Radiant heat question

[curtis]

I just bought a house that appears to have pex in the concrete floor of the basement. The area is 1700 sq ft. There is a forced air furnace that heats the main floor of the house but I would like to hook up the radiant in the basement also. Currently have propane but there will be a natural gas line ran to the house this summer. What would be the best way to finish hooking this system up? Here is a few pics of the pex in the basement.

 

[peakbagger]

Boy someone spent a lot of money burying a lot of tubing. My concern would be why it wasn't hooked up? It could be expensive proposition it they neglected to insulate the slab.

 

[mrdinks]

I would have it pressure checked before anything else. Contact a local HVAC and talk options. It's not cheap but nice heat.

 

[Bad LP]

Boy someone spent a lot of money burying a lot of tubing. My concern would be why it wasn't hooked up? It could be expensive proposition it they neglected to insulate the slab.

No kidding. Somebody spent some serious coin at 300 feet per run. Pressure test for sure before you do anything.

 

[curtis]

There is already a pressure gauge a shrader valve fitting on the one manifold. How much pressure should I put on the system? I have no way of knowing if there is insulation under the concrete or not.

I think it never got hooked up because the basement never got finished. There's a bedroom and bathroom framed in but that as far as it got.

 

[maple1]

I'd try 20 psi. Or maybe 10 then 20 - but if it holds steady at 10 it should be good at 20. Typical system pressure should be in that range.

If it's not insulated, you will have a lot of heat loss to the ground when you go to heat it. Whether the loss would make it too much for you to consider heating it would likely come down to your comfort level in doing so. The floors would still get warm, but maybe not do much to heat the space above them without creating a lot of BTUs.

Maybe try carefully chipping a small hole down through in an inconspicuous spot & see what's there? Could always patch it later.

 

[Bad LP]

I'd try 20 psi. Or maybe 10 then 20 - but if it holds steady at 10 it should be good at 20. Typical system pressure should be in that range.

If it's not insulated, you will have a lot of heat loss to the ground when you go to heat it. Whether the loss would make it too much for you to consider heating it would likely come down to your comfort level in doing so. The floors would still get warm, but maybe not do much to heat the space above them without creating a lot of BTUs.

Maybe try carefully chipping a small hole down through in an inconspicuous spot & see what's there? Could always patch it later.

With a small water heater you could also mickey mouse charging one of the loops and run hot water thru it for a little while. Using a IR thermometer you can easily pip point the tube location in the floor as well as the one next to it. Drill a hole or chip one to determine if there is any insulation. As said, If there is none you will be heating the earth as it will act like a sponge.

I suspect that someone knew what they were doing for the install but you never know. I'd hate to spend a ton of money only to learn it's all screwed up.

 

[peakbagger]

I would not assume it was done right. I have heard of many radiant installs that were put in for comfort rather than for energy efficiency.

Hard to tell in the photo if there is a thermal break/expansion area between the slab and the wall. If its not there that's a possible sign that someone didn't know what they were doing.

 

[Millbilly]

How old is home? Is the builder still around or the previous home owner?

 

[curtis]

House was built in 2006. I'm going to try and see if the previous owner knows if the floor got insulation under it or not.