Radiant heat questions
Comments
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How how about posting some pics?Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
Supply and return at the same temperature? That means there's no heat transfer happening. I'd say that your pump wasn't working or more likely, your system is air bound and you have no water movement through your system.
Is this a new installation?8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab1 -
I read somewhere staple up install without transfer plate need higher SWT around 140+.Thank you,
Hiren Patel0 -
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600 total square feet , tight as all get out. Right now one loop at 225 feet of hose being used....enough? My WH is listed at 40000 btuIronman said:An electric water heater can only produce 15,300 btus. Unless you have a very small/tight house, that’s not gonna do the job.
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Two comments. First, if your inlet and outlet temperatures are the same, there's no heat going into the floor. You need to find out why. No circulation in the floor loop? You should be getting around 1.5 to 2 gpm.
Second, an electric water heater is probably the most expensive possible heat source, even if it did have the capacity -- and at a maximum of 15K BTUh, it might (actually, it probably is close to what that floor area can absorb). But without knowing the actual heat loss of the space, one can't say.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
Dual element 4500 watt implies that there are two 4500watt elements in the tank.
The control design is such that only one is energized at a time.
If the control system is hacked such that both elements are on together then the standard 30 amp #10 wire size will be overloaded. Both elements on will draw a nearly constant 40 amps.
You have 100% glycol in the system, no mix?1 -
Correct dual 4500 elements top and bottom. Yes 100%glycol. So my 40000 btuwill only give me 15000 btu why? 638 square foot tiny home. Only trying to heat 250 square feet right nowJUGHNE said:Dual element 4500 watt implies that there are two 4500watt elements in the tank.
The control design is such that only one is energized at a time.
If the control system is hacked such that both elements are on together then the standard 30 amp #10 wire size will be overloaded. Both elements on will draw a nearly constant 40 amps.
You have 100% glycol in the system, no mix?0 -
jhilly said:
4500 watts X 3.413 = 15,358 btus. That's physics and it doesn't change. As mentioned, only one element can operate at a time. The top one first heats the top 1/3rd of the tank, then it allows the bottom element to heat the remaining 2/3rds of the tank.Ironman said:An electric water heater can only produce 15,300 btus. Unless you have a very small/tight house, that’s not gonna do the job.
As Jamie mentioned, if the supply and return temps are the same, then you're not getting flow through the floor.
How about posting some pics? I suspect it may not be piped correctly.Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
100% glycol? It should be around 30% glycol -- assuming you need glycol at all, which seems unlikely.jhilly said:
Correct dual 4500 elements top and bottom. Yes 100%glycol. So my 40000 btuwill only give me 15000 btu why? 638 square foot tiny home. Only trying to heat 250 square feet right nowJUGHNE said:Dual element 4500 watt implies that there are two 4500watt elements in the tank.
The control design is such that only one is energized at a time.
If the control system is hacked such that both elements are on together then the standard 30 amp #10 wire size will be overloaded. Both elements on will draw a nearly constant 40 amps.
You have 100% glycol in the system, no mix?
And yes, your 4560 watt water heater has a maximum output of 15K BTUh. That's it, that's all. For pure water. That's the way they are wired. I wouldn't care to guess at the output for 100% glycol, but I'm going to guess at considerably less -- and the elements won't last long, since they will overheat due to the poor heat transfer properties of glycol.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
Used all glycol live in northern Michigan lose power often. Don't want lines to freeze.0
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The freeze point of 30% is 7 Fahrenheit; the freeze point of 60% is -55. Which should be adequate... even in northern Michigan...jhilly said:Used all glycol live in northern Michigan lose power often. Don't want lines to freeze.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
If you're using 100% glycol, the viscosity may be too high for the circulator to move it. Most pump manufacturers say no more than 50%.Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
Also, what do you have for a pressure relief valve?
If you are relying on the relief valve that came with the electric water heater, it will open at 125-150 PSI and/or water temp of 210 degrees.
Both parameters are beyond any heating tubing, pumps or mixing valve safe operating limits.
Most hot water boilers have a 30 PSI pressure relief valve installed.
What pressure do you see at the tank?0 -
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The Grundfos pump at the water heater is not necessary as well as being in the wrong place.
Get the glycol level below 50% and remove that pump and see if you get flow after purging.
Also: you need a 10/2 cable on a two pole 30 amp breaker feeding the water heater, not a 14/2 cable. You’re gonna have a fire the way it is.Bob Boan
You can choose to do what you want, but you cannot choose the consequences.1 -
Will do. The 12/2 is for the pump. 10/2 wired to 2 ole 30 amp on water heater.Ironman said:The Grundfos pump at the water heater is not necessary as well as being in the wrong place.
