How houses were cooled before air conditioning

Welcome back to Period Dramas, a weekly column that alternates between rounding up historic homes on the market and answering questions we’ve always had about older structures.

On these sweltering midsummer days, it’s natural to want nothing more than to sit in front of an air conditioner that’s running at full speed. But while today finding relief from the heat takes little more than the flip of a switch (or a smart switch, if you’re lucky), it wasn’t so easy at the turn of the 20th century—before the advent of modern air conditioning.

"The idea of cooling a house in hot climates is nothing new—ancient Egypt used courtyards to promote air flow through buildings," says Jonathan Hogg, associate at Ferguson & Shamamian Architects. "Providing air circulation is simply essential to summertime relief."

One of the most effective forms of air circulation is a “cross draft,” an interior breeze that forms when two openings in a building—windows, doors, and the like—align.

To create a very strong cross-draft, according to Hogg, the house would ideally be one room deep, so that windows and doors can be placed on either side of the structure to best promote airflow. Unsurprisingly, some of the most creative examples of this type of house exist in the South, where the heat is a much more acute problem than in the Northeast.

One such example is the shotgun house, common in Louisiana. The one-room width of the building allows—as Hogg suggested—for windows and doors to be lined up for cross-ventilation.

The porch shields the front room from sunlight, thus keeping it cooler. Sometimes, houses instead have large wraparound porches. These overhangs protect rooms from the sunlight and allow windows to remain open, and thus let air circulate, even when it’s raining.

A cousin of the shotgun is the dogtrot house, typical of the South from the 19th to the early 20th centuries. The open-air hall that runs through its center—called a dogtrot—defines the structure, which is generally two distinct cabins joined by one roof.

The dogtrot allows fresh air to circulate through rooms in a way that is similar to a shotgun house. The large overhanging porch functions exactly the same as on the shotgun house: To provide shelter from the sun as well as a means of keeping the windows open (and furniture dry) even when it rains.

Even more innovative, the 1891-built house the Barnacle in Florida cleverly put a cupola on its roof to act as a ventilator. As hot air rose, it could escape through the cupola. Fresh, cooler air could then enter through one of the many double-height windows and doors that opened directly onto the generous wraparound porches.

Another popular device in the 19th and early 20th centuries was the sleeping porch. "Sleeping porches are often found on houses by bodies of water," says Hogg. "The air was so pleasant in the evenings by the water that people would want to sleep in a protected space outside."

As the name suggests, the structure of a sleeping porch is very much like a balcony—think of it like a three-season sunroom, in a sense. A very good example is at the Gamble House, an Arts & Crafts mansion in Pasadena by Greene and Greene, finished in 1910.

Unfortunately, city dwellers didn’t fare so well when it came to cooling down. “In cities, from tenements to upper-scale brownstones, nothing was really done about heat,” says Salvatore Basile, author of COOL: How Air Conditioning Changed Everything.

“A lot of people would head for the roofs of their buildings, where they would probably sit all night and try to get a little sleep.”

Meanwhile, in the upper classes, it was fashionable to completely ignore the heat. “The idea was that you were immune to temperatures,” says Basile. “You simply did not acknowledge that it was hot.”

One way that buildings—from apartment buildings to townhouses and clubhouses—tried to remain cool was through the use of awnings. Similar to porches, awnings allowed for a room to be shaded from sunlight, thus keeping the interior cooler. The awning also protected the interior and allowed for windows to remain open, and thus air to flow, even in the rain.

Early 20th century awning advertisements describe the benefits of awnings in a similar way to that of air conditioners: “Awnings always reduce the temperatures as well as reduce the glare,” says one 1909 advertisement. “The scorching rays of the sun will make you hurry and bustle when real summer weather strikes the town. Better have your awnings made and put up, then when you really need them they’re ready,” says another.

Another way apartment buildings helped the flow of air was through the use of “transom windows” above door frames. Made of glass, they could be opened to allow air to circulate between interior rooms of an apartment. Many are intact today, although their glass inserts are commonly found painted shut, since modern air conditioning has rendered them obsolete.

Relief started to come in the form of mechanical devices in 1902, when a device called the NEVO, or cold air stove, hit the market. The name of the device is “oven” spelled backwards.

"It was like a gigantic ice cream freezer connected to a fan—you would put in 200 pounds of ice a day and it would blow out cold air," says Basile. "Alexander Graham Bell made a big deal out of it a few years after by air-conditioning his basement and spending his summer there."

These devices, while effective, were messy and cumbersome (200 pounds of ice melted into 200 pounds of water, after all) and required tremendous amounts of expensive ice to be useful. Then, in 1929, Frigidaire created what they called a "room cooler," an ancestor of the in-room air conditioner.

"It weighed 200 pounds, and it had to be connected to a separate compressor somewhere else in the house," says Basile. "That compressor weighed 400 pounds."

This sprawling air conditioner boasted the ability to "cool several feet above the floor," and its price? A shocking $11,000 in today’s money. The device, unsurprisingly, lost money.

Thankfully, technology improved, and by the 1930s rolling air conditioners went into production. While they weren't cheap, they were more attainable than Frigidaire’s model. Eventually, more and more people started buying them, and the age of the modern air conditioner had finally arrived.

This summer, while switching on your window units, adjusting the controls of your central air, or even stepping into a frigid subway car, remember that as little as just under a century ago, people had to rely mostly on architectural tricks to find relief from the heat. And, in the event that you find yourself with a busted air conditioner in these dog days? Throw your windows open—you might discover a cross draft you never knew you had.