Air Conditioning Alternatives

The U.S. is virtually addicted to air conditioning. We use more energy on it than all of Europe, which has twice the number of people, or China, which has over four times as many. In fact, we use more energy on air conditioning than the rest of the world combined.

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See Breaking the A/C Habit for helpful info on ceiling fans & Naturally Cool to learn about passive cooling (both @ nrdc.org).

Living the air-conditioned life means we hardly experience summer anymore except when we go on vacation to other countries. Then, we encounter summertime customs like siesta and call them quaint.

In other developed nations, people continue to live in homes designed for passive cooling — with high ceilings, courtyards, working shutters and other traditional elements that protect them from the heat. In America, homes are more likely to be built for air conditioning and to lack natural cooling features. The same holds true for workplaces.

Also, we Americans have let go of the habits that make summer heat tolerable (siesta being one). It’s as if people starting thinking: Why suffer the inconvenience of closing the blinds or eating cold meals in summer if air conditioning can make it feel like spring?

I’ve known many folks (friends and family among them) who leave the air conditioning running all summer long, regardless of the weather. Offices and apartment buildings often do the same, as a matter of policy. That’s almost a definition of waste.

There are less costly and more sustainable ways to cope with summer heat. These include:

1) Keeping heat from entering the home by reflecting or blocking it with shades, shutters, louvers, awnings, trellises, window and roof coatings, insulation and/or trees.

2) Removing heat by using natural ventilation during the cooler time of day and closing the home up during the hot hours per #1.

3) Reducing heat-producing activities, such as using the oven, dryer and dishwasher’s heat cycle, and limiting them to the cool times of day.

4) Using circulating fans when #1-3 aren’t enough to keep you comfortable or, on extremely hot days, circulating fans combined with air conditioning. The fan magnifies the cooling effect of the A/C, enabling you to raise the temperature by 4 degrees or more and still feel just as cool. So you actually save energy by using both machines, provided you really do turn up the thermostat.

Keep in mind that humans naturally adapt to the customary weather in the place they live — as long as they stay out of the air conditioning long enough to do so. That’s why there is no national definition of a heat wave (what’s dangerously hot to residents of Omaha may not be so to Atlantans) — and why reducing your use of air conditioning will also help reduce your need for it.

See Breaking the A/C Habit for helpful info on ceiling fans & Naturally Cool to learn about passive cooling (both @ nrdc.org).

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8 Responses to Air Conditioning Alternatives

  1. Cynthia July 31, 2013 at 10:27 am #

    One good technique for reducing energy costs during hot and humid weather is to set the thermostat at night to super-cool the house while energy prices are low. Then turn the air-conditioning way down during the day so that it does not come on unless the house becomes extremely warm. This technique has been very effective during heat waves along with the use of ceiling fans and window shades. We also signed up for an energy savings program and tells us the price of electricity by the hour so we set appliances to operate during low-use periods.

    Additionally, the city partnered with the power company to offer home energy audits. We added insulation in the attic that made a significant difference both in reducing heat entering the house in summer and heat loss in winter.

  2. Dale July 31, 2013 at 10:41 am #

    Thanks for the cool tips! We’ve been having a lot of mold and mildew problems due to high humidity this summer and are on the verge of getting an a/c just to reduce the house humidity. Fans don’t help with humidity and a room dehumidifier doesn’t cut it for the whole house and it uses a lot of energy as well.

  3. Ev July 31, 2013 at 11:24 am #

    The article was well written and informative but did not consider areas of high outdoor pollution or those with medical conditions who can not tolerate the heat, humidity, pollens and other natural phenomena. Some of us feel guilty we can not follow the well thought out ideas presented in this article but some of us are prisoners of industry, nature and genetics or some combination of the three.

