As
- We heat our bungalow to a lower temperature than is common.
- We will want a higher temperature as we age.
- A larger heatpump within reason tends to be more efficient provided it is not short cycling.
- A larger heatpump is less likely to get “defrost hell”.
- Most installers will over calculate our current heatlose.
- When we later do other work in the property the heatlose will likely reduce.
- Likely to have a bad mix of UFH and radiators for one winter
I am assumung our heatpump will be oversized for long term requirements.
We are thinking of installing UFH as we renovate. Very likely, we will need to relocate the boiler. So getting a heat pump seems sensible as part of the process rather than a new heat-only gas boiler. (As an LNPG member, a new gas boiler would cost me about £700 plus one day’s labor from the gas-safe person I use.)
We have not decided on the make of the heat pump, but it will have a “degree minutes” anti-cycling configuration or be connected to a third-party controller that is good at avoiding cycling with UFH.
So now for the question!
I am taking it as a given that UFH will be a high thermal conductivity liquid screed over a good thickness of insulation; otherwise, I would rather have a mix of K2/K3 and fan convector radiators.
Does it make any difference to performance or control if the liquid screed is closer to 30mm or 60mm thickness?
Is there any difference between clipping the pipes to insulation or using a “Egg Crate Floor Panel” to layout the pipes? Eg is the difference in context area between the pipe/screed of any practical significant?
Is it better having many loops at say 40m length or fewer loops at 80m length? Does having more loops create any practical limitations on choose of heatpump, eg power of built in pump?
Am I right to assume I should have the closest practical pipe spacing so to to both maximise system volume and contact area?
With about 100 m^2 of floor area, will having say 100mm pipe spacing rather than 200mm spacing create issues with any built-in pump flow rates? Is there any point in going under 100mm spacing other than the bathroom?
Assuming short loops, is there any reason to consider other than 16mm pipes, eg is the higher bending radius on 16mm an issue with close spacing?
(I don’t care about using more pipe and manifold ports as they are a small part of total system cost, and the only part of the system that will never be replaced. )