According to Dr. Gary Hunt, an engineer at Imperial College in London, and an expert in ventilation, most people don’t know how to adjust the classic sash windows designed by Edwardians and Victorians to maximize airflow. His simple lesson helped us cool down the fierce summers in our hot top floor apartment, and lessened our air conditioner use and costs.
Some days it sparks the feeling that illustrator Monica Ramos* evokes in so many of her artworks, of people relaxing in lush bodies of water, which refresh us just looking at them. THAT’s the feeling we want…

According to Dr. Hunt’s research:
The trick to getting the maximum flow of air through the window is to slide the sashes so the window is open equally at the top and bottom…..
The cool external air flushes the warm air out of the room and also cools the walls, floor and ceiling. The cool walls then absorb heat the following day and prevent the internal temperatures from rising as high.

The gist:
When you open your windows, make sure there’s an equal gap at top and bottom to allow cooler air through the lower opening and push warmer air through the top.

Doing this, we’ve been able to delay putting on the AC by hours, if at all, to revel in fresh air…

You can see more of Monica Ramos’ work at The Canvas Project, at Ignant, and Another Magazine.
Related Posts
Decades ago, while waiting for surgery to mend a broken arm, I spent a week in the old wing of Mass. Gen’l Hospital in Boston. It was a July heatwave out on the street; I was cool as a cucumber with the windows open and the breeze singing through the screens. Not sure what the secret was in that case.
Then, three years ago, when we were planning to build a studio, I asked the architect how ancient cultures (and Mass. Gen’l.) cooled buildings without AC. She said you have high windows and low windows & that circulates the air—same principle as the sash window open at top & bottom. In the studio, we have high windows that are opened in June and closed in September; low windows are adjusted daily-ish as needed. Works beautifully.