Hey guys,

I hope someone could provide any advise for me. I've having reversible air-to-air heatpump (R410A). For the winter mode as a defrost strategy I decided to test HGBP solution. As an activation factor for HGBP will be suction pressure (it means that I will measure suction pressure).

In several pdf's it's written that bypassing quantity should not exceed 30%, because in other way I can face improper condenser work (cause too little quantity reaches it).
During bypassing period, discharge pressure should be stable (moreless), compressor power input/speed and suction pressure should start to increase.

In other similar applications with HGBP solution, for HGBP activation pressure difference between evaporator inlet and outlet is measured. Shortly, HGBP is activated when wet/freezed evaporator pressure difference becomes doubled compated to dry evaporator pressure difference. It makes sense to use such kind of HGBP start-finish strategy.

What are other recomendations for HGBP activation start-finish strategy? Whether it is appropriate without measuring pressure difference according to evaporator to set start like 4 bars (R410A) and finish till somekind of limit? All ideas are welcome