Appendix X1 to Subpart B of Part 430 - —Uniform Test Method for Measuring the Energy Consumption of Dehumidifiers

Appendix X1 to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Dehumidifiers

Note:

After January 22, 2024, any representations made with respect to the energy efficiency of a dehumidifier must be made in accordance with the results of testing pursuant to this appendix. Manufacturers conducting tests of a dehumidifier prior to January 22, 2024, must conduct such test in accordance with either this appendix or the previous version of this appendix as it appeared in the Code of Federal Regulations on January 1, 2023. Any representations made with respect to the energy efficiency of such dehumidifier must be in accordance with whichever version is selected.

Any representations made on or after the compliance date of any amended energy conservation standards, with respect to the energy use or efficiency of portable or whole-home dehumidifiers, must be made in accordance with the results of testing pursuant to this appendix.

0. Incorporation by Reference

DOE incorporated by reference in § 430.3, the entire standard for AHAM DH–1–2022, ANSI/AMCA 210, ANSI/ASHRAE 41.1, and IEC 62301; however, only enumerated provisions of those documents are applicable to this appendix. To the extent there is a conflict between the terms or provisions of a referenced industry standard and the CFR, the CFR provisions control.

0.1 AHAM DH–1–2022

(a) Section 3 “Definitions”, as specified in sections 2 and 3.1.2 of this appendix.

(b) Section 4 “Instrumentation”, as specified in sections 3.1.1 and 3.1.2 of this appendix.

(c) Section 5.1 “General”, as specified in sections 3.1.1 and 3.1.2 of this appendix.

(d) Section 5.2 “Test Room”, as specified in sections 3.1.1 and 3.1.2 of this appendix.

(e) Section 5.3 “Positioning of Test Unit”, as specified in sections 3.1.1 and 3.1.1.2 of this appendix.

(f) Section 5.5 “Control settings”, as specified in sections 3.1.1, 3.1.1.4, and 3.1.2 of this appendix.

(g) Section 7 “Test Tolerances”, as specified in section 4.1.1 of this appendix.

(h) Section 8 “Capacity Test”, as specified in sections 4.1.1 and 4.1.2 of this appendix.

(i) Section 8.3 “Standard Test Voltage”, as specified in section 3.2.2.1 of this appendix.

(j) Section 8.4 “Psychrometer Placement”, as specified in section 3.1.1.2 of this appendix.

(k) Section 9 “Energy Consumption”, as specified in sections 4.1.1 and 4.1.2 of this appendix.

(l) Section 9.3.2 “Inactive/Off Mode”, as specified in section 4.2 of this appendix.

(m) Section 9.3.1 “Off-Cycle Mode”, as specified in section 4.3 of this appendix.

(n) Section 9.4 “Calculation of Test Results”, as specified in section 4.1.2 of this appendix.

0.2 ANSI/AMCA 210

(a) Section 5.2.1.6 “Airflow straightener”, as specified in section 3.1.2.1 of this appendix.

(b) Figure 6A “Flow Straightener—Cell Type”, as specified in section 3.1.2.1 of this appendix.

(c) Section 4.2.2 “Pitot-static tube”, as specified in section 3.1.2.2.3.1 of this appendix.

(d) Section 4.2.3 “Static pressure tap”, as specified in section 3.1.2.2.3.1 of this appendix.

(e) Section 4.3.1 “Pitot Traverse”, as specified in section 3.1.2.2.3.1 of this appendix.

(f) Section 4.3.2 “Flow nozzle”, as specified in section 3.1.2.2.3.1 of this appendix.

(g) Section 7.5.2 “Pressure Losses”, as specified in section 3.1.2.2.3.1 of this appendix.

(h) Section 7.3.1 “Velocity Traverse”, as specified in section 3.1.2.2.3.2 of this appendix.

(i) Section 7.3.2 “Nozzle”, as specified in section 3.1.2.2.3.2 of this appendix.

(j) Section 7.3 “Fan airflow rate at test conditions”, as specified in section 5.6 of this appendix.

0.3 ANSI/ASHRAE 41.1

(a) Section 5.3.5 “Centers of Segments—Grids”, as specified in section 3.1.2.2.1 of this appendix.

(b) [Reserved]

0.4 IEC 62301

(a) Section 5.2 “Preparation of product”, as specified in section 3.2.1 of this appendix.

