Old homes used open windows, shades and more to keep cool without air conditioning.

Tim Wood

As the summer heats up, it’s tempting to just shut all the windows and turn on the air conditioning. If you live in a house built before the introduction of air conditioning, though, you may be able to take advantage of your home’s inherent pre-AC cooling features.

Nineteenth century builders knew that, if properly constructed, a building could remain relatively cool in the summer. The photograph at [left, right, above, below?] shows a house on West Chestnut Hill Avenue employing some of these simple cooling techniques in the early part of the last century.

One feature that can help to keep a house cool is the mass of the house itself. The thick stone walls that are common in Chestnut Hill’s architecture absorb heat during the day. This heat is stored in the stone, not in the interior of the house, and is then released as the outdoor temperature drops. This thermal mass effect can keep a house relatively cool for several days during a heat wave.

Curtains and shutters can help keep rooms on the sunny side of the house cooler during the day. Traditional shutters are particularly useful for this purpose, as their louvered construction keeps light out but still allows some air circulation. Awnings, porches, and roof overhangs can also help to keep a room cooler by limiting direct sunlight.

The double-hung sash windows that are common in Chestnut Hill’s homes can also work to cool the house. If the upper sash is operable (most have been painted shut, unfortunately – this is relatively simple to fix, though), by raising the lower sash and lowering the upper a few inches you can take advantage of the natural convectional cooling effect.

If you have modern, triple-track storm windows, you’ll need to adjust the position of screen and window panels to allow air to exit at the top. Since warm air rises, it will leave the house via the opening at the top of the room. The effect of moving air across the skin can lower the perceived temperature in the room by 2 or 3 degrees. Of course, ceiling fans and window fans can also increase this effect.

A similar effect can cool the house in the evening. If you open windows on the ground floor and windows on the top floor, you can take advantage of a natural chimney effect that pulls warm air out of the top of the house, replacing it with cooler nighttime air from the lower windows. This “thermal flushing” can make a summer evening much more comfortable. A large exhaust fan in the attic that can pull air through the house and out through roof or gable vents can also achieve this, often dropping the indoor temperature within a half an hour or so.

So, when the inevitable summer heat wave comes, you might want to give some of these time-tested cooling methods a try. You might just find that they make both the temperature and your air conditioning bill easier to bear.

Tim Wood is resource center manager at the Chestnut Hill Historical Society. He is available to answer your questions about the challenges and advantages of living in and maintaining an older home. Contact him at resource@chhist.org or at 21- 247-0417, x203.