Air heat pump and electricity consumption

@Help: my thought was: air heat pump instead of gas boiler. Initially a few thousand EUR more costs (1500 or 2000 can be offset again since the gas connection for the house is no longer needed). In the medium term, the air heat pump has the edge thanks to lower operating costs compared to gas. However, this is not much more than my idea so far. I also find the possibility of cooling in summer as well as the combination with ventilation/heat recovery very interesting, aside from the financial aspect. Therefore, a big question mark remains behind ventilation technology.

I see that. You really have to put everything on the same denominator. I just didn’t have any figures yet, whether 1,000 kWh or 10,000 kWh.

For efficiency reasons, I’m currently thinking of a 1.5-story house with a gable roof, without dormers, without skylights, without offsets, close to a square floor plan.

Basically, I would aim for KFW-70, but I don’t know if it’s worth doing it officially, as I don’t know the costs for application, certificates, etc. 50,000 at 1.0% sounds good, but the terms at the house bank probably won’t be much worse. I expect that we will (over)fulfill KfW-70, but whether it’s worth doing everything officially, I still need to find out. But that’s almost off-topic.

Regards

Hello nordanney,

how did you determine the share of hot water?

My neighbor has a Stiebel Eltron air-to-water heat pump that records the electricity consumption separately.

I see that. You really have to bring everything to a common denominator. I just had no clue whether it’s 1,000 kWh or 10,000 kWh.

For efficiency reasons, I’m currently thinking of a 1.5-story house with a gable roof, without dormers, without skylights, without offsets, close to a square floor plan.

Basically, I would aim for KfW-70, but I don’t know if it’s worth doing officially since I don’t know the costs for the application, certificates, etc. 50,000 at 1.0% sounds good, but the conditions at the house bank won’t be much worse either. I expect that we will (over)fulfill KfW-70, but whether it’s worth having everything done officially like that, I still have to find out. But that’s almost off-topic.

Regards

There is already a heating load calculation done beforehand, where all conditions are taken into account. Based on that, the heat pump can then be sized. KFW70 – the surcharge compared to the normal Energy Saving Ordinance is manageable here, also regarding the cost-benefit analysis. And in case of a possible later sale, KfW70 also looks better. The effort from KFW70 to KfW55, for example, is significantly greater...

In the medium term, the air heat pump has the edge thanks to lower operating costs compared to gas. However, that is not much more than my idea so far.

I wouldn't carve that in stone either...

Also from us a brief update on the status - uh electricity status report. We heat with a ground source heat pump.
We were told that we have to count on 8,000-10,000 kW in the first 2 years, then 6,000. I'm curious if that's true, but I would tend to say it's set too high.
Our pump was started up at the beginning of September. However, at that time, heating was done entirely by electricity for warming up and screed drying (in my opinion, this was the first 1,500 - 1,800 kW). After we turned down the heating during the self-work (painting), we moved in at the end of November. Until the really cold days (end of December), the hot water was not heated via the electric auxiliary heater.
So after all the backstory now the current status: we have consumed about 2,850 kW since the start of the heat pump. In December I have been checking the meter every morning. We currently have a daily consumption between 20 and 26 kW on the pump - depending on whether the hot water storage tank needs something again.
This consumption is in the currently cold season. I am curious how the consumption will be when it gets spring or summer. Let's see where we end up then.
Oh yes - the house is KfW70 with a size of just over 170 sqm.

At the heat pump (depending on the type) you should be able to at least read the compressor run times for heating and hot water. Then you can calculate it proportionally... - or even the energy consumed directly - and the amount of heat generated...

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Hello,

I need to ask again. Where can I read the compressor run time? On the air-source heat pump control? We do have heat meters in the apartments, but they are connected to the heating circuits. The plumber said that these meters also record these values based on the returned hot water. Which I did not want to believe since hot water is heated to a higher temperature than heating water.