 minutes and 13 minutes*, respectively) and

table 4 lists the results for a boiler over a 33 minute cool-down period.

4.2 OFF-PERIOD INFILTRATION LOSS (QT )

This loss is found from the summation of "MLOS" (the bottom line of the column

under "MLOS") in appendix C and the product of specific heat of air and AT; see equation ( 6 ). Values of "Qi", the calculated infiltration loss for each

test using tracer gas is shown in tables 1, 2, and 4. A comparison of this

value with Qi as determined by the metered burner method has not been done,

since the more important comparison between the two test methods is the sensible

loss (Qs) test results.

4.3 COMPARISON OF THE SIMULATED TEST RESULTS WITH NORMAL COOL-DOWN TEST RESULTS

4.3.1 Comparison of the Tracer Gas Test Results, Cool Down Simulated with

Bunsen Burner Versus Normal Cool Down; (tg/TG)

The first column of tables 5 through 9 show this comparison. The ratios were

obtained using the values of Qs shown in tables 1 through 4. The values of Qs

found from the tracer gas measurements during the simulated test are referred

to as (tg) and the values of Qs found from tracer gas measurements during the

* Thirteen minutes is the typical burner off-period used in the DoE test

procedure for furnaces and 33 minutes for boilers.

13
normal cool-down test are referred to as (TG) in tables 6 though 9. The ratio

of tg/TG is a measure of how well the simulated test condition reproduced the

normal cool-down test. The top graph of figure 8 displays all the data in

figures 1 through 5 for the comparison of tg/TG. As seen in figure 8, test

results from the simulated tests are almost always lower than the values obtained

from normal cool down conditions (i.e., the ratio is less than 1.0). A ratio

of 1.0 would represent perfect simulation. These data show an overall average

of 0.85 for this ratio. There does not appear to be any one type of stack damper

that shows consistency in these results or that gives a ratio consistently

close to 1.0. However, the amount of data scatter is not as great as for the

comparison of burner to tracer gas results which are described below.

4.3.2 Comparison of the Metered Burner Method with Tracer Gas Method During

the Simulated Cool Down Test, (Br/tg)

The comparison of metered burner (Br) versus tracer gas (tg) test methods is

plotted on the bottom graph of figure 8. The ratio is a measure of the difference between a metered burner and a tracer gas test under identical test conditions (i.e., measurements made simultaneously). These data are the ratio of

the Qg values obtained from tables 1 through 4 to the values for the metered

gas method value of Qg calculated by converting the Bunsen burner fuel used

during the test to Btu's. The calculated ratios are shown in tables 6 through

9 in the right-hand column as the ratio (Br/tg). The results show little

consistency except for the 80K Btu/h furnace.

The ability to reproduce results of the tracer gas test shows improvement with

high fuel input burners (i.e., high initial stack temperature) since a small

error in the adjustment of the higher fire rate of the test Bunsen burner

during the simulated cool-down test has less effect than at lower fuel input

rate to the Bunsen burner. This trend can be seen in figure 9 where average

results grouped by fuel input rate shows a trend toward a ratio of 1.0

for (Br/tg) with increasing input rate.

In all cases the critical adjustment of the Bunsen burner is during the first

few minutes of the cool-down period. This criticality is made obvious by

comparing the rapid changes in temperature (TEMP) and mass flow (M) during the

first few minutes (at times one to five minutes) after start of the cool down in

the data of appendix C.

4.3.3 Comparison of the Metered Burner Method With Normal Cool-Down Test

Method Using Tracer Gas (Br/TG)

The object of the Bunsen burner simulated cool down method is to be a low

equipment cost replacement for the tracer gas and measurement equipment needed

for the normal cool-down method. A comparison of the two methods was calculated

using a ratio Br/TG as shown in the center graph of figure 8. Individual

values of (Br/TG) are the product of (tg/TG), top graph, and (Br/tg), bottom

graph of figure 8 since

(Br/TG) = (tg/TG) • (Br/tg)

14
Noting that this ratio is the product of two other results, it is apparent

that Br/TG can be misleading near a ratio of 1.0 since, when tg/TG is lower than

1.0 and (Br/tg) is greater than 1.0, the errors cancel each other. This is the case for the 45K Btu/h and 35K Btu/h room heaters. Conversely, tg/TG could be

higher than 1.0 and Br/tg less than 1.0 which would also result in misleading

data. This compensating effect must be recognized In drawing conclusions as

to the overall applicability of the metered burner test method as a substitute

for the tracer gas method.

15
5. SUMMARY

The results of this evaluation show that a simulated cool-down procedure using

a metered burner to reproduce the normal cool-down conditions of a furnace,

gave reasonably good results for the most common type of furnace, the central

forced air gas furnace with internal draft diverter.

Results for the other type of equipment tested (room heaters, wall furnaces,

and hot water boilers) were conflicting.

By conducting a normal tracer gas test and then a tracer gas test while at the

same time metering the gas flow to the Bunsen burner during a simulated cool

down, it was possible to:

1. Compare both the energy and mass flow for the simulated cool down to the

normal cool down. This comparison evaluated the ability to simulate the

normal cool-down condition when using a burner to reproduce the cool down

temperature profile.

2. Compare the metered burner energy flow during simulated cool down against

calculated energy flow using the tracer gas method — both measured during

the same test. This second comparison showed the equivalency of the

metered burner method vs. the tracer gas (or standard) method.

It has been found that the metered burner method can be off in one direction

while the simulation using tracer gas is off in the other direction making it

appear that the metered burner method accurately reproduced the results of a normal cool down when, in reality, it was due to two errors cancelling out.

Overall test results show the simulated method measured by tracer gas in almost

all tests gave a lower value than the normal cool-down test. The ability to

simulate cool down by the burner method was generally good with a moderate

amount of data scatter. Overall, the ratio of the simulated to normal cool

down energy flow (t

g /TG) was 0.85.

Comparison of the metered burner results with calculated results by tracer gas

under identical conditions (both tests run simultaneously) during the simulated

cool-down test show mixed results. Test units with external draft hoods (two room heaters and boiler) show the burner method to tracer gas energy flow ratio

is almost always above 1.0. Units with internal draft diverters (wall furnace

and forced air sectional central furnace) almost always showed a metered burner

method to tracer gas ratio of less than 1.0. Only the 80K Btu/h central forced

air furnace showed consistently reproducible results with ratios close to 1.0.

Whenever the metered burner technique compared favorably with the tracer gas

method under simulated conditions it did so with all of the thermal damper

designs tested. Therefore, in the case where this alternative method of measurement reproduces the tracer gas method it offers potential as a substitute

test method for the testing of thermal stack dampers.

Further development, testing, and evaluation will be required before this

simulation procedure can be considered as an acceptable alternative test

method for all equipment.

16
6 . REFERENCES

1. Kelly, George et al., "Recommended Testing and Calculation Procedures for

Determining the Seasonal Performance of Residential Central Furnaces and

Boilers," NBSIR 78-1543, October 1978, National Bureau of Standards,

Washington, DC.

2. Federal Register , 43, No. 9, pp. 20181-20294, May 10, 1978.

3. Kweller , E. R. and Mullis, W. F., "Determination of Annual Efficiency of

Vented Heaters Equipped with Thermally Activated Vent Dampers," ASHRAE

Transactions, pp. 763—768, Vol. 87, Part 1.

4. Federal Register , 43 s No. 61, pp. 12148-12178, March 28,1984.

5. Chi, J. and Kelly, G. E., "A Method for Estimating the Seasonal Performance

of Residential Gas and Oil-Fired Heating Systems," ASHRAE Transactions,

84(1), 1978.

6. Park, C. et al., "A Study of the Dynamic Flue-Gas Temperature and OffPeriod Mass Flow Rate of a Residential Gas Furnace," NBS Technical Note

999, July 1979, National Bureau of Standards, Washington, DC.

7. Kelly, G. E. and Kuklewicz, M. E., "Recommended Testing and Calculation

Procedures for Estimating the Seasonal Performance of Residential

Condensing Furnaces and Boilers," NBSIR 80-2110, April 1981, National

Bureau of Standards, Washington, DC.

