underfloor heating under an existing slab
underfloor heating under an existing slab
(OP)
hi, I'm searching if there is any possibility installing a underfloor heating system on an existing concret slab with minimum re-structuring requirement. based on the information i got from google, seems tat the underfloor heating system is usually implemented into the structure during construction. it's much appreciated if anyone can give me some hints/reference to install a the system on an existing slab.





RE: underfloor heating under an existing slab
I have never heard of doing this. Unless it is for some type of industrial freeze protection I think that it would be much more trouble retrofitting an underslab system than it is worth.
I have retrofitted for freeze protection when a building use was changed to a cold storage freezer but we were ripping out the floor anyway. I don't have any experience in residential or commercial underslab heating systems.
RE: underfloor heating under an existing slab
There are also some good electric mat style radiant floor heating systems (Nuheat) that will not take up as much space as a sub-floor system.
The one big issue that you also have to consider is that the existing spab may not be insulated underneath, or around the perimeter, so you will have significant heat losses to the ground, severly comprimising energy efficiency and cost to operate. It may be more efficient and economical to use more conventional wall-fin or panel heaters depending on the occupancy of the space. You could also consider a radiant heating ceiling in the space, if the "warm toes" are not critical for your application.
RE: underfloor heating under an existing slab
http://www.warmtiles.com/aboutwarmtiles.html
RE: underfloor heating under an existing slab
Please use for reference only:
http://www.sunqest.com/radiant%20floor%20page.htm
This sounds like what you want though.
RE: underfloor heating under an existing slab
let me make it clear, I heard tat there is a technology out there, it is like attaching the hydronic tubes underneath an existing concrete slab, and sandwiched by an insulator at the bottom. (concrete - tubes - insulation). the hydronic tubes are apparently "clamped" and attached to the concrete.
i can only find the in-concrete or on-top of concrete floor heating technique, but never see any like wat i mentioned above, so if anyone has idea about tat, it's much mcuh appreciated if i can have a hints on it.
thx
RE: underfloor heating under an existing slab
Are you wanting to heat the floor surface of a slab on grade, or the ceiling surface (bottom surface) of a suspended slab?
If it's a slab on grade, how on earth do you expect to dig under the slab and install heating tubing? And then if you do manage that, how do you expect the heat to conduct up through the thickness of concrete to get to the desired floor surface temperature?
Maybe it's so hard to find anything like that because there's no such thing? Or it's just not done due to the laws of physics getting in the way?
RE: underfloor heating under an existing slab
RE: underfloor heating under an existing slab
the concrete is like 150mm thick, we aware it might take couple of hours for heat conduction from the underneath to the surface of the slab. coz this system is most likely to be operated 24/7 during winter n to keep the floor at a constant temp. so the time it takes to warm up the floor surface initially is not a concern.
coz i m very new to this industry, n i did try to google if there is any system like tat out there in the market but yet find any solution. so im just wondering if u guys have deal with any similar design condition like this ever, n could share yr experience...it's much appreciated...thx
RE: underfloor heating under an existing slab
The closest thing that comes to mind for your fantasy system would be Polytherm - a rigid foam insulation panel with little dimples to press the PEX tube into, and then you might be able to clamp/attach that up to the underside of the concrete, but your contact surfaces from the PEX tube to the concrete slab will be very small, requiring even higher heating water temperatures to get heat to conduct up into the slab over.
My advice: convince the person with the carpet to pull it up and allow a PROPER installation of floor heating instead of some cobbled together bag of problems.
RE: underfloor heating under an existing slab
RE: underfloor heating under an existing slab