Old building renovation + choice of heating system

Hello everyone,

what regularly occupies my mind is the question of the _future_ heating system in renovations; I would therefore like to pass this on to owners of renovated existing properties.

How have you solved this issue for your home and why? Gas condensing boiler + solar, air-to-water heat pump + photovoltaic, CHP, CCHP, or hybrid system, did you consult an energy advisor? And along with that, of course, did you possibly replace existing radiators with the new installation of underfloor heating, and are you still satisfied with your choice today?

I would be happy if those of you who have renovated speak up, as this topic will certainly remain of great interest in the coming years.

Thank you + Rhenish greetings

Air-water heat pumps + underfloor heating are often chosen when it can be realized constructionally with all requirements for the floor structure and building insulation. Of course, this presupposes a complete energetic renovation with [GEB], heat load calculation, ventilation concept, blower door test, etc., at a [KFW-EE] level, which then also makes it possible to use [KfW] funding programs.

Otherwise, of course, there is still the cost-saving gas boiler for the smaller budget, with normal convectors or also with underfloor heating. I gladly refrain from the use of photovoltaic or solar thermal systems if possible, because they complicate and increase the cost of the system technology and in our latitudes, in terms of the Energy Saving Ordinance and the Renewable Energy Heat Act, are initially only an expensive token additional service without real benefit. Photovoltaics will be interesting in the future when there are affordable and efficient storage modules and a heat pump with its own power supply would be possible.

In my opinion, the whole topic of building services engineering should become simpler rather than increasingly complicated + expensive. Building has become about 35% more expensive since 2000 due to the requirements of the Energy Saving Ordinance and the excessive building services engineering.

We did the following during our major renovation: Old oil heating system with 25 kW removed, radiators removed New condensing oil heating system with modulation from 6 to 15 kW and underfloor heating installed. No ventilation system, new roof with insulation, new windows, new screed + insulation, no insulation of the exterior walls. We chose oil again because there is no gas connection in our village. Otherwise, we would have had to use liquid gas or pellets. Liquid gas was ruled out because we did not want a tank in the garden and the pellet system would have cost over €10,000 more in acquisition. Consultation by architect and heating engineer.

Otherwise, of course, still the cost-saving gas condensing boiler for the smaller budget, with normal convectors or also with underfloor heating.

Yes, the TOC (Total Cost of Ownership) over 20 years is still very feasible for a gas condensing boiler at the moment. How this will develop with changing regulations and gas prices remains to be seen. Convectors don't have to be bad either; there are people who don't like underfloor heating......we are "over the moon" with our radiators and very satisfied.

I gladly forego the use of photovoltaics or solar thermal energy if possible, because it complicates and increases the cost of the system technology and, in our latitudes, according to the Energy Saving Ordinance and the Renewable Energy Heat Act, is at first only an expensive token additional service without real benefit. Photovoltaics will be interesting in the future when affordable and efficient storage modules are available and a heat pump with its own power supply would be possible.

My full agreement. Solar thermal is a toy here to stay that never pays for itself but only creates a good conscience. I say this because I know, we have such a system, I know what it cost and what it delivers.

Photovoltaics is also a toy – but it becomes more interesting because of batteries. No one knows how electricity prices will develop (for the end consumer). I like photovoltaics better than solar thermal; I gladly allow myself that toy. Photovoltaics with a high own-use rate definitely makes sense, avoiding CO2. However, one must be clear: The calculation is currently at least break-even; photovoltaics is rather more expensive.

The whole topic of building services engineering should, in my opinion, become simpler instead of always more complicated + expensive. Construction has become about 35% more expensive since 2000 due to the requirements of the Energy Saving Ordinance and the excessive building services engineering.

Finally an architect who calls a spade a spade. Thumbs up. When I enter my technical room, I slowly get the feeling of being in the engine room of a nuclear-powered aircraft carrier, not in a house.

Best regards Thorsten

During the renovation of our 1936 house, we removed all radiators and the old gravity heating pipe system. Complete reinstallation, but again with radiators. The 25 kW natural gas resin boiler from 1996 remained for the time being on the advice of our HVAC master, because it is low-maintenance and rarely prone to faults. We have not regretted this so far. However, the boiler could be replaced within a day if necessary.

Morning

But many builders actually want the rocket technology, btw. the industry has offered a solution for a problem that is not/rarely present.


Olli