17
Table 1. Off-Period Energy Losses (Btu) for three Household Heaters

Test Condition

Normal Cooldown

Me; By Gas

Simulated Cooldown

Measured

By Tracer

Gas Method

(Flue Exit

asured Tracer

Method

Blocked) Metered

Gas Burner

Method

Maximum Input Q

S Qi Qq Qt QS (44640 Btu/h)

- Room Heater Rated 45K Btu /h NET Without Stack Damper 393 234 246 162 249

289 171 268

With Damper A 354 86 204 62 272

With Damper B 285 71 188 55 234

With Damper C 353 138 267 123 300

Reduced Input

(24520 Btu/h)

Without Stack Damper 323 239 185 147 221

With Damper A 179 60 134 52 185

With Damper B 137 46 110 40 168

With Damper C 204 110 194 111 235

Wall Furnace Rated 35K Btu /h —

Maximum Input

(34310 Btu/h) QS Q

I ^S Q

I QS

Without Damper 406 112 282 75 183

With Damper A 402 94 326 74 199

With Damper B 354 52 300 65 150

With Damper C 382 105 320 90 176

Reduced Input

(19890 Btu /h)

Without Damper 239 60 221 80 133

With Damper A 243 64 175 48 140

With Damper B 149 30 156 43 99

With Damper C 249 88 214 76 159

— Room Heater Rated 35K Btu /h

Maximum Input

(41170 Btu/h)

Damper A 313 87 249 74 260

Damper B 269 - 198 56 225

Damper C 325 - 268 129 213

Reduced Input

(26000 Btu/h)

Damper A 169 59 165 58 214

Damper B 176 54 152 40 174

Damper C 222 - 194 108 166

18
Table 2. Off-Period Losses - (Btu) for Gas Furnace

(20 Minute Cooldown Period)

— Operating at 80K Btu/h —

Simulated Cooldown

Normal Cooldown Metered (Notes)*

(Notes)

Tracer Gets Tracer Gas Burner

Test Condition* Q

S q

i Q

S Q

i Qc

o

No Damper (1) 517 205 388 311 ( 2 )

372 307 ( 3 )

386 282 ( 4 )

407 285 ( 5 )

Damper A (1) 426 87 414 97 388 ( 5 )

Damper B (1) 374 76 464 161 389 ( 5 )

(1) 382 77 461 157 391 ( 3 )

Damper C (1) 453 136 317 77 263 ( 5 ) — Operating At 121K Btu/h —

No Damper (5) 752 257 777 268 448

Damper A:

5 ft. Stack 603 123 601 119 543

21 ft. Stack 755 173 661 154 501

Damper B:

5 ft. Stack 656 111 470 98 604

21 ft. Stack 557 155 521 117 687

Damper C:

5 ft. Stack 751 203 661

21 ft. Stack 761 208 658 186 568

*See Figure 10 for details of test conditions corresponding to each note

19
Table 3. Off-Period Energy Losses (Btu) for Gas Furnace

for (13 Minute Cooldown Period) — Cooldown from 80K Btu/h — Simulated Cooldown —

Normal Cooldown Tracer Metered Footnotes

Tracer Gas Gas Burner

Test Condition Qg Method Method

No Damper 474 363 295 (1)

346 293 (2)

262 262 (3)

384 263 (4)

Damper A 403 386 438 (5)

Damper B 354 425 358 (5)

366 426 358 (6)

Damper C 421 299 254 (5) — 315 248 (6) — Cooldown from 12 IK Btu/h

No Damper 702 723 447 0)

*See footnotes on Figure 10.

20
Table 4. Off-Period Energy Loss - (Btu) for Gas Boiler

(33 Minute Cooldown Period)

Run No. Test Condition

Normal Cooldown

Tracer Gas

Is Q

I

Simulated Cooldown

Tracer Gas Bunsen Burner

Q

S Q

I QS (NET)

1) Stack Insulated (a) 1516

2) (a) 1576

3) (b) 1621 542

4) Stack Uninsulated (a) 1402

5) (b) 1478 544 1444 531 1680

6) (b) 1416 497 1665 (d)

7) (c) 1226 434 1807

8) (c,d) 1275 450 1815

9) (c,d,e) 1008 358 1602

10) (c,d,f) 1172 419 1638

By Calculation per DoE Procedure Q

g = 1134, = 413

Test Conditions

(a) Tracer gas in at "A", sampled at "B" in figure 5.

(b) Tracer gas in at "C", sampled at "D" in figure 5.

(c) Tracer gas in at "B", sampled at "D" in figure 5.

(d) Bunsen Burner flame impinging on radiant screens, aluminum foil skirt

positioned around Burner and Screen.

(e) Stack Height reduced by one foot.

(f) Stack Height increased by one foot.

21
Table 5. Off-Period Energy Loss Ratios for Room Heater Rated 45K Btu/h

See Table 1 for Btu Values.

Ratio of L ,, s,of f

Simulated cooldown test method

Measured during simulated using burner (Br)

cooldown test using tracer (tg) -J- +

T measured during normal Normal cooldown Simulated test

Test Condition test using tracer gas (TG) with tracer gas (TG) with tracer gas (tf

No Damper

Max Input

Reduced Input

Stack Damper A:

Max

Reduced

Stack Damper B:

Max

Reduced

Stack Damper C:

Max

Reduced

(tg/TG)

0.63 (1)

0.57

0.58

0.75

0.76

0.80

0.76

0.95

(Br/TG)

0.63 (2)

0.68

0.77

1.03

0.85

1.23

0.85

1.15

(Br/tg)

1 . 01 (3)

1.20

1.33

1.38

1.12

1.53

1.12

1.21

Note: tg/TG and Br/TG are simulated cool-down compared to normal cool-down as the

reference. (Br/tg) is the direct Burner compared with measured tracer gas

method during the simulated cool-down as the reference

(1) Referring to Table 1 . The ratio 0.63 = 246 JL 393

(2) Referring to Table 1 . The ratio 0.63 = 249 -7- 393

(3) Referring to Table 1 . The ratio 1.01 = 249 246

22
Table 6. Off-Period Energy Loss Ratios for 35K Btu/h Wall Furnace

See Table 1 for Btu values.

Ratio of L --

s ,of f

Simulated cooldown test method

Measured during simulated using burner

Test Condition

cooldown test using tracer

T’ measured during normal

test using tracer gas

-f* Normal cooldown

with tracer gas

+

Simulated test

with tracer gas

Without Stack

Damper

(tg/TG) (Br/tg) (Br/tg)

Maximum Input 0.69 0.45 0.65

Reduced Input 0.92 0.56 0.60

Damper A

Maximum Input 0.81 0.44 0.54

Reduced Input 0.72 0.58 0.80

Damper B

Maximum Input 0.85 0.42 0.50

Reduced Input 1.05 0.66 0.63

Damper C

Maximum Input 0.84 0.46 0.55

Reduced Input 0.86 0.64 0.74

23
Table 7. Off-Period Energy Loss Ratios for

Room Heater Rated 35K Btu/h

(See Table 1 for Btu values.)

Test Condition

Ratio of L

s ,of f

Simulated cooldown test method

Measured during simulated using burner

cooldown test using tracer + +

*r measured during normal Normal cooldown Simulated test

test using -tracer gas with tracer gas with tracer gas

Damper A

Max Firing Rate

Reduced Firing

Rate

Damper B

Max Firing Rate

Reduced Firing

Rate

Damper C

Max Firing Rate

Reduced Firing

Rate

(tg/TG) (Br/TG) (Br/tg)

0.80 0.83 1.04

0.98 1.27 1.30

0.74 0.84 1.14

0.86 0.99 1.14

0.82 0.66 0.79

0.87 0.75 0.86

24
Table 8. Off-Period Energy Loss Ratios for an 80K Btu/h

Hot Water Boiler - 33 Minute Cooldown Period

Ratio of L _

s ,of f

Measured during simulated

cooldown test using tracer

+ measured during normal

Test Condition test using tracer gas

Simulated cooldown test method

using burner

+ ~r~ Normal cooldown Simulated test

with tracer gas with tracer gas

See Table 4: (tg/TG) (Br/TG) (Br/tg)

Run No. 5 0.98 1.14 1.16

Run No. 6 0.57 1.18 —

Run No. 7 0.87 1.28 1.47

Run No. 8 0.90 1.28 1.59

Run No. 9 0.71 1.13 1.40

Run No. 10 0.83 1.16 1.42

25
Table 9. Off-Period Energy Loss Ratios for a Gas Furnace 80K Btu/h

(13 Minute and 20 Minute Cooldown Period)

See Tables 2 and 3 for Btu Values.

Test Condition

Comparison Ratio

(Simulated 4- Normal Cooldown)

Tracer Gas (tg/TG) Using (Br/Tg)

to Tracer Gas Metered Burner

(13 min) (20 min) (13 min) (20min)

Simulated Cooldown

Burner + Tracer

Gas Values (Br/tg)

(13 min) (20 min)

No Damper

Max Input (2) * 0.87 0.75 0.62 0.60 0.81 0.80

(3) — — — — 0.85 0.80

(4) — — — — 0.72 0.73

(5) — — — — 0.68 0.70

Damper A (1) 0.96 0.97 0.86 0.91 0.90 0.94

Stack Damper B

(1) 1.20 1.24 1.01 1.04 0.84 0.84

(3) 1.16 1.21 0.98 1.02 0.84 0.85

Damper C (1) 0.70 0.71 0.60 0.58 0.85 0.83

(3) — — — —

— Cooldown

(13 min)

from 120K Btu/h - (20 min) (13 min) (20 min) (13 min) (20 min)

No Damper 0.95 1.03 0.63 0.60 0.62 0.58

Damper A: 5 ft. Stack 1.00 0.90 0.90

21 ft. Stack 0.88 0 . 66 0.76

Damper B: 5 ft. Stack 0.83 1.07 1.29

21 ft. Stack 0.81 0.76 0.94

Damper C: 5 ft. Stack — 0.88 —

21 ft. Stack 0.86 0.75 0.86

*See footnotes on Fig. 10 for details on test conditions.

