SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

PROTOCOL 

NITROGEN OXIDES EMISSIONS 

COMPLIANCE TESTING FOR 

NATURAL GAS-FIRED WATER HEATERS 

AND SMALL BOILERS 

MARCH 1995 

(AMENDED JANUARY 1998) 

SOURCE TESTING AND ENGINEERING BRANCH 

APPLIED SCIENCE AND TECHNOLOGY 
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

PROTOCOL 

NITROGEN OXIDES EMISSIONS 

COMPLIANCE TESTING FOR 

NATURAL GAS-FIRED WATER HEATERS 

AND SMALL BOILERS 

MARCH 1995 

(AMENDED JANUARY 1998) 

SOURCE TESTING AND ENGINEERING BRANCH 

APPLIED SCIENCE AND TECHNOLOGY 
TABLE OF CONTENTS

 PAGE 

-iTABLE OF CONTENTS................................................. i 

1.0 OVERVIEW AND APPLICABILITY................................... 1 

2.0 ENVIRONMENTAL CRITERIA....................................... 3 

3.0 DEFINITIONS.................................................. 4 

3.1 INDEPENDENT TESTING LABORATORY........................... 4 

3.2 NATURAL GAS-FIRED WATER HEATER........................... 4 

3.3 NATURAL GAS-FIRED BOILER................................. 4 

3.3.1 HOT WATER HEATING BOILER........................... 4 

3.3.2 HOT WATER SUPPLY BOILER............................ 5 

3.3.3 STEAM HEATING BOILER............................... 5 

3.4 NATURAL GAS-FIRED POOL HEATER............................ 5 

4.0 TEST CONDITIONS.............................................. 6 

4.1 AMBIENT AIR TEMPERATURE.................................. 6 

4.2 SUPPLY WATER TEMPERATURE................................. 6 

4.2.1 STORAGE, INSTANTANEOUS, AND CIRCULATING WATER 

HEATERS........................................... 6

4.2.2 POOL HEATERS....................................... 6 

4.2.3 STEAM AND HOT WATER BOILERS........................ 6 

4.3 SUPPLY WATER PRESSURE.................................... 7 

4.3.1 WATER HEATERS...................................... 7 

4.3.2 POOL HEATERS....................................... 7 

4.3.3 STEAM AND HOT WATER BOILERS........................ 7 

4.4 NATURAL GAS PRESSURE..................................... 7 

4.5 INSTALLATION REQUIREMENTS................................ 7 

5.0 INSTRUMENTATION.............................................. 8 

5.1 PRESSURE MEASUREMENT..................................... 8 

5.2 TEMPERATURE MEASUREMENTS................................. 8 

5.3 BAROMETRIC PRESSURE...................................... 9 

5.4 LIQUID FLOW MEASUREMENTS................................. 9 

5.5 NATURAL GAS FLOW......................................... 9 

5.6 MASS MEASUREMENT......................................... 9 

5.7 TIME..................................................... 9 

5.8 FLUE GAS ANALYSIS....................................... 10 

5.8.1 NOx CONCENTRATION................................. 10 

5.8.2 CO CONCENTRATION.................................. 10 
TABLE OF CONTENTS

 PAGE 

-ii5.8.3 CARBON DIOXIDE OR OXYGEN ANALYSIS................. 10 

5.8.3.1 CO2 CONCENTRATION........................... 10 

5.8.3.2 O2 CONCENTRATION............................ 10 

5.8.4 SAMPLE CONDITIONING SYSTEM........................ 10 

5.8.4.1 Sample Probe................................ 11 

5.8.4.1.1 Integrating Sample Probes............. 11

5.8.4.1.2 Open Ended Sample Probes.............. 11

5.8.4.2 Sample Lines................................ 11 

5.8.4.3 Moisture Removal System..................... 12 

5.8.4.3.1 Permeation-Type Dryers................ 12

5.8.4.3.2 Refrigerated Condenser/Separator...... 12

5.8.4.4 Sample Pump................................. 12 

5.8.4.5 Flow Indicators............................. 12 

5.8.4.6 Pressure Indicators......................... 12 

5.8.4.7 Sample Vent................................. 13 

5.9 NATURAL GAS COMPOSITION................................. 13 

6.0 ANALYTICAL METHODS.......................................... 14 

6.1 START UP................................................ 14 

6.1.1 ANALYZERS......................................... 14 

6.1.2 SAMPLE CONDITIONING SYSTEM........................ 14 

6.2 CALIBRATION AND PERFORMANCE TESTING..................... 14 

6.2.1 ANALYZER CALIBRATION.............................. 14 

6.2.2 SAMPLING SYSTEM BIAS TEST......................... 14 

6.2.3 RESPONSE TIME..................................... 15 

6.2.4 NO2 TO NO CONVERSION EFFICIENCY................... 15 

6.3 ANALYSIS................................................ 16 

6.3.1 SAMPLE POINT...................................... 16 

6.3.1.1 Appliances with Vents Less Than 12 Inch 

Diameter..................................... 16 

6.3.1.2 Appliances With Vents 12 Inch Diameter or 

Greater...................................... 16 

6.3.1.3 Appliances Which Do Not Have Vents........... 17 

6.3.2 SAMPLING PERIOD................................... 18 

6.3.2.1 Integrating Sample Probes................... 18 

6.3.2.2 Sample Traverses............................ 18 
TABLE OF CONTENTS

 PAGE 

-iii6.3.3 DATA RECORDING.................................... 18 

7.0 INSTALLATION................................................ 19 

7.1 STORAGE TANK WATER HEATERS WITH INPUT RATINGS BELOW 

75,000 BTU/HR........................................ 19 

7.1.1 WATER HEATER MOUNTING............................. 19 

7.1.2 WATER SUPPLY...................................... 19 

7.1.3 WATER INLET AND OUTLET CONFIGURATION.............. 19 

7.1.4 FUEL CONSUMPTION.................................. 20 

7.1.5 INTERNAL STORAGE TANK TEMPERATURE MEASUREMENTS.... 20 

7.1.6 AMBIENT TEMPERATURE............................... 21 

7.1.7 INLET AND OUTLET WATER TEMPERATURE MEASUREMENTS... 21 

7.1.8 FLOW CONTROL...................................... 21 

7.1.9 VENT REQUIREMENTS................................. 22 

7.1.10 NATURAL GAS SAMPLE............................... 22 

7.2 STORAGE TANK WATER HEATERS WITH INPUT RATINGS ABOVE 

75,000 BTU PER HOUR..................................... 23 

7.2.1 WATER HEATER MOUNTING............................. 23 

7.2.2 WATER SUPPLY...................................... 23 

7.2.3 WATER INLET AND OUTLET CONNECTIONS................ 23 

7.2.3.1 Storage Tank Water Heaters................... 23 

7.2.3.2 Instantaneous & Circulating Water Heaters.... 24 

7.2.4 FUEL CONSUMPTION.................................. 24 

7.2.5 INTERNAL STORAGE TANK TEMPERATURE MEASUREMENTS.... 24 

7.2.6 AMBIENT TEMPERATURE............................... 25 

7.2.7 INLET AND OUTLET WATER TEMPERATURE MEASUREMENTS... 25 

7.2.7.1 Storage Tank Water Heater.................... 25 

7.2.7.2 Instantaneous and Circulating Water Heaters.. 25 

7.2.8 FLOW CONTROL...................................... 25 

7.2.9 VENT REQUIREMENTS................................. 25 

7.2.9.1 Appliances Equipped With Draft Hoods........ 25 

7.2.9.2 Direct Vent Appliances...................... 26 

7.2.10 NATURAL GAS SAMPLE............................... 26 

7.3 POOL HEATERS............................................ 26 

7.3.1 Pool Heater Mounting.............................. 26 

7.3.2 Water Supply...................................... 26 
TABLE OF CONTENTS

 PAGE 

-iv7.3.3 Water Inlet and Outlet Connections................ 26 

7.3.4 Fuel Consumption.................................. 27 

7.3.5 Internal Storage Tank Temperature Measurements.... 27 

7.3.6 Ambient Temperature............................... 27 

7.3.7 Inlet and Outlet Water Temperature Measurements... 27 

7.3.8 Flow Control...................................... 28 

7.3.9 Vent Requirements................................. 28 

7.3.10 Natural Gas Sample............................... 28 

7.4 STEAM AND HOT WATER BOILERS............................. 29 

7.4.1 STEAM BOILERS................................. 29 

7.4.1.1 Boiler Installation......................... 29 

7.4.1.2 Water Supply................................ 29 

7.4.1.3 Water Inlet and Outlet Connection........... 29 

7.4.1.4 Water Consumption........................... 29 

7.4.1.5 Fuel Consumption............................ 30 

7.4.1.6 Ambient Temperature......................... 30 

7.4.1.7 Inlet and Outlet Temperature Measurements... 30 

7.4.1.8 Vent Requirements........................... 30 

7.4.1.9 Natural Gas Sample.......................... 31 

7.4.2 HOT WATER BOILERS................................. 31 

7.4.2.1 Boiler...................................... 31 

7.4.2.2 Water Supply................................ 31 

7.4.2.3 Water Inlet and Outlet Connections.......... 31 

7.4.2.4 Water Consumption........................... 32 

7.4.2.5 Fuel Consumption............................ 32 

7.4.2.6 Ambient Temperature......................... 32 

7.4.2.7 Inlet and Outlet Water Temperature 

Measurement................................. 32 

7.4.2.8 Flow Control................................ 32 

7.4.2.9 Vent Requirements........................... 33 

7.4.2.10 Natural Gas Sample.......................... 33 

8.0 TEST PROCEDURE.............................................. 34 

8.1 STORAGE TANK WATER HEATERS WITH INPUT RATINGS OF 75,000 

BTU PER HOUR OR LESS.................................... 34 

8.1.1 POWER INPUT....................................... 34 
TABLE OF CONTENTS

 PAGE 

-v8.1.2 DETERMINATION OF STORAGE TANK VOLUME.............. 34 

8.1.3 SETTING THE THERMOSTAT............................ 34 

8.1.4 EMISSION TESTING.................................. 34 

8.2 STORAGE TANK WATER HEATERS WITH INPUT RATINGS ABOVE 

75,000 BTU PER HOUR..................................... 36 

8.2.1 POWER INPUT....................................... 36 

8.2.2 SETTING THE THERMOSTAT............................ 36 

8.2.3 EMISSION TESTING.................................. 36 

8.2.3.1 Instantaneous Water Heaters with Input 

Ratings of 200,000 BTU per Hour or Less...... 36 

8.2.3.2 Storage with Input Ratings Above 75,000 BTU

per Hour, Instantaneous with Input Ratings 

Above 200,000 BTU per Hour, and Circulating 

Water Heaters................................ 37 

8.3 POOL HEATERS............................................ 38 

8.3.1 Power Input....................................... 38 

8.3.2 Outlet Water Temperature.......................... 38 

8.3.3 Emission Testing.................................. 39 

8.4 STEAM AND HOT WATER BOILERS............................. 40 

8.4.1 STEAM BOILERS..................................... 40 

8.4.1.1 Power Input................................. 40 

8.4.1.2 Outlet Steam Pressure....................... 40 

8.4.1.3 Emission Testing............................ 40 

8.4.2 HOT WATER BOILER.................................. 41 

8.4.2.1 Power Input................................. 41 

8.4.2.2 Outlet Water Temperature.................... 41 

8.4.2.3 Emission Testing............................ 41 

9.0 CALCULATIONS................................................ 43 

9.1 CARBON NUMBER........................................... 43 

9.2 HEATING VALUE........................................... 44 

9.3 HEAT OUTPUT............................................. 45 

9.3.1 STORAGE TANK WATER HEATERS WITH INPUT RATINGS OF 

75,000 BTU/HR OR LESS............................ 45

9.3.1.1 Storage Tank Capacity....................... 45 

9.3.1.2 Computation................................. 45 
TABLE OF CONTENTS

 PAGE 

-vi9.3.2 STORAGE TANK WATER HEATERS WITH INPUT RATINGS 

ABOVE 75,000 BTU PER HOUR, CIRCULATING, AND 

INSTANTANEOUS WATER HEATERS, AND POOL HEATERS.... 46

9.3.3 STEAM BOILERS..................................... 47 

9.3.4 HOT WATER BOILERS................................. 47 

