Adding Radiant heat to house.

[Taylortractornut]

We are about to remodel the house like a a cabing on the inside to facilitate some of ur inherited antiques. As a surprise to my wife for letting me fix the living room like an old barn I want to put in a radiant floor heating system in the bedroom. We have an old house built in Holcut MS when the Tenn Tomm came through and ate Holcut this old house was moved to this location having hit every culvert on the route. Later it partially burnt and Mom and dad redid it with a lower addition for extra rooms. Our room is a 2 feet lower than the main area of the house so the old Ashley heater heates every thing but the 2 bedrooms on the addition. Mom and dad ran Propane heaters there but I hate spending money wasting gas.


The thread on here about the furnace with a domestic heating coil in it has me thinking. I have been reading about these add on coils for wood stoves. I ve laid the pex lines in concrete shop floors before on construction jobs but never in a house especially a frame house like this one. I asked a local heating contractor and he wanted to install an new central unit. Ours hasnt worked in the last several years and I wanted the floor heat.

What I was thinking about doing was pulling up the carpet and puting down 1 by 4 boards to make channels for the PEX. Then after I get my Pex down screw some 3/8ths or 1/2 inch plywood on the 1by4 boards and then install new carpet on top of that. I d have to get a custom door fitted as the floor would be 2 inches higher than it is now. I have a friend that did something like this in his otherhouse and made his top layer in paneled sections with carpet that could but unscrewed and removed for mainenance.

 

[hr3]

I've seen 3/4" ply all grooved for your application and I think they put 1/4" luan down on top of it,,

 

[Redneck in training]

There is a special light (foam) concrete for such purpose. It is pored after PEX is stapled to the floor. Make sure you use oxygen barrier PEX to prevent rusting of the boiler. The disadvantage of the floor heating in your case is that it will require a pump and temperature control mixing valve. If you would opt for radiators then it will circulate without a pump and will not require temperature control. Not speaking about much easier installation. It will work even during power outage.

 

[Robert_in_NY]

Can you get under the floor? If so you can attach the pex directly to the underside of the floor between the joists. You won't have to bother anything above the floor as it would all be done underneath. This is the system I am doing in my house and one that is becoming very popular around here. There are a few ways to attach the pex to the underside of the floor, one design is with staples and a specialized stapler which is how I plan to do mine. Another uses a nailed or screwed on bracket that clamps around the pex. The other way is with aluminum heat transfer plates that attach under the floor and are about 4" wide and the pex runs through a channel in the plate.

If you can't get under the floor then there are numerous options to do it above floor between a light cement, special plywood with grooves and building up the floor like you thought about. But if you can get underneath then that is the easiest way.

I am tearing down the first floor ceilings in my house and putting the radiant heating in the second floor while the joists are exposed. The nice thing about pex and radiant heating is that its easy to set up zones for each room so I can shut down individual rooms when not needed as well as have the bedrooms programed for each persons personal preferences. Good luck and have fun with the project

 

[WayneB]

Robert when you get going on the project it would be great if you can post pictures and construction details.

Wayne

 

[Robert_in_NY]

Robert when you get going on the project it would be great if you can post pictures and construction details.

Wayne

I will be adding it to my house remodeling thread on here. I have not had any time to work on my house this summer but this winter I will be starting to rough in all the electric, heat, ac and plumbing and get ready to foam insulate everything and hopefully be closing up the walls before spring as I don't want to work indoors when it gets nice again and I also don't have much time once spring gets here. But it will be documented and I would be happy to answer and discuss any questions anyone has.

 

[ruren]

Your idea should work, but consider that you are trying to get the heat through the plywood and carpet to the room. If you can insulate the bottom you should do so, otherwise you will end up losing a lot of the heat to whatever is below it.

You can buy the plywood sheets made for this that have grooves laid out in them and a layer of aluminum laminated on them to help radiate the heat. Warmboard is one brand. They work really well but are kind of pricey.

I am not familiar with an add on coil for wood stoves, but look into what temperature water it puts out. For the installation you are describing you want water around 130 degrees, not the higher temperature water you would send out to baseboard heaters. You may have to install a tempering valve control the water temperature.

 

[Taylortractornut]

I think the name of the coilis Hiecoil or Hicoil. Its stain less to heat domestic hotwater and run other things. I thought about a radiator but I dont think thermosyphon will work as I would have to drop down a bit. Im leaving the the duct work for the central unit in place. I may remove the inside parts in the closet and install a radiator in the distritbution box. Then I could use the central fan to push it to the rest of the house.

The main reason I want the floor heat is in the shop I helped poor the floor in really had a great feel to it. THe roo mstayed a comfortable temp. One man suggested that I could go with a pump and put a radiator in the central unit and off the return line on the radiator i could run the floor heater. I can get under the house pretty easily I thought about putting it in between the joists and then putting in foam sheet insulation. Then adding a thin sheet of plywood help hold the insulation and keep the heat up.


I appreciate all the replys and knowledge, Here if its not gas or electric heat Im out of luck with technicians.

