All of our DDB boxes have the brushed metal finish. I painted one of them with some white elastomeric roof coating stuff from Lowes that is meant to reflect solar energy, and the peak internal temp only went down ~5°F. We have a lot of gear in that box, so I think an application with a larger ratio of solar gain to internal heat generation would benefit more. After the paint failed to solve the problem, I replaced the 110cfm fans with a pair of 48vdc 250+cfm fans, and the temp went down 20°F; it does make a lot more noise though.
On Thu, Aug 15, 2019 at 6:31 PM Ken Hohhof <[email protected]> wrote: > The difference between standard machine grey and just bright white spray > paint from the hardware store is dramatic. I suspect everything beyond > that is incremental. > > > > Also back around 2005 when I ordered my first outdoor cabinet from DDB, I > thought I wanted unpainted metal aluminum since all the traffic control > boxes I see are plain metal or stainless steel. The salesperson said I > absolutely didn’t want plain metal because it would get hot in the sun and > what I wanted was the cream color. > > > > *From:* AF <[email protected]> *On Behalf Of *Bill Prince > *Sent:* Thursday, August 15, 2019 6:19 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] Solar load > > > > If you look up insulating paint on Wikipedia, the entry there says all > ceramic heat-reflective coatings are snake oil. > > I did find a good discussion on Scientific American ( > https://www.scientificamerican.com/article/benefits-of-insulating-paint/). > They don't exactly describe it as snake oil, but they also suggest that you > not get your hopes up. > > I suspect you can get your best results with a coat of reflective white > paint, and try to keep it clean. > > > > bp > > <part15sbs{at}gmail{dot}com> > > > > On 8/15/2019 1:12 PM, [email protected] wrote: > > Be interesting to do a bake off between this and the plain “satellite > white” I use. > > > > > > I have always found it interesting that highly reflective things like > polished aluminum, chrome and silver paint seem to be really bad at > reflecting heat/sun. But we have all grabbed a chrome wrench that has been > left in the hot summer sun and realized hot much it absorbs. I am guessing > what we see as reflective, Infra Red sees as flat black. > > > > *From:* Bill Prince > > *Sent:* Thursday, August 15, 2019 1:46 PM > > *To:* [email protected] > > *Subject:* Re: [AFMUG] Solar load > > > > Which reminds me of this material that a friend clued me in on. > > You can get this at Home Depot (for example). It is pricey; around $250 > per 5 gallon bucket, AND it needs a top coat of another material at near > the same price. However, for an advertised reduction in temperature of over > 60 degrees F, it may be worth a look. > > https://superiorcoatingsolutions.com/super-therm/ > > bp > > <part15sbs{at}gmail{dot}com> > > > > On 8/15/2019 12:35 PM, Lewis Bergman wrote: > > I remember Chuck doing a study on this same subject so I thought there > might be some interest. > > Cabinet heat load > <https://www.ddbunlimited.org/wp-content/uploads/2019/08/Solar-Load-on-DDB-Enclosures.pdf> > > > > -- > > Lewis Bergman > > 325-439-0533 Cell > > > > ------------------------------ > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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