26
TABLE 10

UNITS CONVERSION TABLE: SI / INCH-POUND /S

TO CONVERT MULTIPLY BY TO OBTAIN

Lb

( Pounds ) 0.454 Kg

(Kilograms )

Kg

(Kilograms

2.2046 Lb

(Pounds

Cu. Ft.

(Cubic Feet)

28.3

L (Liters)

L

(Liters

0.03531

Cu. Ft.

(Cubic Feet)

in

(Inches)

2.54

cm (Centimeters)

cm (Centimeters) 0.3937 in

(inches)

ft

(Feet)

0.3048 in (meter)

m

(Meters)

3.281

ft

(feet)

BTU

(British Thermal Units) 1.055

K J (Kilojoules) '

kJ

(kilojoules) 0.9479

Btu

—

(British Thermal Units)

TEMPERATURES (T) , CONVERSION EQUATIONS:

FOR TEMPERATURE USE:

°F to °C: [ (T) °F -32°F] (5/9) = (T)°C

°C to °F: [ (T) °C] (9/5) + 32©F = (T) of

FOR TEMPERATURE DIFFERENTIALS OR TOLERANCE USE:

°F to °C : (T) °F (5/9) = (T)oC

°C to °F: (T) °C (9/5) = (T)°F

27
Figure i. Thermal flow paths of energy losses with vented

space heating equipment - stack loss and infiltration

air flow.

Figure 2. Typical part load losses of an in-space

room heater without stack damper

28
00

•H

U*

u3

(/) (Q

rtj B<u 2 9

Figure

3c.

Normal

and

Reproduced

Cool-down

Temperature

Profile.
WATER

VAPOR

PARTIAL

PRESSURE

(psia)

STACK OR FLUE TEMPERATURE ("FI

80 100 120 140 160 180 200

Figure 4. Partial pressure of water vapor in combustion products of natural gas

<V & (^

vg

) vs * percent CO

^ in flue gas and vs. flue gas temperature °F.

30
Figure

>.

Test

conditions

of

method

used

in

obtaining

test

data

for

80K

Btu/h

hot

water

boiler

showing

locations

used

to

inject

and

to

sample

tracer

gas

in

the

flue

and

stack.
Figure 6a. Simulated cool-down test of room

heater. Bubble meter and wet test meter

shown on bench. Figure 6b. Forced air upflow

gas furnace.

Figure 6c. Hot water boiler set up

for normal cool-down test showing

tracer gas injection and sampling

tubes in stack.

Figure 6d. Simulated cool-down test

of boiler stack and draft hood.

Bunsen Burner in place and tracer

gas injection and sampling tubes in

stack

Figure 6. Equipment used in tests.
i X) d CU o Xi

•H

O

4-1 o

•H 1—

co PQ o

Ph COd d cu •H bOd d d

<U

X

d CJ d X d w

PQ

4-1

4-1

d

co 0)

CJ PC H 4-4o • xi 4-1 HX

cu

w

d3 X bO 4-1 •H •H

Pm *4> >4) o

35

bOd

•HsoX

cn

cuo d0) • u d d cu

<U bO > d

•H

d

(fl

D -C

du3

Pn

CJ

d

x

•H

W

d Ml

d <U

d

•H

d cu <J d PC 3

XJ PQ >4-1

4)

<Uad

4-> CO o

Ml ••• o CU •H > Pm H Xw M 4-1 c • O 4-1 0 d

i".

d

d

w o d

LL a) •H o d 4J •H 3 •H 4J bO CO CJ i 'H o CU Pm CL C/3

COd

(UbOdd

j=uXw

4-1 , d Mi

cu c X (UE

U-l 4-1 o dd

4-1 CL H s X o

Cl] cjd

ai

CJ Ml r. d0) QJ > d •H 3 Q

bC •M c

Cm

33

Description

of

test

burner

showing

location

of

burner

for

simulated

cool-down

of

forced

air

furnace.
45

KBtu/h

35

KBtu/h

35

KBtu/h

80

KBtu/h

120

KBtu/h

Average

Room

Room

Wall

Central

Central

80

KBtu/h

value

heater

heater

furnace

furnace

furnace

Boiler

(ail

data)

w EpHB GO

ee

ft 6D

©

©

© 6

19 II II • X IX IX “— i “ • \

1?w 5H

CD ^

g. CD o> (0 w O)

—j— • 4 • 4 H • 2 - 4 2 ® CO o

4^ CO

k.

© -M C rn

a) e • 3 o • % 3 4 ®

»'

CD

C£ C ^ o > o § 4 • • o 7 o• go 44 ° o

X> o

a>

— 4

CO

Li <0 c H 3 *-

a

A |i</) 4 4 4 4 m m a _ * • • • i *

<0 4-o

(D• O• *• 1- O . cd O W c o> 3

.Q

<DO

CD 2 C

CD CD 3 C « 35

(0 3 o_ W o c 7 * i o 0 l « o a oo

4=*

_

(0 (0 1 §

.E o

0) Z 0 0

S” 1- \

4-» © \l_ CO

GO

a>cl.3

13

O)

_

r CD 1 

3 <2

O)

(0(0©

a>o

(0 5 | goi a

!?W O

4-1W

l!w </5* r ^ < CQ O a a a O <D <D a. a a E E E

<0 <0 a o a<

>>

CD

S-

<uc

a»o

S-QJCL

CDC -0 •P- Ql S- i. d :

(/>w

©

C <uE E 4- til O

U) •o fl o > _c

4-> f

Cl)

C E

cu c <uo c

co

v

p : 3 W

CD VI CU c

34
(Upper

figure)

35

Figure

9.

Average

off-period

energy

loss

ratios

for

three

test

methods

with

data

grouped

by

input

rate
NOTES:

Figure

C^\ C^\ CT\

f—S1 V

/—

r~J V

f*—1

1 7^

( 1 )

( 2 )

pr\

i— HiS

(3) (4) (5)

(1) Using Furnace Burner to heat-up to steady-state conditions, heat exchanger open

and diverter open for heat-up (left) and cool-down (right).

(2) Same heat-up condition as in (1) heat exchanger exit blocked on cool-down using

test burner to reproduce the normal cool-down temperatures. Test burner located

toward front of diverter compartment.

(3) Same heat up as in (1) and (2) ; cool-down with heat exchanger exit blocked with

test burner toward rear of diverter section.

(4) Using test burner to obtain steady-state condition for heat-up. Heat exchange

exit blocked on cool-down.

(5) Same heat-up conditions as (4) - but with heat exchanger exit open on cool-down.

10. Various test conditions used to heat-up for normal and for the simulated

cool down testing of the 80K Btu/h warm air furnace.

36
APPENDIX A

Guidelines for Measuring Off-Period Mass Flow Using

the Tracer Gas Method

These guidelines are based on tests performed at NBS. Reference to the equipment

shown in figure A-l and techniques used in these tests are made to augment the

guidelines

A. Introducing the Tracer Gas

Tracer gas may be a single gas or a mixture of gases. The tracer gas used in

this study was a mixture of carbon monoxide (CO) diluted with Nitrogen.

Carbon monoxide was chosen as a tracer gas because its molecular weight (of 28)

is close to that of air (mole weight of 29). Also, the instrumentation used

in its measurement is generally used by equipment manufacturers and testing

laboratories for combustion testing. The injection rate of tracer gas should

be as low as practical but sufficient to result in a measurable reading on

the analyzer used to measure the diluted tracer gas. The injection of tracer

gas should be at the draft relief opening. Either gas wet test or dry meter

(diagphragm type) can be used when the flow rate is at least 0.5 cfh. When

operating at flow rates of less than 2 cfh, it is best to use the bubble meter.

This is simply a glass tube which has a scale etched on the glass: the type

used had two scale marks which were approximately 10 in. apart. The meter

capacity was 25 cc. The tube shown in Fig. A-2 is available at 25, 50 and

100 ml capacities. The bubble meter Fig. A-2 is used as follows. Adjust

the flow to some low rate. A flow meter will be useful to make a rough

adjustment in the initial flow rate. A soap solution is first placed into

the lower part of the tube where a reservoir of soap solution is held at the

bottom in a syringe attached to this tube at the lower end. The tube is

attached to a ring stand with the stand held securely in place. The upper end

of the tube is connected to the injection manifold using flexible tubing.