Get the glycol level below 50% and remove that pump and see if you get flow after purging.
Also: you need a 10/2 cable on a two pole 30 amp breaker feeding the water heater, not a 14/2 cable. You’re gonna have a fire the way it is.0 -
After the above corrections, try opening just one or two loops and see what delta you get.
One loop for 600 q ft?
600 total square feet , tight as all get out. Right now one loop at 225 feet of hose being used....enough? My WH is listed at 40000 btu
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
3 total loops. Only running one 225 foot loop right now.hot_rod said:After the above corrections, try opening just one or two loops and see what delta you get.
One loop for 600 q ft?
600 total square feet , tight as all get out. Right now one loop at 225 feet of hose being used....enough? My WH is listed at 40000 btu0 -
I think you have an air lock.Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
50/50 mix now. 130 inlet 105 return? Better to me but not sure.0
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Is the floor producing enough heat to maintain room temperature?Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
You likely have an airlock at the circulator due to it being physically higher than the water level in the tank, I see this quite a bit. Your system is also piped wrong, the circulator you added does not need to be there and will fight the other two as well as the mixing valve operation. If it were mine, I'd remove that pump altogether and suck the supply water from the relief port on the side of the tank (below the surface of the fluid level) using a tee so the T&P can be reinstalled. As for the glycol, there is a common misconception here and I highly doubt that you have 100% concentration in the system. What did you pump in, exactly? For example, the Cryo-Tek -100 you can buy from Menards is only a 55% concentration out of the bucket. So while it's 100% Cryo-Tek -100, it's only 55% glycol. 100% propylene is like syrup and almost impossible to move with a circulator, so if that is in fact the case here, you definitely need to drain 2/3 of it and refill with water for a 30-35% mixture1
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Jamie Hall said:
Used all glycol live in northern Michigan lose power often. Don't want lines to freeze.
The freeze point of 30% is 7 Fahrenheit; the freeze point of 60% is -55. Which should be adequate... even in northern Michigan...30% is fine for everything but snow melt systems. Those often need 50%.How did you purge the system?0 -
"How did you purge the system? "
That's what I want to know. I don't see how it can be properly done the way it is set up. My money is on the other comments; You have air in the loops.
Also, why is it that when I open the link to the pictures that are available, that I can't get back to the site? The back arrow just keeps refreshing the picture.
Rick0 -
On the pictures -- that may be a browser quirk on your end, @rick in Alaska . Works fine for me (if a little frightening...)Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
I have valves at the manifold for the loop. I close everything else but that one loop. Fluid into my fill valve right before board after air eliminator. Close return valve to WH, just after return purge valve. Transfer pumping thru loop open loop valve, exits out return valve till no bubbles or bursts. Close loop valve, then ball valve at manifold. Fill circulation pumps out return valve. Reopen valve to manifold. Transfer pump on everything open valve to return line to WH.
Thanks a bunch guys I'm just a mailman trying to divert my mind. Bring a frontline worker I'm beat. It's been 9 months 10-12 hours 7 days a week due the the pandemic and everybody's new love the evil.....Amazon. I've finally started to get Sunday off and 'm very appreciative of everyone and the help I'm asking for. This space is a jam room for my kids and dad. If I ever get home early enough to jam!0 -
Got air again. Floor got to 70 degrees. I think I need to move the purge valve to just before the air eliminator and not where it is.0
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Got floor temps of 72-74. I'm going back and installing aluminum fins under sub flooring. Did it in the bathroom area wider radiant dispersed and got 80+ degrees. The test will be when we get in the teens and single digits to see if the water heater can keep up. Thanks for the help guys!!!0
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Fins installed, R30 installed foil barrier over R30. 135 out 100-105 back. Can't get floor heat over 72 and 60-61 at 6 foot. More btu? 175 square feet is all I'm heating.
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Have you confirmed if the water heater is, or isn't, heating all the time? If current is flowing all the time then the heat is going somewhere. More likely the tank is hitting set point and current stops flowing until next call for heat. If it is reaching set point and going off, why is there not 150 degree water to the floor/system? You have some thermostatic mixing valves - are those on fully hot? If they are DHW mixing valves they may not go over 130 degrees which is probably not hot enough for your staple up.0
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I have heard the wh elements turn on and when I have moved my mixing valve to full open 6....I hear fluid moving out of wh. Circulation pump is running constantly has never shut off since thermostat has never seen 68 where it's set.0
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