Hydronic floor heating

[Elec83]

Has anyone had experience running pvc directly underneath hydronic floor heating? I need to know if I need to change to a different temperature column or upsize my pipe to derate? Any information will be helpful.

 

[infinity]

Typically the area below the radiant heat is insulated. Will you be below the insulation?

 

[Elec83]

Typically the area below the radiant heat is insulated. Will you be below the insulation?

So they put the blue styrofoam board down. I was considering channeling through it. If I go under it will that cover me?

 

[Dennis Alwon]

Not sure why you are doing that but if you are under the blue board there should be no issue.

 

[Elec83]

The customer is being difficult

 

[infinity]

Not sure why you are doing that but if you are under the blue board there should be no issue.

I agree that's why I mentioned the insulation. If the conduit is routed below it there will no derating required.

 

[Elec83]

Ok cool thanks

 

[infinity]

The customer is being difficult

Just curious, what kind of push back are you getting?

 

[Fred B]

I agree that's why I mentioned the insulation. If the conduit is routed below it there will no derating required.

Also most hydronic I've come across here has a reflective shield as well, in addition heat rises, so am in agreement if insulated and most likely has a heat reflector the should be no issue running below the hydronic system as long as condition listed in 352.12(D) Ambient Temperature are not exceeded. So you could confirm using a noncontact infrared thermometer and make sure temperature is below the 122^o F limit while hydronic is running.

 

[rnatalie]

I have extensive hydonic heat. The water in the pipes never gets above 120 degrees F.. That's the key to the efficiency. It shouldn't be a problem. T

 

[kwired]

I have extensive hydonic heat. The water in the pipes never gets above 120 degrees F.. That's the key to the efficiency. It shouldn't be a problem. T

It might leave the boiler at about 180, but doesn't have to travel too far in the surface to be heated and it isn't anywhere near 180 anymore.

 

[infinity]

I have extensive hydonic heat. The water in the pipes never gets above 120 degrees F.. That's the key to the efficiency. It shouldn't be a problem.

Yes, typically there is mixing valve on the boiler to limit to water temp that is running through the floor tubing to about 120°.

 

[rnatalie]

It might leave the boiler at about 180, but doesn't have to travel too far in the surface to be heated and it isn't anywhere near 180 anymore.

Again, any such system is horrendously inefficient. You usually don't connect an in-floor system to an old radiator-based boiler. The output of most hydronic systems is not any higher than your usual domestic hot water temps, 120 degrees MAX. I've got thermometers on both the output of the boiler and on the returns from all the lines.

 

[retirede]

Again, any such system is horrendously inefficient. You usually don't connect an in-floor system to an old radiator-based boiler. The output of most hydronic systems is not any higher than your usual domestic hot water temps, 120 degrees MAX. I've got thermometers on both the output of the boiler and on the returns from all the lines.

That’s correct. The hydronic heat in my garage is served by a standard gas water heater.

 

[kwired]

Again, any such system is horrendously inefficient. You usually don't connect an in-floor system to an old radiator-based boiler. The output of most hydronic systems is not any higher than your usual domestic hot water temps, 120 degrees MAX. I've got thermometers on both the output of the boiler and on the returns from all the lines.

I have more experience working on systems that supplied hydronic baseboards, those often were 180 degree output from the boiler. I could see the in floor systems operating at a cooler temp, but generally only run power to the boiler and never really had to service any of those systems, so far.