Electricity consumption during hot gas defrosting

[ginger jiang]

My friend owns a 8Kw(A7/W35) outdoor air/water heat pump,he wants to know the power consumption of the heat pump during 3 mins hot gas defrosting.How to calculate it?

Any comments would be highly appreciated.

[Tesla]

Hi ginger jiang
Measure the current draw of the unit durring the 3 minute defrost and measure the voltage. Multiply the voltage by the current then multiply by the power factor, this gives power. Power = Watts, Watts = Juole/Second. Multiply Watts by 1000 to get kiloWatts.
For consumption (i think this is right) you need kWh kiloWatt hours. If the unit uses 2 kW for the whole hour it would use 2 kWhs. So divide your calculated kiloWatts by 3600 (1 hour / 60 mins / 60 secs) then muliply by 3 (mins) then multiply by 60 (secs). This will give you kWh consumption per 3 minute defrost cycle.