Tracer gas is introduced into the side arm of the bubble meter tube. The

soap solution level is raised up to the level of the side arm using the syringe,

to cause a film (bubble) to form and flow upward. The time needed for the film

to travel between marks A and B see Fig. A-2 and the known volume between those

marks is used to compute the flow rate (cc/s or f t3/h) . Larger volume tubes

should be used to minimize time measurement errors

B. Sampling the Diluted Tracer Gas

A diluted tracer gas sample representative of the flow stream is taken from the

stack when measuring Mg^QFF* Sampling tubes made of 1/4 inch (6 mm) OD stainless

steel or copper tubing with one end closed and having several equally spaced

holes in the tubing wall were used. Sampling rate will be determined by the

analyzer requirements. The sampling rate in these tests was 4 to 6 cfh (31 to

47 ml/ s)

In measuring Ls,0FF it is necessary to know the sampling delay time. This i the time it takes the tracer gas sample to move through the sampling train t the analyzer sensor and result in a meter response. Sampling delay time is

determined as follows:

1. With the sampling flow rate adjusted and pulling room air through the

meter the background reading is read.

2. With the heater operating introduce tracer gas at the draft relist

opening as described above.

37
3. Position the sample probe in the stack and immediately begin measuring

elapsed time until the meter begins to respond. This elapsed time, or sample delay time must be taken into account whenever starting time for

sampling is specified.

C. Measuring the Diluted Tracer Gas

A non-dispersive type infrared analyzer was used in these tests to measure

the amount of carbon monoxide in the sample. The instrument used in these

tests was a dual range unit with 0-100 ppm and 0-500 ppm calibration scales.

38
TRACER

GAS

TO

INJECTION

PROBE

LUQoU <Qin

I-<

ui

3:

a

</s * <

£0O “ o2tt kwt 15<

tt

UI trt 2<>

39

Fig.

A-l

Equipment

used

for

tracer

gas

measurements
APPENDIX B

Computer Calculation Procedure

Appendix B contains four figures illustrating the method of

analysis used to obtain the Off-loss results from the data

obtained from tests performed for this project. During the

test program, many changes were made in the formats used so the illustrations are of the last method used.

Figure 1 shows a data sheet that may be used to manually

record data during tests with hand entered data of an actual

test.

Figure 2 is an example of the data from Figure 1 as entered

into a data file (actually an element or subdivision of a

file) in the computer. This data entry was made using an interactive data terminal and the computer used was the main

NBS computer. The computer program was written to read data

from an input element. The input format is described in the

comments at the start of the program listed in Figure 4.

Figure 3 is the output results of running the computer

program to analize the data in the element shown in Figure 2.

It was the results of such computer runs that were used to

develop the Tables of this report.

Figure 4 is a listing of the Fortran program developed to

analize the test data of this project. The program uses no subroutines. The comments of the report are self explanatory

and the calculations are straightforward. Modifications of

the program may have to be made when employing it on a

different computer, particularly the use of the free form

format of the READ statments which are allowed on the NBS

computer and which allow numeric entry in either real or integer form.

40
Figure B-l Data Sheet

Test H Date Unit tested Xvxx I'Ll ^ — —— 7—

Conditions £ Jvo'l c (:

^ o

u *—

Gas used if sec./cu.ft. Calorimeter /PH Etu/cu.ft.

Gas pres. *4. P in.H20, Gas temp. 7 / g

Room ambient 7. V u Baro. pres. /pp 3

f£02 Flue 10 , Stack fe> *t

Tracer Gas f? , flow 1JT_ cc / /r 0 sec., temp. 7 /

Tim° Tracer ppm. Stack temp

0-1 /Fi.?

1-2 lc 0 II ?. L 2-3 b r *yr 1 3-4 ip if, <F~

4-5 > r ?/. 0

5-6 © 6-7 <? r 63.'

7-8 CV3

8-9 n.A

9-10 t^o <B=t i

10-11 fO T 43, ^ 11-12 ,,0 44 . *> 12-13 ttr -4L,<6

13-14 t UD 4/.l

14-15 1 3 0 1-? £

1 5-1

6" .»Jf _ if.o

16-17 / f

?& f

I'

7—18 / ro JMlfc

1 8-1l <0 ° 34 4

19-20 1 t?S 34.1

20-21

21-22

22-23

23-24

24-25

41
I

FURNACE

122 K

BTUH

co co-r-cMOOAOvoACMvo<r- G3CMO'>AAvoA'^-a'i

r- a a cr^vor^-'sO'^-f-c^-CNj .r-AAVOOO<T»QT-CMAA:sttr-r-r'-C^-C'-C~-OOOOCOOOOOCO S

r-- r— ^ a omt\ cm o ^j- O" CM A ' VO *— A i A AVO VO '

C?

r- cd oo to r- k'i k

LA "M" <— AVO AVO

m- cnvo c\j r a a r- c\j o- cn cn MA>th(OiM(MMr 00 a) <vr r-oihC'iiAAr-^-uxMcr^ cm o cr> oo vo a a

OIOCTiVO A^KMOOJCVIr- -r- -r- •«- iCVI TCh

CM

^OK'.^t-CO COhi-tOCMO AA A WM-AM-tO X)tAC\jM-(\JM-T-COr-t- OD^Ch^-hOlO

A A O AVO 00 >— AAA A »— A-vJ-VOr-CnOCMA T-^r-r-(MWWW(M AAAAAA^^^

PQ

iHHo

ooo^ooc'j<-cniAAV)0]cnm^CMAcrir- aco

ACNJCO AM-r-r- ooco AAVO Kt-OOCMVOACO-vJ- A-^-^Ar-A^tCMT-OCr. 00 M^-AAM- ACMCM

AAACMCMCMW(M(\ICMr-r- r-^t-r-T-^T-'cA 00 CM 00 00 O O A C~- VO VO LT \ C'-CMVO-^CM-r-AVO ^ vQ M’K\A(T' 0'0 AVO O VO CM CQVOOMQCOVO'^tA Wp^Or-AM-M-ACMCVT-r- 0000 0''CTiOMTi

&

A

3

oooooooooooo ooooooo

o

5SAOAOAOA OAVOVOA-AA 00 o

&cr>

A I AO AOOAQOOA O '— t- CM A A AVO VO m

T- CMA'vTAVOACDCOO CM AM-ALOhCOa.O COo

aI—

CM O C— VO CM CM O 00 VO VO CM x-OOOOOA.vO Ar-M-CMT-ACDVOAM'vt'

A-r- AOO^-AOVOCMM-M-^-M-M-KW^.AAK.A i-^-O.r-hLOVOAA pH

A^ O^ A _ qaoaoc aoooaoq O A O A O A O O *— •«— CM A. A AVO CO PI 5 A A VO VO C C 00 00 ©ipsi |

o

42

Figure

B-2

Input

Data

Figure

B-3

Output

Results
Figure B-4 Computer Program in Fortran

* HTRS*FUR?.QOFF IS A PROGRAM TO TAKE INPUT DATA PROM A TRACER-

* GAS TEST, CALCULATE THE FLUE GAS MASS FLOW (MLOS) AND THE

* HEAT LOSS (QLOS) FOR EACH INCREMENT OF TIME, THEN OUTPUT

* THE RESULTS AND THE TOTAL LOSSES TO THE TERMINAL (LU#6).

* WITH THIS PROGRAM, THE INDIVIDUAL DATA POINTS MUST BE TAKEN

* ONE MINUTE APART AND UP TO 60 DATA POINTS MAY BE ENTERED.

* The first two input lines are the title and test conditions..

* The third input line selects the input of CONC to either

* be -£C02 (IC0NC=1) or scale readings from the meter recorder

* which have to be converted to ^C02 (IC0NC=0). It also selects

* the flue gas temperature readings to be in Deg.F (ITEKP=1) or

* in Deg.C (ITM?=0).

* The fourth line inputs the assumed outside air temperature,

* (TOA), the input rating of the unit tested (QIN in Btuh),

* and time on (TON in minutes) of the average heating cycle.

* The fifth line inputs the input concentration of the tracer

* gas (CONCI in PPM), the tracer gas flow rate (VTTT in cc/min.),

* the room temperature (TROOM, C or F), and barometric

* pressure (BARP in In.Hg. or Mb).

* The input of BARP is optional, if 0.0 is entered, standard

* condition is assumed.

* The remaining input lines (up to 60 lines) each contain

* two values, CONCI in ^ and TS in degrees.

* Either spaces or commas may be used to separate data entries.