9.4 EMISSION OF NOX......................................... 48 

9.4.1 NOx EMISSION (ng/J Heat Output)................... 48 

9.4.2 NOx EMISSION (Concentration at 3% O2)............. 48 

9.4.3 NOx EMISSION (lb/MMBtu)........................... 49 

10.0 REPORT..................................................... 50 

10.1 TEST RESULTS........................................... 50 

10.1.1 ENVIRONMENT AND HOT WATER PRODUCTION............. 50 

10.1.2 EMISSION MEASUREMENTS............................ 50 

10.1.3 GAS COMPOSITION ANALYSIS......................... 51 

10.1.4 ANALYZER CALIBRATION AND SAMPLING SYSTEM BIAS 

TEST............................................. 51

10.1.5 NO2 CONVERTER EFFICIENCY TEST.................... 51 

10.2 FORMS USED FOR PERFORMING THE CALCULATIONS............. 51 

10.2.1 CALCULATION OF HEAT OUTPUT....................... 51 

10.2.2 CORRECTION OF GAS METER READING AND 

DETERMINATION OF FIRING RATE..................... 52

10.2.3 CALCULATION OF NOx EMISSIONS..................... 52 

DRAWINGS AND FIGURES............................................. 53 

DATA AND CALCULATION FORMS....................................... 60 
-1- 

NITROGEN OXIDES EMISSIONS COMPLIANCE TESTING 

FOR NATURAL GAS-FIRED WATER HEATERS & BOILERS 

PROTOCOL 

1.0 OVERVIEW AND APPLICABILITY 

The South Coast Air Quality Management District adopted Rule 

1121, Control of Nitrogen Oxides from Residential Type, Natural 

Gas-Fired Water Heaters, on December 1, 1978. This rule imposes 

an emission limit of 40 nanograms of NO

x

 (calculated as NO2) per 

joule of heat output for residential type, natural gas-fired 

water heaters. Natural gas-fired water heaters require testing 

to certify compliance with the 40 nanograms of NO

x

 per joule 

emission limit before they can be supplied, offered for sale or 

sold within the jurisdiction of the South Coast Air Quality 

Management District. 

Proposed Rule 1146.2, which applies to equipment larger than 

those regulated by Rule 1121, seeks to limit NOx emissions from 

commercial water heaters, small industrial boilers, and process 

heaters. These combustion equipment must also be tested and 

certified before they can be supplied, offered for sale or sold 

within the jurisdiction of the South Coast Air Quality Management 

District. Compliance will be based either on a nanogram per 

joule of heat output basis, or a concentration basis (parts per 

million, or pounds per million Btu heat input). 

This protocol has been developed to support Rules 1121 and 1146.2 

to ensure standardization of compliance certification test 
-2- 

procedures including the use of: specified test conditions, 

required test methods, specifications for test equipment, data 

collection/reporting and quality assurance requirements. 

An independent testing laboratory, approved by the South Coast 

Air Quality Management District, shall conduct the testing and 

prepare a report of findings, including all raw data 

sheets/charts and laboratory analytical data. This report and a 

request for product certification must be submitted to the 

Executive Officer. The testing must demonstrate to the 

satisfaction of the Executive Officer that emissions from the 

operation of a natural gas-fired water heater or boiler meets the 

requirements of Rules 1121 and 1146.2 before product compliance 

certification is granted. 

When a natural gas-fired water heater or boiler does not fall 

within the testing guidelines of this protocol, the protocol may 

be modified following an equivalency determination and written 

approval of the Executive Officer. 
-3- 

2.0 ENVIRONMENTAL CRITERIA

Testing shall be conducted indoors with the ambient air 

temperature of the test room maintained between 65oF and 85oF at 

all times during the test. The ambient air temperature during 

these tests shall not vary more than + 7oF from the average 

ambient air temperature determined as the arithmetic average of 

the air temperatures measured periodically at intervals no 

greater than 15 minutes throughout the duration of the test. 

The ambient temperature shall be monitored and recorded before, 

during, and after the tests in accordance with Section 7.1.6 of 

this protocol. 

The relative humidity shall be between 20% and 65% during the 

test. It shall be recorded before and after the test. 

The barometric pressure shall be monitored and recorded before 

and after each test. 
-4- 

3.0 DEFINITIONS

For the purposes of this test protocol, the following definitions 

shall apply: 

3.1 INDEPENDENT TESTING LABORATORY 

 A testing laboratory that meets the requirements of 

South Coast Air Quality Management District's Rule 304, 

Paragraph (K), and is approved by the SCAQMD to conduct 

testing under this protocol. 

3.2 NATURAL GAS-FIRED WATER HEATER 

 A closed vessel, in which water is heated by the 

combustion of natural gas and is withdrawn for use 

external to the vessel at pressures not exceeding 160 

psig, including the apparatus by which heat is generated 

and all controls and devices necessary to prevent water 

temperatures from exceeding 210oF. 

3.3 NATURAL GAS-FIRED BOILER 

 A self-contained gas burning appliance for supplying 

steam or hot water. A boiler can be of the following 

types: 

3.3.1 HOT WATER HEATING BOILER A boiler in which no steam is 

generated, from which hot water is circulated for 

heating purposes and then returned to the boiler. 
-5- 

3.3.2 HOT WATER SUPPLY BOILER A boiler, completely filled 

with water, which furnishes hot water to be used 

externally to itself, and which operates at water 

pressures not exceeding 160 psig (1.10 MPa) and at water 

temperatures not exceeding 250oF (121oC) at or near the 

boiler outlet. 

3.3.3 STEAM HEATING BOILER A boiler in which steam is 

generated and/or produced. 

3.4 NATURAL GAS-FIRED POOL HEATER 

 An appliance designed for heating non-potable water 

stored at atmospheric pressure, such as water in 

swimming pools, spas, hot tubs and similar applications. 
-6- 

4.0 TEST CONDITIONS 

4.1 AMBIENT AIR TEMPERATURE

 The ambient air temperature shall be controlled to a 

value between 65oF and 85oF on a continuous basis. 

4.2 SUPPLY WATER TEMPERATURE

4.2.1 STORAGE, INSTANTANEOUS, AND CIRCULATING WATER HEATERS 

The temperature of water being supplied to the water 

heater shall be maintained at 72 + 4o

F throughout the 

test. Instantaneous and circulating water heaters may 

use a recirculating line with pump to control inlet

water temperature as specified by the manufacturer. The 

specified inlet water temperature for circulating water 

heaters shall not be more than 120oF. 

4.2.2 POOL HEATERS The supply water temperature shall not be 

less than 65oF and the outlet water temperature not more 

than 115oF with a rise of 40oF. When specified by the 

manufacturer the water temperature rise may be adjusted 

to a lower value, but not less than 10oF with the 

average temperature of the inlet and outlet being 90

o

 +

5

o

F. 

4.2.3 STEAM AND HOT WATER BOILERS The temperature of make-up 

water shall be 70o + 2oF. If required, a recirculating 

pump may be used to provide feedwater at the 

manufacturer's specified temperature. 
-7- 

4.3 SUPPLY WATER PRESSURE

4.3.1 WATER HEATERS During tests when water is not being 

withdrawn, the supply pressure shall be maintained 

between 40 psig and the maximum allowable pressure 

specified by the appliance manufacturer. When water is 

being withdrawn, the supply pressure shall be adequate 

to maintain the specified test flows. 

4.3.2 POOL HEATERS The supply pressure shall be adequate to 

maintain the specified test flows. 

4.3.3 STEAM AND HOT WATER BOILERS The supply pressure shall 

be in accordance with the manufacturer's instructions. 

4.4 NATURAL GAS PRESSURE

 Maintain the supply pressure in accordance with the 

manufacturer's specifications. If the supply pressure 

is not specified, maintain a supply pressure of 7-10 

inches of water column. Use natural gas with a dry or 

higher heating value of 1040 + 25 BTU per standard cubic 

foot (14.73 psia and 60oF). 

4.5 INSTALLATION REQUIREMENTS

 Tests shall be performed with the water heater and

instrumentation in accordance with Section 7. 
-8- 

5.0 INSTRUMENTATION 

All instrumentation within this section and pertaining to this 

protocol shall be calibrated as a minimum within the requirements 

set forth in SCAQMD Source Test Methods Chapter III, 

Calibrations. 

5.1 PRESSURE MEASUREMENT

 Pressure measurement instruments shall have an error no 

greater than the following values: 

 Measurement Accuracy Precision

 Gas Pressure + 0.1" of + 0.05" of 

 water column water column 

 Atmospheric + 0.1" of + 0.05" of 

 Pressure Hg column Hg column 

 Water and Steam + 1.0 psi + 0.50 psi 

 Pressure 

5.2 TEMPERATURE MEASUREMENTS

 Temperature measuring instruments shall have an error no 

greater than the following values: 

Accuracy Precision

 Inlet/outlet water temperatures + 0.2o

F + 0.1oF 

 Storage Tank Temperature + 0.5oF + 0.25oF 

 Ambient Temperature + 0.2oF + 0.1oF 

 The time constant of instruments measuring inlet and 

outlet water temperatures shall be 5 seconds or less. 
-9- 

5.3 BAROMETRIC PRESSURE 

 Use a mercury, aneroid, or other barometer capable of 

measuring atmospheric pressure to within 0.1 in. Hg. 

5.4 LIQUID FLOW MEASUREMENTS 

 The accuracy of liquid flow measurements, using 

calibration curves if furnished, shall be equal to or 

less than + 2% of the measured value. 

5.5 NATURAL GAS FLOW 

 The quantity of fuel used by the water heater shall be 

measured in cubic feet with dry gas meter and associated 

readout device that is accurate within + 1% of the 

reading. The dry gas meter reading shall be corrected 

for gas pressure and temperature. 

5.6 MASS MEASUREMENT 

 Mass shall be measured with instruments that are 

accurate within + 1%. 

5.7 TIME 

 The elapsed time measurement shall be measured with an 

instrument that is accurate within + 0.5 seconds per 

hour. 
-10- 

5.8 FLUE GAS ANALYSIS 

5.8.1 NO

x

 CONCENTRATION A chemiluminescence NO

x

 Analyzer 

shall be employed to measure NO

x

 in flue gas. 

Performance specifications of the analyzer shall be in 

accordance with SCAQMD Method 100.1 (Appendix A). 

5.8.2 CO CONCENTRATION A non-dispersive infrared analyzer 

shall be employed to measure CO in flue gas. 

Performance specifications of the analyzer shall be in 

accordance with SCAQMD Method 100.1 (Appendix A). 

5.8.3 CARBON DIOXIDE OR OXYGEN ANALYSIS

5.8.3.1 CO2 CONCENTRATION A non-dispersive infrared analyzer 

shall be employed to measure CO2 in flue gas. 

Performance specifications of the analyzer shall be in 

accordance with SCAQMD Method 100.1 (Appendix A). 

5.8.3.2 O2 CONCENTRATION As an alternative to measuring CO2 for 

emission limits which require an oxygen correction, an 

electrochemical type analyzer shall be employed to 

measure O2 in flue gas. Performance specifications of 

the analyzer shall be in accordance with SCAQMD Method 

100.1 (Appendix A). 

5.8.4 SAMPLE CONDITIONING SYSTEM The NO

x

, CO, and CO2 (or O2) 

analyzers shall sample flue gas delivered by a single 
-11- 

sample conditioning system. The gases shall be measured 

simultaneously after undergoing identical sample 

conditioning. Figures 1 and 2 show acceptable sample 

conditioning systems. Additional components may be

added at the user's discretion. However, deviations 

from the basic design must be approved by the Executive 

Officer. 

