Cooling with air-water heat pump, condensation monitor and transformer needed

Cooling through the ventilation or the heating (underfloor) is more of a marketing thing. It is only a slight buffering. If the money hurts you, better to skip it. It only works through the ventilation if the air exchange is large enough (about 5 times higher than with normal design). With underfloor heating, you have the condensation problem and the floor is cold... Walls and ceilings make more sense. However, the effort is higher here. It is more sensible to provide a climate system or individual units (or at least the connections) right away. The electricity consumption is probably not much higher either since you reach the temperature (with simultaneous dehumidification) in a shorter time.