(b) Section 4.3.2 “Supply voltage waveform”, as specified in section 3.2.2.2 of this appendix.

(c) Section 4.4 “Power measuring instruments”, as specified in section 3.2.3 of this appendix.

(d) Section 4.2 “Test room”, as specified in section 3.2.4 of this appendix.

1. Scope

This appendix covers the test requirements used to measure the energy performance of dehumidifiers.

2. Definitions

Definitions for terms, modes, calculations, etc. are in accordance with AHAM DH–1–2022, section 3, with the following added definitions:

Energy factor for dehumidifiers means a measure of energy efficiency of a dehumidifier calculated by dividing the water removed from the air by the energy consumed, measured in liters per kilowatt-hour (L/kWh).

External static pressure (ESP) means the process air outlet static pressure minus the process air inlet static pressure, measured in inches of water column (in. w.c.).

Process air means the air supplied to the dehumidifier from the dehumidified space and discharged to the dehumidified space after some of the moisture has been removed by means of the refrigeration system.

Product capacity for dehumidifiers means a measure of the ability of the dehumidifier to remove moisture from its surrounding atmosphere, measured in pints collected per 24 hours of operation under the specified ambient conditions.

Product case volume for whole-home dehumidifiers means a measure of the rectangular volume that the product case occupies, exclusive of any duct attachment collars or other external components.

Reactivation air means the air drawn from unconditioned space to remove moisture from the desiccant wheel of a refrigerant-desiccant dehumidifier and discharged to unconditioned space.

3. Test Apparatus and General Instructions

3.1 Active mode.

3.1.1 Portable dehumidifiers and whole-home dehumidifiers other than refrigerant-desiccant dehumidifiers. The test apparatus and instructions for testing in dehumidification mode and off-cycle mode must conform to the requirements specified in Section 4, “Instrumentation,” section 5.1, “General,” section 5.2, “Test Room,” Section 5.3, “Positioning of Test Unit,” and section 5.5, “Control settings” of AHAM DH–1–2022, with the following exceptions. If a product is able to operate as either a portable or whole-home dehumidifier by means of removal or installation of an optional ducting kit, in accordance with any manufacturer instructions available to a consumer, test and rate both configurations.

3.1.1.1 Testing configuration for whole-home dehumidifiers other than refrigerant-desiccant dehumidifiers. Test dehumidifiers, other than refrigerant-desiccant dehumidifiers, with ducting attached to the process air outlet port. The duct configuration and component placement must conform to the requirements specified in section 3.1.3 of this appendix and Figure 1 or Figure 3, except that the flow straightener and dry-bulb temperature and relative humidity instruments are not required. Maintain the external static pressure in the process air flow and measure the external static pressure as specified in section 3.1.2.2.3.1 of this appendix.

3.1.1.2 Instrumentation placement. If using a sampling tree, follow the instrumentation placement instructions in sections 5.3 and 8.4 of AHAM DH–1–2022. If not using a sampling tree, place the aspirating psychrometer or relative humidity and dry-bulb temperature sensors perpendicular to, and 1 ft. in front of, the center of the process air intake grille. During each test, use the psychrometer or relative humidity and dry-bulb sensors to monitor inlet conditions of only one unit under test. When using relative humidity and dry-bulb temperature sensors without sampling trees to test a unit that has multiple process air intake grilles, place a relative humidity sensor and dry-bulb temperature sensor perpendicular to, and 1 ft. in front of, the center of each process air intake grille.

3.1.1.3 Condensate collection. If means are provided on the dehumidifier for draining condensate away from the cabinet, collect the condensate in a substantially closed vessel to prevent re-evaporation and place the vessel on the weight-measuring instrument. If no means for draining condensate away from the cabinet are provided, disable any automatic shutoff of dehumidification mode operation that is activated when the collection container is full and collect any overflow in a pan. Select a collection pan large enough to ensure that all water that overflows from the full internal collection container during the rating test period is captured by the collection pan. Cover the pan as much as possible to prevent re-evaporation without impeding the collection of overflow water. Place both the dehumidifier and the overflow pan on the weight-measuring instrument for direct reading of the condensate weight collected during the rating test. Do not use any internal pump to drain the condensate into a substantially closed vessel unless such pump operation is provided for by default in dehumidification mode.

