Judith Polich/For the Journal
I moved to Santa Fe in the late 1980s. Very few homes had air conditioning. Summer temperatures seldom got above the low 80s. The nights here at 7,000 feet were cool. Monsoons were regular and plentiful. Well-insulated homes and adobes were known to stay cool in the summer. Most of us just opened our windows at night. Some newer homes were built with central air and central cooling, but it was not the norm for some time.
We now have record-breaking heat for months at a time, unprecedented heat domes and droughts. Even at high elevation, some nights the extreme heat is relentless, making it hard to sleep. I do not have central air as I do not have the required venting. I have window air conditioners that strain to keep the inside of my house cool. Of course they cannot be used if there is smoke in the air as there repeatedly was this year, nor can swamp (evaporative) coolers.
Two thirds of the homes in the United States have central air. That number is far less in New Mexico. Many people have homes like mine, and we manage with a few window air conditioners. Some are on fixed incomes and can’t afford to run their air conditioners more than a few hours a day. Many New Mexicans have no air conditioning and rely on fans. Some folks have no electricity at all. Others who are off the grid cannot use their limited solar generating capacity for cooling.
Air conditioners require a lot of energy to run – about 6% of all energy used in the United States. The more we use them, the higher the carbon cost. There is no question that running air conditioning is making climate change worse. But what else can we do?
Studies have shown passive cooling can cut air conditioning use by 50%. Washington Post writer Sarah Kaplan explains that passive cooling involves managing sources of solar radiation in your home and careful timing. When the sun rises, put your window shades down or tons of heat will pour through your window glass. The heavier the shades or blinds, the better. I invested in triple-cell shades some years ago and also use heavy drapes. They keep the heat out in summer and prevent the cold from seeping in during cooler months.
Building scientist Alexandra Rempel studies how to design buildings so they stay cool passively. She says having vegetation around your home will prevent walls from heating up. That is because leaves release water into the air, which cools the exterior environment, just like sweating cools your body. She says, “cool roofs make a difference too.” A cool roof is a light-colored roof that will reflect heat rather than absorb it. All this means that less heat enters your home during the day. Once the sun sets, you have less inside heat to worry about. That is when you pull the shades and open the windows for cross ventilation so cool night air can enter and hotter air can leave. Rempel says, “cool night air is really the best free cooling resource we have.” This is also when you want to turn on your fans. Kaplan and Rempel remind us “that fans don’t cool the air, they just blow it around.” Kaplan suggests “if you are using a window fan, make sure to place it where it will draw in the coolest air like in a window overlooking a leafy backyard.” And replace heat-emitting incandescent light bulbs with LEDs.
Cool nighttime breezes don’t just lower indoor temperatures, they take the heat out of materials like tile and drywall. That is why tile tends to stay cool. “Materials are really the invisible player in all of this,” Remple said. “They can remain cool and be a cool buffer once the day starts to heat up.” And a well-insulated home with tight windows will help with overall cooling. New design standards are essential. Don’t even consider buying a new home that is not designed for passive cooling.
And with older homes we need to be innovative. I have a windowless back office. I bought a $60 6-by-6-inch Arctic Air cooler made by Arctos. I wet and freeze the filter and put in a cup of ice and a bit of water and air blows over the ice, inexpensively and efficiently cooling my office. It is amazingly efficient.
Judith Polich is a New Mexico resident and a climate-change columnist. She can be reached at judith.polich@gmail.com
