ᐅ Cooling Concept for New Construction – Split Air Conditioning / Air-to-Water Heat Pump Cooling Function / Combination

Hello everyone,

I am currently planning the construction of a single-family house and am still undecided about the cooling concept. I have attached the current floor plan. Regarding the layouts, I also started a thread in the floor planning forum (https://www.hausbau-forum.de/threads/grundrissplanung-und-platzierung-efh-ca-200qm-auf-900qm-Grundstück.39104/page-4#post-505270).

This is a KfW 55 new build (Poroton brick, reinforced concrete ceiling) with an air-to-water heat pump, controlled ventilation system, and blinds/shutters on all windows. The garden side with the large windows faces southwest, the entrance side faces northeast. The office facing the garden definitely needs air conditioning, as it is in constant use with many technical devices generating significant heat. Otherwise, I personally prefer it quite cool; I usually vacation in Scandinavia but definitely not in Greece, Egypt, or similar. In other words, my comfort temperature is significantly lower than most other people’s.

Now I am considering the best way to cool the house (aside from shading, etc.).

Option 1:
Split air conditioning unit in the office

Option 2:
Split air conditioning unit in the office + cooling function of the air-to-water heat pump (about 5,000 EUR extra)

Option 3:
Split air conditioning unit in the office + living/dining/kitchen area

Option 4:
Split air conditioning unit in the office + living/dining/kitchen area + upper floor hallway (probably only above the stairs, supply temperature— not ideal because cool air might directly sink to the ground floor)

Option 5:
Split air conditioning unit in the office + living/dining/kitchen area + child’s room + child’s room + bedroom

Furthermore, I wonder how big the difference is between installing this as part of the new build or retrofitting it later (significantly more expensive if done afterward? Potential issues with KfW 55 standards?).

Also, I am unsure whether to use one split unit per room or a multi-split system. Currently, I have no concrete offers with prices.

Thank you in advance!

Best regards,
Sam

Views:

Floor plans:

Based on your requirements, you need version 5.

A multisplit system would be the best choice, ideally a VRV system, which allows you to design everything exactly as you want. However, it is not cheap. Installing it during the new build is more convenient and visually less intrusive since everything can be concealed.

Afterwards, you will likely have to make compromises regarding the necessary wiring. Also, having five outdoor units on the house doesn’t look very appealing.

The cool air from the upper floor naturally sinks down to the ground floor, but it doesn’t stop there. There is still warm air on the upper floor. It just takes a bit longer, but eventually, an equilibrium will be established throughout the entire house. Warm air always rises, then flows to your system.

Thank you for the quick response.

Can you roughly estimate the price range this would fall into? If it’s way beyond reasonable, I would first opt for a cheaper solution and see how the heat development turns out.

Samantheus schrieb:

Thank you for the quick response.

Can you roughly estimate the price range this would fall into? If it’s far too expensive, I would initially go for a more affordable option and see how the heat development turns out.

For our new build, I requested a quote for air conditioning. The conditioned area would be about 150 square meters (1,615 square feet) – 5 indoor units as wall-mounted units – 1 outdoor unit. Entire system by Daikin – 14 kilograms (31 pounds). Ducted units (to be concealed in the suspended ceiling) – 21 kilograms (46 pounds).

It’s hard to say for sure. It also depends on the local companies, what they offer, and how their prices are.

Depending on the manufacturer, a 3, 4, or 5 multisplit system usually costs between 3,500 and 6,000 (plus installation). I would estimate around 10,000 for the complete solution including installation (on the very low end).

Single splits are, of course, much cheaper—around 500 per room—but then you have an outdoor unit for each device. You have to make a lot of compromises, and it might not look very attractive in the end. Also, line extensions might be necessary, and the cost for those could easily exceed the price of the system itself.

Mycraft schrieb:

I would estimate around 10K for the complete solution plus installation (very roughly calculated).

At least for the Nuremberg area, your estimate is quite accurate. Here, 4 indoor units plus an 8.3kW (28,300 BTU) multi-split outdoor unit cost just under 10,000 euros, and installation is about 6,000 euros for a new build.

If you are considering air conditioning, I would recommend including it directly during the new construction phase. Refrigerant pipes as well as condensate drains can be neatly installed within the walls, and most importantly, you can address any issues individually and usually solve them quite easily. This is not necessarily possible with an existing house anymore.