Renewal of heating system in old building, which system?

  • Erstellt am 2020-05-04 14:51:44

tiborb

2020-05-04 14:51:44
  • #1
Hello everyone,

I need your advice on the decision of which heating system we should choose for the planned renewal of the heating system.

Facts:

- Semi-detached house with two separate residential units, built in 1972, newly acquired by us in 2014
- approximately 220 sqm heated space, 186 sqm living area, 95 sqm on the ground floor, 91 sqm on the upper floor
- Building envelope insulated with 10 cm
- New windows triple glazing, winter garden (complete glazing) on the ground floor and upper floor
- Roof not insulated
- Heating distribution: (We currently plan to replace the old radiator panels with low-temperature radiators)

    [*]Basement: An old radiator panel and about 40 sqm underfloor heating (old system - probably keep heating pipes)
    [*]Ground floor: Underfloor heating with 9 loops, installed in 2014, and old underfloor heating system in the winter garden as in the basement
    [*]Upper floor: Six old radiator panels

- Replacement of old oil heating from 1989 (low temperature), oil tank 6000 l steel tank, current consumption approx. 2500 liters per year
- No gas house connection
- Additional planned project is a photovoltaic system with approx. 8 - 9.9 KWp on the south side of the roof with a 10 KWh storage battery
- Ideally use BAFA funding 40% - 45% per system

There have been many considerations regarding the variants of the new heating system:

Option 1: Gas hybrid with solar thermal 8.5 sqm and 600l water buffer tank
(Offer with Buderus or BOSCH systems)

Option 2: Gas hybrid with 400l water tank and small additional air-water heat pump (possibly combined with photovoltaic system on the roof)
(Offer with WOLF systems)

Option 3: Air-water heat pump with integrated water treatment in the indoor unit and with outdoor unit (possibly combined with photovoltaic system on the roof)
(Offer with Vaillant systems)

Everything has its advantages and disadvantages, but I am also interested in your opinions and experiences. In particular, I am unsure about the noise level of the outdoor units of the heat pump. How loud are they really?

Or maybe you are currently planning a replacement and have a similar situation. So, please share your experiences with the systems and which you would recommend for my context.

Thank you very much for your help!!!

Best regards
Chippy
 

nordanney

2020-05-04 16:36:29
  • #2
Uh, stupid question. Why GAS hybrid if you don't even have a gas connection yet (apart from the hybrid topic, which I don't find good/sensible)? Insulate the roof and basement (if necessary) and install a heat pump. Today's devices are efficient and quiet.
 

Joedreck

2020-05-04 16:58:26
  • #3
Insulate the roof in ANY case. Or the top floor ceiling. You can easily save 20% there. Then remove the radiators upstairs and, if possible, have underfloor heating installed. Then move towards a heat pump.
 

tiborb

2020-05-04 17:07:25
  • #4
That means you generally do not consider the GAS hybrid solutions to be reasonable?

What does having underfloor heating milled mean? What are the approximate costs? So far, we have avoided these additional costs for a new underfloor heating because we would then also have to renew the floor coverings.

What costs can we expect for floor slab insulation?

Would these measures also be eligible for funding through BAFA?

Thank you.

Best regards
 

tiborb

2020-05-06 16:26:56
  • #5
What kind of costs can we expect for an insulated ceiling slab approximately? Or could we also do it ourselves and only have the materials subsidized?

Why is GAS-Hybrid not sensible in our particular context? GAS-Hybrid with solar thermal is very often installed in new buildings, or am I mistaken? Or did you mean the variant GAS-Hybrid with heat pump? Of course, I have also wondered what the purpose of that is and tend more towards the pure heat pump solution.

A pure heat pump only works efficiently and economically at a low flow temperature of 30 degrees. If we keep low-temperature radiators on the first floor, then at least 55 degrees must be supplied there, and then the heat pump consumes a lot of electricity, doesn’t it?
 

T_im_Norden

2020-05-06 16:36:08
  • #6
Promotion of the Bafa for heat pumps and also for:

- energetic optimizations of heat distribution (e.g., thermal insulation of pipelines) and heat transfer (e.g., replacement of old standard radiators with low-temperature radiators)

- the preparation of hot water as well as the renovations/conversion work of heating/technical rooms and chimneys required for the new, eligible heat generator.

Simply check the Bafa website for the document with the eligible costs
 

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