Above floor heating panels

RedMonte85

Hi, I am getting close to starting my radiant flooring project in my house. I have existing old hardwood floors in half of the home that I would like to keep so I will be putting extruded aluminum plates under the subfloor for that half of the house. In the living room/dining room/kitchen area, there are currently 2 layers of subfloor. The top layer of plywood is 5/8 thick and the bottom layer is 1x6 t&g pine (3/4" thick). I plan on removing the top layer of ply and adding one of the channeled systems over the t&g pine. I have read so much on the different types of systems out there. They are either prefabricated sheets or a plate/sleeper style of setup. I am looking for the most cost effective way to do this, the area is about 900sq ft. and I would prefer to keep the layer that I add to a minimal thickness as to try and match the level of the existing hardwood as best as posssible. Ive looked at the quiktrak products, rehau, blueridge, thermofin, warmboard, all of it. Ive read on these forums about people using thick industrial roll out foil (not sure if that is effective) and I am not opposed to a DIY setup cutting sleepers and such out of plywood. I am just looking for suggestions on what to do here. Thank you

hot_rod

did you do a load calc to see what output you need from the floor space you have? Mid 20’s btu /sq ft is a safe expectation
keep the amount of wood over the fin to a minimum, good r value below
Where you located? I have a bunch of 8’ ThermoFin to part with

RedMonte85

According to the heat loss calculations I did, I would be around 15btu/sq ft. Not sure how accurate that is. My entire first floor is 21,664 btu according to the slantfin calculator. I am in Michigan.

hot_rod

Certainly the least expensive is the one where you build the components, just buy the aluminum transfer plates. The detail on building it is really the same be it wall, floor or ceiling.

Insulation, furring strips from rips of ply or OSB, plates and flooring. Either the U or C fins could be used.

The U fin is easier to tube, the C fin you need to install the tube, flip the fin, nail it to the sleepers. The C fin has the aluminum right against the flooring, quickest response, much like the factory built dry, "over the top" products.

RedMonte85

I really wouldnt be needing the foam strips below the flooring, right? Just put the heat plates down and put sleepers in between is what I pictured. I figured it would be easier to insulate below the subfloor and ideally keep the added floor height to a minimum. I like the thermofin product and the price doesnt seem too high, wish I was closer to montana though to avoid that freight cost.

hot_rod

yes the least expensive and most r value would be batts from below
Pay attention to sealing all the air gaps around rim joist, foundation connections,etc. Infiltration can be the largest load. Cans of spray foam can save energy $$ for the life of the building