"deliver 4-5 kWh of low-grade heat (or cold) into your home (depending on COP of a heat pump)" If you don't use a reverse cycle system you can more like 8 kwh

"deliver 4-5 kWh of low-grade heat (or cold) into your home (depending on COP of a heat pump)" If you don't use a reverse cycle system you can more like 8 kwh of heat or cold