** RAW 7-31 -83

* CHARACTER*6 LAB(12)

DIMENSION CONC ( 60) , TS( 60) , 0FFLS( 60) , FL0W( 60)

DIMENSION FL0(60) ,0FFLSS(60) *

BAR?=0.0

* * »xxxx* » input data ******* WRITE(6,100)

100 FORMAT (5X, ’INPUT DATA FILE — ©ADD FILE. ELEMENT’ /)

READ (5, 200) (LAB(K) ,K=1 , 1 2)

WRITE(6,201)LAB

READ(5,200) (LAB(K) ,K=1 ,12)

WRITE(6,202)LAB

200 FORMAT(12A6)

201 FORMAT ( /l X, 1 2A6

202 FORMAT ( 3X, 1 2A6

READ ( 5

, * , ERR=999) ICONC , ITEM?

READ(5,*,FRR=999) TOA, QIN, TON

READ(5,*,ERR=999) CONCI . VTTT , TROOM , BARP

READ(5,*,FRR=999,END=1 1 )(C0NC(J),TS(J),J=1 ,60)

1 1 NPTS=J-1 * < )m x x x x

Convert units « *** « *« IF( TROOM . LT . 40 . ) TR00M=1 . 8*TR00M+32

IF(BARP . LT . 1 0. )BARP=1 01 3 • 3

IF ( BARP. LT. 500. )BARP=BARP*33.867 *

IF(ICQNC.EQ.I) GO TO 10

43
>

DO 10 J=1 , NPTS

CONC ( J } =4 . 60484*C0NC f J ) + . 1 481 1 1 F-5*C0NC ( J ) **2

*+ . 395287E-4*C0NC (J)**3

1 0 CONTINUE

IFdTEMP.EQ.I ) 00 TO 20

DO 20 J=1 ,NPTS

TS(J)=1 .8*TS(J)+32.

20 CONTINUE

* **** hkx 3et initial values * *****

0FFL=0.0

FLOS=0.0

OFFLI=0.0

* ******** Calculate results ******* DO 30 J=1 ,NPTS

RATIO= ( CONCI -CONC ( J) ) /CONC ( J)

FLOW ( J ) =0 . 01 *VTTT*RATI0*BARP/60960.

FLOS=FLOS+FLOW ( J

EI/y J)= FLOS

OFFLSS ( J ) =0 . 24*FL0W( J ) * ( TS ( J )-TROOM)

OFFL=OFFL+OFFLSS ( J

0FFLS(J)=0FFL

OFFLI=OFFLI+0 . 24*FLOW ( J ) * ( 70. -TOA

30 CONTINUE

* ******** output results to terminal * ** * *** WRITE(6, 1 50)

VRITE(6,160) (J,C0NC(J),TS(J),FL0W(J),FL0(J),

*OFFLSS( J) ,0FFLS(J) , J=1 ,NPTS)

WRITE(6,180) OFFL,OFFLI

31 GO TO 990

*150 FORMAT ( 20X ,

’ TRACER GAS MEASURMENTS ' , /,3X, 'TIME'

,3X, ’CONC* , 5X, 'TEMP* ,7X, ’M' ,6X, 'MLOS' ,7X, 'Q' ,6X, 'QLOS'

160 F0mT(3X,I3,3X,F6.1,3X,F6.1,3X,F6.3,3X,F6.2,3X.F6.2,3X,F6.l)

180 FORMAT (/5X, 'QSOFF (BTU) = 'F6.0, 10X, 'QIOFF (BTU) = ’F6.0,/)

999 WRITE(6,203)

203 FORMAT (//IX, ****** BAD INPUT FILE, CORRECT AND RERUN ******)

990 STOP

END

END OF FILE

->

44
Appendix C

Example of computer output of tracer gas test results

for the 45K Btu/k room heater for normal cool-down

and simulated cool-down test methods. Test results

for no damper and for three types of thermally activated

vent dampers are presented. See page 10 for a description

of test dampers.

45
Max i mum Input? No rma

R o o m He a t e r? 45KBtuh? Damper A ? c o o 1 d o uj n TRACER GAS MEASUREMENTS

T I ME CONIC TEMP M Ml.,.0S Q QLOS

1 45.0 “• O ‘Z[ 3. 449 3 . 45 139.45 1 39 .

85 .

204 .

1 . 826 5. 27 59 . 07 1 98 .

o 155.0 177.6 1 „ 00

/.t *7.* pj 25. 90 224 .

4 2 1

. 0 .1 58. 5 . 739 7

0

3 5.73 240.

5 235 „ 0 1 5 1 .

. 660 7.67 12.92 253. 1 6 255 . O 147.2 . 608 y m .d. 1 1 . 30 264.4

7 275 .

143.8 . 564 8.85 10.02 274.4

pt 280 .

141.1 . 554 9 . 40 9. 48 283 . 9

9 3 1 0 .

138. 4 . 500 9 . 90 8 . 24 292. .1. 10 320 .

136.4 . 485 1. 39 7.75 299 .

1335 .1 34 .. 463 1 0 . 85 7. 16 307 .

12 345.

132. 4 . 450 1 1 . 30 6 . 76 313.8

13 365. 0 131.

. 425 11.72 6 . 24 320. 0

.1.4 400 .129. 4 . 388 12 . 1 1 5.54 325 .

15 405 .

1 27 .

88.8 12. 49 5 . 34 330 .

16 4 1 0 .1 27 .. 378 12.87 5 . 20 336. 1

1 7 420.

1 25 .. 369 13. 24 4 . 96 34 3. . 1 18 450.

1 24 .

. 345 13.59 4 . 54 345.6

19 460 .

1 23 .. 337 13.92 4 . 37 350 .

20 465.

123. 1 O *“* 1 4 . 26 4 . 26 354.2

Room Heater? 45KB tub? Damper A? Maximum Input? Simulated cooldown

TRACER GAS MEASUREMENTS

IME CONC TEMP M MLOS Q QLOS

1 1 35

0 195. 1 1 . 149 1 . 15 34 .61 34 .

145.0 192. 2 1 . 070 2 . 22 31 . 49 66 . 1

*7* 205 „ 0 171.

. 757 2 . 98 18.57 84.7

4 245 .

159. 3 . 633 3. 61 13. 63 98 . 3

5 270 .

149. 7 . 575 4. 18 1 1 . 05 1 09 . 3

6 285 .

151.5 . 544 4.73 1 0 . 70 1 20 . 0

7 300 .142.0 .517 5 . 25 O C/O 129. 0

o 3 3. 0 .

143. 2 . 500 5.75 8 . 84 1 37 .

9 330

0 1 38 .. 470 6.22 7.72 145.

10 350 . 0 1 35 .

. 443 6 . 66 7 . 0152. 6

3 3 365 . 0 1 33 .

. 425 7 . 08 6 . 50 159. 1 12 375.0 132.6 .414 7 . 50 6. 26 165.4

1395 . 0 3 30 .

. 393 7 . 89 5.72 171.

14 4 3. 0 .

1 28 . 1 .. 378 8 . 27 5.31 176.4

.1.5 420.

3 27 . 2 . 369 8 . 64 5.11 3. 8 .3. . 5

.1. 6 435

3. 25 .

„ 356 8 . 99 4 .3. 1 86 .

17 440 ..1 25 . 4 . 352 9 „ 35 4.72 191.

.1

450.121 .

. 345 9 . 69 4 . 29 1. 95 .

3.9 465.0 126.

.888 1

. 02 4 . 58 1 99 u 9

20 475.0 .1 2

.

. 326 1. 35 4 . 05 203 .

46
loom He ater, 4SKBtuh, No dampe r 7 Maximum Input? No r m a 1 c 0 0

TRACER GAS MEASUREMENTc* TIME CONC TEMP M MLOS Q QLOS

1 SO. 0 170.2 4.549 4.55 109.21 109. 2

•7 90.

138. 7 4.043 O CjC/ 66 . 51 175. 7

3 1 00 . 0 119.8 3.639 12.23 43.35 219. 1 4 1 90 . 0 1 02 .

1.915 14. 15 1 4 . 95 234 .

5 200 .

99 . 7 1.819 15.96 12. 87 246 .

6 210.

98.1 . 732 17.70 11.81 258 . 7

7 215.0 98 . 2 1 . 692 1 9 . 39 1 1 . 39 270. 1 8 220.

97.7 1 . 654 21.04 10.91 28 1 .

9 225.0 98 .

1.617 22 . 66 1 0 . 88 291 .

10 230.

98

6 1 . 582 24.24 10.78 .302. 7

1 1 235 .

98. 1 1 . 548 25.79 10.35 313.0

12 238 . 0 97 .1 . 528 27 . 32 9 . 82 822

8

13 240.0 97.2 1.516 00 00 9. 81 332. 6

14 243. 0 95.1 . 497 30. 33 9. 17 341.8

15 245.0 95.4 1 . 485 31.81 8 . 97 350 .

