Heating with air-water heat pump with cooling function

Hello everyone,

we are currently planning our house. One of the first questions from the providers is always about the "heating method."

So far, I have mostly shrugged and said "gas heating."

One provider recommended air-to-water heat pumps over the weekend. Until now, I didn’t even know such a thing existed.

I’m now trying to educate myself a bit and found the following model from the company "Stiebel Eltron":

WPL 13-23 cool

The description says that it can heat and cool.

Now my question:

Can the cooling function be imagined like an "active" air conditioner (performance of a split air conditioning unit), or is it a kind of "pseudo cooling" that cools the building from 35°C to 34.5°C? (So practically zero cooling)

What do you think of such technology at all? (I have so far only lived in houses/apartments with gas heating)

(Warm in winter with gas, cool in summer with an extra air conditioner)

I want it to be warm in winter (without a thick wool sweater in the house) and cool/cold in summer.

So far, I have never really dealt with energy values.

In winter, I prefer a (very) "warm hut" and am willing to pay extra before I get cold in winter and receive 100 euros back.

With acquaintances and friends who have installed "new" technologies, I often get the feeling in winter that their house is (too) cold. (You don’t freeze directly, but it’s not cozy warm either).

When they visit us, they almost always say, "Oh, it’s so warm here with you."

Best regards

Bubb

Hello Bubb, 1. first of all about the manufacturer Stiebel Eltron. In my opinion, you can get the same for less money from Mitsubishi Ecodan or Daikin. 2. I would never cool with the heat pump. - Mold growth (cold floor or cold walls), - What happens if you want warm water and cooling at the same time? - For that, there are normal split units. 3. You can only save effectively with the heat pump if you have a low flow temperature (max 35°C), this can be achieved by relatively large radiators or underfloor heating. Then you can cut your heating costs by at least half. Many of my friends have heat pumps, and if you choose a reasonable manufacturer, size the air-source heat pump properly and consider everything when installing, then everything fits with energy saving and the house stays warm.

Hello Maxim,

thank you very much for your response,

what worries me a bit now are the many "ifs" (if the correct manufacturer, - if properly installed etc. the house will be warm).

Does this mean that it is a gamble?

As I wrote, I currently have zero knowledge about this. (That every provider says/recommends something different does not make things easier).

I’d rather stick with gas and the house will definitely be warm.

You are right about the cooling. Since we are planning underfloor heating, the floor would be cold when cooling (I hadn’t thought that far).

Regards

Bubb

Hello Bubb,
It is not much ifs, I am planning my house with underfloor heating and an air heat pump. The energy demand is 8 KW according to the architect, I will take an 11 KW heat pump from Mitsubishi or Daikin, as they can regulate their performance independently. And I will take a large buffer tank, then it does not cycle so often and that is also energy saving. The flow temperature will be 28°C and that is also a saving of 10-20%. The good thing about it is that I can do without solar because on sunny days the air heat pump runs even cheaper anyway.
And that is all I have thought about for the design.
With underfloor heating, a heat pump is usually worthwhile.
Regards
Maxim

Hello,

Can the cooling function be imagined like an "active" air conditioner (performance of a split air conditioning unit), or is it a kind of "pseudo-cooling" that cools the building from 35°C to 34.5°C? (So cooling almost NONE) What is to be made of such a technology at all?

All manufacturers advertise that the air-water heat pump can also be used for cooling, but in reality you can only expect a temperature difference of 2-3 degrees; so rather separate systems – either via an additional air-air heat pump or more cost-effectively via strategically positioned air conditioning units. In addition, the air-water heat pump with cooling has another disadvantage – where the floor is tiled, condensation can form and with appropriate footwear it creates a nice slip hazard.

With acquaintances and friends who have installed "new" technologies, I often have the feeling in winter that their house is (too) cold. (You don’t freeze directly, but it is not cozy warm either).

This is usually not due to the new technologies, but to Germans' favorite pastime: "oh, it’s warm outside, let’s turn down the heating," forgetting that nowadays every heating system adjusts itself according to the outside temperature. Besides, the new systems do not tolerate it so easily when their settings are constantly being "tweaked."

My recommendation: one system for heating, optionally combined with ventilation if there is sufficient space in the utility room, and a separate system for cooling.

Kind regards

Hello,

..., I am planning my house with underfloor heating and an air heat pump. According to the architect, the energy demand is 8 kW, I will take an 11 kW heat pump from Mitsubishi or Daikin, as they can regulate their power independently.

not particularly sensible. Does the heating load calculation according to DIN 12831 state that? By the way, take a close look at the COP and heating performance curves of the aforementioned devices, maybe something will stand out regarding modulation.

...The flow temperature will be 28°C ..

What is the surface temperature at which room temperature and underfloor covering? Don't forget heat loss flow downwards!

Best regards