CSA C745-03 pdf free download

CSA C745-03 pdf free download.Energy Efficiency of Electric Storage Tank Water Heaters and Heat Pump Water Heaters.
During water draws, the temperature of the outlet and inlet water shall be measured using the thermocouples installed in accordance with Clauses 4.7.2 and 4.7.3. The arithmetic mean of the inlet and outlet water temperatures shall be calculated by averaging readings taken after the first 15 s of the draw and at every subsequent 5 s interval.
5.4 Room Temperature Measurement
The room temperature shall be determined using the test room thermocouple installation described in
Clause 4.7.1.
5.5 Mean Tank Water Temperature Measurement
The mean tank water temperature shall be the mean of the temperatures determined by using the water heater tank thermocouples described in Clause 4.7.3.
5.6 First-Hour Rating Test
5.6.1 Draw Initiation Criteria
A first-hour rating test shall begin by imposing a draw on the storage-type water heater. After completion of this first draw, successive draws shall be initiated based on the following criteria:
a) For electric water heaters having a single element or multiple elements that all operate simultaneously, initiate successive draws when the thermostat acts to reduce the electrical input supplied to the element(s).
b) For electric water heaters having two or more elements that do not operate simultaneously, initiate successive draws when the applicable thermostat acts to reduce the electrical input to the element located vertically highest in the storage tank.
c) For heat pump water heaters that do not use supplemental resistive heating, initiate successive draws immediately after the electrical input to the compressor is reduced by the action of the water heater’s thermostat.
d) For heat pump water heaters that use supplemental resistive heating, initiate successive draws immediately after the electrical input to the compressor or after the uppermost resistive element is reduced by the action of the applicable water heater thermostat.
The draw initiation criterion for heat pump water heaters that use supplemental resistive heating, however, shall only apply when the water located above the thermostat at cut-out is heated to
57.2 ± 3 °C (135 ± 5°F).
5.6.2 Test Procedure
The test procedure shall be as follows:
a) Test Set-up:
Step 1 Establish normal water heater operation with temperatures and pressures set in accordance with Clauses 4.4. 4.8, and 4.10.
Step 2 Draw water until the heat source cuts in. Stop drawing water and wait until the maximum mean tank water temperature, Tmax 57.2 ± 3 °C (1 35 ± 5°F) is achieved after the single or lower element or the heat pump and electrical heating element(s) cut out. CSA C745-03 pdf free download.