ASHP - Underfloor Heating - Warm Up Time

nxdmsandkaskdjaqd

ASHP with underfloor heating.  How long does it take to warm up (i) in autumn 1st year switch on (ii) following a overnight setback (iii) an increase in temperature demand of say a degree C? I know every property is different, but just looking for some general data. 

Updated.  The floor is screeded.

Netexporter

It largely depends on the type of UFH. A traditional screeded system will take a lot longer to warm up than, say, a gypsum board overlay system. Conversely, the screeded system will retain heat for longer. Experiment/measurement will give you the answer. 

MP1995

Depends on how you are measuring the heat up. 

By foot on floor ours is noticeable after 1 hour at a flow temp of 35oC from cold 

We are just programming the heat pump as the weather report for the next 10 days show a sharp drop in temp day and night  so looks like we will be going on a bit earlier this year compared to last year.

YorkshireTea2020

I have one section of the house (extension) which is screeded and will heat up within a couple of hours when first switched on, probably reaching temperature within 3-4, the older section of the house which is installed with foam boards takes less time, around 1-2 hours but doesn't retain heat as well. 

matelodave

We have an overlay system which feels warm after an hour or so but as the floor temp is only around 28 degrees it take a fair amount of time for it to actually transfer it into the house. Bear in mind that the Delta T (difference between the room temp and floor temp) is only around ten degrees or less) so the heating response time is pretty slow.
(one memorable winter we shut it down to a very low temp when we went on holiday and it took nearly two days to get the house temp back up to comfortable)

We have weather compenstion set and let ours idle away, all night if necessary, with an overnight flow temp setback of -3 degrees from 21:30 to 06:00. It takes until nearly lunchtime until the place is back up to temp although with the small set back it really doesn't get cold. As we are at home all day it suits us.

The bathroom and kitchen floors are tiled so feel quite warm quite quickly, the lounge and bedrooms are slower because they are carpeted (low tog carpet and underlay) and have furniture which obvious has the effect of reducing the heat transfer into those rooms. Having u'f heating means that there really aren't any draughts and any that there are are wormed by the floor.

In the end you have to tweak it to suit your comfort levels and lifestyle - there is no one size fits all