ᐅ Installation of the underfloor heating system in the upper floor hallway area

Hello everyone,

As you can see from the attachment, we are currently installing the underfloor heating. We are a bit uncertain about the next steps for the hallway on the upper floor, so here is an explanation:

The heating circuit manifold (HKV) is located in the master bedroom behind the door. From there, the supply and return lines each run into the children's room. If I don’t run the underfloor heating from the bathroom through the wall to the manifold (which was still possible until now), a third supply and return line would have to go through the hallway.

A separate heating circuit for the hallway would be quite small, as the pipes to the adjacent rooms already take up considerable space.

Additionally, the hallway on the ground floor is also heated. That leads me to wonder how the hallway on the upper floor can be controlled, since it is actually an open space between the ground and upper floors. I have planned a KNX system with appropriate regulation based on temperature sensors.

Should I simply omit the separate circuit for the upper hallway, since it will naturally warm up from below and the supply and return lines will also heat the hallway somewhat? Or should I install a separate circuit? Or will the floor become too cold in areas where there are no supply and return lines?

If I do add a small heating circuit, how would the control work? In theory, the two hallways would then be "working against each other."

Thanks for your answers and best regards!

Dachshund90 schrieb:

That makes me wonder how the hallway upstairs can be controlled at all, since it is basically an open space from the ground floor to the upper floor. I have planned KNX with appropriate regulation using temperature sensors.

Underfloor heating is not "controlled." It is designed, installed, and adjusted. Save your KNX money and invest in professional underfloor heating planning instead.

Dachshund90 schrieb:

Should I simply skip having a dedicated circuit for the hallway since it will anyway be warmed from below, and the supply and return pipes also slightly heat the hallway, or should I install a separate circuit?

That’s what your planning will tell you.

Dachshund90 schrieb:

Or will the floor in areas without supply and return pipes get too cold?

“Cold” is relative. With today’s underfloor heating systems and low supply temperatures, floors don’t really get warm anymore anyway.

nordanney schrieb:

Underfloor heating is not “controlled.” It is calculated, installed, and adjusted. Save your KNX money and invest it instead in professional underfloor heating design.

This is currently planned and will remain so; it is controlled via the temperature sensor. I have a design that includes a single loop. However, I cannot implement it that way because of the supply and return pipes, as I no longer have the space.

Therefore, I now have to decide what to do.

Dachshund90 schrieb:

It is planned that way now and will remain so; it will be controlled via the temperature sensor.

OK – it’s your money, and no further discussion about whether the sensors might get bored.

Dachshund90 schrieb:

That’s why I need to decide now what I’m going to do.

Run all circuits through the hallway, possibly with a loop, so you cover the area evenly.

nordanney schrieb:

Run all loops through the hallway, possibly with a curve, to ensure an even coverage of the area.

Okay, is it disadvantageous here to route the bathroom loop with curves through the hallway? After all, the bathroom is the warmest room, and if I lose some heat from the supply pipe in the hallway, wouldn’t that be unfavorable?

Dachshund90 schrieb:

Ok, is it disadvantageous to run the bathroom circuit with loops through the hallway? After all, the bathroom is the warmest room, and if I already lose some heat in the hallway from the supply line, might that not be ideal?

First of all, you lose about one or two meters (around 3 to 6 feet). That is negligible. Besides that, you have a calculation that can be adjusted if the bathroom is meant to emit a particularly high amount of heat.
What is the exact design? Please share the data and the actual installation plan. Then it will be easier to give more precise advice.