5.8.4.1 Sample Probe

5.8.4.1.1 Integrating Sample Probes Integrating sample probes 

may be used with vents less than 12 inches in diameter. 

Figure 3 shows an acceptable hole layout for an 

integrating sample probe. The probe shall be of 316 

stainless steel construction. 

5.8.4.1.2 Open Ended Sample Probes Open ended sample probes 

shall be used to sample vents 12 inches in diameter and 

larger. They shall also be used to measure emissions 

from heaters and boilers designed for outdoor use which 

do not have vents. 

5.8.4.2 Sample Lines The sample line shall be of Teflon 

construction. It shall be electrically heated. The 

allowable temperature range is 175oF - 300oF. The use 

of self-limiting heated sample line is permitted. 
-12- 

5.8.4.3 Moisture Removal System

5.8.4.3.1 Permeation-Type Dryers A Permapure permeation-type 

dryer may be employed to dry the sample gas. The air 

to the dryer shall be dried with a heat-less dryer,

which includes a colored moisture indicator. 

5.8.4.3.2 Refrigerated Condenser/Separator A refrigerated 

condenser/separator designed to minimize contact 

between the condensate and the sample gas may be used 

to dry the sample gas. The dew point of the dry gas 

shall be less than 35oF. 

5.8.4.4 Sample Pump The sample pump shall be a diaphragm type. 

The diaphragm shall be Viton A; other wetted parts of 

the pump shall be 316 stainless steel. 

5.8.4.5 Flow Indicators Because the flow indicators in the 

sample conditioning system are for the operators 

convenience, they do not have to be calibrated. Water 

shall not be allowed to collect in the indicator tubes. 

5.8.4.6 Pressure Indicators Because the pressure indicators in 

the sample conditioning system are for the operators 

convenience, they do not have to be calibrated. 
-13- 

5.8.4.7 Sample Vent The analyzers shall have an unrestricted 

atmospheric sample vent. 

5.9 NATURAL GAS COMPOSITION

 Heating value or gas composition of the fuel must be 

measured. If the heating value is measured, the 

reproducibility of the measurement device shall be + 1% 

of full scale. The precision of the device shall be 

+ 2 Btu/dscf. Calibration shall be conducted weekly

using the device manufacturer's directions. 

 If the composition of the fuel is measured, it shall be 

measured with a gas chromatograph having a TC detector. 

Ethane, Propane, C4+, CO2, and permanent gases will be 

measured directly. Methane may be determined by 

difference. The reproducibility of the gas 

chromatograph shall be + 1% of full scale for each 

measured component. 
-14- 

6.0 ANALYTICAL METHODS 

6.1 START UP 

6.1.1 ANALYZERS Allow analyzers to warm up according to 

manufacturer's instructions. It is recommended that the 

analyzers be allowed to run overnight before testing. 

6.1.2 SAMPLE CONDITIONING SYSTEM Energize sample pump and 

sample line. Allow temperatures and flows to come to 

equilibrium. 

6.2 CALIBRATION AND PERFORMANCE TESTING 

6.2.1 ANALYZER CALIBRATION Use calibration gases which are 

certified according to EPA Traceability Protocol Number 

1. CO calibration gases may be certified to an accuracy 

of + 2%. Select analytic ranges so that measured gas 

concentrations are between 20% and 95% of full scale 

during the last 10 minutes of each test. Calibrate the 

analyzers according to the manufacturer's instructions 

and SCAQMD Method 100.1. It is recommended that the 

calibration of each analyzer be checked after each test. 

A 2% drift invalidates the analysis. SCAQMD Method

100.1 is included as Appendix A. 

6.2.2 SAMPLING SYSTEM BIAS TEST A sampling system bias test 

must be performed in accordance with SCAQMD Method 100.1 
-15- 

before and after each day of testing. The sample bypass 

flowrate shall not be altered during this test. 

6.2.3 RESPONSE TIME The system response time test must be 

performed before each day of testing if NO

x

concentrations are to be determined by multi-point 

traverse. The response time test may be performed in 

conjunction with the sampling system bias test. 

 To determine response time, first introduce zero gas 

into the sample probe until all readings are stable; 

then switch to high-level calibration gas until a stable 

reading is obtained. Record the upscale response time, 

which is defined as the amount of time for the system to 

display 95% of the step change. Next re-introduce zero 

gas until all readings are stable. Record the downscale 

response time. The greater time is the "response time" 

for the system. 

6.2.4 NO2

 TO NO CONVERSION EFFICIENCY The converter 

efficiency shall be measured in accordance with EPA

Method 20 at least once a month. If the efficiency does 

not meet the requirements listed in Form I, the 

converter must be replaced, and all data acquired since 

the last converter efficiency test shall be considered 

suspect. The conversion efficiency test is included as 

Appendix B. 
-16- 

6.3 ANALYSIS

6.3.1 SAMPLE POINT

6.3.1.1 Appliances with Vents Less Than 12 Inch Diameter An 

integrating sample probe of the proper length is 

installed six inches from the upper end of the vent

pipe. The probe must pass through the center of the 

vent and contact the opposite side. A system bias check 

and leak check shall be performed after changing 

integrating sample probes. 

6.3.1.2 Appliances With Vents 12 Inch Diameter or Greater An 

open ended sample probe will be used to traverse the 

vent pipe at 1/2 vent diameter below its upper end. The 

traverse will be conducted along two diameters 

perpendicular to the axis of the vent and to each other. 

Eight points will be sampled on each diameter. The

distance of the sample points from the inside surface of 

the vent pipe are given in inches in the following 

table: 
-17- 

 VENT ----------------SAMPLE POINT---------------------- 

DIAMETER 1 2 3 4 5 6 7 8 

——————————————————————————————————————————————————————————— 

 12 0.5 1.3 2.3 3.9 8.1 9.7 10.7 11.5 

 13 0.5 1.4 2.5 4.2 8.8 10.5 11.6 12.5 

 14 0.5 1.5 2.7 4.5 9.5 11.3 12.5 13.5 

 15 0.5 1.6 2.9 4.8 10.2 12.1 13.4 14.5 

 16 0.5 1.7 3.1 5.2 10.8 12.9 14.3 15.5 

 17 0.5 1.8 3.2 5.5 11.5 13.8 15.2 16.5 

 18 0.6 1.9 3.5 5.8 12.2 14.5 16.1 17.4 

 19 0.6 2.0 3.7 6.1 12.9 15.3 17.0 18.4 

 20 0.6 2.1 3.9 6.5 13.5 16.1 17.9 19.4 

 The sample probe will be progressively inserted into the 

vent pipe along one diameter and then the other until 

all 16 points have been sequentially sampled. 

6.3.1.3 Appliances Which Do Not Have Vents Appliances designed 

for outdoor use which do not have vents shall be sampled 

by traverse with an open ended probe. The vent guard 

will be divided into 16 rectangles of equal area on a 

4x4 matrix. The sample probe shall be sequentially

inserted through the vent guard at the center of each 

rectangle and the emissions analyzed. 
-18- 

6.3.2 SAMPLING PERIOD

6.3.2.1 Integrating Sample Probes When sampling with an 

integrating sample probe, the analytical system shall 

operate continuously during the complete test cycle of 

the appliance. Sampling during appliance warm-up is not 

required for storage-type water heaters. 

6.3.2.2 Sample Traverses When sample traverses are required, 

sampling shall begin after the appliance has reached 

steady state as defined in Section 8 for each water

heater or boiler. Each traverse point shall be sampled 

for at least one minute plus the system response time. 

6.3.3 DATA RECORDING The output of each analyzer shall be 

recorded on a strip chart recorder having a minimum

width of six inches. Alternately, the outputs may be 

recorded with a data logger. The sampling rate of the 

logger must allow each point to be read at least once 

every 5 seconds. 
-19- 

7.0 INSTALLATION 

7.1 STORAGE TANK WATER HEATERS WITH INPUT RATINGS BELOW

75,000 BTU/HR

7.1.1 WATER HEATER MOUNTING Mounting shall be in accordance 

with the manufacturer's instructions. 

7.1.2 WATER SUPPLY The water supply shall be capable of 

delivering water at conditions as specified in Sections 

4.2 and 4.3 of this protocol. 

7.1.3 WATER INLET AND OUTLET CONFIGURATION Inlet and outlet 

piping connections shall be configured as illustrated in 

Figures 4, 5, or 6, except a water heater 36 inches high 

or less intended for installation either beneath, 

adjacent to, or in conjunction with a counter shall have 

the inlet and outlet connections configured as 

illustrated in Figures 7a and 7b. Type "L" hard copper 

tubing, the same size as the connections on the water 

heater, shall be connected to the tank and extend 24 

inches in length. If a water heater 36 inches high or 

less is not equipped with pipe to extend the field 

connection point of the water heater lines to outside 

the jacket or cabinet, type "L" hard copper tubing shall 

be used to extend the water line horizontally to the 

exterior of the jacket or cabinet. Unions may be used 

to facilitate installation and removal. A pressure
-20- 

gauge shall be installed in the supply at a location 

upstream of the 24 inch cold water inlet pipe. An 

appropriately rated pressure and temperature relief

valve shall be installed on all water heaters at the 

port specified by the manufacturer. Discharge piping 

for the relief valve shall be non-metallic. All energy 

conservation accessories which are supplied with the 

water heater shall be installed for testing. 

7.1.4 FUEL CONSUMPTION Install one or more instruments to 

measure the quantity of natural gas consumption in 

accordance with section 5.5 of this protocol. 

7.1.5 INTERNAL STORAGE TANK TEMPERATURE MEASUREMENTS Install 

six temperature measurement sensors inside the water 

heater tank with a vertical distance of at least four 

inches between successive sensors. A temperature sensor 

shall be positioned at the vertical midpoint of each of 

the six equal volume nodes within the tank. Nodes 

designate the equal volumes used to evenly partition the 

total volume of the tank. As much as possible, the

temperature sensors should be positioned away from any 

anodic protective devices, tank walls, and flue pipe 

walls. If the tank cannot accommodate six temperature 

sensors and meet the installation requirements, install 

the maximum number of sensors which comply with the

installation requirements. The temperature sensors
-21- 

shall be installed either through: (1) the anodic 

device opening; (2) the relief valve opening; or (3) the 

hot water outlet. If installed through the relief valve 

opening or the hot water outlet, a tee fitting and elbow 

shall be installed such that the outlet piping is as 

close as possible to its original location. If the hot 

water heater includes a heat trap, the tee fitting shall 

be between the heat trap and the storage tank. Fittings 

added to accommodate the temperature sensors shall be 

covered with thermal insulation having a thermal 

resistance (R) value not less than 4 hr-ft2-

o

F/BTU. 

7.1.6 AMBIENT TEMPERATURE The ambient temperature shall be 

measured at the approximate vertical mid-point of the 

heater and approximately 2 feet from the surface of the 

water heater. The sensor shall be shielded against

radiation. 

7.1.7 INLET AND OUTLET WATER TEMPERATURE MEASUREMENTS Install 

temperature sensors in the cold-water inlet pipe and 

hot-water outlet pipe as shown in Figures 4, 5, 6, or 7, 

as applicable and in accordance with ASHRAE STD 41.1-

1986. 

7.1.8 FLOW CONTROL A flow control valve shall be installed to 

provide flow as specified within Section 8 of this 

protocol. 
-22- 

7.1.9 VENT REQUIREMENTS Establish a natural draft in the 

following manner. For water heaters having a vertically 

discharging draft hood outlet, a five foot vertical vent 

pipe extension having a diameter equal to the largest 

flue collar size of the draft hood outlet shall be 

installed. For water heaters having a horizontally

discharging draft hood outlet, a 90o elbow having a 

diameter equal to the largest flue collar size of the 

draft hood shall be connected to the draft hood outlet. 

