APPENDIX N TO SUBPART B OF PART 430-UNIFORM TEST METHOD FOR MEASURING THE ENERGY CONSUMPTION OF FURNACES

1. Definitions. Definitions shall include the definitions specified in section 3.0 of ANSI ASHRAE 103-82 and the following additional definitions:

1.1 ASHRAE means the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

1.2 ANSI/ASHRAE 103-82 means the test standard published in 1982 by ASHRAE, approved by the American National Standards Institute (ANSI) on June 21, 1983 and titled "Methods of Testing for Heating Seasonal Efficiency of Central Furnaces And Boilers."

1.3 Electro-mechanical stack damper means a type of stack damper which is operated by electrical and/or mechanical means.

1.4 Isolated combustion system means an installation in which a furnace is installed indoors and all combustion and ventilation air is admitted through grills or ducts from outdoors and (all such air) does not communicate with air in the conditioned space.

1.5 Modulating control means either a step modulating or a "two-stage control"

1.6 Reduced heat input rate means the factory adjusted lowest reduced heat input rate for furnaces equipped with either two stage thermostats or step-modulating thermostats.

1.7 Single stage thermostat means a thermostat that cycles a burner from the maximum heat input rate and off.

1.8 Step-modulating control means a modulating control that cycles a burner from the reduced input rate to off if the heating load is light. If a higher heating load is encountered which cannot be met with the reduced input rate, the control either gradually increases or steps up the input rate to meet the higher heating load. At that point if a

trol either gradually decreases or steps down to a lower rate, or gradually increases the heat input to meet any higher heating load that cannot be met with the low firing rate. 1.9 Thermal stack damper means a type of stack damper which is dependent for operation exclusively upon the direct conversion of thermal energy of the stack gases into closure of the damper.

1.10 Two stage control means a modulating control that cycles a burner from reduced heat input rate and off or cycles a burner at the maximum heat input rate and off.

2.0 Testing conditions. The testing conditions shall be as specified in section 8 of ANSI/ASHRAE 103-82 with the exception of section 8.4.2.3, and the inclusion of the following additional testing conditions:

2.1 Gas burner adjustment at maximum input rate. The following paragraph is in addition to the requirements specified in section 8.4.1.1 of ANSI/ASHRAE 103-82:

For gas fueled furnaces and boilers equipped with modulating type controls, adjust the controls to operate the unit at the maximum fuel input rate. Set the thermostat control to the maximum setting. Start the furnace or boiler by turning the safety control valve to the "on" position. Use a supply water temperature for boilers that will allow for continuous operation without shut off by the thermostat control.

2.2 Gas burner adjustment at reduced input rate. The following paragraph is in addition to the requirements specified in section 8.4.1.1 of ANSI/ASHRAE 103-82:

For gas fueled furnaces and boiler equipped with modulating type thermosta controls, adjust the controls to operate the unit at the reduced fuel input rate. Set the thermostat control to the lowest settin that does not cause the burner to cycle o and off. Start the furnace or boiler by turn ing the safety control valve to the "on" posi tion. Use supply water temperature for boll ers that will allow for continuous operatio without shut off by the thermostat control If necessary, supply water may be increase above 120° F in order to maintain continuou operation at the reduced setting.

2.3 Gas and oil fueled low pressure stea and hot water boilers (including direct vent tems). The following paragraphs are in pls of section 8.4.2.3 of ANSI/ASHRAE 103-83:

For non-condensing hot water boilers, water flow rate shall be adjusted to produ a water temperature rise, during the stead state test described in section 9.1 of AN ASHRAE 103-82, of 19° F -24° F. During steady-state and heat-up tests, the hot wat boiler shall be supplied with water having temperature of at least 120° F but not me than 124° F.

For steam boilers, the pressure shall be atmospheric or at a pressure not exceeding psig during the steady-state test.

3.0 Test procedure. Testing and measurements shall be as specified in section 9 of ANSI/ASHRAE 103-82 with the exception of sections 9.2.2 and 9.3.2, and the inclusion of the following additional procedures:

3.1 Gas fueled gravity furnaces, forced air central furnaces, and low pressure steam and hot water boilers (including direct vent systems, excluding condensing furnaces or boilers). The following paragraphs are in addition to the requirements specified in section 9.1.1 of ANSI/ASHRAE 103–82:

For all gas fueled furnaces and boilers, the steady-state efficiency shall be determined at the maximum fuel input rate measured in accordance with sections 2.1 of this appendix and section 9.1.1 of ANSI/ASHRAE 103-82. Also, for gas fueled furnaces and boilers equipped with either two stage thermostats or step-modulating thermostats, the steadystate efficiency shall also be determined at the reduced fuel input rate measured in accordance with sections 2.2 of this appendix and section 9.1.1 of ANSI/ASHRAE 103–82.

