The attorneys who sold me their building ran nine window unit air conditioners to keep the offices cool during the summer. I know because they left me all of them. After 4 years of running between 3 and 6 of those units my wife and I made the decision to try something different. We had insulated the basement and all the walls and the ceiling of the top floor where there quite literally had been none, and I climbed up on to the membrane roof and painted it white with some leftover acrylic paint. (Just two years ago we had to replace the old roof and did so with one intended to be white in color.) We free-cycled the AC units and bought some fans.
Since then my summer routine has been to blow in air on the first floor and set three or for industrial fans to blow air out on the top floor; he basement apartment stays fairly cool without any involvement in the process, and having those windows open would be a security risk. In the morning I close up the house and during the day I see to it that no sunlight enters the home. It does an excellent job of keeping the house nice and cool on most days.
On most days.
The Weather Channel reported two days ago that July was the hottest month ever recorded in Boston, and in Windsor Locks, Connecticut. Windsor Locks might seem like a random community to choose, but it is the location of the shared Hartford/Springfield “Bradley International Airport” (The Best Airport in America!). On the other hand, a professor at UMass put last month down as the 6th hottest on record in Chicopee (the former Springfield neighborhood where Westover Air Reserve Base is located).
Either way, last month was hot. Hot enough to make me wonder if the climate was changing if not for my awareness through the media? I still don’t know. In any case one interesting factoid was that not a single daily high temperature record had been broken and despite the threat to do so not once did it reach 100 degrees. On two occasions, however, records had been broken: records for the highest low temperature.
That is especially important to me because my strategy for keeping the house cool depends much more on getting cool air in than it does on keeping the hot air out.
This is a situation where the house being huge is a good thing energy wise; it takes a lot of warmth from the outside to heat it up during the day and the east side is “insulated” by two other townhouses. On a normal summer night the temperatures drop into the mid to low 60’s and getting the house down to 68 degrees or lower is a piece of cake. Early in the summer I can get it down to almost 60. With the white roof, insulation, and keeping the curtains closed it is 5 or 6 o’clock at night before the temperature creeps up say 5 degrees. By 9 o’clock I’m opening up again to let in more cool air and the process starts all over.
One thing I’ve always known is that the dew point holds the key to all of this. The dryer the air, the more quickly it cools and the farther the temperature will fall. If, however, the dew point is in the high 60’s or even the low 70’s things won’t cool until 10 or 11 at night, and the temperature will only fall so far. On two successive nights last month the dew point was in the upper 70’s. That’s tropical stuff, Florida stuff.
I was glad that some warmer days in the past few summers had concerned me enough that I purchased one high efficiency portable AC unit for the basement. It’s a two hose unit, important for higher efficiency, which works perfectly with the openings I had made for my solar heater; I swap out the outdoor solar box with the indoor cooler-dehumidifier and the already cooler basement can be cooled even more.
This is no joke. I take the potential of climate change seriously. A recent report had said that Springfield was, so far, among the least impacted metros in the country from increased heat with only 3 days per summer than normal over the average summer temperature in recent decades compared to the mid 20th century. The average for all metros was 15. That said the combination of the urban heat island effect and Springfield’s location in a very distinct valley location makes it warmer than surrounding communities.
I know that as I age heat can be more dangerous for me than cold. Just as I have purchased a wood stove, built a solar heater, and added storm windows in part to be able to “shelter in place” in any sort of “cold emergency”, I don’t want to have to abandon my home for a cooling center in case of extreme heat. The basement is its own self sufficient apartment with two beds, a kitchen, a full bathroom and its own entrance. It stays cooler than the rest of the house anyway, as most basements do, and giving it a little help makes it quite comfortable.
So last month, whether the hottest month ever, or just really hot, we ran the air conditioner for all or part of 7 days, and slept down there twice. Twice, for a period of two days each, the upstairs got in to the 80’s, and on two nights the house never got below 78 degrees. It was nasty. It was nice to have the downstairs there for a cooling break. Elizabeth and Luna only slept down there once, and I was the only one who spent any serious time during the day in the basement; doing some boring organizational stuff I had put off for as long as I could. I just wanted an excuse to be in the cold air I think!
In any case, lower lows are more important than lower high temperatures when it comes to keeping a big house cool without air conditioning. A heat wave arriving earlier in the summer makes keeping the house cool more challenging overall. Having a backup plan in place when your Plan A “crashes and melts” is always a good idea. And putting together an outdoor kitchen has become my top domestic priority for Summer 2020. Don’t worry, I’ve already begun to pick Johnny Sanphillippo’s brain for ideas!
Nice work! I put solar panels on my house this spring, and maybe next year I’ll get around to working out how to use a DC compressor for the few days we need a/c. In the meantime, because of our commonwealth’s very rich incentives, the panels are a ridiculously good financial deal—and they also to some extent do what your white roof paint did—prevent the sun from heating up our house as much. Our third floor is way more bearable in hot days now.
If you have any interest in solar, the financials are way better than I realized. There’s not only a tax break and free electricity, they also actually pay you directly, for ten years, based on how much you produce.
Anyway, thanks for the interesting account.
Cool Roofs in California
One of the roofing provisions unique to California is the idea of a cool roof. Cool roofs are made up of materials that reflect the sun’s heat off the roof’s surface so that they retain and pass on less heat. They reduce the need for air conditioning by naturally cooling the property and, in turn, reduce electricity bills and carbon emissions. For this reason, cool roofs became part of California’s energy code, the Title 24 Building Energy Efficiency Standards. Cool roofs are required for both residential and nonresidential projects in certain climate zones throughout the state of California, generally those with high-sun conditions. Requirements vary by roof style or slope.
Cool roofs are also required for homes in certain climates where more than 50 percent of the roof is replaced, recovered or recoated. Under Title 24, cool roofs are required for commercial buildings where either 50 percent or 2,000 square feet of the existing roof is replaced, recovered or recoated, whichever is less.
Only certain roofs qualify as cool roofs. Under Title 24, the roofing materials need to be sufficiently rated by the Cool Roof Rating Council. They must also meet the Solar Reflective Index values indicated in the code for being able to reflect the sun’s energy back into the atmosphere. Cool roofs come in most any color and style, including shingle, tile and spray-on liquid coatings.