In bay floor heater concern

[Steve30477]

I’m having issues with my bay floor heater. I have 12 bays. Estimating 7000 ft of line. Maybe I’m way off. I found that it was low on antifreeze. I have put 62 gallons of straight antifreeze along with 62 gal. Of water to get my 50/50. This thing still is not full and barely returns any back to the pot. I have checked everywhere for any kind of leak. I can’t find anything leaking anywhere. It seems no matter how much I put it once I turn the pump on it’s just gone in a few seconds. I googled how much liquid 1/2 pipe holds per ft. Multiplied that times the est. ft. & come up with around 72 gal plus I have several feet of 2” pipe inside the building. Im still thinking somethings not right. Am I somehow missing something or is this amount typical?

 

[toddmullens]

You have a leak somewhere

 

[GoBuckeyes]

A thermal camera probably won't help right now if you can't even fill it. I would shut the valves (assuming there are valves) to and from All zones and open your by-pass completely. Fill your boiler, turn the thermostat down so it doesn't fire and then open one loop at a time until you find one that seems to drain the system. You could also try it with air pressure instead. If your valves are old and won't close 100% I'm not sure what you can do. Good luck!

 

[cantbreak80]

Same issue earlier this fall…after added 120 gallons of glycol/water
this is how we fixed it.

 

[slash007]

Same issue earlier this fall…after added 120 gallons of glycol/water
this is how we fixed it.
View attachment 5137

Did you break up the old concrete, or overlay? How thick?

 

[cantbreak80]

Concrete contractor does the tear out, re-grade and 4" pour.
We do the layout and install the manifolds and PEX.
(Pic is from one of three floor heat jobs this fall...I'm still recuperating!)

 

[slash007]

I really need to do that at my older site. Worst floor heat you will find. Barely covers a small circle in each bay and on two of them it miss one whole side. Is 4" enough for concrete?

 

[PaulLovesJamie]

For 1/2" ID tubing I use .92 gal of liquid per 100', this gives me a fairly accurate estimate. Based on personal experience and calcs.
So based on the numbers you gave, yes I'd say your estimate of 72 gallons total is in the ballpark. If you put in double that, I agree you have a leak.
Do basically what gobuckeyes said, you need to figure out where the leak is.
Where are you, ie what temps do you have to deal with

 

[cantbreak80]

Is 4" enough for concrete?

4” of 3000psi concrete is typically sufficient for "car" wash bays. Higher PSI if you expect HD truck traffic.

I believe concrete must have been cheaper than road base in the 1970s…this tear-out had many sq ft measuring 6”+ scattered about the project.



IIRC, energy code requires R6 minimum under slab insulation. Crete-Heat is R10, 2” thick. It’s expensive stuff that requires a bit more planning and additional grade work for the concrete guys, but the results are astonishing…energy wise. We’ll never do another job without it.
The concrete guys loved not having to pull up the re-mesh/PEX.




Uninsulated vs. insulated slabs. Photos taken on the same day at different car washes (6°F outdoor temp)

 

[Zal]

I just bought a FLIR infrared adapter for my iphone. Can't tell you how valuable this thing is on in floor heat. If you can get system to hold glycol, even for a short time it may find the leak for you. It's kinda like reading Xrays, you will feel like you can't see anything for an hour or two then it will start to make sense. I think you would see where it is pooling if it leaks that bad. I also have redone an old bay with 1980's version 1" black poly pipe. Changed it to insulated slab and 3/4 pex and it is about 12 degrees air temp warmer than previous system with same return water temp and closed doors. 5 bays to go to get them all if my back will stand it.

 

[bert79]

Same issue earlier this fall…after added 120 gallons of glycol/water
this is how we fixed it.
View attachment 5137

I'm very curious as to how much this cost you? Also, how many bays? I think this may be something I may have to deal with in the future considering the in floor heating system was installed at our wash in the mid 1980's. Looks like they did a nice job!

 

[Zal]

Cost is about $200 for the FLIR ONE available on Amazon. I have used it for a few weeks to locate floor heat and slab heat pipes to avert drilling through them. I have concrete 5" to 8" thick with heat tubes near bottom of pour and it "sees" them fine. Fancier units are available, but this seems fine to me. I was familiar with FLIR from past experiences and they are top notch in the infrared field

 

[GoBuckeyes]

cantbreak80, I'm suprised the old floor had no wire in it? How did they even keep the runs straight?

That crete heat looks like its worth its cost. Any way you can give some rough numbers for that job either a per bay cost or square foot cost separately for the tear out, creteheat, pex and concrete pour? I know the numbers will vary but it'd be nice to have some rough estimate in my mind as I'm staring at my bay floors and complaining.

 

[slash007]

cantbreak80, I'm suprised the old floor had no wire in it? How did they even keep the runs straight?

That crete heat looks like its worth its cost. Any way you can give some rough numbers for that job either a per bay cost or square foot cost separately for the tear out, creteheat, pex and concrete pour? I know the numbers will vary but it'd be nice to have some rough estimate in my mind as I'm staring at my bay floors and complaining.

I'm in the same boat and have debated it for years. Waking up this morning and seeing 40% of the the bays covered in ice and snow really makes me want to tear it out.

 

[cantbreak80]

Bert, Slash & Go...

2” Crete-Heat adds about $2.20/sq.ft to the job.

1/2" PEX, Manifolds, Manifold Boxes about $1.50/sq.ft

Propylene Glycol about $0.75/sq.ft. (This stuff has more than doubled in price over the past 14 months!)

Supply and return piping...Uponor hePex Pipe, ProPex fittings, insulation…about $2,000.

I believe the owner said his concrete contractor’s bid was about $45,000…so, about $11.25/sq.ft.

Concrete crew, with 2 Skid Steers, spent a few hours lowering the grade by 2” to accommodate the Crete-Heat. They installed fiberglass(?) rebar right on top of the Crete-Heat/PEX. The crew was happy that they didn’t have to pull the PEX up into the mud.

We figured about 30% reduction in time to install the PEX…and about 70% reduction in back pain!

All in price? Probably just shy of $19.00/sq.ft.

 

[mjwalsh]

Seeing the difference in specs on the Flir One ... the following might be worth the extra money:

FLIR One Pro Thermal Camera for Smartphones (USB-C)

Buy FLIR One Pro Thermal Camera for Smartphones (USB-C) featuring Thermal Imaging Camera for Android, Reads Temps from -4 to 752°F, 70 mK Thermal Sensitivity, 19,200 Pixel Resolution, VividIR Image Processing, USB-C Connection, Increased Case Compatibility with OneFit, Works with FLIR Tools...

www.bhphotovideo.com

 

[slash007]

Bert, Slash & Go...

2” Crete-Heat adds about $2.20/sq.ft to the job.

1/2" PEX, Manifolds, Manifold Boxes about $1.50/sq.ft

Propylene Glycol about $0.75/sq.ft. (This stuff has more than doubled in price over the past 14 months!)

Supply and return piping...Uponor hePex Pipe, ProPex fittings, insulation…about $2,000.

I believe the owner said his concrete contractor’s bid was about $45,000…so, about $11.25/sq.ft.

Concrete crew, with 2 Skid Steers, spent a few hours lowering the grade by 2” to accommodate the Crete-Heat. They installed fiberglass(?) rebar right on top of the Crete-Heat/PEX. The crew was happy that they didn’t have to pull the PEX up into the mud.

We figured about 30% reduction in time to install the PEX…and about 70% reduction in back pain!

All in price? Probably just shy of $19.00/sq.ft.

Man that looks like a 70k + job for my site. And I would need to buy a boiler/heater, right now it's running off of a pool heater.