Differences between Direct-heating Air Source Heat Pump and Circulating Air Source Heat Pump

There are significant differences between direct-heating air source heat pump and circulating air source heat pump in terms of working principle, structure, operating conditions, outlet water temperature stability and applicable scenarios.

1. Working principle

Direct-heating air source heat pump: cold water directly enters the heat pump unit, and after one heating, it can reach the set temperature of hot water, and then output to the water storage tank.

Circulating air source heat pump: cold water first enters the water storage tank, and after the water tank is full, it is sent to the heat pump unit for heating through the circulating pump. It takes multiple cycles to reach the set temperature.

2. Structure

Direct-heating air source heat pump: no water pump is required, tap water pressure is used to directly inject into the main unit, and the system is relatively simple.

Circulating air source heat pump: requires a high-power water pump, the system is complex and power-consuming, and usually requires an auxiliary water storage tank and a connecting water pump.

3. Operating conditions

When the inlet water temperature is lower than 45℃, the working conditions of direct heating and circulating types are similar; when the inlet water temperature is higher than 45℃, the direct heating compressor maintains a stable load and extends the life of the compressor; while the working conditions of the circulating compressor deteriorate as the water temperature rises, and the efficiency, safety and life of the circulating compressor decrease.

4. Stability of outlet water temperature

Direct heating air source heat pump: The outlet water temperature is constant and adjustable, and there is no problem of fluctuating between hot and cold.

Circulating air source heat pump: Due to the circulating heating of the water storage tank, the outlet water temperature is unstable and the comfort level is low.

5. Applicable scenarios

Direct heating air source heat pump: Suitable for places that need to be turned on and heated immediately, such as hotels, guesthouses and other places with high hot water demand.

Circulating air source heat pump: Suitable for places with high hot water demand, such as construction sites, swimming pools, hot springs, etc.

6. Cost and energy efficiency

Direct heating air source heat pump: The system cost is high, but the energy efficiency is high and the energy saving effect is good.

Circulating air source heat pump: The system cost is lower, but the overall energy efficiency may be lower, especially in low temperature environments.

Final summary

Direct air source heat pumps and circulating air source heat pumps each have their own advantages and disadvantages. The choice of which type should be determined based on specific application requirements and scenarios.