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Radiator Heat Feflectors

Posted by edlincoln (My Page) on
Tue, Nov 5, 13 at 10:46

My parents have an oldish house with steam radiators. I read online that placing a reflective barrier behind steam radiatorsa increases their efficiency by reflecting back into the room radiant heat that would otherwise be lost to the walls.

There are products that do this and apparently they are recommended by the UK government:

What I'm wondering is, couldn't I just use those foam insulation panels with the foil coating you get at Home Depot? My one concern is that they would be too flammable. Others online recommended wrapping cardboard in foil.

I am extremely unhandy and am looking for some "low hanging fruit" in terms of energy efficiency to keep me occupied when I visit for Thanksgiving.

Follow-Up Postings:

RE: Radiator Heat Feflectors

Sorry I got involved. Good luck. :-)

This post was edited by mxyplx on Wed, Nov 6, 13 at 8:14

RE: Radiator Heat Feflectors

First - Yes, the reflectors do work, and they can also provide protection for the wall. I would glue the foil panels to something more rigid, or make the reflector out of one of the lightweight steel sheets they sell at Lowes. There is a section at both Lowes and Home Depot where they have steel rods, angle iron, and pieces of steel and aluminum in various sizes. Take a look through them and see if one of the sheet standard sizes would work.

Also, are you sure they are steam radiators, or they just hydronic hot water? You could use reflectors with either type of radiator, but a standard hydronic radiator operates at a much lower temperature. I have old cast iron radiators and a new Buderus boiler, and the operating temp is about 145 degrees maximum. I don't think there is any way it could start a piece of insulation on fire.


RE: Radiator Heat Feflectors

All the best. :-)

This post was edited by mxyplx on Wed, Nov 6, 13 at 8:15

RE: Radiator Heat Feflectors

We used the radiant barrier for roofing. It had no problems in south Texas where attics can easily get over 150oF. Use a long drywall screw to suspend it a little away from the wall and attach in the corners. We have steam heat and the temperature drops off pretty quickly from the radiator body. As long as the foil is not touching the rad, I don't think you will have any problem.

We just did this and you can really feel the increased heat through the top. I don't notice much of a change for the sides.

RE: Radiator Heat Feflectors

mxyplx: No need to apologize. We are "brainstorming" here. All suggestions are welcome. I wish you hadn't deleted your comments. The walls are insulated, but it is an old house, so probably not well.

maryinthefalls: I'm excited to talk to someone who tried it. What product did you use? The styrofoam stuff, or something else? I'm kinda wanting to use the foil wrapped styrofoam panels because it would be simplest and cheap, but I'm worrying about fire hazards and now outgassing.

bcarlson78248: I'm pretty sure they are steam radiators. They hiss. They get hot enough to hut if you touch them, but not hot enough to burn badly. Someone I know speculated the steam is under pressure so can get to about 300F.

My main decision is whether to buy the Styrofoam panels, use bubble foil insulation, or buy the commercial products designed for this:

Here is a link that might be useful: Peel 'N Stick Heat Reflector

RE: Radiator Heat Feflectors

We used the foil covered bubble stuff. It was16" wide and cost about $20 from the orange box for 25ft. I didn't have the room for anything thicker. Search for radiant barrier.

My radiators run a lot cooler. My system is only under very slight pressure, if any, and operates around 215oF.

RE: Radiator Heat Feflectors

Steam heating systems operate at a very low pressure like about 1 psi so they do not allow steam to rise above 212 degrees, in fact the radiator will be losing heat to the room so the surface may not reach 212 degrees.

An old fashioned radiator is designed to maximize the surface area so it is more efficient in convection than in radiation. Adding materials that might reflect infra-red energy back to the radiator can increase the radiator's efficiency unless it decreases air flow.

Most steam radiators are oversized and poorly controlled so maximizing the heat from them can lead to overheating of the room. Many people enclose their radiators which works well for forced water systems where warmer water is returned to the boiler and quickly reheated but not so well for steam systems where steam must condense for water to return to the boiler. I suspect a better way to save energy would be to use a programmable thermostat.

This post was edited by Renovator8 on Sun, Nov 10, 13 at 7:55

RE: Radiator Heat Feflectors

At Lowes they have stainless steel sheets for use as a backsplash behind stoves. They are in the appliance department. Seems those would be perfect behind a radiator -- check the dimensions.

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