Need Help With Radiant Floor Heating-How to operate my system

Rich_49

Very good Jumper . I agree . However , water most times does not require rebuilding , just drying out and replacement of some things . I never heard of anyone drowning from a leak . Will there not be water damage if there is a fire ? Can folks not die in fires and is that not common in such events ?

Nothing , I repeat , nothing is more catastrophic , devastating , than FIRE . Case in point , every community has a fire department , wheres the flood department in those places ? >70% of the population of the planet lives in close proximity to water , there should be more flood departments .
How bout a compromise , use a fireplace safely , no electric , no water .

hot_rod

bridgerguide said:

Hot Rod I like your view on this not sure how to determine if the loops can cover the load of the rooms.

Here is a free heat load calc ap. Measure up the space that is heated to come up with a load number.

I'm not sure how you will know if insulation was used, tube spacing, or actual tube length. At least a heat load calc will give you a stable starting point.

Gordy

Spend 50 bucks on an infra red temp thermometer.

You said you feel some warming in spots. The IR thermometer will pick up the tube as the warmest point then decrease until the next tube is read as an increase. May take a little playing around, but you can map the floor out for tube centers.

Insulation as HR pointed out is another matter. Perimeter insulation is not so hard. The lack of it does not mean it will not work. It just means it will take considerably more energy, and warmer water temps to get the same result.

bridgerguide

Okay here is the latest on this system. I opened each loop up all the way and ran the pump at high. I set the temp to 60F as I was leaving for 4 days. The flow on each was about 1/2gpm with all three opened.

Some back info on this house. It was flooded due to a pipe freeze in 2013. I bought in in 2015. The previous owner who never lived it it at all bought it at an auction. He told the realtor that after he repaired the damage to the sheetrock and fixed the burst pipe, he ran a dehumidifier for 4 months. Upon turning the radiant floor heating it buckled the wood floor. He fixed the floor. In the disclosure statement he only said that he thinks there may be a leak in the radiant floor heating.

So I came home on Sunday the house was warm and at 60F.

The two bedroom floors did not seem so warm as the kitchen floor as really warm and the bathroom.

However the floor did buckle again and I am pretty sure the system ran all the time as the temp outside for those days were highs in the teens and lows in the single digits.

I am attaching the floor pics.

http://imgur.com/Ikwf9z9
http://imgur.com/RV7SWij


I did notice when looking under the board that came up that there was about 6 drops of water on the under side of the raised board. Also it looks like the loops are in sand, and most of that is covered with particle board then the hardwood floor.

I tested all loops with air for 2 hours at 60psi and no lose before even filling the system. I am not sure if there was still moisture there and the heat created steam that made the boards really expand or not.

So I will be getting that board back down and I might have to pull it all up and maybe have someone pour gypcrete. However I really would like to keep the hardwood floors .

Thanks for all the input and help so far!

hot_rod

Is this assembly over a concrete slab?

So wood sleepers nailed to a slab, tube in-between with sand around the tubes?
Any insulation below the sand?

Ideally the tube would be in contact with the flooring or in a concrete mix that the wood comes in contact with.

Basically it looks like the tube heats the sand, but the sand is not in contact with the bottom side of the wood?

If so, don't expect a lot of heat transfer from that assembly,., Sand is not a great conductor, unless it's wet and you do not have a good transfer mechanism between the warm sand and the final floor covering.

Maybe 10- 15 BTU/ square foot output? It is more like a suspended tube method.

Finding a small leak in a sand bed could be tough, the wet spot may not be where the actual leak is if the fluid follows the slab or sand.

bridgerguide

I honestly don't know if there is insulation under the sand. I see your point about the contact surface. I will try and get that board pulled up to see more. I think it could be sand and then 1\2 or 3\4 particleboard then the wood floor probably 3\4 so that is not going to be a good conductor. How is this normally done when a wood floor is installed?

hot_rod

Wood floor over an existing slab is a tricky detail. There are some retro-fit subfloor products from Uponor, Viega, Warmboard and Sunboard that can go over the concrete. Then a thin engineered wood flooring "floats" over that.

Radiant Engineering, over in Bozeman builds some aluminum heat transfer plates. Those would attach to the sleepers, then a nail down flooring could go over and fasten to the sleepers. That puts the wood in contact with aluminum for excellent conduction transfer.

You would want a good vapor barrier at the very least, and some insulation below the radiant. Moisture and wood- not so good, as you have discovered.

After the fact "over the slab" radiant are always a compromise. they can and do work, maybe not $$ efficiently.

bridgerguide

Good info. Thanks so much.

Gordy

That sand has to be saturated, or at least damp. From the flooding of the burst piped.

The concrete below probably absorbed huge amounts of that moisture also. Now wicking out into the sand, and into the wood.

I would pull up the flooring, get rid of the sand, dry things out.

Pour gypcrete between sleepers, or a hand mix.....depends on ambition.

You will be fighting buckling wood for a Loooong time. If not.

hot_rod

It's not unusual for a flooring nail to hit one of those free roaming tubes. They typically hold pressure for a year or more and slowly start leaking as the nail rusts away.

If you are losing pressure slowly, and suspect a leak, find someone with an infrared camera to locate the potential leak.

Many home inspectors now have them as realtors are starting to insist on home scans for the buyers. Also energy audit companies and some fire departments have IR cameras.

Here is how a hot spot shows.

jumper

Sorry to repeat but why go to this trouble if energy source is electric resistance? Unless you're storing heat and then blending.
Also wood buckling may not be related to heating system.Water migration with slabs can cause problems especially when material like sand behaves like a sponge.