Hang A Radiant Barrier From My Soffit to Reduce Exterior Wall Temp?
My neighbor pulled down a tree that used to provide shade to the west wall of my home.
Now that the tree is gone, the west wall of my home (painted brick in Houston, TX), receives direct sunlight from about noon until 5-6 PM when the sun is low enough that my neighbor’s house blocks the rays.
As a result, the exterior wall becomes hot, sometimes far too hot to touch. And inside (my kitchen area), one can open the kitchen cabinets and it is obvious that its much warmer inside than elsewhere in the house.
I’ve read about the limited usefulness of radiant barriers in attic applications but I want to know if they would work well here. Rather than simply hanging a sun shade from the soffit, which I expect would simply absorb energy, then re-emit it to the house wall, I was thinking about hanging a bubble backed barrier (bubble backed to make it easier to roll up/down).
It would seem to me that a radiant barrier would be a better solution than a simple sun shade and I would appreciate comments yay or nay. Thank you.
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Simple sun shades can work. Aluminized bubble pack can work too, but it'll break down over time in direct sunlight. An aluminized fabric type radiant barrier would have a longer useful lifecycle than the bubble pack, and would roll more tightly. Since it's a shade open to the outdoor air on both sides, not an air tight enclosure, the additional ~R1-R2 of the bubble pack vs. aluminized fabric is meaningless.
But since it's painted brick, painting it with a high solar reflective index paint (>50 SRI) can make a real difference, and would be the first thing to try out. While most high SRI paints are white or very light in color, there is still a range. You can probably dig up an appropriate product on the Cool Roof Rating Council database. While most products listed are designed for roofs and inappropriate for walls, the Field Applied Coatings listings can probably work. Most of the listed products are white or bright white (titanium oxide pigments mostly), but they have some blue versions with 3-year aged SRIs WAY north of 50:
http://coolroofs.org/products/results/search&channel=products&orderby=cf_product_color+asc&cf_product_pri_prod_type=%22Field-Applied+Coatings%22
There are of course other colors, eg:
http://www.texcote.com/pdf/tsr_chart.pdf
Do you have enough space on the west side your property to plant trees? They may not provide much shade in the next couple years, but will provide shade in the future.
Unfortunately, at my age, I'll be dead and gone before newly planted trees will do any good. Nevertheless, we have planted for the future... good trees take time to grow, though.
The paint is an interesting idea. I'll take a look at the database you mentioned. However, I suspect that the shade of taupe we have is outside the bounds of what is possible, while the lighter shades are probably outside the bounds of my wife's decorating tastes.