As you may have heard, the average annual temperature has been trending upward for about the last 200 years, and in the last generation, it has really picked up steam — no pun intended. As the reality becomes undeniable and our opportunities to prevent it from happening have evaporated — again, not a pun — people have begun looking for ways of coping with the warming.
One benefit from the COVID-19 pandemic has been that we have been reminded of just how much of our daily lives we can conduct from home. This gives us a big advantage in dealing with hot weather, since the more time we spend at home, the more we can concentrate our efforts on just keeping home cool.
People still tend to think of insulation primarily as a way of keeping the heat of a stove from leaking out in cold weather, but of course anything that keeps heat in will also keep heat out.
Fiberglass is the most common form of insulation, but it has distinct problems: it takes a lot of heat to manufacture, and stray fibers are suspected of being a much bigger health hazard than we had originally thought. Hemp fiber, on the other hand, not only doesn’t take as much heat to produce, but also draws carbon out of the atmosphere.
Another approach to insulation is to make the walls of the house dense and massive. Concrete and brick are excellent insulators, but the manufacture of cement powder tends to release huge amounts of CO2, and so does the firing of bricks. Industrial applications of solar power are a helpful alternative, but it’s better to reduce the amount of heat used in manufacturing.
Unfired clay bricks are one option. Another is forced-earth building, one of the oldest methods of construction, in which soil is compressed mechanically inside a form to produce dense walls without the need for cement powder or fired bricks.
On the other hand, instead of forcing the soil into your walls, you can force your walls into the soil with earth-sheltered construction: not only does the soil provide excellent insulation, but heat rising from below will provide a positive heat source, even if you only dig a short distance below the surface.
Not everyone realizes it, but windows are basically holes cut into your walls. And holes let heat in or out — generally in the opposite direction from what you want.
There are all sorts of ways to improve the heat-barrier function of windows, from simply using two or more panes with a dead-air space inside, panes with a vacuum between them, and using glass surfaced with a tint that you can control electrically, widely known as “smart glass.” There’s even a company in Corvallis, Crown Electrokinetics, that is working on some of the most advanced “smart glass.”
You can never perfectly keep heat in during the winter or out during the summer. You can, however, move heat between the inside and the outside with a heat pump with great efficiency, as heat pumps move heat rather than create heat.
You can also store heat during the summer, or cold during the winter, with a very simple mechanism that uses an insulated box containing a tank of water, or a box full of water-filled balls, as a heat sink. A liquid with a very low freezing point is piped through the water, or air is blown through the box of water-filled balls, cooling the water until it freezes or warming the ice until it melts. The water inside the box can be refrigerated using off-peak electricity. If you have a large enough volume of water and very good insulation, you can use “Seasonal Thermal Energy Storage” to literally store the cold of winter and use it to cool your home in summer.
Evaporative cooling— also known as swamp cooling — is an extremely simple mechanism for cooling a house. The most modest form involves a device installed in the house, but a more direct form of evaporative cooling sprays the roof of the house with water to cool it much like sweating cools your body. It can be installed by several contractors in Corvallis, or you could even rig it up yourself by simply running a hose to a lawn sprinkler on the roof. A greywater tank that collects used water from showering and laundry can allow you to use evaporative cooling without worrying about wasting drinking water, which is liable to be in short supply during the hottest part of summer.
The take-away from all of this is that whether you are building a new house or improving an old one, there are things you can do right now that will reward you this year, next year and in 30 years to come. An investment of effort is generally one of the wisest investments you can make, and the dividends are more than just monetary.
“When we build, let us think that we build forever. Let it not be for present delight nor for present use alone.” – John Ruskin