Hot water heat pump: hot water, cool technology.

The hot water heat pump, also known as a domestic hot water heat pump, is designed specifically for heating water. It efficiently and sustainably generates hot water by harnessing existing heat from ambient air, outdoor air, and heating return flow. Perfectly complementing a heating system, it ensures a future-proof solution for domestic hot water production.

The electricity consumption of a hot water heat pump varies depending on household size and hot water demand. A Vaillant hot water heat pump typically boasts an efficiency of around 3.5 (COP value), making it highly energy-efficient.

Example calculation for a four-person household:
If one person requires 40 litres of hot water per day at an average temperature of 45°C, this results in an energy consumption of approximately 600 kWh per year. For a four-person household, that means roughly 2,400 kWh annually for hot water. With an efficiency of 3.5 (COP), you can calculate electricity consumption as follows:

Electricity consumption (kWh) = Annual hot water demand (kWh) / COP
^{Electricity consumption = 2,400 kWh / 3.5 ≈ 685 kWh}

Your hot water heat pump uses about 685 kWh of electricity per year to meet the hot water needs of a four-person household. In this example, an instantaneous water heater consumes the full 2,400 kWh of electricity, making it 3.5 times more expensive in consumption than the hot water heat pump.

1. Hot water heat pumps extract heat from the air or the heating return. This is used in the evaporator to vaporise the liquid refrigerant.

2. In the next step, the now gaseous refrigerant is passed to an electrically powered compressor, which compresses it and increases its pressure until the desired temperature is reached.

3. The heated refrigerant vapour transfers its thermal energy via a heat exchanger (condenser) to the built-in hot water tank. The vapour cools down and condenses.

4. Finally, the refrigerant, which is liquid again, is depressurised by an expansion valve while it continues to cool down considerably and is thus ready to absorb heat from the environment again.