Adapting My Conventional House to My Hot, Humid Climate

Old photo of my house from GoogleMaps

Last week, my A/C went out, and I had a repairman in to get it fixed. It was an interesting coincidence because just the day before I'd been doing research on building techniques for hot, humid climates, such as what we have in the Lower Rio Grande Valley. You see, I have a dream: I'd like to learn to live without A/C. Unfortunately, my house is not well-designed for the climate.

Housing practices/customs in the USA are optimized for a more-temperate climate. In cooler areas of North America and Europe, the goal is to build a comfy, efficient heat trap. But in the subtropical, coastal Lower Rio Grande Valley, we need the opposite – except for a couple weeks in the year that actually get cold. (And in a few decades, those cold snaps will likely go away.)

"Shaping Buildings for the Humid Tropics: Cultures, Climate, and Materials," by Patti Stouter has great advice and examples for building. And while my house is far from ideal, she's given me some ideas on how to improve my existing home for comfort.

• Ventilation – The key idea here is that you want cross-ventilation in the building from the predominant wind directions. Most of the winds in my area come from the South and South-South East, yet my house is oriented East-West. My living room and dining room are a contiguous area with large, East-facing windows on one side and French doors on the West side, so some cross-ventilation is possible, especially if I redirect the South winds into the building with plants or wing walls, but cross-ventilation is impossible for my bedrooms.

• Shading

• Roof – The roof should extend out beyond the walls enough to shade them. But my roof's eaves are only maybe a foot deep and provide little shade. Ideally, it should be white, or at least very light. One possible adaptation would be to build shaded porches along the East and West sides of the house to shade the interior walls, then paint my brown shingles white.

My house has the worst orientation possible.

• Orientation – In the Northern Hemisphere, you ideally want the house with the long sides North-South and the short sides East-West to reduced heat gain from the sun. My house is opposite that, the worst possible orientation. Indeed, my West-facing bedroom is usually several degrees hotter than the rest of the house.

• Ceiling – This should be high to let the hot air rise. And the ceiling should be insulated and possibly have a radiant barrier. My conventional ceiling is 8 ft. high in the rooms with an attic space. I could add more insulation to the attic, a radiant barrier, and a ridge vent to increase air flow. This won't help my rooms, but I could possible take the ceiling out and insulate under the actual roof, taking out the attic space.

• Plantings – Plants provide shade, green chlorophyll in their leaves absorbed infrared heat, and their respiration cools the air. All in all, plants are a great thing to have around the house – especially trees – so long as they don't block the breezes. Indeed, smart planting can actually focus breezes into the house. In my case, I think the best thing would  be to add a shade tree on the North-East side of the house by one bedroom, where there will never be good cross-ventilation, as well as the North side. On the North-West side, I want to plant bananas to create a shade wall to halt the Western sun from heating up the back bedroom.

Maybe once all that is done, my house will be more comfortable to live in during the hot eight months we have in deep South Texas. And if it gets a little hotter one day than sitting still with a fan on myself will fix, I can always make a cheap chiller, like the video below, and run it off a solar panel.

#permaculture #A/C #greenbuilding #cooling