A five foot length of standard double walled vent pipe 

(Type B vent) shall be connected to the elbow and 

oriented to discharge vertically upward. Optionally, a 

five foot length of single walled vent pipe may be 

installed if it is insulated up to the sampling port 

with glass fiber having a thermal resistance (R) value 

of not less than 4 hr-ft2-

o

F/Btu. 

 Direct vent water heaters shall be installed with 

venting equipment specified in the manufacturers 

instructions using the minimum vertical and horizontal 

lengths of vent pipe recommended by the manufacturer. 

7.1.10 NATURAL GAS SAMPLE Valving and a tap shall be provided 

in the natural gas supply to allow collecting a sample 

of fuel for composition analysis. 
-23- 

7.2 STORAGE TANK WATER HEATERS WITH INPUT RATINGS ABOVE

75,000 BTU PER HOUR; CIRCULATING AND INSTANTANEOUS WATER 

HEATERS. 

.7.2.1 WATER HEATER MOUNTING Mounting shall be in accordance 

with the manufacturer's instructions. 

7.2.2 WATER SUPPLY The water supply shall be capable of 

delivering water at conditions as specified in 4.2 and 

4.3 of this protocol. 

7.2.3 WATER INLET AND OUTLET CONNECTIONS

7.2.3.1 Storage Tank Water Heaters Storage tank water heaters 

which are not equipped with integral heat traps shall 

have inlet and outlet piping connections configured as 

illustrated in Figures 4, 5, or 6. Storage tank water 

heaters which incorporate integral heat traps may have 

the inlet and outlet piping installed in any convenient 

fashion. Unions may be utilized to facilitate 

installation and removal. 

 If the manufacturer has not provided a temperature and 

pressure relief valve, one shall be installed on the 

water heater at the port specified by the manufacturer. 

Discharge piping for the relief valve shall be nonmetallic. 
-24- 

 The relief valve and the inlet and outlet piping 

including heat traps shall be insulated with a material 

having a thermal resistance (R) value not less than 4 

hr-ft2-

o

F/Btu. The insulation on the inlet and outlet 

piping shall extend four feet from the connection with 

the appliance. 

7.2.3.2 Instantaneous and Circulating Water Heaters Inlet and 

outlet piping shall be installed as shown in Figure 8. 

If the manufacturer has not provided a temperature and 

pressure relief valve, one shall be installed for test 

purposes. 

 The inlet and outlet piping including recirculating 

loop, if used, shall be insulated with material having a 

thermal resistance (R) value not less than 4 hr-ft2-

o

F/Btu. 

7.2.4 FUEL CONSUMPTION Install one or more instruments to 

measure the quantity of natural gas consumption in 

accordance with Section 5.5 of this protocol. 

7.2.5 INTERNAL STORAGE TANK TEMPERATURE MEASUREMENTS Internal 

tank temperature measurements are not required. 
-25- 

7.2.6 AMBIENT TEMPERATURE The ambient temperature shall be 

measured in accordance with Section 7.1.6 of this 

protocol. 

7.2.7 INLET AND OUTLET WATER TEMPERATURE MEASUREMENTS

7.2.7.1 Storage Tank Water Heater The inlet and outlet 

temperature sensors shall be installed as shown in 

Figures 4,5, and 6 as applicable and in accordance with 

ASHRAE STD 41.1-1986. 

7.2.7.2 Instantaneous and Circulating Water Heaters Install 

temperature sensors as shown in Figure 8 and in 

accordance with ASHRAE STD 41.1-1986. Supply and outlet 

water sensors shall be located as close to the appliance 

as is practical. 

7.2.8 FLOW CONTROL A flow control valve shall be installed to 

provide flow as specified within Section 8 of this 

protocol. 

7.2.9 VENT REQUIREMENTS

7.2.9.1 Appliances Equipped With Draft Hoods A water heater 

having a vertically discharging draft hood shall have 

attached to and vertically above the outlet, five feet 

of vent pipe the same size as the draft hood outlet. A 

water heater having a horizontally discharging draft 
-26- 

hood shall have attached a 90o elbow and five feet of 

vent pipe the same size as the draft hood outlet. If 

necessary to prevent condensation, the vent pipe must be 

insulated with an (R) value not less than 4 hr-ft2-

o

F/Btu. 

7.2.9.2 Direct Vent Appliances The appliance shall be installed 

with the venting arrangement specified in the 

manufacturer's instructions. The venting must be 

insulated if the inlet flow of combustion air is not 

restricted. 

7.2.10 NATURAL GAS SAMPLE Valving and a tap shall be provided 

in the natural gas supply to allow collecting a sample 

of fuel for composition analysis. 

7.3 POOL HEATERS 

7.3.1 Pool Heater Mounting Mounting of the pool heater shall 

be in accordance with the manufacturer's instructions. 

7.3.2 Water Supply The water supply shall be capable of 

delivering water at conditions as specified in 4.2 and 

4.3 of this protocol. 

7.3.3 Water Inlet and Outlet Connections Piping connections 

shall be as shown in figure 8. Heat traps, insulation, 
-27- 

and other conservation equipment supplied with the 

heater shall be installed for testing. When required to 

achieve temperature rise and minimum flow as specified 

by the manufacturer, a recirculating loop of minimum 

length and a pump shall be provided by the manufacturer. 

The recirculating loop shall be insulated with material 

having a thermal resistance (R) value of at least 4 hrft2

-

o

F/Btu. 

 Any device provided to maintain water flow rate shall be 

removed or adjusted to prevent bypassing of water around 

the heat exchanger. 

7.3.4 Fuel Consumption Install one or more instruments to 

measure the quantity of natural gas consumed in 

accordance with Section 5.5 of this protocol. 

7.3.5 Internal Storage Tank Temperature Measurements Internal 

tank temperature measurements are not required. 

7.3.6 Ambient Temperature The ambient air temperature shall 

be measured in accordance with Section 7.1.6 of this 

protocol. 

7.3.7 Inlet and Outlet Water Temperature Measurements Install 

temperature sensors as shown in Figure 8. Supply and 

outlet water sensors shall be located as close to the 
-28- 

appliance as is practical and in accordance with ASHRAE 

STD 41.1-1986. 

7.3.8 Flow Control A flow control valve shall be installed to 

provide flow as specified within Section 8 of this 

protocol. 

7.3.9 Vent Requirements For pool heaters having a vertically 

discharging draft hood outlet, a 5 foot vertical vent 

pipe extension having a diameter equal to the largest 

flue collar size of the draft hood shall be connected to 

the draft hood outlet. For heaters having a 

horizontally discharging draft hood outlet, a 90o elbow 

having diameter equal to the largest collar size of the 

draft hood shall be connected to the draft hood outlet 

and a vertical 5 feet of length of vent pipe shall be 

connected to the elbow. If necessary to prevent 

condensation, the vent pipe must be insulated with an 

(R) value not less than 4 hr-ft2-

o

F/Btu. 

 An appliance for outdoor installation with the venting 

system provided as part of the appliance shall be tested 

with the venting system in place. 

7.3.10 Natural Gas Sample Valving and a tap shall be provided 

in the natural gas supply to allow collecting a sample 

of fuel for composition analysis. 
-29- 

7.4 STEAM AND HOT WATER BOILERS 

7.4.1 STEAM BOILERS

7.4.1.1 Boiler Installation The boiler shall be installed in 

accordance with the manufacturer's instructions and all 

applicable safety codes. 

 Feed water to the boiler shall be automatically 

controlled to maintain a constant water level in the 

boiler. 

7.4.1.2 Water Supply The water supply shall be capable of 

delivering water at conditions as specified in 4.2 and 

4.3 of this protocol. 

7.4.1.3 Water Inlet and Outlet Connection Piping connections 

shall be in accordance with the manufacturers 

instructions and have the general arrangement shown in 

Figure 9. All conservation equipment supplied with the 

boiler shall be installed for testing. 

7.4.1.4 Water Consumption Install one or more instruments to 

measure the quantity of water delivered to the boiler in 

accordance with Section 5.4 of this protocol. 
-30- 

7.4.1.5 Fuel Consumption Install one or more instruments to 

measure the quantity of natural gas consumed in 

accordance with Section 5.5 of this protocol. 

7.4.1.6 Ambient Temperature The ambient air temperature shall 

be measured in accordance with Section 7.1.6 of this 

protocol. 

7.4.1.7 Inlet and Outlet Temperature Measurements Install a 

temperature sensor in the water inlet pipe approximately 

24 inches from the boiler inlet. Install a temperature 

sensor in the steam outlet pipe within 24 inches of the 

boiler outlet in accordance with ASHRAE STD 41.1-1986. 

7.4.1.8 Vent Requirements The boiler shall be connected to a 

sheet-metal vent pipe the same size as the draft hood 

outlet. When the flue gases are vented horizontally, a 

90-degree, four-piece, sheet metal elbow and five feet 

of vertical stack shall be attached to and above the 

outlet. When the flue gases are vented vertically, five 

feet of vertical stock shall be attached to and 

vertically above the outlet. The vent pipe shall be 

insulated with a thermal resistance (R) value not less 

than 4 hr-ft2-

o

F/Btu. 
-31- 

 A boiler with a power burner or direct vent system shall 

have vent pipe installed in accordance with the 

manufacturer's instructions. 

 An appliance for outdoor installation with the venting 

system provided as part of the appliance shall be tested 

with the venting system in place. 

7.4.1.9 Natural Gas Sample Valving and a tap shall be provided 

in the natural gas supply to allow collecting a sample 

of fuel for composition analysis. 

7.4.2 HOT WATER BOILERS

7.4.2.1 Boiler The boiler shall be installed in accordance with 

the manufacturer's instructions and all applicable 

safety codes. 

7.4.2.2 Water Supply The water supply shall be capable of 

delivering water at conditions specified in Sections 4.2 

and 4.3 of this protocol. 

7.4.2.3 Water Inlet and Outlet Connections Piping connections 

shall be in accordance with the manufacturer's 

instructions and have the general arrangement shown in 

Figure 8. Any conservation equipment supplied with the 

heater shall be installed for testing. When required, a 

recirculating loop of minimum length and a pump shall be 
-32- 

provided by the manufacturer. The recirculating loop 

shall be insulated with material having a thermal 

resistance (R) value of at least 4 hr-ft2-

o

F/Btu. 

7.4.2.4 Water Consumption Install one or more instruments to 

measure the quantity of water delivered to the boiler in 

accordance with Section 5.4 of this protocol. 

7.4.2.5 Fuel Consumption Install one or more instruments to 

measure the quantity of natural gas consumed in 

accordance with Section 5.5 of this protocol. 

7.4.2.6 Ambient Temperature The ambient air temperature shall 

be measured in accordance with Section 7.1.6 of this 

protocol. 

7.4.2.7 Inlet and Outlet Water Temperature Measurement Install 

temperature sensors in the water inlet and outlet piping 

approximately 24 inches from the boiler and in 

accordance with ASHRAE STD 41.1-1986. The outlet piping 

between the boiler and the temperature sensor shall be 

insulated with material having a thermal resistance (R) 

value of not less than 4 hr-ft2-

o

F/Btu. 

7.4.2.8 Flow Control A flow control valve shall be installed in 

the outlet piping downstream of the temperature sensor 
-33- 

to provide flow as specified in Section 8 of this 

protocol. 

7.4.2.9 Vent Requirements The boiler shall be connected to a 

sheet-metal vent pipe the same size as the draft hood 

outlet. When the flue gases are vented horizontally, a 

90-degree, four-piece, sheet-metal elbow and five feet 

of vertical stack shall be attached to and above the 

outlet. When the flue gases are vented vertically, five 

feet of vertical stack shall be attached to and 

vertically above the outlet. The vent pipe shall be 

insulated with a thermal resistance (R) value not less 

than 4 hr-ft2-

o

F/Btu. 

 A boiler using a power burner with positive vent 

pressures, or with a direct vent system shall have vent 

pipe installed in accordance with the manufacturer's 

instructions. 

 An appliance for outdoor installation with the venting 

system provided as part of the appliance shall be tested 

with the venting system in place. 