3.1.1.4 Control settings. Follow the control settings instructions in section 5.5 of AHAM DH–1–2022.

3.1.1.5 Run-in period. Perform a single run-in period during which the compressor operates for a cumulative total of at least 24 hours prior to dehumidification mode testing.

3.1.2 Refrigerant-desiccant dehumidifiers. The test apparatus and instructions for testing refrigerant-desiccant dehumidifiers in dehumidification mode must conform to the requirements specified in section 3, “Definitions,” section 4, “Instrumentation,” and section 5.1, “General,” section 5.2, “Test Room,” and section 5.5, “Control settings,” of AHAM DH–1–2022, except as follows.

3.1.2.1 Testing configuration. Test refrigerant-desiccant dehumidifiers with ducting attached to the process air inlet and outlet ports and the reactivation air inlet port. The duct configuration and components must conform to the requirements specified in section 3.1.3 of this appendix and Figure 1 through Figure 3. Install a cell-type airflow straightener that conforms to the specifications in Section 5.2.1.6, “Airflow straightener”, and Figure 6A, “Flow Straightener—Cell Type”, of ANSI/AMCA 210 (incorporated by reference, see § 430.3) in each duct consistent with Figure 1 through Figure 3.

3.1.2.2 Instrumentation.

3.1.2.2.1 Temperature. Install dry-bulb temperature sensors in a grid centered in the duct, with the plane of the grid perpendicular to the axis of the duct. Determine the number and locations of the sensors within the grid according to Section 5.3.5, “Centers of Segments—Grids,” of ANSI/ASHRAE 41.1 (incorporated by reference, see § 430.3).

3.1.2.2.2 Relative humidity. Measure relative humidity with a duct-mounted, relative humidity sensor with an accuracy within ±1 percent relative humidity. Place the relative humidity sensor at the duct centerline within 1 inch of the dry-bulb temperature grid plane.

3.1.2.2.3 Pressure. The pressure instruments used to measure the external static pressure and velocity pressures must have an accuracy within ±0.01 in. w.c. and a resolution of no more than 0.01 in. w.c.

3.1.2.2.3.1 External static pressure. Measure static pressures in each duct using pitot-static tube traverses, a flow nozzle or a bank of flow nozzles. For pitot-static tube traverses, conform to the specifications in section 4.3.1, “Pitot Traverse,” of ANSI/AMCA 210 and section 4.2.2, “Pitot-Static Tube,” of ANSI/AMCA 210, except use only two intersecting and perpendicular rows of pitot-static tube traverses. For a flow nozzle or bank of flow nozzles, conform to the specifications in section 4.3.2, “Flow nozzle,” of ANSI/AMCA 210 and section 4.2.3, “Static pressure tap” of ANSI/AMCA 210. Record the static pressure within the test duct as follows. When using pitot-static tube traverses, record the pressure as measured at the pressure tap in the manifold of the traverses that averages the individual static pressures at each pitot-static tube. When using a flow nozzle or bank of nozzles, record the pressure or in accordance with section 4.2.3.2, “Averaging,” of ANSI/AMCA 210. Calculate duct pressure losses between the unit under test and the plane of each static pressure measurement in accordance with section 7.5.2, “Pressure Losses,” of ANSI/AMCA 210. The external static pressure is the difference between the measured inlet and outlet static pressure measurements, minus the sum of the inlet and outlet duct pressure losses. For any port with no duct attached, use a static pressure of 0.00 in. w.c. with no duct pressure loss in the calculation of external static pressure. During dehumidification mode testing, the external static pressure must equal 0.20 in. w.c. ± 0.02 in. w.c.

3.1.2.2.3.2 Velocity pressure. Measure velocity pressures using the same pitot traverses or nozzles as used for measuring external static pressure, which are specified in section 3.1.2.2.3.1 of this appendix. When using pitot-static tube traverses, determine velocity pressures at each pitot-static tube in a traverse as the difference between the pressure at the impact pressure tap and the pressure at the static pressure tap and calculate volumetric flow rates in each duct in accordance with section 7.3.1, “Velocity Traverse,” of ANSI/AMCA 210. When using a flow nozzle or a bank of flow nozzles, calculate the volumetric flow rates in each duct in accordance with section 7.3.2, “Nozzle,” of ANSI/AMCA 210.

3.1.2.2.4 Weight. No weight-measuring instruments are required.

3.1.2.3 Control settings. Follow the control settings instructions in section 5.5 of AHAM DH–1–2022.

3.1.2.4 Run-in period. Perform a single run-in period during which the compressor operates for a cumulative total of at least 24 hours prior to dehumidification mode testing.

