Warmsmeallup
Member
- Location
- Upstate, NY
We install electric radiant, and that's all we do. You can use a 4" box and it would give you lots of room to play but we use single gang deep boxes and they work fine if you work clean. All the line voltage systems require a GFI tstat. The low voltage systems use the same tstat as the Nuheat systems use (Honeywell) but with no GFI.
The most important part is being sure that you do or have done a Heat Loss Calculation for the space you're heating. A "floor warming system" that fits a 10 x 10 area may not be enough heat (in watts psf) for the space. The Heat Loss Calc will tell you what is being lost naturally and then you install a system that far surpasses that number. We use 50% higher as a standard. i.e. if the space looses 5000btu's of heat an hour, install a system that produces 7500 or greater. This is done by spacing the elements closer together or, in Nuheats case, ordering the mat that meets the load. Though that would be a special order.
You could also use a low voltage cable system that meets the requiremenst and space the cable accordingly.
Personally speaking, we never install a line voltage system as primary heat. The line voltage element, by it's very design, will stop functioning "at some point". And as mentioned, I wouldn't want to be the guy who installed one that went bad before the warranty period is up and have to prove it was the element. That is relatively impossible to do. The mfr wants the element back to view what went wrong. Go ahead, take the floor up and remove the element without damaging it! (Do you have a week and very small archeologists chisel?? :thumbsdown
So, we install low voltage when it's primary heat or we don't install it. The low voltage element is a single #14thhn wire that uses the rating of the wire to create the resistance heat. If you don't over amp it, it doesn't burn out. Unless someone damages the element on install, you may have to replace a transformer or tstat in 10 years but that's the worst. We have never had an element go bad and the mfr hasn't either for 28 years. They also have another bronze screen element that can be installed directly under hardwood. Nail through it, no problem! But that's another thread.
Heat loss calculation!!!
One last thing; install 2 floor sensors and don't connect one. If one goes bad, you have a backup without having to tear up an area to replace it. They are nothing more than thermisters. Thermisters go bad too!
The most important part is being sure that you do or have done a Heat Loss Calculation for the space you're heating. A "floor warming system" that fits a 10 x 10 area may not be enough heat (in watts psf) for the space. The Heat Loss Calc will tell you what is being lost naturally and then you install a system that far surpasses that number. We use 50% higher as a standard. i.e. if the space looses 5000btu's of heat an hour, install a system that produces 7500 or greater. This is done by spacing the elements closer together or, in Nuheats case, ordering the mat that meets the load. Though that would be a special order.
You could also use a low voltage cable system that meets the requiremenst and space the cable accordingly.
Personally speaking, we never install a line voltage system as primary heat. The line voltage element, by it's very design, will stop functioning "at some point". And as mentioned, I wouldn't want to be the guy who installed one that went bad before the warranty period is up and have to prove it was the element. That is relatively impossible to do. The mfr wants the element back to view what went wrong. Go ahead, take the floor up and remove the element without damaging it! (Do you have a week and very small archeologists chisel?? :thumbsdown
So, we install low voltage when it's primary heat or we don't install it. The low voltage element is a single #14thhn wire that uses the rating of the wire to create the resistance heat. If you don't over amp it, it doesn't burn out. Unless someone damages the element on install, you may have to replace a transformer or tstat in 10 years but that's the worst. We have never had an element go bad and the mfr hasn't either for 28 years. They also have another bronze screen element that can be installed directly under hardwood. Nail through it, no problem! But that's another thread.
Heat loss calculation!!!
One last thing; install 2 floor sensors and don't connect one. If one goes bad, you have a backup without having to tear up an area to replace it. They are nothing more than thermisters. Thermisters go bad too!
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