16 248. 0 95 .

1 . 467 • -j O 2'!-{ 8 . 73 359 . 5

17 250.

95 . 4 1 . 455 34.74 8 . 79 368. 3

IS 255.0 95 .

1 . 427 36 . 18 . 49 376.8

19 258.

94. 1 1 .410 37.57 8 . 09 384.9

20 260 . 0 93 . 6 1 . 399 38.97 7.84 392 . 7

om He a t e r ? 4 5KBtu h 7 No damper ? Maximum Input? S imu 1 a ted

TRACER GAS MEASUREMENTc* IME CONC TEMP M MLOS Q QLOS

1 1 50 . 0 147.7 2.426 2.43 45.37 45. 4

160.0 1 36 .

2 . 274 4.70 36. 44 81.8

O 1 70 .

1 3 1 .

2 . 1 40 6. 84 31.90 113. 7

4 205 .

112. 1 1 . 775 8. 61 1 8 . 02 131 .

5 235.

108. 7 1 . 548 10.36 14.44 146.

6 300 . 0 96. 4 1.212 11.37 7.75 153.

7 308 . 0 94.8 1 . 183 1 2 . 56 7. 09 161 .

8 312.

96 .1 . 1 66 13.72 7.55 1 68 . 6

9 315.

96. 1 1 . 155 14.88 7.28 175. 9

10 318. 0 95 .3 . 144 16.02 7. 07 1 82. 9

1 1 320.0 95 .

1.137 17.16 7.02 189.9

12 322.0 95 . 2 1 . 1 30 18.29 6.88 196.8

13 325. 0 96. 1 1.119 19.41 7. 06 203 • 9

14 328 .

94.5 1.109 20 . 5

6 . 56 210.

15 320 .

93 . 4 3.337 2 1 . 65 6. 43 216.9

1 6 335 .

93 . 7 1 . 086 22. 74 6.24 223. 1 17 340 .

93.0 1 . 070 23. 81 5. 96 .

' 18 345.

9 ~ P, 3 . 054 24.86 5. 83 234 .

1

350 .

93 _ 0 3 . 039 25 . 90 5. 79 240. 7

20 355 .

92 .

1 . 024 26 . 92 5.53 246. 2

d o u) n

ri o l down

47
R 0 ITl H a ter-j 4 5KB tuhi Dam pe r B 7 Ma;: ; i m u m In put 7 Normal C 0 0 1

TRAC ER GAS MEASUREMENTS

I ME CONO TEMP M MLOS Q QLOS

1 20 . 0 211.

4 . 09

4 . 09 139.44 1 39 .

c!. 60.198. 1 1 . 364 5. 45 42

00 1 8 1 .

© 150.

179.2 . 545 6 . 00 1 4 . 32 1 95

8

4 1 750 161.

. 467 6 . 47 1 0 . 24 206 .

5 1 85

0 152. 1 . 442 6 . 9

8.73 214.7

Lx 1 95

0 146.3 . 419 7. 33 7 . 70 222. 4

7 205 .141.4 OCVQ 7 . 73 6 . 86 229. 3

8 215.1 37 .. 380 8 . 1 1 6 . 18 235 . 5

y 225 .

1 34 .. 364 8.47 5. 64 24 1 . 1 10 232 .

131.

. 353 © ©© 5 . 22 246.3

1

240 .

1 '"•‘•‘ft . P . 34 1 9.17 4 . 83 25 1 .

12 248., 0 1 27 .. 330 9. 49 4.53 255 .

.13 255 .

1 25

2 . 32 1 9. 82 4.27 260.

14 260 .

1 23 .

. 3 11

. 14 . 04 264.0

15 268. 0 1 22 . 0 . 305 10.44 © ©© 267. 8

16 272 .1 20 .

. 30 1 10.74 3

68 27 1 .

17 278 .

1 1 9 .. 294 1 1 . 03 3 . 5

275.0

i p 282 .

118.. 290 1 1 . 32 3. 40 278. 4

1

288 .117.5 . 284 1 1 . 60 3 . 25 28 1 .

20 293.0 1 1 6 .

. 279 1 1 . 88 3. 12 284 .

Room Heater 7 4 SKBtuhi Dam par B 7 Ma:= si mum Input? Simulate d c

TRAC ER GAS MEASUREMENTS

T I ME CONC TEMP M MLOS Q QLOS

1 350 1 85 . 7 2. 338 2. 34 64.31 64.3

900 195.6 „ 909 3 . 25 27. 36 92 . 2

© 3 60. 0 3 77 „ 6 .513 3. 76 13.1

3 05 . 4

4 1 90

0 164. 1 . 430 4.19 9 . 70 115.1

nr 2 1

. 0 154.4 . 389 4 . 58 7 . 87 1 22 . 9

6 222.145.2 . 368 4 . 95 6.63 129. 6

7 230 „ 0 140., 4 . 356 5 . 30 5 . 99 135.5

8 238 „ 0 3 36. 6 . 344 5 . 65 5.47 141.

9 243 .

134.2 . 337 5. 98 5.17 1 46 .

10 253 „ 0 1 30 .

©©© 6 . 3

4 . 66 150.

1 1 260. 0 128. 3 „ 3 3.

6. 62 4 . 39 155. 2

1

268., 0 1 26 .

. 305 6 . 93 4. 14 1 59 . 4

1272. 0 3. 25 . 3. . 30

7 . 23 3. 96 163. 3

1 4 275 .

123. 8 „ 297 7. 52 © O; -J 167.2

15 278 .

1 23 .

. 294 7.82 3.75 170. 9

1

282.3. 22 . 4 ., 290 8 . 1 1 3. 63 3. 74 .

17 285 « 0 3 23 .

. 287 8 . 39 3. 53 3 78.3

18 290 .

1 20 „ 4 . 282 8. 68 3. 40 .181 .

1 9 295 .

118.

. 277 8 . 95 184.7

20 308 „ 0 116.1 . 266 9 . 22 187.6

:mjn

48
om He ater, 45KBtuh. Damper- C, Ma:- i m u m Input, Normal c o o 1 d o u) n

TRAC ER GAS MEASUREMENTS

'I ME CONG TEMP M MLOS Q QLGS

1 62.0 197.2 . 869 3.87 118. 33 1 1 8 „ 3

9 95

0 163. 2 2. 525 6 . 39 56 . 6

3 74 .

3 135 . 0 140.7 1 . 777 8.17 30 . 24 205 .

4 1 SO . 0 123.8 1 . 332 9 . 50 1 7 . 27 222. 4

5 205 . 0 .1 18.9 1 . 1 70 10.67 3 3 . 80 236. 2

6 230

0 116.1 . 043 11.71 1 1 . 62 247.9

7 240. 0 3. 3. 4 .

. 999 12.71 10. 79 258. 7

Q 250

0 113.2 . 959 13. 67 9. 99 268.6

9 265.0 112.3 . 905 1 4 . 58 9 . 22 277.9

1 0 275.0 111.2 . 872 15. 45 8 . 66 286 .. 5

1 1 285 .

1 09 .

. 841 6 . 29 8 . 07 294 .

12 295 . 0 1 09 .

. 8 117.10 7 . 65 302. 2

13 303. 0 107.8 . 791 1 7 . 90 7.21 309.5

14 312. 0 107. 1 . 768 18.66 6 . 87 3 1 6 .

15 317.

3. 06 . 2 „ 756 19. 42 6. 60 322. 9

1 6 325 . 0 3. 05 .

. 738 20 . 3 6 6 . 37 329 . 3

17 330.105.3 . 726 20 . 88 6.18 335 . 5

18 335 . 0 104.7 . 7 1

2 3. . 60 6 . 00 34 3 .

19 345.0 104 .

. 695 22 . 29 5.70 347. 2

20 350.103.6 . 685 22 » 98 5.56 352 . 8

Room Heater, 45KBtuh, Damper C, Maximum Input, Simulated cooldown

TRAC

TIME

ER GAS

CONG

MEASUREMENT:

TEMP M MLOS Q QLGS

1 105.163.6 2.284 2 . 28 5 1 . 30 51 .

[c'l 3. 30 .

156.3 . 845 4.13 38 . 09 89 . 4

145.0 147. 4 1 . 654 5 . 78 30 . 72 120 . 1 4 3. 85 .

3 30 .

3. . 296 7 . 08 3. 8 . 75 1 38 .

CT 220 . 0 3 19.5 1 . 090 8 . 1

1 2 . 94 3 51.

6 230 .

117.

1 . 043 9

211.84 163. 6

y 245. 0 1 3. 5 .

. 979 10.1 9 10. 57 3.74 .

