The Traditional Air Conditioner

Design and Drawing by James Ray Polk, Architect

This week's newspaper column: (Read it in the Hattiesburg American)

In spring, thoughts turn to love. In summer – even for hopeless romantics - thoughts turn to air conditioning.

Nowadays, we Americans have all become accustomed to the expectation that every building must be equipped with air conditioning to mitigate the summer heat. Air conditioning is as ubiquitous as walls, roof, and floor in any modern home. Who could live without it? I’ll tell you who: our ancestors.

Now when I say ancestors, I’m not referring to Ice Age cave painters, I’m talking about our immediate predecessors. The first modern electric air conditioner was invented by Willis Haviland Carrier in 1902, barely over a century ago, and air conditioners did not become “standard equipment” in homes until after World War II.

That means, most likely, everybody reading this article had parents, grandparents, or great grandparents who lived much of their lives in non-air conditioned houses. How did they do it?

In short, houses were built to “be” air conditioners.

You’ve probably noticed that older homes have tall ceilings. Far from being a statement of high style, those ceilings had a purpose. They helped cool a home in the summer by taking advantage of a basic law of physics called convection. Hot air rises and cool air sinks, thus those high ceilings took into consideration the proportions of our human frame distributing the hottest air in the house to the empty space above the heads of its inhabitants.

Look closer at that vintage home and you’ll see transoms above the interior doorways. Again, the origin of this detail had nothing to do with aesthetics. Open the transoms in the summer months and hot air migrated from room to room until it escaped through a high vent. (The most elaborate vents took the form of ornate hat-shaped roof embellishments called cupolas.) And as hot air escaped, the home naturally balanced the air pressure within by drawing cooler air through large low windows under shaded porches.

Presto! - natural air conditioning.

Can we still do this today? Of course! It’s a simple matter of design. It may be a lost art, but consider this: any run-of-the-mill builder a century ago knew how to build a home that conditioned itself. It’s not rocket science. Although our reconstituted sensitivities to summer heat may require that electric air conditioning be utilized in the hottest parts of summer, especially at midday, a modern-day home can be cooled using this principle.

So if you’re planning to build a new home or renovate an existing one, think about the air flow. Use porches or landscaping to shade windows, install operable transoms, and allow the air to escape through a ceiling vent. For added comfort, add a few ceiling fans to keep the air moving.

You may not want to give up your central air, but with a little forethought, you can bring down the temperature and your summer electric bill – naturally.