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

Created on: 15 Oct 2015 20:19
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daytona
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?
Sunny15 Oct 2015 22:14
Towel radiator + RTL valve simply perfect. The towels can dry, and the underfloor heating is controlled via the return flow.
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Sebastian79
16 Oct 2015 12:05
It doesn’t help with such low flow temperatures – besides, a thermostatic bypass valve (RTL valve) is always just a makeshift solution.

We have underfloor heating even in the large shower area, covering almost 10m² (108 sq ft) of heating surface. Additionally, there are infrared heating panels that emit heat for a set time when activated by a switch, as well as an electric towel warmer with remote control and timer. The electricity used is negligible, very flexible to operate, and not comparable to a continuously heated bathroom that would disrupt the entire hydraulic system.
Sunny18 Oct 2015 00:57
Sebastian79 schrieb:
It doesn’t help at such low flow temperatures – besides, an RTL valve is always just a makeshift solution.

We have underfloor heating even in the large shower area, providing nearly 10 m² (108 sq ft) of heating surface. Additionally, there are infrared heating panels that emit heat for a set time at the push of a button, and an electric towel warmer with remote control and timer. The electricity used is minimal, very flexible, and not comparable to a continuously heated bathroom, which would disrupt the entire hydraulic system.

I don’t understand the point about it being a makeshift solution!
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Sebastian79
18 Oct 2015 08:33
Because a towel radiator requires a high flow temperature, but underfloor heating needs a low one, and with the RTL you take the water from the return, you keep restricting the flow because the valve responds to the water temperature instead of the room temperature.

Therefore, it’s a workaround, as underfloor heating should have its own regulated circuit. However, this is a cheaper solution.

With a modern heating system using a heat pump, the flow temperatures are very low anyway, so this issue becomes irrelevant.
Mycraft18 Oct 2015 09:51
In my opinion, a towel radiator in a modern house should ONLY be operated electrically. Anything else is pointless and unnecessarily wastes resources, whether due to the required additional piping and valves beforehand or the extra high temperatures afterward.