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Reflective Heat Gains

Refrigeration Condenser Outdoors, Ambient temperature +28 to +30c, sun direct onto aluminium wall causing a temperature of +45c.

I would like to know what type & colour product could the walls be coated with to reduce the reflective heat gain.

Richard Whincup
Refrigeration Manager - Hull, Humberside, England
2006

Looks like the problem is sunlight heat absorption. You need a reflective coating or a paint. The cheapest would be a white paint. Otherwise wrap some Al foil around to reflect the light.

Mandar Sunthankar
- Fort Collins, Colorado
2006

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You need a radiant heat barrier coating. White is the best color if you are using normal paint. Various companies use Aluminum flake or glass balloons in the coating. Check out low e coatings.
Regards,

Jim Wood
- Concord, California, USA
2006

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White paint, either acrylic or latex, with titanium dioxide (or tin dioxide) pigment. It has the desired high solar reflectance (albedo) and high infrared emittance. From studies by Oak Ridge National Laboratory, Lawrence Berkeley National Laboratory, and the Florida Solar Energy Center.

If manufacturing the enclosures, bright anodizing might be the best finish, as it would aid removing heat from the interior. Anodized aluminum emits infrared (heat) about 20 times better than bare, polished aluminum. See optical and thermal properties of anodic coatings in Chapter 12 of The Surface Treatment and Finishing of Aluminum and Its Alloys, 6th Edn.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2006

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2006

It is good to be brief, but there is a risk of not stating the problem fully
Refrigeration Condenser Outdoors, Ambient temperature +28 to +30c, sun direct onto aluminium wall causing a temperature of +45c. What wall and where is it situated relative to the condenser?

I would like to know what type & colour product could the walls (there are more than one wall?)be coated with to reduce the reflective heat gain.

The purpose of a condensed is to radiate heat. Therefore it should be black. If it is being heated by reflected radiation reflected from adjacent walls, the walls should be black - but this would cause the wall itself to heat up and transmit heat to whatever is on the other side of the wall! I would suggest that the condenser itself should be shielded from direct or reflected sunlight and allowed free or forced (fan) circulation of air. It sounds like the condenser is situated in the wrong place.

Geoff Smith
Hampshire, England