 

[Taylortractornut]

Heres the link to the coil I want to use. Woodstove Water-Heater Coil by Thermo-Bilt, stainless steel, for wood stove, corn stove, coal stove.

 

[Robert_in_NY]

Your idea should work, but consider that you are trying to get the heat through the plywood and carpet to the room. If you can insulate the bottom you should do so, otherwise you will end up losing a lot of the heat to whatever is below it.

You can buy the plywood sheets made for this that have grooves laid out in them and a layer of aluminum laminated on them to help radiate the heat. Warmboard is one brand. They work really well but are kind of pricey.

I am not familiar with an add on coil for wood stoves, but look into what temperature water it puts out. For the installation you are describing you want water around 130 degrees, not the higher temperature water you would send out to baseboard heaters. You may have to install a tempering valve control the water temperature.

I am not sure if your replying to me but there is a foil backed insulation that goes between the floor joists after the pex is installed to keep the heat moving up and to help with efficency. I didn't get too involved in explaining the entire process because I was just tossing an idea out for him to consider. If he had no access to get under the floor then this system isn't an option.

 

[Robert_in_NY]

I think the name of the coilis Hiecoil or Hicoil. Its stain less to heat domestic hotwater and run other things. I thought about a radiator but I dont think thermosyphon will work as I would have to drop down a bit. Im leaving the the duct work for the central unit in place. I may remove the inside parts in the closet and install a radiator in the distritbution box. Then I could use the central fan to push it to the rest of the house.

The main reason I want the floor heat is in the shop I helped poor the floor in really had a great feel to it. THe roo mstayed a comfortable temp. One man suggested that I could go with a pump and put a radiator in the central unit and off the return line on the radiator i could run the floor heater. I can get under the house pretty easily I thought about putting it in between the joists and then putting in foam sheet insulation. Then adding a thin sheet of plywood help hold the insulation and keep the heat up.


I appreciate all the replys and knowledge, Here if its not gas or electric heat Im out of luck with technicians.

There is a bubble type insulation with foil on it designed to go between the floor joist. When attached properly you don't need any plywood or any thing else underthere. If you can get under there that would be the easiest and cheapest way to add heat to the floor.

 

[rScotty]

We are about to remodel the house like a a cabing on the inside to facilitate some of ur inherited antiques. As a surprise to my wife for letting me fix the living room like an old barn I want to put in a radiant floor heating system in the bedroom.
SNIP
What I was thinking about doing was pulling up the carpet and puting down 1 by 4 boards to make channels for the PEX. Then after I get my Pex down screw some 3/8ths or 1/2 inch plywood on the 1by4 boards and then install new carpet on top of that. I d have to get a custom door fitted as the floor would be 2 inches higher than it is now. I have a friend that did something like this in his otherhouse and made his top layer in paneled sections with carpet that could but unscrewed and removed for mainenance.

Taylor, you are on the right track. Seven years ago I built half of our house with heat PEX buried in three inches of concrete poured right on top of plywood sub-flooring. The other half of the floor basically has the PEX in channels cut into boards with hardwood flooring over that like your describe. The whole house is divided into multiple zones - each one with regular wall thermostats connected to low voltage motor valves back by the boiler & pump room. In that room is a large Marathon hot water heater - same kind as is commonly used in any house for hot water - which heats the antifreeze which is circulated by a little inline pump. The fluid doesn't need to be real hot, so no tempering is needed and the fluid stays pure.

From a performance standpoint, hydronic heating is so easy and so efficient that it now looks to me like it would be hard to make a system that didn't work well. However, I had also heard that the heating system components themselves were very sensitive to good craftsmanship and being of the right materials. So I used the best in PEX pipe, connectors, valves and pumps. Plus a non-metallic hot water heater. And then designed it as a completely closed system without additional tempering. After all, you want it to last; not leak.
rScotty
an old JD530, new Kubota M59, and a Yanmars

 

[Taylortractornut]

I found a trailer load of the groved plywood mentioned eailier from another poster. It belongs to a bank rupt McMansion builder. I think I can get a couple bundels for 1/2 cost. I want to install this in one room for now. If it works as good as I hoe I will do the other 2 bedrooms. Im looking at several ways to heat the water with wood heat. I as looking at the heater coil but a friend of mine told me today of a heater coil that was attached to the back of a wood stove. This also had astainless tank that was placed near the heater with the coil to provide heat to the radiator in another room.

 

[jcato]

I would research the pre-manufactured radiant floor panels that are ready to install the PEX. Some even have aluminum sheeting that are formed around the PEX and help spread the heat.

Take a look at Warmboard Radiant Heat Subfloor: Simply Smarter Radiant Heat (as one example - can Google similar items). Also, can get just the aluminum 'heat spreaders' (see Radiant Floor Heating Systems, Electric Floor Heatings, PEX Plumbing Supplies as yet another example) - if you want to fabricate your own 'sleepers'.

Be sure to insulate well below floor.

-- john.