ᐅ Cooling with air-to-water heat pump requires condensation sensor and transformer

Cooling through the ventilation system or the (underfloor) heating is mostly just a marketing claim. It only provides slight buffering. If the cost is a concern, it’s better to skip it. Cooling via ventilation only works if the air exchange rate is significantly higher (about 5 times higher than standard design). Using the floor for cooling causes condensation issues and results in a cold floor surface. Walls and ceilings are more practical options, although the effort required is greater. It makes more sense to install a dedicated air conditioning system or individual units (or at least prepare the connections) from the start. The electricity consumption is probably not much higher since you reach the desired temperature (along with simultaneous dehumidification) in a shorter time.