3.1.3 Ducting for whole-home dehumidifiers. Cover and seal with tape any port designed for intake of air from outside or unconditioned space, other than for supplying reactivation air for refrigerant-desiccant dehumidifiers. Use only ducting constructed of galvanized mild steel and with a 10-inch diameter. Position inlet and outlet ducts either horizontally or vertically to accommodate the default dehumidifier port orientation. Install all ducts with the axis of the section interfacing with the dehumidifier perpendicular to plane of the collar to which each is attached. If manufacturer-recommended collars do not measure 10 inches in diameter, use transitional pieces to connect the ducts to the collars. The transitional pieces must not contain any converging element that forms an angle with the duct axis greater than 7.5 degrees or a diverging element that forms an angle with the duct axis greater than 3.5 degrees. Install mechanical throttling devices in each outlet duct consistent with Figure 1 and Figure 3 to adjust the external static pressure and in the inlet reactivation air duct for a refrigerant-desiccant dehumidifier. Cover the ducts with thermal insulation having a minimum R value of 6 h-ft² − °F/Btu (1.1 m² − K/W). Seal seams and edges with tape.

3.1.4 Recording and rounding. When testing either a portable dehumidifier or a whole-home dehumidifier, record measurements at the resolution of the test instrumentation. Record measurements for portable dehumidifiers and whole-home dehumidifiers other than refrigerant-desiccant dehumidifiers at intervals no greater than 10 minutes. Record measurements for refrigerant-desiccant dehumidifiers at intervals no greater than 1 minute. Round off calculations to the same number of significant digits as the previous step. Round the final product capacity, energy factor and integrated energy factor values to two decimal places, and for whole-home dehumidifiers, round the final product case volume to one decimal place.

3.2 Inactive mode and off mode.

3.2.1 Installation requirements. For the inactive mode and off mode testing, install the dehumidifier in accordance with Section 5, Paragraph 5.2 of IEC 62301 (incorporated by reference, see § 430.3), disregarding the provisions regarding batteries and the determination, classification, and testing of relevant modes.

3.2.2 Electrical energy supply.

3.2.2.1 Electrical supply. For the inactive mode and off mode testing, maintain the electrical supply voltage and frequency indicated in section 8.3, “Standard Test Voltage,” of AHAM DH–1–2022. The electrical supply frequency shall be maintained ±1 percent.

3.2.2.2 Supply voltage waveform. For the inactive mode and off mode testing, maintain the electrical supply voltage waveform indicated in Section 4, Paragraph 4.3.2 of IEC 62301 (incorporated by reference, see § 430.3).

3.2.3 Inactive mode, off mode, and off-cycle mode wattmeter. The wattmeter used to measure inactive mode, off mode, and off-cycle mode power consumption must meet the requirements specified in Section 4, Paragraph 4.4 of IEC 62301 (incorporated by reference, see § 430.3).

3.2.4 Inactive mode and off mode ambient temperature. For inactive mode and off mode testing, maintain room ambient air temperature conditions as specified in Section 4, Paragraph 4.2 of IEC 62301 (incorporated by reference, see § 430.3).

3.3 Case dimensions for whole-home dehumidifiers. Measure case dimensions using equipment with a resolution of no more than 0.1 in.

4. Test Measurement

4.1 Dehumidification mode.

4.1.

1 Portable dehumidifiers and whole-home dehumidifiers other than refrigerant-desiccant dehumidifiers. Measure the energy consumption in dehumidification mode, EDM, in kilowatt-hours (kWh), the average percent relative humidity, Ht, either as measured using a relative humidity sensor or using Tables

2

and 3 when using an aspirating psychrometer, and the product capacity, Ct, in pints per day (pints/day), in accordance with the test requirements specified in section 7, “Test Tolerances,” section 8, “Capacity Test,” and section 9, “Energy Consumption,” of AHAM DH–1–2022, with two exceptions. First, the rating test period must be 2 hours. Second, maintain the standard test conditions as shown in Table 1.

