The patent classification number of heat exchanger is

First of all, ultra-low temperature air source heat pump is also a kind of central air conditioning.

Secondly, the compressor of ordinary air conditioner can't start when the temperature is-15 degrees, so it needs ultra-low temperature heat pump.

Third, if indoor floor heating is used, the effect will be better if the floor heating is designed better.

Finally, if the indoor floor heating is capillary, the effect will be even more unusual, not to mention 26 degrees and 29 degrees is not a problem.