8 255 . 0 1 12. 5 . 940 3 1.18 9 . 58 1 83. 8

9 265 .111.6 . 905 12.04 9.02 192.8

3 0 275.0 110.7 . 872 12.93 8.51 20 3 .

3 1 282.3 1 0 . 7 . 850 3 3. 76 8 . 30 20r>

. 6

12 295 .1 08 .. 8 1 3 14.57 7.54 217.2

3. 3 308 „ 0 107.2 . 778 15.35 6 . 96 224 . 3 14 315.

106.7 . 76 1 16.11 6.70 230.8

1 5 3203 060 . 749 1 6 . 86 6.47 237 . 3

3 6 325 .1 04 . 5 . 738 3 7 . 60 6 . 1 2 243. 4

17 330 .104.4 . 726 18.32 5 . 99 249. 4

18 3353 04 .

. 7 119.04 5.87 # ^

19 340. 0 104.

. 705 19. 74 5. 75 26 1 .

20 345.0 1 03 .. 695 20. 44 5.61 266 .

49
om He ater-v 45KB tu h i No damper 7 R& d u c © d Input v No rmal cooo ci 1 d o u) n

TRAC

I ME

ER IjA':.' CONC

MEASUREMENT

TEMP M MLOS Q QLOS

.1 g*5 „ o 1 4 1 .

A . 284. 28 74. 12 74. 1

1 00 a 0 117.7 3. 639 7 . 92 42. 25 116.

o 1 55

0 1 05 .2. 347 1 0 . 27 20 „ 36 136. 7

4 1 95

0 9© 4I 2 1 . 866 1. 11

. 96 149. 7

5 197.

97 .1 . 847 1 3 . 98 12. 43 162. 1 200 .

96 .1 . 819 1 5 . 80 12 . 01 174.1

7 202.96 . 6 1 . 80

1 7 . 60 1 1 . 8

185.

8 203. 0 97.0 1 . 792 1 9 . 39 J 1 . 9

197.8

9 205 . 0 96 .

1 775 2 1.17 1 1 . 48 209 .

10 207 .95 .

1 . 757 2

. 92! 1 1 . 22 220 .

1 1 208. 0 95 . 9 3 . 749 24. 67 11.17 231 .

1 2 2

0 . 0 95 „ 2 1 . 732 26 . 40 1 0. 76 242.5

13 2 1

. 0 95.

1.71 6 28. 12 1

. 58 253.0

1 4 2 1 3 .94 .1 . 708 29 . 83 10. 46 263.

15 2

5 . 0 94. .1. 1 . 692 3 1 . 52 1 0 . 07 273.6

1

2 1 6 . 0 94.3 1 . 684 33 „ 210.1 0 283. 7

1 7 2 17.0 93 a V 1 . 676 34 . 88 9 . 9

293. 6

1 0 2 1 8 .

94 . 1 1 . 669 36 . 55 9 M 93 303.

:i. 9 2 1 9 .

93 .. 7 1 . 661 38 . 2

9 . 74 3 1 3 .

20 220 .93 h 2 .1 . 654 39 . 86 9.48 322. 7

om He a ter? 4 5KB t u h v No damps r

Redu cad Top u7 S i m u 1 a t e d

TRAC

IME

:ER GAS

CONC

MEASUREMENT

TEMP M MLOS Q QLOS

1 145.0 127.

2 . 509 2 . 51 34.77 34 .

160.

J 1 3 .2.274 4 . 78 24 . 34 59. 1 9 1 80

0 102.7 2 . 02

6 . 80 1 6 . 22 75.

4 295 .

1 02 .

1 . 233 8.04 9 . 95 85 .

5 305 . 0 94 . 1 1 . 193 9. 23 7 . 3 0 92 . 4

/_ 3 1 5

0 96.4 1 . 1 55 1 0 . 38 7.52 99 .

7 320 .

96.8 1 . 1 37 1 1 . 52 7 . 50 107. 4 o 330

0 97.0 1 . 1 02 12 . 62 7. 32 13 4.7

9 335 .

95. 7 1 . 086 1 3 . 7

6 . 88 121.6

10 345.0 94. 6 1 . 054 14.76 6 . 41 3 28. 0

1

350 .94 „ 5 1 . 039 1 5 . 80 6 . 27 134.3

1.360 „ 0 94 .

1 „ 0

0 1 6 . 8

6.06 140.4

1365 .

93 u 9 . 996 1 7 . 85 . 89 146. 2

14 370 .

94. 1 . 983 1 8 . 79 5 . 85 152. 1 1 5 372. 0 93 . 4 . 978 •0 •Nj 5 . 65 157.7

16 375.0 93 .

. 970 20.74 5.73 163.5

17 377

92. 8 . 965 2 1 . 70 5 . 45 3 68.9

J 8 379. 0 92. 7 . 960 22 . 66 5 . 38 174.

1

380 - 0 92 .

„ 957 23. 62 5.41 179.7

20 385 .

92 . 5 . 945 24. 57 5 . 25 1 85 .

50

o 1 d o uj n
Room Heater* 45KBtuh* Damper A* Reduced Input* Normal c o o 1 d o uj n

TRA1CER gas MEASUREMENTS

T I ME CONG TEMP M MLOS Q QLOS

1 90 .

205 . 3 1 . 724 1 . 72 55.71 55.

7 1 50 .

171.1 034 2. 76 25. 07 80

o 235 .

1 50 .. 660 3. 42 12.66 93.4

4 305 .137. 1 . 509 3. 93 8. .1 1 1 0 1 .

trj 335

1 3, 5 . 463 4 . 39 6 . 76 108. 3

6 345. 0 1 28 . 8 . 450 4 „ 84 6.27 114.

7 360.

1. 27 . 0 . 431 5.27 5.83 1 20 . 4

ft 370 .

1 25 . 8 . 4 1

5 . 69 5.54 126.0

C/ 385 . 0 1 24 .

. 403 6 . 09 5. 24 1 3 1 .

1

3900 1 24 . 3 . 398 6 . 49 5 . 1 2 1 36 . 3

1

395 .123.

„ 393 6 . 88 4 . 99 141.3

12 4 15.0 1 23 .

. 374 7 . 26 4.71 1 46 .

1 3 425. 0 122. 5 . 365 7 . 62 4 „ 54 150.5

14 435 . 0 122.0 . 356 7 . 98 4 . 39 154.9

.1 5 445.0 1 21.5 . 348 C;

^ ft ft 4.25 159. 2

16 450.0 121.

, 345 8.67 4. 18 163. 4

17 455. 0 1 20 . 7 . 349 . 0

4 . 09 1 67 . 5

18 460.120.6 „ 337 9 . 35 4 „ 03 171.5

19 465.1 20 . 2

•”i ft 9 . 68 3.96 175. 5

20 470. 0 .1 1. 8 . 880 1. 0

ft 0Q 179. 3

Room Heater* 45KBtuh* Damper A* Reduced Input* Simulated cooldown

TRAC:ER GAS MEASUREMENTS

TIME CONG TEMP M ML. OS Q QLOS

1 1 60 .1 89 . 1 . 970 . 97 26. 68 26 . 7

Ll! 1 90 .

1 76 .

. 817 1 . 79 1 9 . 96 46.6

o 260 .

153.5 . 597 ft ft 1 1 . 3

58. 0

4 335 .

1 38 . 2 . 463 2.85 7.08 65 .

5 365 .

1 3: 1 .

,. 425 3. 27 5 . 76 70.

6 375 .

1 27.6 .414 3. 68 5.27 76. 1 7 390 .

124.9 . 398 4 . 08 4.81 80.

8 4 1 0 . 0 1 27 .

ft ~j c» 4. 46 4 . 83 85 . 7

9 420. 0 124.3 . 369 4 . 83 4.42 90. 1 10 425 .

1 22 .. 365 5. 19 4.21 94.

1 1 430. 0 1 20 . 7 . 36

5 . 56 4 . 00 C/ft ft 12 435.0 1 22 .

. 356 5.91 4. 06 102.4

13 440.0 123.3 . 352 6 . 26 4.12 106.5

14 445.

1 24.. 2 „ 348 6 . 64.15 1 1 0.

15 450 „ 0 1 24 .. 345 6. 96 4.17 114.8

16 455 .

1. 23 . 4 . 341 7 . 30 4 . 00 118.8

17 460 „ 0 1 23 .

. 337 7 . 63 3. 99 122.

18 465.0 123. 1 a 3-i 7.97 3. 89 126.7

19 470. 0 1 22. 0 . 330 8 . 30 3 . 76 130.5

20 475.

122.5 . 326 8. 62 3.76 1 34.

51
Room Heater v 4 5KBtutu Damper B ? Reduced Input? Normal cooldown

TRACER GAS MEASUREMENTS

I ME CONC TEMP M MLOS Q QL.0S

1 45 .195.3 1 . 876 1 . 88 56.74 56.7

1 60 .1 75 .