7.4.2.10 Natural Gas Sample Valving and a tap shall be provided 

in the natural gas supply to allow collecting a sample 

of fuel for composition or heating value analysis. 
-34- 

8.0 TEST PROCEDURE 

8.1 STORAGE TANK WATER HEATERS WITH INPUT RATINGS OF 75,000 

BTU PER HOUR OR LESS

8.1.1 POWER INPUT Burners shall be adjusted to their BTU 

input rates at + 10% of the stated manifold pressure. 

The heater shall be tested within + 2% of the 

manufacturer's specified normal hourly BTU input rate. 

8.1.2 DETERMINATION OF STORAGE TANK VOLUME Determine the 

storage tank capacity, VST, of the water heater, in

gallons, by subtracting the tare weight - measured while 

the tank is empty - from the gross weight of the storage 

tank completely filled with water with all air 

eliminated and dividing the resulting net weight by the 

density of water at the temperature. 

8.1.3 SETTING THE THERMOSTAT The thermostat dial shall be 

adjusted so that the maximum mean temperature after cutout is 135o

F + 5o

F. 

8.1.4 EMISSION TESTING With the water heater turned off, fill 

the water heater with supply water and apply pressure as 

described in Section 4.3.1. Turn on the water heater 

and allow heater to come to operational temperature. 

The water heater may be allowed to come to temperature 

overnight. 
-35- 

 Initiate burner cut-in by withdrawing 10 gallons of 

water; wait until cut-out occurs. Measure the mean tank 

temperature using the temperature sensors described in 

section 7.1.5 every minute until the maximum mean 

storage tank temperature is achieved. This is the start 

of the test. Record the time, the mean tank temperature 

(To), and the gas meter reading. Note the test start on 

the analyzer recorders. 

 Draw water from the tank at the rate of 3.0 + 0.25 

gallons per minute until 10.7 + 0.5 gallons are 

withdrawn. If burner cut-in has not occurred when 10.7 

gallons have been withdrawn, continue withdrawal until 

cut-in occurs. 

 Measure the inlet and outlet water temperature beginning 

15 seconds after the draw is initiated and at subsequent 

5 second intervals through the duration of the draw. 

Record the time of cut-in and cut-out. The arithmetic 

mean of the hot water discharge temperature and the cold 

water inlet temperature shall be determined for the

draw. Record the weight or volume of water withdrawn. 

At the end of the recovery period, record the maximum 

tank temperature observed after cut-out, Tmax and the 

volume of fuel consumed. Collect a sample of fuel for 

composition analysis. Determine the arithmetic mean of 

the CO2 and NO

x

 concentrations measured during each of 

the last three one-minute periods prior to cut-out;
-36- 

record the maximum CO concentration measured during the 

test. 

8.2 STORAGE TANK WATER HEATERS WITH INPUT RATINGS ABOVE

75,000 BTU PER HOUR; CIRCULATING AND INSTANTANEOUS WATER 

HEATERS 

.8.2.1 POWER INPUT Burners shall be adjusted to their BTU 

input rates at + 10% of the stated manifold pressure. 

The heater shall be tested within + 2% of the 

manufacturer's specified normal hourly BTU input rate. 

8.2.2 SETTING THE THERMOSTAT The thermostat shall be placed 

in the maximum position, or bypassed if the device 

cycles. 

8.2.3 EMISSION TESTING

8.2.3.1 Instantaneous Water Heaters with Input Ratings of 

200,000 BTU per Hour or Less The water flow shall be 

adjusted to provide a discharge temperature of 135 +

5

o

F. After the outlet temperature has become constant, 

as indicated by no variation in excess of 1oF over a 

three minute period, record the time, water meter and 

gas meter reading. Do not interrupt fuel to the water 

heater. Record the inlet and outlet temperatures at 

every 15 seconds interval throughout the test. 

Temperature rise cannot change by more than 2oF during 
-37- 

the test. Continuously record the NO

x

, CO and CO2 (or 

O

2

) emissions. After 15 minutes or twice the water 

residence time, whichever is longer, record the water 

meter and gas meter readings. Determine the arithmetic 

mean of the hot water discharge temperature and the cold 

water inlet temperature during the draw. Collect a

sample of fuel for composition analysis. Determine the 

arithmetic mean of CO2 (or O2) and NO

x

 concentrations 

measured during the last three minutes of the test. 

Record the maximum CO concentration measured. 

8.2.3.2 Storage with Input Ratings Above 75,000 BTU per Hour, 

Instantaneous with Input Ratings Above 200,000 BTU per 

Hour, and Circulating Water Heaters The water flow 

shall be adjusted to provide a discharge temperature of 

140o + 2oF. After the outlet temperature has become 

constant, as indicated by no variation in excess of 1oF 

over a three minute period, record the time, gas meter 

and water meter readings. Do not interrupt the flow of 

fuel to the water heater. Record the inlet and outlet 

temperatures at every 15 second interval throughout the 

test. Temperature rise cannot change by more than 2

o

F 

during the test. Continuously record the NO

x

, CO and 

CO2 (or O2) emissions. After 15 minutes or twice the 

water residence time, whichever is longer, record the 

water meter and gas meter readings. 
-38- 

 If a sample traverse is required, identify the traverse 

point being sampled on the strip chart recorder and

record the concentration of NO

x

 and CO2 (or O2) at each 

point. When the traverse is complete or after 

15 minutes, whichever is longer, record the gas and

water meter readings. 

 Determine the arithmetic mean of the hot water discharge 

temperature and the cold water inlet temperature during 

the test. Collect a sample of fuel for composition

analysis. If an integrating sample probe was employed, 

determine the arithmetic mean of CO2 (or O2) and NO

x

concentrations measured during each of the last three 

one-minute periods of the test. Record the highest CO 

concentration during the test. 

8.3 POOL HEATERS 

8.3.1 Power Input Burners shall be adjusted to their BTU 

input rates at + 10% of the stated manifold pressure. 

The heater shall be tested within + 2% of the 

manufacturer's specified normal hourly BTU input rate. 

8.3.2 Outlet Water Temperature The outlet water temperature 

shall not be more than 115oF, with a temperature rise of 

40oF. When specified by the manufacturer, the water 

temperature rise may be adjusted to a lower value, but 
-39- 

not less than 10oF, with the average of the inlet and 

outlet water temperature being 90o + 5oF. 

8.3.3 Emission Testing Allow the heater to operate until 

equilibrium conditions are attained. Equilibrium is 

defined as no variation in excess of 2oF over a three 

minute period. 

 Record the time, gas meter and water meter readings. Do 

not interrupt the flow to the heater. Record the inlet 

and outlet temperatures at every 15 second interval

throughout the duration of the test. Temperature rise 

cannot change by more than 2oF during the test. 

Continuously record the NO

x

, CO, and CO2 (or O2) 

emissions. If a sample traverse is required, identify 

the traverse point being sampled on the strip chart

recorder and record the concentration of NO

x

 and CO2 (or 

O

2

) at each point. When the traverse is complete or 

after 15 minutes, whichever is longer, record the water 

and gas meter readings. Determine the arithmetic mean 

of the hot water discharge temperature and the cold

water inlet temperature during the test. Collect a

sample of fuel for composition analysis. Determine the 

arithmetic mean of CO2 (or O2) and NO

x

 concentration 

measured during each of the last three one-minute 

periods of the test. Record the maximum CO 

concentration during the test. 
-40- 

8.4 STEAM AND HOT WATER BOILERS 

8.4.1 STEAM BOILERS

8.4.1.1 Power Input Burners shall be adjusted to their BTU 

input rates at + 10% of the stated manifold pressure. 

The boiler shall be tested within + 2% of the 

manufacturer's specified normal hourly BTU input rate. 

8.4.1.2 Outlet Steam Pressure The boiler shall be tested at 

atmospheric pressure. 

8.4.1.3 Emission Testing Allow the boiler to operate until 

equilibrium conditions are attained but not less than 

one hour. 

 When equilibrium conditions are attained, begin 

monitoring CO2 (or O2) and NO

x

 emissions. Record the 

time, water and fuel meter readings. Record the inlet 

water and outlet steam temperatures at 15 second 

intervals throughout the test. If a sample traverse is 

required, identify the traverse point being sampled on 

the strip chart recorder and record the concentration of 

NO

x

 and CO2 (or O2) at each point. When the traverse is 

complete or after 30 minutes, whichever is longer, 

record the water and gas meter readings. Determine the 

arithmetic mean of the steam discharge temperature and 

the cold water inlet temperature during the test. 
-41- 

Collect a sample of fuel for composition analysis. If 

an integrating sample probe is employed, determine the 

arithmetic mean of CO2 (or O2) and NO

x

 concentration 

measured during each of the last three one-minute 

periods of the test. 

8.4.2 HOT WATER BOILER

8.4.2.1 Power Input Burners shall be adjusted to their BTU 

input rates at + 10% of the stated manifold pressure. 

The boiler shall be tested within + 2% of the 

manufacturer's specified normal hourly BTU input rate. 

8.4.2.2 Outlet Water Temperature The outlet water temperature 

shall be 180o + 2oF. The water temperature limiting 

device shall be set to its maximum temperature. 

8.4.2.3 Emission Testing Allow the boiler to operate until the 

equilibrium conditions are attained, but not less than 

one hour. Equilibrium conditions are indicated by no 

change in outlet water temperature in excess of 5oF over 

a 5 minute period. 

 After equilibrium conditions are attained, begin 

monitoring CO, CO2 (or O2) and NO

x

 emissions. Record 

water and fuel meter readings and time. Record the

inlet and outlet water temperatures at 15 second 

intervals throughout the duration of the test. 
-42- 

Temperature rise cannot change by more than 5oF during 

the test. If a sample traverse is required, identify 

the traverse point being sampled on the strip chart

recorder and record the concentration of NO

x

 and CO2 (or 

O

2

) at each point. When the traverse is complete or 

after 15 minutes, whichever is longer, record the water 

and gas meter readings. After 30 minutes record the gas 

and water meter readings. Determine the arithmetic mean 

of the inlet and outlet water temperatures during the 

test. Measure the heating value of the fuel or collect 

a sample of fuel for composition analysis. If an 

integrating sample probe is employed, determine the

arithmetic mean of CO2 (or O2) and NO

x

 concentrations 

measured during each of the last three one-minute 

periods of the test. 
-43- 

9.0 CALCULATIONS 

9.1 CARBON NUMBER 

 The carbon number of the fuel can be determined from 

the measured heating value or determined from gas 

composition analysis. 

 Carbon number based on measured heating value is 

determined from the equation below: 

 2 x Heating Value (Btu/scf) 

 Cf = ————————————————————————————— - 0.130 (1) 

 1771 

 Carbon number based upon gas composition analysis of 

the fuel is determined as follows: 

 C1 + 2C2 + 3C3 + 4C4 + C

o 

 Cf = —————————————————————————— (2) 

 100 

 Where Cf is a dimensionless number; 

 C1 is concentration of methane in fuel, percent; 

 C2 is concentration of ethane in fuel, percent; 

 C3 is concentration of propane in fuel, percent; 

 C4 is concentration of butane in fuel, percent; 

 C

o

 is concentration of CO2 in fuel, percent. 
-44- 

9.2 HEATING VALUE 

 If heating value is measured, H equals that value in 

Btu/dscf. If gas composition analysis is performed, 

determine heating value as follows: 

 First compute the compressibility (Z) of the fuel:

 Z = 1.0 - .001473(C1 x .0116 + C2 x .0239 + 

 C3 x .0344 + C4 x .0480 + C

o

 x .0197 + 

 I x .0044)2 (3) 

 Where "I" is the concentration of Nitrogen in fuel, 

percent; 

 Then calculate the heating value (H) of the fuel as 

follows: 

 H = (C1 x 10.120 + C2 x 17.737 + C3 x 25.221 

 + C4 x 32.70) / Z (4) 

 Where H is the heating value of the fuel in BTU per 

cubic foot at base conditions of 14.73 pounds per square 

inch absolute and 60 degrees Fahrenheit. 
-45- 

9.3 HEAT OUTPUT 

9.3.1 STORAGE TANK WATER HEATERS WITH INPUT RATINGS OF 75,000 

BTU/HR OR LESS

9.3.1.1 Storage Tank Capacity Storage tank capacity is computed 

with the following: 

 Vst = (Wf - Wt)/Ds (5) 

 Where Vst is the storage capacity of the water heaters, 

 gallons; 

 Wf is the weight of the water heater completely filled 

 with water, pounds; 

 Wt is the weight of the empty water heater, pounds; 

 Ds is the density of water at the appropriate 

 temperature, lbs/gallon. 

