Outside Buildings
Water. On hot days, you need to increase the amount of water
you drink, particularly if you're exercising. When drinking large
amounts of water, check you're getting enough electrolytes. If
you get muscle cramps at night after a hot day, you may be low on
electrolytes. They're available in grocery stores as tablets, powder,
or drinks for sports.
Exercise. If you are free to do so, schedule heavy exercise during the coolest time of the day, normally early morning.
Shade. If possible, work and play in shady areas. Avoid unshaded stretches of pavement, cars, and walls. Green plants offer shade, and cool the air through transpiration. Spending time in wooded areas offers the dual benefit of shade and latent cooling.
Clothing. If you're going to be out in the sun, wear baggy white (or light-colored) cotton clothes to protect the skin from solar radiation while allowing air to flow past the skin for cooling by evaporation of sweat. A hat with a broad brim helps protect the face.
Glasses. If you're near snow or water in sunny weather, wear dark glasses. Reflective outer lens surfaces, and polarized dark lenses reduce eye exposure. Buy good dark glasses, and a protective case, then don't lose them.
Inside Buildings
Motivation. Air conditioning contributes to global warming, and global warming increases the desire for air conditioning. Clearly this is not a good pattern. So here are some ideas for keeping cool in a building while minimizing use of air conditioning to what is needed.
Clothing. Wearing skimpy clothes inside will help cool you off through evaporation of sweat from the skin. Short shorts and no shirt, for men, and short shorts and a bikini type top for women.
Night Flushing. Many places cool down outside at night during hot weather. At night, when it cools down, pull up the window shades and open the windows. If you are worried about burglars climbing through open windows at night, consider installing decorative security grilles (already typical in some countries) over key large windows to allow for cross ventilation. Otherwise, get up early in the morning and flush out the house with cool outside air before the sun starts streaming through the windows and the outside air heats up. Turning on bathroom exhaust fans may help night flushing, particularly if there's no cross ventilation. In the morning, close the windows and pull down the shades as it warms up outside, to prevent sunlight from streaming in, and to trap the cold air brought in overnight.
When looking for a place to live, choose a dwelling that has windows that will provide cross ventilation.
Window Shades.
Install effective window shades, and pull them down in the morning before the sun comes up. Consider the following in selecting window shades:
- If used properly by the occupant, cellular (accordion) shades reduce direct sunlight into the space during hot weather, and reduce heat loss from the house in cold weather. Some are translucent, others are opaque.
- Shades ("blinds") with rotating metal, wood, or plastic blades are effective in reducing solar gain if the user rotates the blades so that they are shut or roughly perpendicular to the incoming rays.
- Black cloth roller shades that allow you to see outside while the shade is down are not very effective for cooling down a space.
- Simple old-fashioned opaque roller shades offer an inexpensive way to block out the sun.
Simple Fans. A little fan on your desk, or a paddle fan on the
ceiling above your bed, will help cool you down if you are in the room
while the fan is on. If you're in the room while the fan is on, it's
more energy efficient than air conditioning.
Trees. Highest priority: Grow deciduous trees outside your windows where sunlight otherwise streams in during hot weather...possibly east, south and west for the northern hemisphere. General: Plant deciduous threes anywhere in the yard you'd like to have a cool, lovely place to rest or play in the hot weather, particularly during hot afternoons and evenings. The leaves will also provide mulch useful for the gardens in the fall.
Basements. The basement is a good place to cool down. Consider putting a bed or two and a desk in the basement to offer a comfortable retreat when things get hot outside.
When looking for a place to live, consider the advantages of basements during protracted hot weather.
Extreme conditions. If things still get too hot inside, consider putting your shirt under the faucet then putting it back on. That will cool you down! Place a little fan on the table next to you. Little fans that clamp onto a table are inexpensive, and make a big difference when you are next to them. Discontinue cooking hot food (except in microwave) until the weather cools down. Try washing your dishes in cold water. Dry clothes on a line outside (a good idea anyway). Turn off lights and other electric devices if they aren't needed. Pay special attention to anything that's warm to the touch when on. Find out in advance where there are air conditioned buildings--such as libraries--near you if your living accommodations don't have air conditioning and you're afraid of suffering from extreme heat.
Air conditioning. If you feel you must install air conditioning, seek an air conditioner that uses a refrigerant with a low global warming potential (GWP). Select an Energy Star air conditioner so that it's energy efficient. Consider just air conditioning one room, such as a bedroom with a desk, so you have a comfortable place to go when it's too hot. Continue to use the above methods to minimize use of the air conditioner, and use a reasonably high cooling setpoint on the thermostat (78F is reasonable). Be sure the thermostat avoids bringing on the heat in the summer. Most important, when you buy an air conditioner, buy a heat pump if your building requires heating in the winter. Heat pumps are both air conditioners and heaters. They include an automatic reversing valve to switch between heating and cooling. As heaters, heat pumps are roughly twice as efficient as electric resistance heat, such as electric furnaces, baseboards or "cove" heaters. (When buying a heat pump, seek low noise ratings, make sure any ducts that are used are sized large enough. Check that the selected heat pump performs well in very cold weather if you have very cold winters. Check whether the fans and compressor have variable speed drives. These tend to improve efficiency and reduce noise. Talk to a friend who already bought one, to get ideas.)
A place to go for more information on heat pumps: https://makingheatpumpssuccessful.blogspot.com/
Direct Evaporative Cooling. In dry, desert-like areas, what used to be called "swamp coolers" can be used. The swamp cooler dribbles water over a porous surface and moves air over that surface with a fan, cooling down the air by evaporation. It's far more efficient than an air conditioner, but only works in regions with low humidity during hot weather.
Heat Pump Water Heaters. You may already have a heat pump water heater (for showers, etc), or may be thinking of buying one. Heat pump water heaters normally have nothing to do with air conditioning, but here's a curious thought:
Some heat pump water heaters are installed in basements or garages. Remember that the heat pump water heater heats water by taking heat out of the surrounding air. So there may be an opportunity, in the summer, to cool your house somewhat with the heat pump water heater by ducting the cooled air upstairs during the summer, or opening up a door and window to encourage air circulation up out of the basement into the first floor. (Because heat pumps and air conditioners--and refrigerators--move heat from one place to another, all of them simultaneously perform heating and cooling. Ideally one could use both effects...)
Passive Solar Design.
In designing buildings for the northern hemisphere, south-facing
windows with overhangs can offer direct solar gain during the winter
(when the sun is low in the southern sky) and block the direct solar
gain in the summer (when the sun is higher in the sky).
Safety
Getting too hot and or dehydrated can be dangerous. Drinking a lot of water without electrolytes once you are already too hot and dehydrated can also be dangerous.
Become familiar with
expert advise,
and seek medical attention immediately if you get in trouble. If you
aren't in an emergency but are too hot, rest in a cool
shady place, and drink a moderate
amount of water until you feel better, then think carefully about the best way to avoid getting too hot over the long term.
7.8.2024
