Hi all

New here so bear with me. Does anyone know what the minium air on coil is for a dx coil in a AHU when operating in the heating/reverse cycle mode in winter (eg. in winter can we use full fresh air at -4 deg c on to the coil). I heard that it was around +10 deg c minimum. We are looking to use a full fresh air AHU with the addition of a seperate heat pump condensing unit.