Air-to-water heat pump, central ventilation system, and air conditioning

Hello dear forum,

I am new to this forum and have a question that fits the forum topics

Heating/Climate
Solar/Energy and
Ventilation systems/Heat recovery.

Our house is expected to have a wide south-facing side. For this reason, I am somewhat afraid that it will become unbearably warm inside the house during the summer. Since I am basically environmentally conscious, I am rather skeptical about air conditioning. However, I think that in the long run, its installation will be unavoidable. We would then want to offset the energy costs and environmental impact with solar systems, for which we will definitely install a preparation during the house construction. I would now like to ask you how to proceed best in this case.

We plan to install an air-to-water heat pump as the heating type with underfloor heating. We are not yet quite sure about installing a ventilation system. If we do install one, it will definitely be central and not decentralized (due to noise pollution from outside). I now have several questions:

a) Is it possible to connect an air-to-water heat pump with the central ventilation system, especially with its heat recovery? A salesperson from a construction company (which we have not yet decided on) said this is not possible. But I do not really believe that.

b) From a physical point of view, it should be easy to reverse the operation of the heat pump and thus get an air conditioner. Is this also practically possible? In other words: Are there air-to-water heat pumps that cool in the summer? If yes: Does the cooling then run through the underfloor "heating" or through the central ventilation system? In the latter case, the ventilation system and heating would have to be connected, right?

c) If b) does not work: Are there combined units that include the heat pump, the ventilation system, and the air conditioning?

d) What is the best approach if one wants to install an air conditioner later? From my naive point of view, it should then be sensible to choose a central ventilation system, right? Then the ducts could certainly be used later for the air conditioning. Or can an air conditioner also be installed later easily without a central ventilation system being present?

I am already very grateful for every answer!

I would separate the heat pump and ventilation system. There are no good reasons to rely on an expensive and possibly complex device from a single manufacturer. At the latest in case of a defect or replacement after several years, this is a significant disadvantage.

The heat recovery of the ventilation system reverses in many systems in summer, and the air is slightly cooled down. Not to be confused with the "summer bypass," which merely deactivates the heat recovery. However, the ventilation system does not perform miracles when it comes to cooling.

Cooling via heat pump is actively possible with air-to-water heat pumps, that is, with electricity usage. With geothermal heat, passive cooling is possible. The cooling function is not as effective as with an air conditioner. Among other things, an air conditioner dehumidifies the air while the humidity increases with the heat pump. With the heat pump, we keep it around 24 degrees in mid-summer, but thanks to automatic shading, it doesn’t get warmer than 26 degrees for us anyway.

The electricity consumption for cooling with a heat pump is relatively low, especially if you install photovoltaics, allowing you to cool during the day with your own solar power.

If the house tends to overheat and you need it cool, an air conditioner makes sense. However, my first focus would be to avoid overheating through appropriate insulation and shading.

Our house is expected to have a wide south side. For this reason, I am a bit afraid that it will become unbearably hot inside the house in summer.

The concern is justified. Without effective shading, you quickly have the same heat inside as outside.

Since I am actually environmentally conscious, I am rather skeptical about an air conditioner.

Hmm, but you want to install a heat pump. That’s basically the same thing.

However, I think that in the long run the installation of this will not be avoidable.

If you want to have it cool but not give up the sun, then yes.

a) Is it possible to connect an air-to-water heat pump with the central ventilation system, especially with its heat recovery? A salesperson from a construction company (which we have not yet decided on) said that this is not possible. But I don’t really believe that.

It is possible, but it wouldn’t necessarily be the most efficient solution, because it basically ends up like an air-to-air heat pump and you often create more problems and costs than necessary.

b) From a physical point of view, it should be easy to reverse the function of the heat pump and thus have an air conditioner. Is this also practically possible? So: Are there air-to-water heat pumps that cool in summer? If yes: Does the cooling then run via the underfloor "heating" or via the central ventilation system? In the latter case, the ventilation system and heating system would have to be coupled, right?

Yes, that is one of the absolute bestsellers. However, with moderate results afterwards, because a cold floor only cools the warm air at about 1.5 m height and above to a limited extent. The sun is simply stronger and the effect fizzles out.

c) If b) doesn’t work: Are there combination devices that include the heat pump, the ventilation system, and the air conditioner?

Yes, of course there are. But often they are unaffordable for the average home builder.

d) What is the best approach if you want to install an air conditioner later? From my naive perspective, it should be sensible to decide in favor of a central ventilation system then, right? Then you could certainly use the ducts later for the air conditioner. Or is it also easy to install an air conditioner afterward without having a central ventilation system?

First you have to clarify whether you want to air condition the whole house or only parts of it. After that, you can look at which system suits best, what you can do in advance, and whether and how a retrofit can be prepared and carried out.

Hello dear forum,

I am new to this forum and have a question that fits the forum topics

Heating/Climate
Solar/Energy and
Ventilation systems/heat recovery.

Our house will probably have a wide south-facing side. I am therefore a bit afraid that it will become unbearably warm inside the house in summer. Since I am actually environmentally conscious, I am rather skeptical about an air conditioning system. However, I think that in the long run, installation will be unavoidable. We would then want to compensate energy costs and environmental impact through solar systems, for which we will definitely install a preparation during the house construction. I would now like to ask you how to proceed best in this case.

We plan to install an air-to-water heat pump as the heating type with underfloor heating. We are not yet quite sure about installing a ventilation system. If we do have one installed, it will definitely be a central and not a decentralized one (due to noise pollution from outside). I now have several questions:

a) Is it possible to couple an air-to-water heat pump with the central ventilation system, especially with its heat recovery? A seller from a construction company (we have not yet decided on) said this is not possible. But I really do not believe that.

b) From a physical point of view, it should be easy to reverse the functioning of the heat pump and thus have an air conditioning system. Is this practically possible? So: Are there air-to-water heat pumps that cool in summer? If yes: Does the cooling then run through the underfloor "heating" or through the central ventilation system? In the latter case, the ventilation system and heating would have to be coupled, right?

c) If b) does not work: Are there combination devices that include the heat pump, the ventilation system and the air conditioning?

d) How is it best to proceed if you want to install an air conditioning system later? From my naive point of view, it should be sensible to choose a central ventilation system, right? Then you could certainly use the ducts later for the air conditioning. Or can an air conditioning system be installed easily afterwards without a central ventilation system being present?


I am already very grateful for any answer!

Hi

I am currently planning the same, but am not yet sure which combination.

How did you decide?
Would you do it the same way again?
How is the cooling?

My thoughts for our two-family house (270 sqm):
Air-to-water heat pump (underfloor heating)
+
central ventilation system with active cooling


As mentioned above, I would buy the systems separately so I get the most effective result -> space available in the basement

Do you have to connect/couple the systems?
Are there problems if they are from two different manufacturers?

Thank you, I hope you are still active
But I would also welcome feedback from experts

central ventilation system with active cooling

How does the latter work? Is there a heat pump installed? Does the ventilation system have an exceptionally high throughput?