What to replace an oil heater from 1989 with in an old witch's house?

I would also schedule an appointment with a structural engineer. In wooden houses, the floor slabs have a bracing function. They hold the exterior walls together under tension through the beams, which would otherwise be pushed outward by the thrust of the roof. The floor area acts like a diaphragm that braces the house against wind loads on the roof. Generally, this can only be raised at very high effort and cost. In my experience, complete removal is out of the question.

The beams of the floors should stay inside, only the floor in between should be removed.

Today was finally the appointment with the energy consultant; he encouraged me to continue pursuing the heat pump issue.

So far, I have called five heating engineers, four categorically reject heat pumps in old buildings. One has been trying to find an appointment to come by for 8 weeks :/

If anyone here has a recommendation for a heating engineer in the Ammersee / LL area, I would be very grateful.

Maybe there is also someone whose HP in an old building I could visit once (Bavaria area)?
I would really like to see such a system in person.

Thank you very much for your help!

In the meantime, I have found a heating engineer. I am now faced with the difficult choice regarding the heat pump.

To recap so you don’t have to go through the entire thread:
* Heat load calculation by energy consultant 10kw
* of which 4.3kw is for the extension
* fluctuating occupancy in the house, mostly 1, often 2-4 people
* extension is only heated when there are 2+ people in the house
* often nobody at home (vacation and the house needs to be protected from freezing)
* heating support planned through wood stoves (currently there is a stove that is to be replaced by a stove with storage function)

Due to all these factors, there is a strongly fluctuating real heat load. Nevertheless, I probably have to size my heat pump so that it can heat the house monovalently to an acceptable level. It is important that the pump can modulate its output well.

What size heat pump should we choose now? Our heating engineer said that based on the data a 9KW unit is appropriate, but the on-site appointment has yet to take place.

We are also facing the decision of whether Split or Monoblock. One definite advantage of Split is that I would have fewer worries in the event of a power outage and/or absence?

Unfortunately, the Panasonic T-Cap series is only available as a Monoblock with R32 (J series). The split units are still on the H series standard with R410A.

Does anyone know if and when a T-Cap Split with R32 is planned?

In the LT series, there are both Split and Monoblock units with R32 (J series).

The LT series, with the smaller outdoor unit, would be better suited for installation on the east side. However, the T-Cap seems to be particularly suitable for higher flow temperatures and stronger subzero temperatures as I will probably have with our radiators? Nevertheless, we have already mentally arranged for a large T-Cap Monoblock on the east side.

In addition, I am considering installing two wall heaters in the house to increase the heating surface area. As I understand it, it does not seem to be a major problem to operate a second heating circuit with a lower flow temperature? I am faced with the choice between wet and dry construction methods and have come across manufacturers who offer both wall heaters in dry and wet construction variants.

My plan is to equip an interior wall each with such a surface heating system (hallway + dining room). Is there a recommendation here?

Which size heat pump should we choose now? Our heating installer said that based on the data, a 9KW unit is recommended

Sounds like someone knows their stuff.

Also, we are facing the decision between split or monoblock. One advantage of split is definitely that I have less to worry about in case of power outage and/or absence?

Why?

Does anyone know if and when a T-cap split with R32 is planned?

It will come. When? No idea. 2022? 2024? Basically, the Panasonics are good devices that can also handle low temperatures. I have two monoblocks here myself. They can also run multiple heating circuits with different temperatures.

Why?

With a monoblock, I have to run water pipes out of the house, which of course is annoying during a longer power outage and could freeze. If I need a new heat pump in 10-15 years, a monoblock is probably easier to replace and maintain? That's why I'm leaning towards the monoblock now, then the question is whether to choose the T-CAP or HT series? As far as I understand, a monoblock could also serve two heating circuits?

Sounds like someone knows what they're talking about.

Is that sarcasm?

With a monoblock I have to run water pipes outside the house, which of course is problematic during a longer power outage and can freeze.

1. I can't remember a suitable power outage since my youth and 2. you can put antifreeze in the water pipe for that.

As I understand it, could a monoblock also serve two heating circuits?

Yep, with additional module XY. But I only know it from theory and not yet from practice.

Is that irony?

No, actually not. The heating technician often offers a larger heat pump than necessary at 10 kW heating load "just to be safe". P.S. Small bonus of the Panasonics. If you had exclusively underfloor heating, you could also use the heat pump for cooling. Just activate it in the software, nothing more is necessary.