UFH + Combi Boiler

[SoliD]

Hi,

 

Just starting to embark upon my next project to make my house more livable. Following on from this thread, i'm planning to insulate between my Suspended Timber Floor downstairs, as part of this work I am looking to add UFH, partially for the comfort and the other part as a selling point to the wife for another few months of disruption. However I'm now second guessing my UFH plan.

 

As per the other thread i'm looking to install UFH in a 9.5x3m long kitchen and sitting room, Currently this space has a 3500BTU radiator in place from memory at the far end of the sitting room under the front window so well away from the the kitchen area which leads into a dining room that was a conservatory with cavity brick ended walls and bi folds, this also has a tall column radiator. 

 

My current heating and power sources are as follows:

 

Valiant ecoTec plus 837 Combi Boiler

Split Aircon - all upstairs bedrooms and lounge. 

6.3kWh solar array with 16.4kwh batteries.

 

I generally run the rads at about 52c,(upping to 57-60 if it's really cold) but the majority of the time leave the heating off and leave the aircon upstairs ticking over at 17c, this keeps the upstairs plenty warm but the downstairs can be pretty cold in the mornings and it's never comfortable downstairs unless I really crack the heat up, we generally hide away in the lounge with the aircon on for 3-4 months of the year, but I would want to make the whole space usable and comfortable year round without having to just have one radiator on and pushing out 75c heat...

 

So i'm planning to add UFH to the kitchen and sitting room area, insulating 100mm pir and 100mm eps underneath with a 25mm dry screed between the joists and then 18mm chip/osb over the top and then LVT. As I understand I need a two port valve to separate the ufh and rad pipework to ensure the boiler only provides the ufh separately from the radiators to ensure I can have the UFH on keeping it up to temp effectively for the majority of the time. Obviously I could look at some of the polystyrene infill boards, and kick out the higher temps, but I would like to future proof myself for ASHP as I foresee moving to one at some point and being able to utilise my battery store etc.

 

 

TLDR : Can I add UFH to my Valiant ecoTec plus 837 Combi efficiently and effectively? 

 

 

 

 

 

[SoliD]

Almost due to start this now, I will be able to lay about 200mm below the screed which would be 60-70mm deep. Now I have quite a bit of 50mm EPS left from my previous purchase for my lounge and hallway but will need to buy more PIR. Should I use the EPS elsewhere in the house (could chuck it all in the loft probably) or would I be ok in using a base of 50mm EPS and then 150mm PIR above this? (100+50mm Celotex)