# wall heaters in foam wall



## readydave8 (Sep 20, 2009)

Sparky360 said:


> Is it okay to install a Cadet wall heater in a wall with sprayed-in foam insulation? I know they"re good for most insulation, but this stuff crumbles to a powder, which makes me iffy about safety. I asked a few other well-experienced guys and received the same answer from each- "Hmm, I dunno," which gives me even more concern. Does anyone know yea or nay for sure?


would Cadet know?


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## Sparky360 (Aug 11, 2015)

I called Cadet (Thanks Dave8), and here is what I was told by tech support- The spray foam insulation "has not been tested," but that this installation will "likely cause 'gas-out'" with the ultimate result being a very bad smell that won't go away. So, for anyone's future reference- don't do it.


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## foothillselectrical (Mar 17, 2013)

Could you not just cut back an extra four to six inches of spray foam insulation, install your heater, and pack the extra space between the heater and spray foam with fiberglass or, even better, rock wool insulation?


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## RIVETER (Sep 26, 2009)

Sparky360 said:


> Is it okay to install a Cadet wall heater in a wall with sprayed-in foam insulation? I know they"re good for most insulation, but this stuff crumbles to a powder, which makes me iffy about safety. I asked a few other well-experienced guys and received the same answer from each- "Hmm, I dunno," which gives me even more concern. Does anyone know yea or nay for sure?


It's all about surface temperature. I would make sure that the unit had a thermal protector like in a rated CAN.


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## papaotis (Jun 8, 2013)

most electric heaters i encounter have a sticker or plate that says surface mount or 'this much' distance to combustibles


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## guest (Feb 21, 2009)

I installed a pair of the Cadet "register" (looks just like a standard forced-air register vent) units here in the palatial estate's new master suite. 

I framed out a standard 2x4 wall over the existing cinderblock and insulated it with fiberglass roll R-13 insulation.

I added a 2x4 cross block about 2" above the can and used the mounting foot (see left side of can in the picture) to space a bottom 2x4 cross block. There is no insulation in the space between the two blocks and the heater rough in can. (This pic was before the cross blocks and NM were in place) :










I ran the NM cable down the adjoining stud bay and up through the bottom cross block...most likely not really necessary but I wanted to keep the cable from anywhere near the heater can's sides or top. 

None of that was required by Cadet..but the manual was annoyingly sparse on info and made no mention at all about insulation contact (allowed/not allowed) with the rough in can. 

The wall in the pic is the interior wall between bedroom and living room..the other heater is on the front wall which is an exterior wall, framed and insulated in the same manner. There was no noticeable cold air infiltration around that heater despite some -20deg days.


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## RIVETER (Sep 26, 2009)

mxslick said:


> I installed a pair of the Cadet "register" (looks just like a standard forced-air register vent) units here in the palatial estate's new master suite.
> 
> I framed out a standard 2x4 wall over the existing cinderblock and insulated it with fiberglass roll R-13 insulation.
> 
> ...


Palatial estates can't afford Geo and they have bedrooms in the basement???


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## guest (Feb 21, 2009)

RIVETER said:


> Palatial estates can't afford Geo and they have bedrooms in the basement???


LOL this is a 1200 sq ft cinderblock 1 story house in rural Idaho....

"palatial estate" and "upholstered toilet" are common names I use for this disaster zone undergoing major renovation. :thumbup:


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## RIVETER (Sep 26, 2009)

mxslick said:


> LOL this is a 1200 sq ft cinderblock 1 story house in rural Idaho....
> 
> "palatial estate" and "upholstered toilet" are common names I use for this disaster zone undergoing major renovation. :thumbup:


I could tell that from the photo. The framing tipped me off.:thumbsup:


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## MTW (Aug 28, 2013)

mxslick said:


>


#12 on bedroom receptacle circuits.


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## guest (Feb 21, 2009)

MTW said:


> #12 on bedroom receptacle circuits.