In addition, for gas fueled furnances and boilers equipped with draft hoods, measure CO2 in stack after dilution during the steady state condition.

3.2 Flue temperature

measurements-cool down test. The following paragraphs are in addition to the requirements specified in section 9.2 of ANSI/ASHRAE 103–82:

For furnaces and boilers equipped with step-modulating thermostats, the cool down test shall be conducted after steady-state conditions have been reached at the reduced input rate, as specified in section 2.2 of this appendix. For furnaces and boilers equipped with two stage controls, separate cool down tests shall be conducted after steady-state conditions have been reached at both the refuced and maximum fuel input rates.

3.3 Gas and oil fueled boilers-cool down est. The following paragraphs are in place of The requirements specified in section 9.2.2 of SHRAE 103-82:

After steady-state testing has been completed, turn the main burner(s) off and measare the flue gas temperature at 3.75 (TF.OFF(13)) ad 22.5 (TF.OFF(4) minutes after the burner huts off, using the thermocouple grid decribed above. During this off period for nits that do not have pump delay after hut-off, no water shall be allowed to cirulate through the hot water boilers. For mits that have pump delay on shut-off, exept those having pump controls sensing ater temperature, the pump shall be sopped by the unit control and the time, t*, etween burner shut-off and pump shut-off hall be measured within one second accuacy. For units having pump delay controls hich sense water temperature, the pump all be operated for 15 minutes and t⚫ shall 15 minutes. While the pump is operating. he inlet water temperature and flow rate

shall be maintained at the same values as used during the preceding steady-state test. Make a third flue gas temperature measurement 45 minutes after the burner shuts off to determine the off-period minimum flue gas temperature (TF.OFF(~)).

During this cool down test, measure the energy input rate to the pilot light (QP), if the unit is so equipped, to within an error no larger than ± 3 percent. Record all measured values. For oil fueled units not equipped with stack dampers, maintain the draft in the flue within the same ranges specified in section 9.2.1 of ANSI/ASHRAE 103-82. For direct vent systems with flue dampers or boilers equipped with both stack dampers and barometric dampers, close the flue or stack damper during the cool down test.

3.4 Flue gas temperature measurementsheat-up test. The following paragraph is in addition to the requirement specified in section 9.3 of ANSI/ASHRAE 103–82.

For furnaces and boilers equipped with step-modulating thermostats, the heat-up test shall be conducted at the reduced fuel input rate, as specified in section 2.2 of this appendix. For furnaces and boilers equipped with two stage controls, separate heat-up tests shall be conducted at both the reduced and maximum fuel input rates.

3.5 Gas and oil fueled boilers. The following paragraph is in place of the requirements specified in section 9.3.2 of ANSI/ASHRAE 103-82.

Fifty minutes or more after the main burner(s) is turned off for the cool down test, turn on the steam or hot water boiler and measure the flue gas temperature at 1.0 (Tom)) and 5.5 (Tron(12)) minutes after the main burners are turned on. The pump circulating the water through the hot water boiler shall be started simultaneously with the main burner(s). The water flow rate shall be the same as that maintained during the steady-state test described in section 9.1 of ANSVASHRAE 103-82. During the heat-up test for oil fired boilers maintain the draft in the flue pipe within ± 0.01 inch of water column of the manufacturer's recommended onperiod draft. Record the measured temperatures.

3.6 Direct measurement of condensate. For condensing furnaces and boilers, the condensate heat loss shall be determined either by the method specified in section 11.2.33 of ANSVASHRAE 103-82 or by the following test procedures:

Control devices shall be installed to allow cyclical operation of the unit and return water or air flows as described in sections 9.2 and 9.3 of ANSI/ASHRAE 103-82 and sections 3.2, 3.3, 3.4 and 3.5 of this appendix. The test unit shall be leveled prior to test. Operating times and beginning and end of condensate collection shall be determined by a clock or timer with a minimum resolution of one sec

ond. Humidity of the room air shall, at no time, exceed 80 percent.

Control of on or off operation actions shall be within ± 6 seconds of the scheduled time. Condensate drain lines shall be attached to the unit as specified in the manufacturer's installation instructions. A continuous downward slope of drain lines from the unit shall be maintained. Additional precautions shall be taken to facilitate uninterrupted flow of condensate during the test.