    • Sheryl July 31, 2013 at 3:10 pm #

      As I said in the NRDC column, air conditioning can be both a “godsend” and a “lifeline.” By all means, use it if and when you need it. No guilt necessary! –Sheryl

  4. Gunta July 31, 2013 at 2:55 pm #

    Agree with Ev. I’ve tried to get by with window fans, but have sucked in neighbors smoke from outside and pollen, setting off allergies. But I do follow the other suggestions and mostly only turn the A/C on at night. I can take the heat during the day, but need it cooler to sleep.

  5. S. Keith July 31, 2013 at 9:14 pm #

    It’s an interesting article, but as many are, geared to home owners. I live in an apartment and have no control over my heat. The windows used to be old casement ones that not just let in tons of fresh air, but circulated it too. The slumlord management replaced them with sliding bottom windows – which forced us, after ten air-conditioner-free years, to get a unit. The triple-glazed glass and tiny space that lets in air now create a heat trap. I hate being forced to be unenvironmental because of cheap building priorities. If we could plant trees, the temp would go down about 10 degrees – another great “alternative” to AC. I think North America it should be the law to have at least one tree per building lot. People are very over-AC’d. Look at all the condos now, their windows don’t open at all. Do people really prefer that?

  6. Mike August 1, 2013 at 2:41 pm #

    Great article on keeping cool. One thing I have used both in my home and now in an apartment, is reflectors on the inside of doors and windows. I started with using car windshield reflectors on the inside of my house and could keep the living space 5-8 degrees cooler. Also, installed a solar attic fan later. This can keep the living space at least an additional 5 degrees cooler, and does have some affect on the amount of humidity entering the home.
    Now in an apartment I use reflector curtains made from foil covered bubble wrap insulation attached to cardboard that completely fills the window area. However, I have also experienced outgassing when the plastic heats up, so am going to just attach aluminum foil directly to cardboard with packing tape. A nice inexpensive way to keep your cool!

  7. Mike MacCracken August 3, 2013 at 11:34 am #

    A real key in keeping air conditioning costs down is controlling the amount of water vapor that gets inside. When the dew point is relatively high (say 70 F) or so, it takes about 20 times as much energy to remove the humidity as to cool the air (rough estimate as I recall). Back in 1950s when in high school, I worked for my Dad’s company, which had developed an air conditioning system to put into older homes that did not have an air duct system. So, it cooled the air an extra amount and the installed smaller ducts that fit in the stud space in walls to carry the colder air to each room. We put first system into a neighbor’s home in August on the East Coast, so very humid. The system ran and ran the first day, and the house did not get cool; same thing the second day; third day the house was cool and system hardly ran at all; fourth day came with thunderstorms, so they turned system off and opened the windows to get cooler air; fifth day was again hot and system ran a lot and house did not cool off; sixth day system did not run much and house was cool. What was happening was that system had to get moisture in the home under control (initially, out of air, plaster walls, etc.–all the places where can get mildew, etc.); once that was done, it took little energy to cool the house. So, at least on the East Coast where dew points can get high, if you open the windows and let the moist air in, even if the air feels cool, your air conditioning system will have to devote a lot of energy to getting that moisture out (same thing would go if you keep a steaming coffee pot going all day or have a pot luck with steaming dishes, etc.). The typical system is working to cool the air down to 60 F or so and so any moisture in air above that dew point has to be taken out, and on East Coast it is rare during summer for dew point temperature to go below 60 F (if evening temperatures do go down to about that, fine to open the windows–otherwise you will be paying to remove the water vapor). On West Coast, with the Pacific Ocean temperature being about 60 F, that generally controls the dew point (in areas of irrigated agriculture or marshy river areas, it can be more), and so fine to open windows during cool part of day (typically evening and early morning). But for the humid part of the country, it really can increase costs if what you do is to have system on during most of day and then open windows at night and let moisture in when dew point is not low. Best to get inside humidity under control inside, keep sources of inside water vapor low, and keep windows closed (there will be enough air coming through the cracks in house to keep air reasonably fresh, even though also brings some humidity).

    At least that is my experience–and a bit of physics.