Table 1 to Paragraph 4.1.1—Standard Test Conditions for Dehumidifier Testing

Configuration Dry-bulb temperature ( °F) Aspirating psychrometer Wet-bulb temperature ( °F) Relative humidity sensor relative humidity (%) Portable dehumidifiers65 ± 2.056.6 ± 1.060 ± 2 Whole-home dehumidifiers73 ± 2.063.6 ± 1.060 ± 2

When using relative humidity and dry-bulb temperature sensors, for dehumidifiers with multiple process air intake grilles, average the measured relative humidities and average the measured dry-bulb temperatures to determine the overall intake air conditions.

Table 2 to Paragraph 4.1.1—Relative Humidity as a Function of Dry-Bulb and Wet-Bulb Temperatures for Portable Dehumidifiers

Wet-bulb temperature ( °F) Dry-bulb temperature ( °F) 64.5 64.6 64.7 64.8 64.9 65 65.1 65.2 65.3 65.4 65.5 56.360.3259.9459.5759.1758.858.4258.0457.6757.356.9356.56 56.460.7760.386059.6259.2458.8658.4858.1157.7357.3656.99 56.561.2260.8360.4460.0659.6859.358.9258.5458.1757.857.43 56.661.6661.2760.8960.560.1259.7459.3658.9858.658.2357.86 56.762.461.7261.3360.9560.5660.1859.859.4259.0458.6758.29 56.862.5662.1761.7861.396160.6260.2459.8659.4859.158.73 56.963.0162.6262.2361.8461.4561.0660.6860.359.9259.5459.16

Table 3 to Paragraph 4.1.1—Relative Humidity as a Function of Dry-Bulb and Wet-Bulb Temperatures for Whole-Home Dehumidifiers

Wet-bulb temperature ( °F) Dry-bulb temperature ( °F) 72.5 72.6 72.7 72.8 72.9 73 73.1 73.2 73.3 73.4 73.5 63.360.5960.2659.9259.5959.2658.9258.658.2757.9457.6257.3 63.460.9860.6460.3159.7559.6459.3158.9858.6558.325857.67 63.561.3761.0360.760.3660.0259.6959.3659.0358.758.3858.05 63.661.7661.4261.0860.7560.4160.0859.7459.4159.0858.7658.43 63.762.1661.8161.4761.1360.860.4660.1359.859.4759.1458.81 63.862.5562.261.8661.5261.1860.8560.5160.1859.8559.5259.19 63.962.9462.662.2561.9161.5761.2360.960.5660.2359.959.57

4.1.2 Refrigerant-desiccant dehumidifiers. Establish the testing conditions set forth in section 3.1.2 of this appendix. Measure the energy consumption, EDM, in kWh, in accordance with the test requirements specified in section 8, “Capacity Test,” and section 9, “Energy Consumption,” respectively, of AHAM DH–1–2022, with the following exceptions and adjustments:

(a) Each measurement of the temperature and relative humidity of the air entering the process air inlet duct and the reactivation air inlet must be within 73 °F ± 2.0 °F dry-bulb temperature and 60 percent ± 5 percent relative humidity, and the arithmetic average of the inlet test conditions over the test period shall be within 73 °F ± 0.5 °F dry-bulb temperature and 60 percent ± 2 percent relative humidity;

(b) Disregard the instructions for psychrometer placement;

(c) Record dry-bulb temperatures, relative humidities, static pressures, velocity pressures in each duct, volumetric air flow rates, and the number of measurements in the test period;

(d) Disregard the requirement to weigh the condensate collected during the test;

(e) The rating test period must be 2 hours; and

(f) To perform the calculations in section 9.4, “Calculation of Test Results,” of AHAM DH–1–2022:

(i) Replace “Condensate collected (lb)” and “mlb”, with the weight of condensate removed, W, as calculated in section 5.6 of this appendix; and

(ii) Use the recorded relative humidities, not the tables in section 4.1.1 of this appendix, to determine average relative humidity.

4.2 Off-cycle mode. Follow requirements for test measurement in off-cycle mode of operation in accordance with section 9.3.2 of AHAM DH–1–2022.

4.2 Off-cycle mode. Establish the test conditions specified in section 3.1.1 or 3.1.2 of this appendix, but use the wattmeter specified in section 3.2.3 of this appendix. Begin the off-cycle mode test period immediately following the dehumidification mode test period. Adjust the setpoint higher than the ambient relative humidity to ensure the product will not enter dehumidification mode and begin the test when the compressor cycles off due to the change in setpoint. The off-cycle mode test period shall be 2 hours in duration, during which the power consumption is recorded at the same intervals as recorded for dehumidification mode testing. Measure and record the average off-cycle mode power of the dehumidifier, P_OC, in watts.

