Radiant Ceiling Heat

I inspected a house yesterday that had radiant ceiling heat. That is the type where the wiring is embedded directly into the plaster. There was quite a bit of cracking in the plaster and I thought that I remembered that there was a safety issue with this type of heating ( possibility of fire?) The trade name “Chromalox” seems to have significance.

Does anyone have any information on this, or is this prolonged winter freezing my poor old brain? :shock:
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George,

I have inspected several homes that had Electric radiant resistance heat in the plaster or pamnels directly mounted to the ceiling. I have yet to see one that was actually functioning.

Of the homes that had electric radiant, all had discontinued its use due to inefficiencies or failure. Replacement was usually made with forced air so that AC could also be added.

Thanks Joe. Believe it or not but this system was still functioning! I thought that there was a safety issue with this heating system and that it’s further installation had been officially terminated.

Below copied (en Francais) from: http://consommateur.qc.ca/acqc/29.htm

Les produits visés par l’ordre de la RBQ

Les marques visées par l’ordre de débranchement de la RBQ:

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  • Flexwatt
  • Thermaflex

aussi commercialisées sous les marques

  • FlexelSafe-T-Flex
    Safe-T-Heat
    Aztec Flexel
    Aztec Flexel Scotland

  • Thermo-flex Scotland

Notez que depuis le début des problèmes, la RBQ a imposé un moratoire sur toute nouvelle installation de pellicules de chauffage radiant, moratoire qui demeure en vigueur. Malgré ce moratoire, les pellicules de chauffage radiant de marque Eswa sont toujours considérées sécuritaires et ne sont pas visées par l’ordre de débranchement. Par ailleurs, d’autres systèmes de chauffage radiant demeurent sécuritaires et peuvent toujours être installés:

  • le gypse radiant (fils conducteurs à l’intérieur des panneaux de gypse)
  • les autres systèmes radiant, par exemple, les planchers radiants

Hope this helps,

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I am not aware of any specific issues with regard to electric radiant.

Some good info with regard to radiant heating here…

http://www.radiantdesigninstitute.com/page59.html

Sounds like a great opportunity for infrared imaging…

http://www.ofm.gov.on.ca/ENGLISH/Publications/Communiques/1994/94-033at.asp Also do a Google search: “radiant heating panel reacall”

Yes that wil give you a pretty picture and if I had one I’d use it but a simple infrared/laser thermometer works fine for ceiling electric heat.

George You can also mist the area with a spritzer bottle. If the panel is functioning you will get a distinct drying pattern.

…Provided the vendor doesn’t object to you spritzing water on his/her ceiling. :twisted:

The IR Camera is awesome for something like this. You can find gaps and totally non-functioning wires.

I’ve run across quite of few houses with ceiling radiant heat and as George witnessed, most ceilings were cracked…some badly. Plaster doesn’t enjoy being expanded and contracted over and over and over…

Bill Mullen
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I haven’t seen panels cause cracking, but have seen the heat cables which are imbedded in the plaster to cause cracking and in some cases ghosting.

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If you do a search on Radiant heat, you will find many discussions about this topic.

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Here’s the scoop on radiant heat in the Maritimes:

“Thermaray” gyproc panels (14 inches wide) with heating elements embedded had problems in the late 1980’s with the heating elements (quite thin wires) in parallel. They would break iindividually over time losing more wattage. The best way to check how much is still in play is to remove the wall mounted thermostat and check circuit amperage with a clamp-on meter. From there you can ascertain the wattage still good and if it should be adequate to heat the room. No fires resulted form this brand.

“Flexwatt” : This and others mentioned by MGratton have beeen related to fires. Most of the product was sold in Quebec and British Columbia. I believe virtually none was sold in the Maritimes but I heard a story that some may have gotten into Northern New brunswick from Quebec…Never confirmed.

ESWA Heating Foils: Manufactured in Finland (I believe), these are flexible flat elements laminated into heavy plastic or mylar type product. They come rolled up and are designed to be rolled out/installed on the lower face of strapping at 16 OC. I installed a bit of this in the 1970’s. Have never heard of any problems with it.

Cable covered by plaster: early form in some 50’s-60’s houses; not much around but never heard of any problems.

Great way to heat, but radiant panels only heat that which is direct line of site. In other words if you are seated at a table your upper body would be heated but your legs and feet are not as they are in the shadow created by the table fwiw.

Speaking of ghosting, as I sit here today for a while longer, I’m working on a litigation against an award winning architect and builder in which one wall of a commercial/residential building had to be steel studded due to being on/near property line. They didn’t design a thermal break into the wall (with steel siding to boot) and now we have some 2 storey high walls showing ghosting. That’s just one of the many problems- this building has probably the worst designed and installed HRV and bathroom fan systems I have ever seen. (been familiar with HRV’s-installing and inspecting- since 1981.)

Back to work…damm- been up since 5:30…still have a meeting with another arch at 1:30 and inspection at 3:00 and have to drive 45 miles to get there!!! Then back home to this report. Some days…retirement looks good.

Thanks guys. Did search on ‘radiant heat’ but did not come up with anything specific on this type (cable in plaster). Probably good news for owner / client!

(Merci Marcell)

I had this in a home I owned 5 years ago, all rooms worked fine, the inner walls all insulated and this was good for shutting down the temp in the rooms we did not use to much.House built in the 70’s.

Many homes here have electric radiant heat in the ceiling. All I have come across so far have been via electric mats in the attic space, non from wires embedded in the plaster. Almost all have been functioning as designed and in use and working well.

I verify their proper operation without a thermal imaging camera, a simple ir thermometer works well.

People with them like the even distribution of heat and the ability to control each room (zone) independently. There really is little ‘ghosting’ effect, with any radiant heat source, as the object blocking the radiant heat itself radiates the heat it builds up so it is a very short term effect.

People don’t like the speed of the heat, if you go on vacation for a couple weeks and turn the thermostat down to 50, when you get back it takes a few hours to heat up the house. Also, some are concerned with the price/efficiency of heating with electric vs. gas systems.