Got a question for those well versed in radiant heat….
I have a customer who has a home that was built in 1909. The old style (more than likely original) cast radiant heaters are an eyesore. Many layers of paint cover the metal. He asked me today about either repainting them or looking into covers that would be custom made. Do covers affect the performance anymore than another coat of paint? Does paint in general affect performance? Would appreciate your thoughts. Thank you.
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Replies
Paint them a dark color for maximum effectiveness. Like Black, perhaps.
Not sure what you mean by a cover, but any barrier in space between a radiator and the space its heating will reduce its ability to radiant directly. You'll still get heat, but between the two paint is much better.
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I had great luck sandblasting and then powdercoating radiators. I then had them pressure tested prior to re-install.
Regular metallic spray paint looks good and will stand up to the heat. You may read about metallic paints slightly dropping the efficiency, but radiators from 1909 are sized for an open window on the coldest day, so the effect is negligible. I am paraphrasing Dan Hollohan here. Got see Dan's website, http://www.heatinghelp.com for tons of information. In one of Dan' books, We've Got Steam Heat!, Dan gives details for the most effective radiator cover, if that is what the client ultimately wants. Even the best designed cover however, will cut the effectiveness of the radiators dramatically.
The hardest part is cleaning them. If they can be removed, take them to get media blasted. Powder coating is even more cost effective when they are already removed for blasting.
Painted radiators look great in an old house and setting a pair of boxers on a radiator before getting dressed is one of life's pleasures.
...that's not a mistake, it's rustic
I'd go with black paint for the same reason the metal coils on the back of your fridge are black - dark colors radiate heat more affectively.
with metal radiator covers (usually painted white) i think any diminished performance is theoretical. at least i have never noticed any difference in performance. i have noticed that instead of an unsightly hunk of metal, i have a cabinet. this is both more attractive and adds functionality: its very difficult to balance anything on a radiator, while a radiator cover can be used like any other piece of furniture - except you don't want to put anything heat sensitive like candles on them. i should also add that if you have very hot radiators, the cover creates a safety barrier for children.
might begin by saying all the radiators I've treated operated in an A plus efficiency quotient before I "treated" them ( and I second your looking into that invaluable heating website mentioned in post 3 or 4 ) the metallic paints good way to go sprayed on - very little skin added, sometimes primer included in finish application, easy to do - prep work important and beware overspray! after living w/ a couple 12 plus yrs w/ no trouble I built cabinets around them glued nailed and caulked - built nice face frame stiles 2" and base 8" and mulled three shutters together and capped w/ top using about 30 pieces 1 X 1" set about 1/4" apart - breathes great and you would not know it is there as far as heat goes - more surface area to radiate?! ( no other walls have more insulation than those where there is now a radiator boxed in front - even hung some old camping space blankets on ext. walls - can't see them ) worst case is my most recent endeavor - cleaned etc. then spot primed w/ metal primer then w/ shellac based bin primer then two ( or more ) coats brushed on of a gloss Rodda acrylic paint we are using for trim - definitely least satisfactoryCaalk - do you have some info as to pricing on the sandblasing to powdercoating process?