4.3 Inactive and off mode. Follow requirements for test measurement in inactive and off modes of operation in accordance with section 9.3.1 of AHAM DH–1–2022.

4.3.1 If the dehumidifier has an inactive mode, as defined in section 2.10 of this appendix, but not an off mode, as defined in section 2.11 of this appendix, measure and record the average inactive mode power of the dehumidifier, P_IA, in watts.

4.3.2 If the dehumidifier has an off mode, as defined in section 2.11 of this appendix, measure and record the average off mode power of the dehumidifier, P_OM, in watts.

4.4 Product case volume for whole-home dehumidifiers. Measure the maximum case length, D_L, in inches, the maximum case width, D_W, in inches, and the maximum height, D_H, in inches, exclusive of any duct collar attachments or other external components.

5. Calculation of Derived Results From Test Measurements

5.1 Corrected relative humidity. Calculate the average relative humidity, for portable and whole-home dehumidifiers, corrected for barometric pressure variations as:

H_c,p = H_t × [1 + 0.0083 × (29.921 − B)]

H_c,wh = H_t × [1 + 0.0072 × (29.921 − B)]

Where:

H_c,p = portable dehumidifier average relative humidity from the test data in percent, corrected to the standard barometric pressure of 29.921 in. mercury (Hg);

H_c,wh = whole-home dehumidifier average relative humidity from the test data in percent, corrected to the standard barometric pressure of 29.921 in. Hg;

H_t = average relative humidity from the test data in percent; and

B = average barometric pressure during the test period in in. Hg.

5.2 Corrected product capacity. Calculate the product capacity, for portable and whole-home dehumidifiers, corrected for variations in temperature and relative humidity as:

C_r,p = C_t + 0.0352 × C_t × (65 − T_t) + 0.0169 × C_t × (60 − H_C,p)

C_r,wh = C_t + 0.0344 × C_t × (73 − T_t) + 0.017 × C_t × (60 − H_C,wh)

Where:

C_r,p = portable dehumidifiers product capacity in pints/day, corrected to standard rating conditions of 65 °F dry-bulb temperature and 60 percent relative humidity;

C_r,wh = whole-home dehumidifier product capacity in pints/day, corrected to standard rating conditions of 73 °F dry-bulb temperature and 60 percent relative humidity;

C_t = product capacity determined from test data in pints/day, as measured in section 4.1.1 of this appendix for portable and refrigerant-only whole-home dehumidifiers or calculated in section 5.6 of this appendix for refrigerant-desiccant whole-home dehumidifiers;

T_t = average dry-bulb temperature during the test period in °F;

H_C,p = portable dehumidifier corrected relative humidity in percent, as determined in section 5.1 of this appendix; and

H_C,wh = whole-home dehumidifier corrected relative humidity in percent, as determined in section 5.1 of this appendix.

5.3 Annual combined low-power mode energy consumption. Calculate the annual combined low-power mode energy consumption for dehumidifiers, E_TLP, expressed in kWh per year:

E_TLP = [(P_IO × S_IO) + (P_OC × S_OC)] × K

Where:

P_IO = P_IA, dehumidifier inactive mode power, or P_OM, dehumidifier off mode power in watts, as measured in section 4.3 of this appendix;

P_OC = dehumidifier off-cycle mode power in watts, as measured in section 4.2 of this appendix;

S_IO = 1,840.5 dehumidifier inactive mode or off mode annual hours;

S_OC = 1,840.5 dehumidifier off-cycle mode annual hours; and

K = 0.001 kWh/Wh conversion factor for watt-hours to kWh.

5.4 Integrated energy factor. Calculate the integrated energy factor, IEF, in L/kWh, rounded to two decimal places, according to the following:

Where:

C_r = corrected product capacity in pints per day, as determined in section 5.2 of this appendix;

2 = dehumidification mode test duration in hours;

E_DM = energy consumption during the 2-hour dehumidification mode test in kWh, as measured in section 4.1 of this appendix;

E_TLP = annual combined low-power mode energy consumption in kWh per year, as calculated in section 5.3 of this appendix;

1,095 = dehumidification mode annual hours, used to convert E_TLP to combined low-power mode energy consumption per hour of dehumidification mode;

1.04 = the density of water in pounds per pint;

0.454 = the liters of water per pound of water; and

24 = the number of hours per day.

