Feedback on heat pump / offer requested!

What do you think of passive cooling, useful or just a gimmick?

useful gimmick. Good shading is more important, don't forget.

Good shading is more important, don't forget.

That's probably true, so we're getting roller shutters throughout the whole house... For the ground floor and the terrace doors, I'm still considering whether maybe Venetian blinds, we'll see how high the extra cost will be p

I have some concerns about condensation...

Just make sure that the supply temperature during cooling does not fall below the dew point temperature, then there will be no problems with condensation. This can also be monitored, for example, by a dew point monitor that is installed directly on the supply heating pipe. Otherwise, you might also consider concrete core activation. This way, the floor will not be too cold for the feet during the cooling phases in summer, and you have a larger surface through which you can cool. In winter, you can also use CCA for heating, which supposedly improves the perception of warmth inside the room.

For the ground floor and the terrace doors, I am still considering whether perhaps [Raffstores], let's see how high the additional cost will be p

I couldn't imagine having roller blinds anymore in our living room and offices; it would always be dark in summer. We also use them as privacy screens from the inside. I wouldn't base that/not base it much on price but rather on how often the shading will be down for you downstairs. It depends on the floor plan, natural shading, window size, and habits.

Because a cooling function of the heat pump was also mentioned here: how satisfied are you with your air-to-water heat pump?

Our general contractor would have offered us a "Viessmann-Vitocal 200-S". The additional costs for a split heat pump with cooling function / dew point monitor / room thermostats with cooling function would be €2,500 (compared to Viessmann Vitocal 200). Since we are currently trying to contain the costs, I wonder whether an air-to-water heat pump with cooling function: - is a sensible investment? - can be retrofitted later (or whether the heating system must be designed accordingly from the start)? - usually costs an additional price of around €2,500?

what kind of air-to-water heat pump do you have?

If the house tends to overheat for whatever reason and you rely on cooling, then cooling via heat pump is not the right solution. In that case, I would invest in good shading, heat insulation, or a vacation. If you really need it very cool, you can't avoid a proper air conditioning system.

The cooling function via heat pump is a nice gimmick. We had no additional costs (no dew point monitor or ERR) and use the cooling function maybe 10 days a year to lower the temperature by 1-2 degrees or to maintain a max of 25°C. Much more doesn’t make sense because, like with a proper air conditioner, no moisture is removed. Our house remains relatively cool in summer thanks to the design, mass, shading, and [Kontrollierte-Wohnraumlüftung mit Wärmerückgewinnung], and we would manage well without cooling.

In short: it wouldn’t be worth €2500 to me. Since you are looking for cost savings, I wouldn’t invest in it. It can probably be retrofitted later, but in that case, better measures to avoid heat should have been taken.