9.3.1.2 Computation Heat output is computed using the 

following: 

 H

o

 = MCpi(Tdel - Tin) + VstD

n

C

p2(Tmax

 - T

o

) (6) 

 Where H

o

 is heat output, BTU; 

 M is the mass of the water withdrawn, pounds; 

 Cpi is the specific heat of water at the average 

 temperature (Tdel + Tin)/2, BTU/pound oF; 

 Tdel is average delivery temperature, oF; 

 Tin is average inlet temperature, oF; 
-46- 

 Vst is storage tank capacity, gallons (Section 9.3.1.1); 

 D

n

 is the density of water at the average temperature

 (T

max

 + T

o

)/2, pounds/gallon; 

 Cp2 is the specific heat of water at the average 

 temperature (T

max

 + T

o

)/2, Btu/pound oF; 

 T

max

 is the maximum mean tank temperature recorded after 

 cutout following the test draw, oF; 

 T

o

 is the maximum mean tank temperature recorded prior 

 to the test draw, oF. 

9.3.2 STORAGE TANK WATER HEATERS WITH INPUT RATINGS ABOVE 

75,000 BTU PER HOUR, CIRCULATING, AND INSTANTANEOUS

WATER HEATERS, AND POOL HEATERS

 Heat output is computed using the following: 

 H

o

 = Cp

avg

 x (Tdel - Tin) x V x Di (7) 

 Where H

o

 is heat output, BTU; 

 Tdel is the average delivery temperature, oF; 

 Cp

avg

 is the specific heat of water at (Tdel + Tin)/2, 

 BTU/pound oF; 

 Tin is the average inlet temperature, oF; 

 temperature, BTU/pound oF; 

 V is the volume of water withdrawn, gallons; 
-47- 

 Di is the density of water at the average inlet 

 temperature, pounds/gallon. 

9.3.3 STEAM BOILERS Heat output is computed using the 

following: 

 H

o

 = VD x (H

s

 - H

w

) (8) 

 Where H

o

 is heat output, BTU; 

 V is volume of feed water during test, gallons; 

 D is density of water at average delivery temperature, 

 pounds/gallon; 

 H

s

 is the enthalpy of saturated steam at the 

 average delivery temperature, Tdel; Btu/lb; 

 H

w

 is the enthalpy of water at the average 

 inlet temperature, Tin; Btu/lb. 

9.3.4 HOT WATER BOILERS

 Heat output is computed using the following: 

 H

o

 = Cp

avg

 x (Tdel - Tin) x V x Di (9) 

 Where H

o

 is heat output, BTU; 

 Tdel is the average delivery temperature, oF; 

 Cp

avg

 is the specific heat of water at (Tdel + Tin)/2. 

 BTU/pound oF; 
-48- 

 Tin is the average inlet temperature, oF; 

 V is the volume of water withdrawn, gallons; 

 Di is the density of water at the average inlet 

 temperature, pounds/gallon. 

9.4 EMISSION OF NOX

9.4.1 NOx EMISSION (ng/J Heat Output) 

 Compute using the following: 

 5211 x Cf x P x F 

 N = ——————————————————— (10) 

 Ho x C 

 Where N is emissions of NO

x

 as NO2, nanograms/joule 

 (output); 

 P is NO

x

 concentration in flue gas, ppm (vol); 

 Cf is carbon number of fuel, from Section 9.1; 

 F is volume of fuel burned, cubic feet (30 in.Hg, 60oF); 

 C is concentration of CO2 measured in flue gas, percent 

 H

o

, as determined in Section 9.3. 

9.4.2 NOx EMISSION (Concentration at 3% O2) 

 Compute using the following: 

 20.9 - 3 

 N = P ———————————— (11)

 20.9 - %O2 
-49- 

 Where N is emissions of NO

x

 as NO2, concentration 

 corrected to 3% oxygen; 

 P is NO

x

 concentration in flue gas, ppm (vol); 

 %O2 is the concentration of oxygen measured in flue gas, 

 percent. Note that the CO2 concentration (C) in 

 the flue may be related to %O2 using the following 

 relation: 

 %O2 = 20.9 - 1.75 (C) 

9.4.3 NOx EMISSION (lb/MMBtu) 

 Compute using the following: 

 100 

 N = 1.194x10-7 (P)(1040) ————— (12) 

 C 

 Where N is emissions of NO

x

 as NO2, lb/MMBtu 

 (input); 

 P is NO

x

 concentration in flue gas, ppm (vol); 

 C is concentration of CO2 measured in flue gas, percent. 

 The O2 concentration (%O2) in the flue may be 

 related to (C) using the following relation: 

 C = 0.5713 (20.9 - %O2) 
-50- 

10.0 REPORT 

10.1 TEST RESULTS 

 The following forms may be used in reporting test 

results: 

10.1.1 ENVIRONMENT AND HOT WATER PRODUCTION 

 Form A. Storage tank water heaters with input rating of 

75,000 Btu/Hr or less 

 Form B. Storage tank water heaters with input rating 

above 75,000 Btu/Hr, instantaneous and 

circulating water heaters, pool heaters, and hot 

water boilers. 

 Form C. Steam boilers. 

10.1.2 EMISSION MEASUREMENTS 

 Form D. Appliances with vents less than 12 inches in 

diameter. 

 Form E. Appliances with vents 12 inches in diameter and 

larger. 

 Form F. Appliances without vents. 
-51- 

10.1.3 GAS COMPOSITION ANALYSIS 

 Form G. Gas composition analysis and average carbon 

 number 

10.1.4 ANALYZER CALIBRATION AND SAMPLING SYSTEM BIAS TEST 

 Form H. Daily sampling system analyzer calibration

 and bias test 

10.1.5 NO2 CONVERTER EFFICIENCY TEST 

 Form I. Monthly NO2 converter efficiency test 

10.2 FORMS USED FOR PERFORMING THE CALCULATIONS 

10.2.1 CALCULATION OF HEAT OUTPUT 

 Form J. Storage tank water heaters with input rating of 

75,000 Btu/hr or less. 

 Form K. Storage tank water heaters with input rating 

above 75,000 Btu/Hr, Instantaneous and circulating water 

heaters, pool heaters, and hot water boilers. 

 Form L. Steam boilers. 
-52- 

10.2.2 CORRECTION OF GAS METER READING AND DETERMINATION OF 

FIRING RATE 

 Form M. Correction of gas meter reading and 

determination of firing rate. 

10.2.3 CALCULATION OF NO

x

 EMISSIONS 

 Form N. Calculation of NOx Emissions (ng/J Heat Output) 

 Form O. Calculation of NOx Emissions (at 3% Oxygen) 

 Form P. Calculation of NOx Emissions (lb/MMBtu) 
-53-
-54-
-55-




-60-

Run No.: _______________ Date: ____________ 

Form A. STORAGE TANK WATER HEATERS WITH INPUT RATING OF 75,000 

BTU/HR OR LESS. 

WATER HEATER

Manufacturer __________________; Model No.____________; Serial 

No.____________ 

Input Rating: ________BTU/HR 

Water Heater Weight: Full (Wf) _______ ; Empty (Wt) _______ pounds. 

Collection Tank: After Draw _______ ; Empty _______ pounds 

 S T A R T F I N I S H 

Ambient Temperature ________ oF ________ 

o

F 

Relative Humidity ________ % ________ % 

Barometric Pressure ________ in Hg ________ in Hg 

Gas Meter Reading ________ cu ft ________ cu ft 

Gas Pressure ________ in H20 ________ in H20 

Gas Temperature ________ 

o

F ________ 

o

F 

Heating Value of Gas (optional) ________ BTU/Cu.Ft. 

 Mean Tank Temperature at Start of Draw (To) ________ 

o

F 

 Maximum Mean Temperature Following Draw (Tmax) ________ 

o

F 

 Start Time ________ 

 Burner Cut-In ________ 

 Burner Cut-Out ________ 

 Water Inlet (Tin); Hot Water Delivery (Tdel); Temperature (oF). 

 Min:Sec Tin Tdel Min:Sec Tin Tdel Min:Sec Tin Tdel 

 0:15 ____ ____ 1:25 ____ ____ 2:35 ____ ____ 

 0:20 ____ ____ 1:30 ____ ____ 2:40 ____ ____ 

 0:25 ____ ____ 1:35 ____ ____ 2:45 ____ ____ 

 0:30 ____ ____ 1:40 ____ ____ 2:50 ____ ____ 

 0:35 ____ ____ 1:45 ____ ____ 2:55 ____ ____ 

 0:40 ____ ____ 1:50 ____ ____ 3:00 ____ ____ 

 0:45 ____ ____ 1:55 ____ ____ 3:05 ____ ____ 

 0:50 ____ ____ 2:00 ____ ____ 3:10 ____ ____ 

 0:55 ____ ____ 2:05 ____ ____ 3:15 ____ ____ 

 1:00 ____ ____ 2:10 ____ ____ 3:20 ____ ____ 

 1:05 ____ ____ 2:15 ____ ____ 3:25 ____ ____ 

 1:10 ____ ____ 2:20 ____ ____ 3:30 ____ ____ 

 1:15 ____ ____ 2:25 ____ ____ 3:35 ____ ____ 

 1:20 ____ ____ 2:30 ____ ____ 3:40 ____ ____ 
-61- 

Run No.: _______________ Date: ____________ 

Form B. STORAGE TANK WATER HEATERS WITH INPUT RATINGS ABOVE 

75,000 BTU/HR, INSTANTANEOUS AND CIRCULATING WATER 

HEATERS, POOL HEATERS AND HOT WATER BOILERS. 

Manufacturer __________________; Model No.____________; Serial 

No.____________ 

Type ____________; Input Rating: ________BTU/HR 

S T A R T F I N I S H 

Ambient Temperature ________ oF ________ 

o

F 

Relative Humidity ________ % ________ % 

Barometric Pressure ________ in Hg ________ in Hg 

Gas Meter Reading ________ cu ft ________ cu ft 

Gas Pressure ________ in H20 ________ in H20 

Gas Temperature ________ 

o

F ________ 

o

F 

Water Meter Reading ________ gal ________ gal 

Heating Value of Gas (optional) ________ BTU/Cu.Ft.

Start Time ________ 

 Water Inlet (Tin); Hot Water Delivery (Tdel); Temperature (oF). 