What's it to you Skippy? This is MY house, not some contract tract home, so I'll wire the damn circuits above Code minimums if I want to. :tt2::nerd:


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## MTW (Aug 28, 2013)

mxslick said:


> What's it to you Skippy? This is MY house, not some contract tract home, so I'll wire the damn circuits above Code minimums if I want to. :tt2::nerd:


You do that, drama boy. :thumbsup:


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## A Little Short (Nov 11, 2010)

mxslick said:


> LOL this is a 1200 sq ft cinderblock 1 story house in rural Idaho....
> 
> "palatial estate" and "upholstered toilet" are common names I use for this disaster zone undergoing major renovation. :thumbup:


If you haven't closed that wall up yet you might want to put some plastic between the block and studded wall for a moisture barrier.


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## guest (Feb 21, 2009)

A Little Short said:


> If you haven't closed that wall up yet you might want to put some plastic between the block and studded wall for a moisture barrier.


The wall in the post pic is interior on both sides, and it is already closed up on that side (I haven't gotten to the living room side yet.) I was told no barrier (or insulation for that matter) is required....

The exterior walls had interior plastic, but on the advice of a local contractor it was removed as I will be doing a full Tyvek wrap of the outside of the wall when I do the new wood exterior siding. (I guess that is the practice up here...it is a fairly dry climate here even in the winters..)

The interior framing is overkill anyways..I am doing it to avoid having to punch into the block for electrical boxes (and plumbing in the kitchen and baths). 

I need to get a few more of the Cadet heaters in before winter....


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## A Little Short (Nov 11, 2010)

mxslick said:


> The wall in the post pic is interior on both sides, and it is already closed up on that side (I haven't gotten to the living room side yet.) I was told no barrier (or insulation for that matter) is required....
> 
> The exterior walls had interior plastic, but on the advice of a local contractor it was removed as I will be doing a full Tyvek wrap of the outside of the wall when I do the new wood exterior siding. (I guess that is the practice up here...it is a fairly dry climate here even in the winters..)
> 
> ...


I was just thinking of here where I'm at the plastic is used. Mostly on remodels and add-ons. But it is humid here and wasn't thinking about where you are. But thinking about it more, the block walls getting the plastic are usually in a basement.

Carry on!:thumbsup:


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## 99cents (Aug 20, 2012)

Sparky360 said:


> I called Cadet (Thanks Dave8), and here is what I was told by tech support- The spray foam insulation "has not been tested," but that this installation will "likely cause 'gas-out'" with the ultimate result being a very bad smell that won't go away. So, for anyone's future reference- don't do it.


I don't know if I buy that. The surface temperature of your electric heater shouldn't be any higher than that of a heating duct passing through spray foam.


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## CADPoint (Jul 5, 2007)

If you really want to make it a project you can go find some rock wool 
and crave out the spray foam from the cavity about two to three inches.

Your going to have to go to a building supplier to find rock wool and it ain't cheap and comes in the a block of 2X 4 as far as I know.

Rock wool is for installing around any opening cavity's that require sealing for
stopping air flow.

It's easy to crave and create shapes with this material.


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## billn (Aug 31, 2011)

99cents said:


> I don't know if I buy that. The surface temperature of your electric heater shouldn't be any higher than that of a heating duct passing through spray foam.


 Forced air is generally only mildly heated - it relies on volume rather than temperature differential. The air is sourced from an intake well away from the heating vent. With these devices, the air is likely to be hotter, lower volume and higher velocity. The manufacturer warns of a burn hazard from a hot grill. I don't think I have ever seen that with a regular forced air system. Not that I think anything is wrong with them. They are great for supplemental heat or primary heat in mild climates.


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## backstay (Feb 3, 2011)

mxslick said:


> What's it to you Skippy? This is MY house, not some contract tract home, so I'll wire the damn circuits above Code minimums if I want to. :tt2::nerd:


Then you went and put those hack boxes in!:blink:


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## guest (Feb 21, 2009)

backstay said:


> Then you went and put those hack boxes in!:blink:


Those are the Super Blues, they aren't the hack ones. :thumbsup::laughing:


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## MTW (Aug 28, 2013)

mxslick said:


> Those are the Super Blues, they aren't the hack ones. :thumbsup::laughing:


The regular Carlon's aren't hack either. :no:


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## KennethR (Aug 27, 2015)

For me its yea. Great structure of installations.


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