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HELP! 1" Pex over concrete slab its cold want to optimize heat transfer

THE SETUP:
1" Pex mounted on side of 2x4 runners bolted into concrete floor through panels of DOW TUFF R reflective foam insulation board. The subfloor sitting over the Pex is 4x8 sheets of 22/32 engineered ply. Total 2400sqft pushed through by Two 50 gallon electric Water heaters with an expansion tank pumping 70/30 water to glycol. I dont know enough about the pump offhand if thats critical I will look into it with more detail. Guages report steady movement.
THE ISSUE:
The heat is not impacting the 2400sq ft space enough. I suspect the wooden subfloor sitting over the pex may be too thick to allow the heat to transfer adequately. I read somewhere that reflective panels installed in the cavity under the pex to spread heat do not work overtime due to dust buildup on the plate. Would a passive floor grates improve the situation.
THE KICKER:
I was in a car accident while preparing this studio for use. I trusted my landlord to manage the project in my absence. I suspect he sandbagged my floor intentionally into his space to prevent me from ever taking out the materials ( even though I own it by the terms of the lease ) by having the carpenters glue down the plywood subfloor onto the 2x4's. I know it is common to glue down subfloors to prevent excessive movement but not when heated tubes are under it. Am I being paranoid or did this guy just use a detail of the install to force me to leave the floor in place. He did place access panels where the pex is coupled. I would never have glued it down just in case there was some accident and I needed to get into the floor. I am suspect of this choice of his which he never happened to mention to me and which I would not have discovered had my upstairs neighbor not had a spill into my space that made me want to pull up some ply. What say yee experts who made it this far down the line?
1" Pex mounted on side of 2x4 runners bolted into concrete floor through panels of DOW TUFF R reflective foam insulation board. The subfloor sitting over the Pex is 4x8 sheets of 22/32 engineered ply. Total 2400sqft pushed through by Two 50 gallon electric Water heaters with an expansion tank pumping 70/30 water to glycol. I dont know enough about the pump offhand if thats critical I will look into it with more detail. Guages report steady movement.
THE ISSUE:
The heat is not impacting the 2400sq ft space enough. I suspect the wooden subfloor sitting over the pex may be too thick to allow the heat to transfer adequately. I read somewhere that reflective panels installed in the cavity under the pex to spread heat do not work overtime due to dust buildup on the plate. Would a passive floor grates improve the situation.
THE KICKER:
I was in a car accident while preparing this studio for use. I trusted my landlord to manage the project in my absence. I suspect he sandbagged my floor intentionally into his space to prevent me from ever taking out the materials ( even though I own it by the terms of the lease ) by having the carpenters glue down the plywood subfloor onto the 2x4's. I know it is common to glue down subfloors to prevent excessive movement but not when heated tubes are under it. Am I being paranoid or did this guy just use a detail of the install to force me to leave the floor in place. He did place access panels where the pex is coupled. I would never have glued it down just in case there was some accident and I needed to get into the floor. I am suspect of this choice of his which he never happened to mention to me and which I would not have discovered had my upstairs neighbor not had a spill into my space that made me want to pull up some ply. What say yee experts who made it this far down the line?

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Comments
That system will fail miserably if that tubing is not up against your subfloor with plates. The reflective foam has zero effect for reflecting radiant energy if that's why you used it.
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Minnich Hydronic Consulting & Design, LLC
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The other is your choice of heating equipment. An electric water heater with a 4.5kw element has an out put of 15k btu's. With two of them, you've got 30k btu's. Your heat loss is probably close to twice that much at design temp.
Who designed this? Was an accurate heat loss calculation done?
The only simple thing that can be done short of tearing up the floor is to get a heat source with adequate output and crank the supply temp up high enough to get enough output from the floor. The down side to that is that running water temps too high can damage the floor.
There's no easy fix for improper design.
You can choose to do what you want, but you cannot choose the consequences.
2 electric water heaters provide 30,000 BTU's.
With 1" pex you need some pretty good flow rates to provide 2-4 fps to get air out and assure turbulent flow. What pump and how long of loops?
With enough electrical power you could get 60,000 BTU/ hr from two tanks with both elements firing. 72,000 BTU/hr if you stepped up to 5.5KW elements.
But the bottleneck may be the tube spacing and heat transfer. consider it a floor warming system
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Conduction is king . Reflective is not a good term to use or apply in transferring btus to a surface enough said.
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ramermechanical.com
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As Gordy said "conduction is king".
You can choose to do what you want, but you cannot choose the consequences.
ramermechanical.com
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I heard a sales person at the supply house, giving a presentation to the manager and a bunch of HVAC guys about how aluminized bubble wrap was equal to R-19 fiberglass batt insulation. They sold a lot of rolls of bubble wrap.
I never saw it work as advertised. But they sure sell a lot of it.
Panel rads, low temp baseboard or a fan coil(s) are the obvious solutions, but you'll need an adequate heat source to drive them.
You can choose to do what you want, but you cannot choose the consequences.
I guess that's why we need to give the RPA our full support. That way they can become the go to name for research in Radiant.
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All I can say to people looking at this thread. Is all aspects of construction involve science, and calculations from the roof down to the foundation, and all mechanicals with in.
Millions? I think billions in the over all construction industry.
The Internet is a great tool to research anything of our hearts content. The problem is as Ice puts it the "cheap gene"over powers the mental drive to do things right, there is a cost.
As in this example reflective polyiso insulation costs more than xps. 1/2", or even 3/8" pex would have been plenty big for this installation at 12" on center or better yet 8". The addition of Plates would have made this installation a dream. Using two 50 gal water heaters may have been cut to one with a larger element, or a small electric boiler, along with many other options on the fire side if gas was an option.
To the OP I'm not coming down on you. It sounds like maybe you did not have total control of this project. My mumblings are said to people who hopefully are doing research here, and stumble on to this thread...... Before they start.
Or shall I say conduction to all the wrong contact points of the tubing in the cavity detail.
https://us.v-cdn.net/5021738/uploads/editor/0z/5w6j4rj62d8x.jpg
Each water heater has two elements that are internally wire so that only one can operate at a time. As HotRod pointed out, they can be wired to operate simultaneously, but the size of the electric circuit would have to be increased to each heater. This would double your btu production but not do anything for the floors ability to emitt those btu's. Raising the supply water temp will have far more benefit than anything else you can do as it will increase the Delta T between the tubing and the floor. Heat moves toward cold; the greater the temperature difference ( delta T), the faster it moves. Of course, there's only so much temp the floor materials can take.
On another note: what is the voltage being supplied to the water heaters? It appears you're in a commercial building of some size which means it would be supplied by a 3 phase electric service. A 3 phase Y connected service may only be supplying 208 volts, not 240. As noted on the water heater data tag, you only get 3500 watts @ 208 volts, not 4500 watts. That means instead of 15k btu's output, the water heater only has 12k btu's output.
You can choose to do what you want, but you cannot choose the consequences.
You should seriously consider an electric resistance boiler. They're surprisingly affordable, even when you include outdoor reset control.
If you move, I wouldn't bother ripping out the PEX. Your time is worth far more than it would cost to replace with new, properly sized pipe. The pump is marginal, assuming it's exactly the size you need for the new space.
If you need more heat, I'd give some thought to adding an infrared radiant heater. Do you have gas available in the building?
There is the option of added cost if head room allows of doing 3/8 pex with 1/2" plywood sleepers, and extruded plates over the top of the existing floor in place. Reuse existing manifold, and add another 6 loop set. Closer centers 9"- 12" would require more loops. Existing heat source still maybe questionable, but then no one did a heatload calc.......yet.