Min:Sec Tin Tdel Min:Sec Tin Tdel Min:Sec Tin Tdel 

 0:15 ____ ____ 5:15 ____ ____ 10:15 ____ ____ 

 0:30 ____ ____ 5:30 ____ ____ 10:30 ____ ____ 

 0:45 ____ ____ 5:45 ____ ____ 10:45 ____ ____ 

 1:00 ____ ____ 6:00 ____ ____ 11:00 ____ ____ 

 1:15 ____ ____ 6:15 ____ ____ 11:15 ____ ____ 

 1:30 ____ ____ 6:30 ____ ____ 11:30 ____ ____ 

 1:45 ____ ____ 6:45 ____ ____ 11:45 ____ ____ 

 2:00 ____ ____ 7:00 ____ ____ 12:00 ____ ____ 

 2:15 ____ ____ 7:15 ____ ____ 12:15 ____ ____ 

 2:30 ____ ____ 7:30 ____ ____ 12:30 ____ ____ 

 2:45 ____ ____ 7:45 ____ ____ 12:45 ____ ____ 

 3:00 ____ ____ 8:00 ____ ____ 13:00 ____ ____ 

 3:15 ____ ____ 8:15 ____ ____ 13:15 ____ ____ 

 3:30 ____ ____ 8:30 ____ ____ 13:30 ____ ____ 

 3:45 ____ ____ 8:45 ____ ____ 13:45 ____ ____ 

 4:00 ____ ____ 9:00 ____ ____ 14:00 ____ ____ 

 4:15 ____ ____ 9:15 ____ ____ 14:15 ____ ____ 

 4:30 ____ ____ 9:30 ____ ____ 14:30 ____ ____ 

 4:45 ____ ____ 9:45 ____ ____ 14:45 ____ ____ 

 5:00 ____ ____ 10:00 ____ ____ 15:00 ____ ____ 
-62- 

Run No.: _______________ Date: ____________ 

Form C. STEAM BOILERS (Page 1 of 2)

STEAM BOILER

Manufacturer __________________; Model No.____________; Serial 

No.____________ 

Input Rating: ________BTU/HR 

S T A R T F I N I S H 

Ambient Temperature ________ oF ________ 

o

F 

Relative Humidity ________ % ________ % 

Barometric Pressure ________ in Hg ________ in Hg 

Gas Meter Reading ________ cu ft ________ cu ft 

Gas Pressure ________ in H20 ________ in H20 

Gas Temperature ________ 

o

F ________ 

o

F 

Water Meter Reading ________ gal ________ gal 

Steam Drum Pressure ________ psig ________ psig 

Manifold Pressure ________ in H20 ________ in H20 

Heating Value of Gas (optional) ________ BTU/Cu.Ft.

Start Time ________ 

Record inlet and outlet temperatures on Page 2. 
-63- 

Run No.: _______________ Date: ____________ 

Form C. STEAM BOILERS (Page 2 of 2) 

 Water Inlet (Tin); Steam Delivery (Tdel); Temperature (oF). 

Min:Sec Tin Tdel Min:Sec Tin Tdel Min:Sec Tin Tdel 

 0:15 ____ ____ 10:15 ____ ____ 20:15 ____ ____ 

 0:30 ____ ____ 10:30 ____ ____ 20:30 ____ ____ 

 0:45 ____ ____ 10:45 ____ ____ 20:45 ____ ____ 

 1:00 ____ ____ 11:00 ____ ____ 21:00 ____ ____ 

 1:15 ____ ____ 11:15 ____ ____ 21:15 ____ ____ 

 1:30 ____ ____ 11:30 ____ ____ 21:30 ____ ____ 

 1:45 ____ ____ 11:45 ____ ____ 21:45 ____ ____ 

 2:00 ____ ____ 12:00 ____ ____ 22:00 ____ ____ 

 2:15 ____ ____ 12:15 ____ ____ 22:15 ____ ____ 

 2:30 ____ ____ 12:30 ____ ____ 22:30 ____ ____ 

 2:45 ____ ____ 12:45 ____ ____ 22:45 ____ ____ 

 3:00 ____ ____ 13:00 ____ ____ 23:00 ____ ____ 

 3:15 ____ ____ 13:15 ____ ____ 23:15 ____ ____ 

 3:30 ____ ____ 13:30 ____ ____ 23:30 ____ ____ 

 3:45 ____ ____ 13:45 ____ ____ 23:45 ____ ____ 

 4:00 ____ ____ 14:00 ____ ____ 24:00 ____ ____ 

 4:15 ____ ____ 14:15 ____ ____ 24:15 ____ ____ 

 4:30 ____ ____ 14:30 ____ ____ 24:30 ____ ____ 

 4:45 ____ ____ 14:45 ____ ____ 24:45 ____ ____ 

 5:00 ____ ____ 15:00 ____ ____ 25:00 ____ ____ 

 5:15 ____ ____ 15:15 ____ ____ 25:15 ____ ____ 

 5:30 ____ ____ 15:30 ____ ____ 25:30 ____ ____ 

 5:45 ____ ____ 15:45 ____ ____ 25:45 ____ ____ 

 6:00 ____ ____ 16:00 ____ ____ 26:00 ____ ____ 

 6:15 ____ ____ 16:15 ____ ____ 26:15 ____ ____ 

 6:30 ____ ____ 16:30 ____ ____ 26:30 ____ ____ 

 6:45 ____ ____ 16:45 ____ ____ 26:45 ____ ____ 

 7:00 ____ ____ 17:00 ____ ____ 27:00 ____ ____ 

 7:15 ____ ____ 17:15 ____ ____ 27:15 ____ ____ 

 7:30 ____ ____ 17:30 ____ ____ 27:30 ____ ____ 

 7:45 ____ ____ 17:45 ____ ____ 27:45 ____ ____ 

 8:00 ____ ____ 18:00 ____ ____ 28:00 ____ ____ 

 8:15 ____ ____ 18:15 ____ ____ 28:15 ____ ____ 

 8:30 ____ ____ 18:30 ____ ____ 28:30 ____ ____ 

 8:45 ____ ____ 18:45 ____ ____ 28:45 ____ ____ 

 9:00 ____ ____ 19:00 ____ ____ 29:00 ____ ____ 

 9:15 ____ ____ 19:15 ____ ____ 29:15 ____ ____ 

 9:30 ____ ____ 19:30 ____ ____ 29:30 ____ ____ 

 9:45 ____ ____ 19:45 ____ ____ 29:45 ____ ____ 

 10:00 ____ ____ 20:00 ____ ____ 30:00 ____ ____ 
-64- 

Run No.: _______________ Date: ____________ 

Form D. EMISSION MEASUREMENTS - Appliances with vents less than 12 

inches in diameter. 

Type ___________________; Manufacturer _____________________; 

Model No.________________; Serial No. _______________________. 

 Z E R O G A S S P A N G A S 

ANALYZERS Manufacturer Model Serial No. Value Reading Value Reading 

CO2 (O2) ___________ _____ _________ _____ _______ _____ _______ 

NOx ___________ _____ _________ _____ _______ _____ _______ 

CO ___________ _____ _________ _____ _______ _____ _______ 

CONCENTRATION MEASUREMENTS CO2 (or O2) - %; NOx - ppm; CO - ppm 

CO2/O2 NO

X

 CO

Last minute before cut-out 

or end of test _____ _____ ____ 

Next to last minute _____ _____ ____ 

Preceding minute _____ _____ ____ 
-65- 

Run No.: _______________ Date: ____________ 

Form E. EMISSION MEASUREMENTS - Appliances with vents 12 inches in 

diameter and larger. 

Type_________; Manufacturer____________; Model No.________; Serial No.________ 

 Z E R O G A S S P A N G A S 

ANALYZERS Manufacturer Model Serial No. Value Reading Value Reading 

CO2 (or O2) ___________ _____ _________ _____ _______ _____ _______ 

NO

X

 ___________ _____ _________ _____ _______ _____ _______ 

CO ___________ _____ _________ _____ _______ _____ _______ 

CONCENTRATION MEASUREMENTS CO2 (or O2) - %; NO

X

 - ppm; CO - ppm 

 Point CO2/O2 NO

X

 CO Point CO2 NO

X

 CO 

 1 ____ ____ ____ 9 _____ _____ ____ 

 2 ____ ____ ____ 10 _____ _____ ____ 

 3 ____ ____ ____ 11 _____ _____ ____ 

 4 ____ ____ ____ 12 _____ _____ ____ 

 5 ____ ____ ____ 13 _____ _____ ____ 

 6 ____ ____ ____ 14 _____ _____ ____ 

 7 ____ ____ ____ 15 _____ _____ ____ 

 8 ____ ____ ____ 16 _____ _____ ____ 

Circle the eight highest CO2 concentrations. 

 Traverse Points 

 Ref: 6.3.1.2 
-66- 

Run No.: _______________ Date: ____________ 

Form F. APPLIANCES WITHOUT VENTS 

Type_________; Manufacturer____________; Model No.________; Serial No.________ 

 Z E R O G A S S P A N G A S 

ANALYZERS Manufacturer Model Serial No. Value Reading Value Reading 

CO2 (or O2) ___________ _____ _________ _____ _______ _____ _______ 

NO

X

 ___________ _____ _________ _____ _______ _____ _______ 

CO ___________ _____ _________ _____ _______ _____ _______ 

CONCENTRATION MEASUREMENTS CO2 (or O2) - %; NO

X

 - ppm; CO - ppm 

 Point CO2/O2 NO

X

 CO Point CO2 NO

X

 CO 

 1 ____ ____ ____ 9 _____ _____ ____ 

 2 ____ ____ ____ 10 _____ _____ ____ 

 3 ____ ____ ____ 11 _____ _____ ____ 

 4 ____ ____ ____ 12 _____ _____ ____ 

 5 ____ ____ ____ 13 _____ _____ ____ 

 6 ____ ____ ____ 14 _____ _____ ____ 

 7 ____ ____ ____ 15 _____ _____ ____ 

 8 ____ ____ ____ 16 _____ _____ ____ 

Circle the eight highest CO2 concentrations. 

 Traverse Points 

 Ref: 6.3.1.2 
-67- 

Run No.: _______________ Date of Run: _________________ 

Date of Analysis: ____________ 

Form G. GAS COMPOSITION ANALYSIS 

ANALYZER: Manufacturer______________; Model No._________; Serial No.__________ 

Heating Value Measurement if Performed: 

Measured Heating Value: _____________ 

Cf based on Heating Value (from Section 9.1): ______________ 

Gas Chromatograph Analysis if Performed: 

 S p a n G a s S a m p l e R e a d i n g 

COMPONENT Value Reading #1 #2 #3 Average 

Ethane (C2) _____% _______% _____% _____% _____% _______% 

Propane (C3) _____% _______% _____% _____% _____% _______% 

Butane+ (C4) _____% _______% _____% _____% _____% _______% 

Nitrogen (I) _____% _______% _____% _____% _____% _______% 

Carbon 

Dioxide (Co) _____% _______% _____% _____% _____% _______% 

TOTAL _____% _____% _____% _______% 

Methane (C1) (100%-Total) _____% _____% _____% _______% 

 Cf CALCULATION 

 1. Methane Contribution C1/100.0 __________ 

 2. Ethane Contribution C2/50.0 __________ 

 3. Propane Contribution C3/33.33 __________ 

 4. Butane Contribution C4/25.0 __________ 

 5. CO2 Contribution C0/100.0 __________ 

 6. Total is Cf __________ 
-68- 

Date: _________________ 

Form H. CALIBRATION CHECK AND SAMPLING SYSTEM BIAS TEST. Must be 

conducted before and after each day of testing. 

(Page 1 of 2) 

START OF DAY 

 Time: ______________ 

 Analyzer Response System Response BIAS 

 Value CO2* NOx CO CO2* NOx CO % of Range 

Zero Gas _____ ___ ___ ___ ___ ___ ___ __________ 

CO2

*

 Span _____ ___ X X ___ X X __________ 

NOx Span _____ X ___ X X ___ X __________ 

CO Span _____ X X ___ X X ___ __________ 

END OF DAY 

 Time: ______________ 

 Analyzer Response System Response BIAS 

 Value CO2

*

 NOx CO CO2

*

 NOx CO % of Range 

Zero Gas _____ ___ ___ ___ ___ ___ ___ __________ 

CO2

*

 Span _____ ___ X X ___ X X __________ 

NOx Span _____ X ___ X X ___ X __________ 

CO Span _____ X X ___ X X ___ __________ 

 DRIFT (% of range) 

 Zero ________ 

 CO2

*

 ________ 

*

 CO2 or O2 Analyzer 

 NOx ________ 

 CO ________ 

If system bias and/or drift for the CO2, O2, or NOx analysis exceeds 

the ranges specified in this protocol, all tests for the day are void. 
-69- 

Date: _________________ 

Form H. CALIBRATION CHECK AND SAMPLING SYSTEM BIAS TEST. 