5.5 Absolute humidity for refrigerant-desiccant dehumidifiers. Calculate the absolute humidity of the air entering and leaving the refrigerant-desiccant dehumidifier in the process air stream, expressed in pounds of water per cubic foot of air, according to the following set of equations.

5.5.1 Temperature in Kelvin. The air dry-bulb temperature, in Kelvin, is:

Where:

T_F = the measured dry-bulb temperature of the air in °F.

5.5.2 Water saturation pressure. The water saturation pressure, expressed in kilopascals (kPa), is:

Where:

T_K = the calculated dry-bulb temperature of the air in K, calculated in section 5.5.1 of this appendix.

5.5.3 Vapor pressure. The water vapor pressure, expressed in kilopascals (kPa), is:

Where:

RH = percent relative humidity during the rating test period; and

P_ws = water vapor saturation pressure in kPa, calculated in section 5.5.2 of this appendix.

5.5.4 Mixing humidity ratio. The mixing humidity ratio, the mass of water per mass of dry air, is:

Where:

P_w = water vapor pressure in kPa, calculated in section 5.5.3 of this appendix;

P = measured ambient barometric pressure in in. Hg;

3.386 = the conversion factor from in. Hg to kPa; and

0.62198 = the ratio of the molecular weight of water to the molecular weight of dry air.

5.5.5 Specific volume. The specific volume, expressed in feet cubed per pounds of dry air, is:

Where:

T_K = dry-bulb temperature of the air in K, as calculated in section 5.5.1 of this appendix;

P = measured ambient barometric pressure in in. Hg;

P_w = water vapor pressure in kPa, calculated in section 5.5.3 of this appendix;

0.287055 = the specific gas constant for dry air in kPa times cubic meter per kg per K;

3.386 = the conversion factor from in. Hg to kPa; and

16.016 = the conversion factor from cubic meters per kilogram to cubic feet per pound.

5.5.6 Absolute humidity. The absolute humidity, expressed in pounds of water per cubic foot of air, is:

Where:

HR = the mixing humidity ratio, the mass of water per mass of dry air, as calculated in section 5.5.4 of this appendix; and

ν = the specific volume in cubic feet per pound of dry air, as calculated in section 5.5.5 of this appendix.

5.6 Product capacity for refrigerant-desiccant dehumidifiers. The weight of water removed during the test period, W, expressed in pounds is:

Where:

n = number of samples during the test period in section 4.1.1.2 of this appendix;

AH_I,i = absolute humidity of the process air on the inlet side of the unit in pounds of water per cubic foot of dry air, as calculated for sample i in section 5.5.6 of this appendix;

X_I,i = volumetric flow rate of the process air on the inlet side of the unit in cubic feet per minute, measured for sample i in section 4.1.1.2 of this appendix. Calculate the volumetric flow rate in accordance with Section 7.3, “Fan airflow rate at test conditions,” of ANSI/AMCA 210 (incorporated by reference, see § 430.3);

AH_O,i = absolute humidity of the process air on the outlet side of the unit in pounds of water per cubic foot of dry air, as calculated for sample i in section 5.5.6 of this appendix;

X_O,i = volumetric flow rate of the process air on the outlet side of the unit in cubic feet per minute, measured for sample i in section 4.1.1.2 of this appendix. Calculate the volumetric flow rate in accordance with Section 7.3, “Fan airflow rate at test conditions,” of ANSI/AMCA 210 (incorporated by reference, see § 430.3);

t = time interval in seconds between samples, with a maximum of 60; and

60 = conversion from minutes to seconds.

The capacity, C_t, expressed in pints/day, is:

Where:

24 = number of hours per day;

1.04 = density of water in pounds per pint; and

T = total test period time in hours.

Then correct the product capacity, C_r,wh, according to section 5.2 of this appendix.

5.7 Product case volume for whole-home dehumidifiers. The product case volume, V, in cubic feet, is:

Where:

D_L = product case length in inches, measured in section 4.4 of this appendix;

D_W = product case width in inches, measured in section 4.4 of this appendix;

D_H = product case height in inches, measured in section 4.4 of this appendix; and

1,728 = conversion from cubic inches to cubic feet.

[80 FR 45826, July 31, 2015, as amended at 88 FR 48052, July 26, 2023]