Way back in the beginnings of Green Home Mega Store (GHMS), I wrote a post called “natural air conditioning”, and it is still attracts readers today, even though it has been off-line for many months! I think that deserves a renewed push to get it back in the circulation, don’t you?
What in the world is natural air conditioning? Well, it is really a very simple concept. It is based on the natural phenomenon that it is cooler at night and warmer during the day. It also requires a house (or building) that can be opened up and closed on demand, and a building structure that holds heat or cold for some time. So probably a stone house, or maybe a newer one made from concrete and bricks, would be the best candidate.
Here is the way it works.
- In the summer, the house will get too hot if you leave it open all day. So the natural thing to do is to make sure that the doors and windows and the window shades are closed, to keep the inside of the house as cool as possible during the day.
- At night, the doors and windows should be open as much as is possible, considering potential security problems. For us out in the countryside in Italy and with two or three dogs and a complete fence (as much to keep people out as to keep the dogs in), there were no security problems.
And that is it. Simple, but we had a bed and breakfast with 22 windows plus 6 exterior doors on three floors, so opening and closing the windows and doors was a 15 minute job every morning and evening. But it was worth it – the house was markedly cooler all day (my guess is about 6 to 8 degrees C which is 11 to 14 degrees F). We used the same practice in the winter to reduce our heating bills. But in the winter, opening the shutters while leaving the windows closed was usually more effective.
We used the same natural air conditioning practice in Martinez, California, some years ago. Our house was built without a/c because we felt that the climate there really did not require a/c. Our neighbours had a different opinion, and installed a complete system for heating and cooling for their entire house. We were in an area (one of the many microclimates in the Bay Area) where we got a sea breeze (well, at least a bay breeze) in the evening, and the heat from the Alhambra Valley in the daytime. This meant that we typically had temperature spreads between 55F (14C) in the morning and 100F (38C) in the mid-afternoon. What we discovered was that the natural air conditioning system worked perfectly for us. For our neighbour, I expect he had electricity bills in the area of $400 per month in the summers. His house never cooled down, and the a/c was running all night as well as all day, while we needed blankets most nights!
For $400/month, we could do some serious partying!
In today’s security situation, it might not be possible to use our experience to advantage. However, for a detached house, it is probably less expensive to fence the property properly and provide intruder security than it would be to use air conditioning consistently. And most likely, you would feel more comfortable with the fence and security systems as well.
For areas where the summer nighttime temperatures are not much better than the daytime temperatures (like a lot of the US Great Plains and the Southwest), natural air conditioning is not going to be the hit. The same is true for hot, humid climates like Houston or New Orleans or Miami. In those areas, the inside walls will turn green with fungus within a week if the air conditioning is not functioning in mid-summer to take moisture out of the house. But there are many locations where natural air conditioning can save you a considerable amount of money and keep your electricity bill to much lower levels than without it.
One additional note: “intelligent” buildings (buildings where a central system controls the heating, air conditioning, ventilation, and louvers to shut out direct sunlight or let it in or close out cold winds in the winter) take advantage of exactly the same principles as natural air conditioning as I described it above. The differences lie in the system itself that does all the work for you. It opens blinds and louvers to increase the internal temperatures and closes the same blinds and louvers to reduce heat loss when it is cooler outside. The building itself is generally configured so that cooler or warmer air can be moved to where it is most needed. Also, in cooler climates, the heat produced by internal lighting is used to minimise the heat required to heat the building. I guess you could call this “intelligent natural air conditioning,” right?
If you want to set up an intelligent interior climate control system, talk to your local HVAC specialists. S/he should have the answers for you.
Natural Air Conditioning