Cooling concept new building - split air conditioning / air-to-water heat pump cooling function / combination

Yes, it is a reinforced concrete ceiling on the ground floor and upper floor. I would have thought that you wouldn't get comparable cooling performance through concrete core activation? If you still need a split air conditioner for dehumidification, I also wonder how it becomes cheaper then?

I talked to the construction company about brine-water heat pumps, but that makes no sense. Deep drilling is insanely expensive because all companies are extremely busy (surcharge about 30k), surface collectors also come with a hefty surcharge (I believe about 15k), and the heating installer has never done ring trench collectors. I just don't want to be the first experimental customer there...

Yes, I also find the 5k surcharge extremely high. I also can't explain why it's so high. But for BKA I would also need the cooling function of the air-water heat pump, right? Do you know roughly how much one has to calculate for BKA and how the cooling performance compares? Especially for the office on the south side that is full of heat-generating technology, I'm worried whether BKA will be enough in summer...

We took 3 split units. Office, living/cooking, and one in the hallway for the entire upstairs. This way, we then cool the bedrooms with open doors. You can notice a bit of the effect that the cold air falls down to the ground floor, but the split units can be adjusted in terms of angle and direction they blow, which helps a lot. We are very satisfied with the solution so far. We usually only run them when we get power from the roof and have it pleasantly cool in the house.

I now have a first offer for a Daikin R32 multi-split outdoor unit and a total of 5 [I]DAIKIN R32 wall units comfora [/I] for approx. 19k EUR (incl. installation). That seems quite high compared to your numbers, I will look for alternative offers again. Have you generally had good experience with Daikin and are you satisfied?

We have also installed a Daikin R32 system, 1x outdoor unit and 5 indoor units. It has been running perfectly for 2 years ;) For the indoor units, we chose Emura. The price of 19K€ is probably again due to Corona. Two years ago it would have been around 16K.

So if anyone can recommend a company in the region, I would really appreciate a tip or a personal message.

You have a PM from me. I hope you can read it even with fewer posts than required.

Yes, it is a reinforced concrete ceiling on the ground floor and upper floor. I thought you wouldn’t get a comparable cooling capacity with concrete core activation? If you still need a split air conditioner for dehumidifying, I also wonder how it becomes cheaper then?

The cooling function on our heat pump (Nibe S1155-6 brine-water heat pump) would have cost around 3,000 euros – without concrete core activation (CCA).

... and the heating installer has never done ring trench collectors. I just don’t want to be the first experimental customer there...

Depending on how fit you are and how much you want to read up, a ring trench collector is very easy to implement yourself. We also did it for the first time on our property and it was super easy thanks to free software (Trenchplanner). Because of Corona, there were only three of us (an excavator driver who only excavated, my father and I who laid the pipe) and it took almost exactly 8 hours. There is very good support in the "pink forum" for planning.

Do you know roughly how much you have to budget for CCA and how the cooling capacity compares?

Of course, it depends on the area to be covered and also on what the ceilings are made of. With a wooden beam ceiling, the costs are significantly higher than with a concrete ceiling. For two concrete ceilings in a 150 m² house, I would estimate 800 euros for materials plus 14-16 installer hours.

I would have thought you can’t achieve comparable cooling performance with concrete core activation?

It depends entirely on the design: for example with 18 degrees supply temperature, 23 degrees return temperature, and 20 l/min flow rate: (20*60)/1000 * 1.16 * (23-1) = 6.96 kW. However, this first requires determining the required cooling load (usually significantly lower than the heating load). Are there already any results on this? By the way, for me that would generally be the first step before selecting the technology.

(Surcharge approx. 30k), flat collectors also come with a hefty surcharge (I think approx. 15k) and the heating engineer has never done ring trench collectors. I just don’t want to be the first experimental customer there...

Without ring trench collectors, absolutely not economical.

But for BKA I’d also need the cooling function of the air-water heat pump, right? Do you know roughly how much to calculate for BKA and how the cooling capacity compares? Especially for the south-facing office full of heat-generating technology, I’m worried whether BKA is sufficient in summer...

Yes, air-water heat pumps also require cooling functionality. Regarding the price, I would agree with Strahlemann. In the office I would position an additional single split air conditioner.

As I said, I would first have the required cooling capacity determined by an energy consultant or preferably a building services planner.

One more point regarding the Nibe S1155-6 brine-water heat pump: it is available for a small surcharge as the PC version with passive cooling (significantly lower energy consumption), so the 3000 EUR for active cooling doesn’t make much sense.

Another point regarding the Nibe S1155-6 ground-source heat pump: It is available for a small extra charge as a PC version with passive cooling (significantly lower energy consumption), so the 3000 EUR for the active cooling function makes little sense.

That is correct, I was also referring to these two variants. For us, the price difference between the S1155-6 PC and non-PC with accessories was about 3,000 euros.