Must be conducted before and after each day of testing (Page 

2 of 2) 

Analyzer: 

Range: 

 

Cylinder 

Value 

(Indicate 

Units) 

Analyzer 

Calibration 

Response 

(Indicate 

Units) 

Absolute 

Difference 

(Indicate 

Units) 

Difference 

(Percent 

of 

Range) 

Zero Gas 

 

Mid-Range 

Gas 

 

High-Range 

Gas 

 

 Linearity Error percent range 
-70- 

Date: _________________ 

Form I. NO2 CONVERTER EFFICIENCY TEST. Must be performed 

monthly. 

ANALYZER CALIBRATION 

 Analyzer 

 Value Reading 

Zero Gas _______ ________ 

 

Span Gas _______ ________ 

CONVERTER TEST 

 Time Analyzer 

 Reading 

Start _______ ________ 

Max Reading _______ ________ 

Finish _______ ________ 

If final analyzer reading is more than 2.0% less than the 

maximum analyzer reading, the converter must be repaired or 

replaced. 
-71- 

Run No.: _______________ Date: ____________ 

Form J. CALCULATION OF HEAT OUTPUT - STORAGE TANK WATER HEATERS WITH 

INPUT RATING OF 75,000 BTU/HR OR LESS (Page 1 of 2). 

A. STORAGE TANK CAPACITY 

 1. Wf, weight of water heater filled with 

 water (Form A) _______ pounds 

 2. Wt, weight of empty water heater (Form A) _______ pounds 

 3. Ds, density of water at the temperature 

 weighted * _______ pounds/gal 

 4. Vst, storage tank capacity is: 

 Vst = (Wf - Wt) / Ds 

 Substituting the corresponding line 

 numbers gives: 

 (1 - 2)/3 _______ gallons 

B. HEAT OUTPUT 

 5. Weight of collection tank and water 

 at end of test (Form A) _______ pounds 

 6. Tare weight of collection tank (Form A) _______ pounds 

 7. M, mass of water withdrawn (lines 5-6) _______ pounds 

 8. Tdel, average delivery temperature, sum 

 of all outlet temperatures on Form A 

 divided by number of measurements _______ oF 

 9. Tin, average inlet temperature, sum of 

 all inlet temperatures on Form A divided 

 by number of measurements _______ oF 

 10. Average of inlet and outlet temperature is 

 (Tdel + Tin)/2.0 

 substituting the corresponding line 

 numbers gives 

 (8 + 9)/2.0 _______ oF 

* The values of these parameters may be found in handbooks such as 

Perry's Chemical Engineers Handbook. Use correct units. 
-72- 

 11. Cpi, specific heat of water at temperature 

 in line 10* _______ BTU/lboF 

 12. Tmax, maximum mean tank temperature after 

 cut-out (Form A) _______ oF 

 13. To, initial mean tank temperature 

 (Form A) _______ 

o

F 

 14. Average tank temperature is (Tmax + To)/2 _______ 

o

F 

 15. Dn, density of water at the temperature 

 in line 14.* _______ lb/gal 

 16. Cp2, specific heat of water at the 

 temperature in line 14.* _______ BTU/lboF 

 17. Ho, heat output is 

 Ho = M x Cpi x (Tdel-Tin) + Vst x Dn x Cp2 x (Tmax-To), 

 substituting the corresponding line numbers gives: 

 Ho = 7 x 11 x (8-9) + 4 x 15 x 16 x (12-13) _______ BTU 

* The values of these parameters may be found in handbooks such as 

Perry's Chemical Engineers Handbook. Use correct units. 
-73- 

Run No.: _______________ Date: ____________ 

Form K. CALCULATION OF HEAT OUTPUT - Storage Tank Water Heaters With Input 

Rating Above 75,000 BTU/HR, Instantaneous and Circulating Water 

Heaters, Pool Heaters and Hot Water Boilers. 

A. HEAT OUTPUT 

 1. Tdel, average delivery temperature, sum of all 

 delivery temperatures in Form B divided by 

 number of measurements (60 if 15 min. test) _______ 

o

F 

 2. Tin, average inlet temperature, sum of all 

 inlet temperatures in Form B divided by 

 number of measurements (60 if 15 min. test) _______ 

o

F 

 3. Tavg, (Tdel + Tin) / 2 _______ oF 

 4. Cp

avg

, specific heat of water at the temperature 

 in line 3.* _______ BTU/lboF 

 5. V, volume of water withdrawn, final water 

 meter reading - initial water meter 

 reading (Form B) _______ gallons 

 6. Di, density of water at the average inlet 

 temperature (line 2)* _______ lbs/gal 

 7. Ho, heat output is: 

 Ho= Cp

avg

 x (Tdel - Tin) x V x Di 

 substituting the corresponding line number 

 gives: 

 4 x (1 - 2) x 5 x 6 _______ BTU 

* The values of these parameters may be found in handbooks such as 

Perry's Chemical Engineers Handbook. Use correct units. 
-74- 

Run No.: _______________ Date: ____________ 

Form L. CALCULATION OF HEAT OUTPUT - STEAM BOILERS.

A. HEAT OUTPUT - STEAM BOILERS 

 1. V, volume of feed water during test, final 

 water meter reading - initial water meter 

 reading (Form B) _______ gallons 

 2. Tdel, average delivery temperature, sum of 

 all delivery temperatures in Form C 

 divided by number of measurements (120 if 

 30 minute test) _______ oF 

 3. Tin, average inlet temperature, sum of all 

 inlet temperatures in Form C divided by 

 number of measurements(120 if 30 min.test) _______ 

o

F 

 4. Hs, enthalpy of saturated steam at 

 the average delivery temperature, line 2*. _______ BTU/lb 

 5. Hw, the enthalpy of water at the 

 average inlet temperature, line 3*. _______ BTU/lb 

 6. D, density of water at the average inlet 

 temperature (line 3)* _______ lbs/gal 

 7. Ho, heat output is: 

 Ho= V x D x (Hs - Hw) 

 substituting the corresponding line number 

 gives: 

 1 x 6 x (4 - 5) _______ BTU 

* The values of these parameters may be found in handbooks such as 

Perry's Chemical Engineers Handbook. Use correct units. 
-75- 

Run No.: _______________ Date: ____________ 

Form M. CORRECTION OF GAS METER READING AND DETERMINATION OF FIRING 

RATE 

A. CORRECTION OF GAS METER READING 

 1. Final Gas Meter Reading (Form A, B, or C) _______ cu.ft. 

 2. Initial Gas Meter Reading (Form A, B, or C) _______ cu.ft. 

 3. Uncorrected Volume of Gas Burned 

 (Line 1 - Line 2) _______ cu.ft. 

 4. Gas Pressure (Form A, B, or C)* _______ in H20 

 5. Barometric Pressure (Form A, B, or C) _______ in Hg 

 6. Pressure Correction to 30 in Hg is 

 ((Line 5 + (Line 4 / 13.57)) / 30.0 _______ No Units 

 7. Gas Temperature (Form A, B, or C)* _______ oF 

 8. Temperature Correction to 60oF is: 

 519.7 / (Line 7 + 459.7) _______ No Units 

 9. Meter Correction Factor (from Meter 

 Calibration Curves) _______ No Units 

 10. Corrected Volume of Gas Burned 

 (Line 3 x Line 6 x Line 8 x Line 9) _______ cu.ft. 

B. FIRING RATE 

 11. Time of Burner Operation From Form A,B, or C _______ minutes 

 12. Heating Value of Fuel from Form A, B, or C, or

 compute using equations in Section 9.2 _______ BTU 

 13. Firing Rate 

 Line 12 x Line 10 x (60/Line 11) _______ BTU/HR

* If initial and final values are different, record the average. 
-76- 

Run No.: _______________ Date: ____________ 

Form N. CALCULATION OF NOx EMISSIONS (ng/J Heat Output Basis) 

1. Cf, average carbon number of fuel (Form G) _______ No Units 

2. C, percent of CO2 measured. If an integrating 

 sample probe was used, the percent CO2 is the 

 average of the three measurements from Form D. 

 If a traverse was required, the percent CO2 is 

 the average of the eight highest readings 

 recorded in Form E or F. _______ % 

3. P, is part per million NOx measured. Use the 

 average of the NOx readings from the sample 

 points which were used to determine the average 

 CO2 reading in Line 2. _______ ppm 

4. F is the corrected fuel burned (Form M) _______ cu.ft. 

5. Ho is the heat output (Form J, K, or L) _______ BTU 

6. N is the NOx emissions 

 5211 x Cf x P x F 

 N = ————————————————— 

 Ho x C 

 Substituting the corresponding line numbers 

 gives 

 5211.0 x 1 x 3 x 4/(5 x 2) _______ nanograms 

 per joule 
-77- 

Run No.: _______________ Date: ____________ 

Form O. CALCULATION OF NOx EMISSIONS (Corrected to 3% Oxygen) 

1. C, percent of CO2 measured. If an integrating 

 sample probe was used, the percent CO2 is the 

 average of the three measurements from Form D. 

 If a traverse was required, the percent CO2 is 

 the average of the eight highest readings 

 recorded in Form E or F. _______ % 

2. %O2, percent of O2 measured. If an integrating 

 sample probe was used, the percent O2 is the 

 average of the three measurements from Form D. 

 If a traverse was required, the percent O2 is 

 the average of the eight lowest readings 

 recorded in Form E or F. If %O2 is calculated 

 from CO2 measurements, use the following equation: 

 %O2 = 20.9 - 1.75 (C) 

 where C is the reading from Line 1 _______ % 

3. P, is part per million NOx measured. Use the 

 average of the NOx readings from the sample 

 points which were used to determine the average 

 CO2 reading in Line 2. _______ ppm 

4. N is the NOx emissions Corrected to 3% Oxygen 

 20.9 - 3 

 N = P x ———————————— 

 20.9 - %O2 

 Substituting the corresponding line numbers 

 gives 

 (Line 3) x (17.9)/(20.9 - Line 2) _______ ppm @ 3% 

 oxygen 
-78- 

Run No.: _______________ Date: ____________ 

Form P. CALCULATION OF NOx EMISSIONS (lb/MMBtu) 

1. C, percent of CO2 measured. If an integrating 

 sample probe was used, the percent CO2 is the 

 average of the three measurements from Form D. 

 If a traverse was required, the percent CO2 is 

 the average of the eight highest readings 

 recorded in Form E or F. If C is calculated 

 from O2 measurements, use the following equation: 

 %CO2 = 0.5713 (20.9 - %O2) 

 where %O2 is the averaged reading from 

 Form O, Line 2. _______ % 

2. P, is part per million NOx measured. Use the 

 average of the NOx readings from the sample 

 points which were used to determine the average 

 CO2 (or O2) reading in Line 2. _______ ppm 

3. N is the NOx emissions 

 100 

 N = 1.194x10-7 (P)(1040) ————— 

 C 

 Substituting the corresponding line numbers 

 gives 

 0.01242 (Line 2/ Line 1) _______ lb/MMBtu 

 
APPENDIX A 

SCAQMD METHOD 100.1 

Method 100.1 can be found at this location: 

http://www.aqmd.gov/tao/methods/stm/stm-100-1.pdf
APPENDIX B 

NO2 to NO Conversion Efficiency 
NO2

 to NO Conversion Efficiency 

Add gas from the mid-level NO in N2 calibration gas cylinder to 

a clean, evacuated, leak-tight Tedlar bag. Dilute this gas 

approximately 1:1 with 20.9 percent O2 purified air. 

Immediately attach the bag outlet to the calibration valve 

assemble and begin operation of the sampling system. Operate 

the sampling system, recording the NO

x

 response, for at least 30 

minutes. If the NO2 to NO conversion is 100 percent, the 

instrument response will be stable at the highest peak value 

observed. If the response at the end of 30 minutes decreases 

more than 2.0 percent of the highest peak value, the system is 

not acceptable and corrections must be made before repeating the 

check.