Prefabricated house heating: Gas / Air heat pump / Underfloor heating

Hello,

Geothermal energy is expensive, but firstly there is a €4,500 BAFA subsidy, secondly you save later on consumption, even if the insulation is only standard.

I am always waiting for users to speak up and share their experiences with brine-water heat pumps ...

With an air-water heat pump I would insulate very well, because otherwise the heating consumes large amounts of expensive electricity.

No; if you are referring to the gentleman below, in my opinion he makes a mistake on his site by grouping the air-water heat pump under the category air heat pumps. An air-water heat pump requires about 0.2% of the annual operating costs per year as pure electricity costs for defrosting the fan in the outdoor unit.

Some user recently published their consumption values regarding the air-water heat pump here in euros; if he reads this - Doc, was that perhaps you? - hopefully he will speak up again. Unfortunately, I forgot which member it was

The benefit of a photovoltaic system depends strongly, as far as I know, on whether the roof has a nice southern orientation.

Nowadays, one deviates from the pure south side as a prerequisite; roof surfaces oriented east-west deliver very good yields.

A website on the topic of "heating comparison" by the energy consultant Alois Zimmermann is recommended, where different heating systems are calculated based on an example house.

I have read that from you twice now. Isn’t the good man the enfant terrible of the energy sector or am I confusing something here?

Rhenish regards

I am always waiting for users to speak up and share their experiences with brine-water heat pumps ...

I can do that starting September 2016.

No; if you are referring to the gentleman further down, in my opinion he makes a mistake on his site by grouping the air-water heat pump under the section air heat pumps. An air-water heat pump requires about 0.2% of the annual operating costs per year purely as electricity costs for defrosting the fan in the outdoor unit.

Can you explain that in more detail? I am interested.

Nowadays, people deviate from the pure south side as a prerequisite; roof surfaces oriented east-west deliver very good yields.

Okay, it may be that very good yields are possible with a west-east orientation as well, but with a south orientation the yields are definitely significantly higher, since it is physically logical that with a south orientation, where the angle between solar radiation and the collector remains closer to the right angle of 90 degrees, more radiation arrives than with a west-east orientation, where the collectors are always rather slanted and never perpendicular to the solar radiation.

Isn’t the good man the enfant terrible of the energy industry, or am I confusing something here?

I would also be interested in further information on this, gladly also by PM if this should not be public.

Ok, it may be that very good yields are also possible in a west-east orientation, but yields are definitely significantly higher in a south orientation, because it is physically logical that with a south orientation, where the angle between the sunlight and the collector remains closer to the right angle of 90 degrees, more radiation arrives than with a west-east orientation, where the collectors are always rather slanted and never perpendicular to the sunlight.

Caution - the total irradiation over the day counts. There, the east and west sides are not so bad anymore, especially with steeper roofs. Then there is the question of when most of the energy gained here is needed. How well can it be stored?

I can do that starting September 2016.

That would be great!

Can you explain that in more detail? I'm interested.

Argh – now I have this; I'm not a technician after all... very rudimentary, as much as is possible for me as a DAU; okay?

It should be undisputed that the system of the air-to-water heat pump is comparable to a reversed refrigerator principle, right?
So, after the air heated by this reversed principle – using an evaporator + refrigerant – has done its job, it is directed back outside. Since the outside air passes directly through the evaporator of the air-to-water heat pump, the outside air condenses and the water that forms must be drained. If it is cold outside, the condensed air can lead to icing of the evaporator. Defrosting this requires about 0.2% of the annual electricity costs.

In the case of a pure air-to-air heat pump, it is – again simplified – such that cold air is supposed to be warmed by the indoor room heat. Logically, this doesn't work so well at low outside temperatures – how do you want to warm 5° cold outside air with 21° warm indoor air, for example? Therefore, heating via electricity is necessary, or the use of this system is only recommended in houses starting from efficiency house status 40 upwards; that is, single-family homes with as little heat demand as possible. There it then works effectively or in conjunction with a photovoltaic system.

Unfortunately, everything runs under the term air heat pump and this leads to the systems not really being distinguished. There are certainly quite a few builders who have installed an air-to-water heat pump as a heat generator. They could certainly give you better information than I can, which is solely dependent on feedback from our customers regarding their consumption. The tenor here so far is that in a 4-person household, with normal shower behavior and a house size of about 150 sqm, the costs for hot water and heating amount to around €600.00 to €800.00 per year.

...in south orientation, the yields are definitely significantly higher, since it is physically logical that with a south orientation, where the angle between solar radiation and collector remains closer to the right angle of 90 degrees, more radiation arrives...

You will certainly know that better than I do; but the fact is also that only ¼ of all offered plots are purely south-facing.

I would also be interested in more information on this, preferably via PM if it should not be public.

There is no secret that would require a PM.

If I remember again, I will gladly let you know. At the moment, only a trace of a memory is lingering in my head, which says that this person – if it is indeed this gentleman – does not enjoy a good reputation in the energy consultant sector because he apparently deals with conspiracy theories regarding targeted misinformation about fuel cells.

Rhineland regards

Hello,

that's right, we have installed a Weberhaus with a Tecalor THZ (identical to Stiebel Eltron), but the model 403 SOL.

The 403 model was chosen because our heated area is a bit larger. This system also offers the possibility to connect solar collectors for hot water preparation. We had the necessary pipes installed from the technical room to the attic, but (so far) no collectors connected.

You absolutely don't have to worry about the noise of the air-water heat pump. Ours is located in the basement in the technical room behind a normal living room door. When this door is closed, the air-water heat pump cannot be heard on the ground floor or even in the adjacent guest room despite the open staircase.

The electricity costs are also moderate - our electric auxiliary heater has been in operation only once - on the day the heating was started at -22°C. However, even then it switched off after just under an hour and has not switched on since.

We have installed a photovoltaic system with 4.25 kWp on the roof right from the start - on our most productive day so far, this system generated 32.4 kWh. Currently, we receive EUR 36.00 credited monthly from the grid operator for our fed-in surpluses, though this amount is likely to increase after the first annual billing.

If you have the option, I would invest about EUR 10,000 in a photovoltaic system right at the time of construction – on the other hand, I would (personal opinion) wait a bit longer for a battery storage, as these will most likely become cheaper.

We are more than satisfied with our air-water heat pump.

Regards,

Dirk

Hi!

First of all, thank you very much for the many responses!


Which air-to-water heat pump system do you have installed in your house? How is the noise level for you? Since we won’t have a basement, the air-to-water heat pump would be placed in our utility room, and I’m still a bit unsure how much you can hear the heating in the adjacent rooms.


Yes, you’re right, a gas boiler also means additional costs for the gas connection and a chimney... and solar also has to go on the roof, otherwise you don’t meet the requirements.

@Computersyvlia
Thanks, I will contact DocSchnagels.
EDIT: Oh, he already replied at the same time – thanks!

Best regards
Gatho