ᐅ Heating System Planning – Choosing the Right Option: So Many Questions...

Hello everyone,
the topic of heating is slowly driving me crazy; for me, it is one of the most challenging issues when building a house. Depending on whom you ask or which study you find, there are quite different facts and opinions...

To share my situation: We are planning a KfW70 house with underfloor heating through a general contractor (GC). The GC has mostly installed gas boilers in the past, which is absolutely out of the question for us. My assessment is that the GC therefore has a lot of experience with gas but less with heat pumps. Now he has presented us with a proposal involving a heat pump and solar thermal system, but I am somewhat skeptical about the cost-effectiveness.

I would therefore like to get an (hopefully) independent opinion or an economic assessment. How would you approach this topic? How did you have your heating system planned (GC, heating specialist company, engineering/planning office)? How much would it roughly cost to hire a specialist planner?

Thermal storage with a heat pump is generally not practical—there is usually no need for a buffer tank in heating systems with heat pumps. If anything, use it with photovoltaic systems.
Also—this is something we are currently learning the hard way—find a heating engineer who regularly installs heat pumps (preferably nothing else)... with others, you risk them not having sufficient knowledge.
I believe if you find a really good one, you won’t need a specialist planner or an engineering office.
Pay attention to details and question the execution—for example, 6 cm (2.4 inches) of cement screed is not enough for 20 mm (0.8 inches) pipes.
Consider wall heating panels in the bathrooms instead of towel radiators.
Verify the plausibility of the heating load calculations you receive.

daytona schrieb:
Hello everyone,
the topic of heating is slowly driving me crazy; for me, it’s one of the most challenging aspects of building a house. Depending on who you ask or which study you find, there are quite varying facts and opinions...

To give you my facts: We are planning a KfW70 energy-efficient house with underfloor heating through a general contractor (GC). In the past, the GC has mostly installed gas boilers, which is completely out of the question for us. My impression is that the GC has a lot of experience with gas systems but less with heat pumps. Now, he has proposed a heat pump combined with solar thermal panels, though I’m quite skeptical about its cost-effectiveness.

Therefore, I would like to get a (hopefully) independent opinion or cost-effectiveness assessment. How would you approach this topic? How did you arrange the planning of your heating system (GC, specialized heating contractor, or planning office)? What would roughly be the cost of hiring a professional planner?

Why no gas? Do you have a ventilation system? The GC will probably look for a cheap heating contractor to install the heat pump. Whether it will run flawlessly afterward could—like Baheija mentioned—be a gamble.

There is no gas line in the street, and KfW70 standards cannot be met, according to the certified KfW planner for the house.
Options included even better windows, although triple glazing is already installed, and partial cost coverage for the gas line in the street (gas supplier).

BeHaElJa schrieb:
no towel radiator

No good experience? I was thinking of a combination of underfloor heating plus electric.

Electric heating uses 1 kWh of electricity for every 1 kWh of heat produced... Electricity is expensive – it’s better to increase the heating surface area in the bathroom to meet the demand from the ceiling, or simply accept lower temperatures than 24°C (75°F).