. 528 2. 40 13. 42 70.

~» 195- 0 1 55 .

. 433 2.84 8 . 96 79. 1 4 225 .

140.7 . 375 3. 21 6.43 85.6

5 245.0 133.0 . 344 3. 56 5.27 90 .

6 260 .

1 27 .

. 325 o o© 4.54 95 .

7 270 .1 24 .

. 3 14.19 4.11 99 .

o. 285 .

1 20 .. 296 4 . 49 3. 67 103. 1 9 290 .

118.. 291 4.78 3.47 1 06 .

10 295 .117. 3 . 286 5 . 07 3. 30 109. 9

1300 .115.9 . 285.35 3 . 1

113. 1 12 305 .

115.

. 277 5 . 62 3. 04 1 1 6 . 1 13 3 1 0 .

1 14.1 . 272 5 . 90 2. 93 1 19. 0

14 3 1 5 .113.4 . 268 6. 16 2. 84 121.

15 320 .112. 3 . 264 6 . 43 2. 72 124.6

.1 6 325 .

1 1 1 .. 260 6 . 69 2. 64 1 27 .

17 330 .

111.0 . 256 6.94 2.56 1 29 .

IS 335.1 10.. 252 7 . 20 2.50 132. 3

19 340.0 no. 3 . 248 7.44 2. 44 134.7

20 345 .1 1 0 . 1 . 245 7 . 69 2. 40 1 37 . 1

Room Heater? 45KB t u h ? Damper B? Reduced Input? Simulated cooldown

TRACER GAS MEASUREMENTS

I ME CONC TEMP M MLOS Q QLOS

1 75.0 1 87 .1 . 1 26 1.13 31 . 99 32.0

“>

1 65 .178.7 . 5 1.1 . 64 13.43 45.4

o 2 1 0 .

1 57 . 6 . 402 2. 04 O cj 53. 9

4 235 .143.6 . 359 2 . 40 6 . 40 60.

5 250 .

136.6 “i •—i o 2. 74 5. 45 65.8

6 265. 0 .1 30. 6 „ 3 13 . 05 4 . 69 70.5

7 275. 0 1 26 .

. 307 3- 36 4.21 74.7

8 290 .

1 22 .. 293. 65 3. 74 78. 4

9 305 .

119. 8 . 277 3 . 93 3. 36 8 1 .

10 320 .

117.7 . 264 4.19 3 . 06 84 .

1 1 330.

1 15.5 . 256 4.45 2. 84 87.7

12 335 . 0 114.

. 252 4 . 70 2. 72 90 .

13 340 .

113.2 . 248 4.95 2. 61 93. 0

14 345.

.1 1 2 .

. 245 5. 19 2. 53 95 . 6

15 350.

111.7 . 241 5.43 2. 46 98 .

16 355 .

1 1 1 .

©© 5. 67 OO 1 00 .

17 360 .

1 1 0 .

. 234 5.91 2. 34 102. 7

1

362 .110.

. 233 6.14 2 . 32 105. 1 19 367. 0 110.5 . 230 6 . 37 2 . 27 107.3

20 370 u o 109. 8

**> .~i © 6 . 60 2. 21 109. 5

52
o m Ho*ater» 4 5KB t u h i Da. m p a r C » Ra d U C a d Input 7 Normal c 0 o 1 TRACER GAS MEASUREMENTS

I ME CONC TEMP M MLOS Q QLOS

1 1 00 . 0 1 6 1.8 2.512 2.51 56.01 56.

2 1 60 . 0 134. 2 1 . 570 4 . 08 24 . 62 80 .

3 2 1

. 0 1 1 8 .. 9 1.1 96 5. 28 1 4 . 37 95

0

4 255. O 1 09 . 6 . 985 6 . 26 9. 62 104.

5 270 .

1 06 . 3 . 930 7. 19 8 „ 36 1 1 3 . 0

/;, 295 „ 0 105.8 .851 8. 05 7.54 1 20 .

7 3 1 0 . 0 1 05 . 3 . 8 1 0 8 . 86 7 . 07 1 27 . 6

o 3 1 5 . 0 104.4 .797 9 . 65 6 . 79 1 34 .

C; 320. 0 104.4 .785 10. 44 6 . 68 141.0

10 325 . 0 103.6 .773 11.2

6.44 147.5

.1330 .

103.3 .761 1 1 . 97 6 . 28 153.8

12 335. 0 102.7 .750 12 . 72 6 . 09 1 5-9 . 9

13 340.

102.7 .739 13. 46 6 . 00 165.

14 345 .

102.4 .728 14.15 . 85 171.7

.1.5 350 . 0 1 01.7 .7 11 4 . 9

5. 64 177.

16 355 .

102.0 .707 15.61 5. 62 1 83 . 0

17 360 .

101.5 .698 1 6 . 35.45 188. 4

1365.0 .101.1 .688 1.

. 00 5. 32 1 93 .

1 ? 370 .

101.1 .679 17.68 5.25 1 99. 0

20 3750 100.4 .670 1 8 . 35 5. 06 204. 1

om Ha a t a r , 4 Si KB t ij h 7 Da. iti f a r C 7 Ra d u c a d Input, Sim

1 a. t a d c TRACER GAS MEASUREMENTS

I ME CONC TEMP M MLOS Q QLOS

1 1 350 149. 7 1 „ 86 1 1 . 86 36. 19 36 • 2

1 60 . 0 1 36 .1 . 570 3. 43 -?*=; op 6 1 .

1 950 126.9 1 . 288 4.72 1 7 . 98 79.5

4 245

0 115.2 1 . 025 5.74 1 1 . 43 91.0

5 280 .

1 09

2 . 897 6.64 8.72 99 . 7

O 290 . 0 1 040 . 866 7.51 7 . 34 107.0

7 295 .1 02 . 4 p ^ 8 . 36 pp 11 . & 300 .

101 .. 837 9 . 20 6 . 62 120.5

»::/ 305 .

.1 02 .» Oj£. 10. 02 6.73 127.3

10 3 1 0 .

102. 7 „ 8 1

10.83 6 . 62 133. 9

i i 3 1 3 „ 0 1 02 . 9 . 802 1

„ 63 6 . 59 140.5

12 3 1 60 1 02. 7 795 12. 43 6 . 49 147.0

1320 . 0 102.7 „ 785 1 3. 21 6 . 41 153.4

14 322 .102. 4 . 780 13. 99 6 . 30 1 59 . 7

1

325 ..1. 0 .1 .. 773 1 4 . 76 6 . 05 1 65 . 7

.1 6 380 „ O 1 00 „ 8 . 761 15.53 5 . 86 171.6

17 332 .

1 00 . 8 . 756 1 6 . 28 *=; 09 177.4

1

335. 0 1 00 . 8 . 750 1 7 . 03 5. 77 1 83. 2

19 3 4 0

0 1 00 . 6 . 739 17.77 5. 65 188. 8

20 345. 0 1 00 . 8 . 728 1 8 . 50 5 .

0 134.4

d o uj n

o o 1 d o uj n

53
NBS-114A (REV. 2-80

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR 2 REPORT NO.

NBSIR 84-2869

. Performing Organ. Report NoJ 3. Publication Date September 1984

4. TITLE AND SUBTITLE

TEST METHODS FOR THE DIRECT MEASUREMENT OF STACK ENERGY LOSS DURING THE

OFF-PERIOD OF SPACE HEATING EQUIPMENT

5. AUTHOR(S) E _ Kweller

R.A. Wise

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions) 7. Contract/Grant No. national bureau of standards

DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

WASHINGTON, D.C. 20234

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

The Department of Energy

Office of Conservation and

Nenewable Energy

Washington, D.C. 20585

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 bliography or literature survey, mention it here)

Evaluations have been made of a possible alternative to the tracer gas test

method now being used to measure off—period energy loss of space heating

equipment with vent dampers.

This alternative method offers the potential of a direct measurement method

without the need for expensive tracer gas type instrumentation. The method

uses a controlled flow of gas to a small gas fueled burner to simulate normal

flue or stack temperatures previously measured during a cool-down test.

Energy metered though the gas burner during the simulation gives a direct

measurement of the thermal energy losses out of the stack. Results in comparison with the tracer gas method of test were lower for off-period energy loss

meaurements. A trend to better agreement between the two methods was noticeable

for test furnaces with greater fuel input rates. Further development testing

and evaluation will be required before the simulation can be considered as an acceptable alternative test method.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

boilers; fossil fueled heating systems; furnaces; household heating

equipment; part load efficiency; stack energy loss.

13. AVAILABILITY

[x] Unlimited

| | For Official Distribution. Do Not Release to NTIS

Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

[^j Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

65

15. Price

$ 10.00

USCOMM-DC 6043-P80