The flue pipe installation must not allow condensate formed in the flue pipe to flow back into the unit. An initial downward slope from the unit's exit, an offset with a drip leg, annular collection rings, or drain holes must be included in the flue pipe installation without disturbing normal flue gas flow, as specified in section 7.2.2 of ANSI/ ASHRAE 103-82. Flue gases should not flow out of the drain with the condensate.

Collection-containers must be glass or polished stainless steel, so removal of interior deposits can be easily made. The collectioncontainer shall have a vent opening to the atmosphere.

The scale for measuring the containers and sample condensate mass shall be calibrated with an error no larger than ± 0.5 percent over the range of interest.

The condensing furnace or boiler shall be tested by the flue loss method in accordance with the provisions for condensing units, as specified in section 9 of ASNVASHRAE 103-82 and section 3 of this appendix. The condensate collection-containers shall be dried prior to each use and shall be at room ambient temperature prior to a sample collection. Tare weight of the collection-container must be measured and recorded prior to each sample collection.

The unit should be operated in a cyclical manner until flue gas temperatures at the end of each on-cycle are within 5° F (2.8° C) of each other for two consecutive cycles. Oncycle and off-cycle times are listed in Table 2 of this appendix. Begin three test cycles. Return air temperature for furnaces shall be as specified in section 9 of ANSI/ASHRAE 103-82 and section 3 of this appendix. Return water temperature for boilers shall be as specified in section 2.3 of this appendix. Operation of the furnace blower or boiler pump shall conform to the time delay requirements specified in sections 9.2 and 9.3 of ANSI/ASHRAE 103-82 and sections 3.2, 3.3, 3.4, and 3.5 of this appendix for cool down and heat up tests. Operation of the boiler pump shall conform to the time delay requirements specified in section 3.3 of this appendix.

Begin condensate collection at one minute before the on-cycle period of the first test cycle. The container shall be removed one minute before the end of each off-cycle period of the sixth test cycle. Condensate mass shall be measured for each test cycle.

Fuel input shall be recorded during the entire test period starting at the beginning of the on-time period of the first cycle to the beginning of the on-time period of the second cycle, etc., for each of the test cycles. Fuel higher heating value (HHV), temperature and pressures necessary for determining fuel energy input (Q.) shall be recorded. The fuel quantity and HHV shall be measured with errors no greater than one percent. Determine the mass of condensate for each cycle (m.) in pounds. If at the end of three cycles, the sample standard deviation is within 20% of the mean value for 3 cycles use total condensate collected in the three cycles as me, if not, continue collection for an additional three cycles and use the total condensate collected for the six cycles as me. Determine the fuel energy input during the three or six test cycles (Q) expressed in Btu.

Begin a steady-state condensate collection after steady-state conditions have been achieved as specified in section 8 of ANSI/ ASHRAE 103-82 and section 2 of this appendix. The steady-state collection period shall be 30 minutes. Condensate mass shall be measured immediately at the end of the collection period to prevent evaporation loss from the sample. Fuel input shall be recorded for the one hour steady-state test period. Fuel Higher Heating Value (HHV), temperature and pressures necessary for determining fuel energy input Qc.ss will be ob served and recorded in Btu's. The fuel quantity and HHV shall be measured with errors no greater than one percent. Determine the mass of condensate for the steady-state test, mc.ss, in pounds by subtracting the tare container weight from the total container ande condensate weight measured at the end of the 30 minutes test period.

3.7 Direct measurement of off-cycle losses testing method. Reserved.

3.8 Direct measurement of the S/F factors for. oil furnaces and boilers. For oil furnaces and boilers that are marketed and sold with st tached barometric dampers, the S/F facto shall be determined either by using assigned factors in Table 2 of ANSI/ASHRAE 103–82 o by the following test procedure:

To directly measure the S/F factor, ses the barometric damper plate in the closed position. Operate the furnace or boiler unti steady-state temperatures are attained. Ad just the draft in the flue within one foot ₫ the heat exchanger exit to be between 0.0 and 0.085 inch water column. A mechanical draft inducer or a natural draft developed b adjusting the height of the test stack may bil used. Remove the seal from the barometri damper and adjust the damper gate t achieve proper draft, as specified by th manufacturer. If the draft over the fire specified as a range, adjust the draft to th mid-point of that range.

After steady-state conditions are agail achieved with the draft adjusted as specified

6.1.3

Distribution of Actual Cooling Load Hours (CLH) Throughout the United States