insulating radiator cover

I'm looking for suggesting for upping the r-value on top of my radiator. Every window in my apartment has a radiator underneath it. I'd like to have some plants by those windows ('cause y'know, they need light and all) but I'm concerned about heat from below drying & killing the plants. A couple of the radiators have covers, but they're metal, so no insulation there. Ceramic pots may provide some insulation, but I'd really like to lay down a layer of some kind of building insulation proper just to be safe. The question is, what kind? Batting won't work, and the foam insulation panels I've seen at the hardware store I know are a fire hazard... plus not too fond of plastic-type materials. My dad suggested something he called "thermal block" which I believe is aerated concrete panels, but which I can't find a source to purchase. I'd like to spend less than $20, preferably less than $10 on this. Please help!

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caitlinsdad8 years ago
I would suggest you first built an angular sheet metal cover for your radiator cover. A flat sheet of aluminum that is sloped toward the back at maybe 45 degrees. You still want the radiator to work effectively and that will draw/reflect the heat rising up to flow out into the room. Then build or install a separate shelf for your plants on top of the new reflector. You should not need to insulate your radiator. Get a roll of aluminum roof flashing and some sheet metal screws to put the reflector together. Good luck.
timeismine (author)  caitlinsdad8 years ago
Thanks for the suggestion! I did think about a shelf, but this is a short-ceiling'ed attic apartment, and the radiators are a good 3-4 inches higher than the window sills as is (the sills are not very far from the floor, maybe a foot, foot and a half.) I don't think I have space for anything under a shelf!
Maybe try some of those suspended plant hanger metal bars/hooks attached to the windowframe/wall or ceiling to bring the plants away from the window but still not directly above the radiator. Or a patio box hung between the window.
110100101108 years ago
2 or more stacked chip or wood plates with small air distance between them let the ends of the structure go up like the ends of a chinese roof. this way the hot air won't get to the plant from the sides in addition : install a low speed fan behind the top of the radiator. the fan will blow the hot air into the room and not let it go up unless its freezing for the plants its better to keep them outside of the window. then you dont have to bother about the radiator at all
timeismine (author)  110100101108 years ago
The chinese roof thing is good a thought. Do you think chip board would keep shape and not warp? The window sills that the radiators are under have warped already, long before I got here so I don't know how long that took.
it may warp then. to prevent it blow the hot air into the room and away from it with a fan