Like many houses built in the 1960s, Nathan Efrusy’s 2,000-square-foot colonial in Detroit has baseboard heat but no central air. A single wall-mounted air conditioner keeps the first floor of the house comfortable, but Efrusy would like to extend AC to the second floor — the question is now to do that effectively.
In a Q&A post, Efrusy says he’s been given several options for cooling on the second floor, but he’s leaning towards a ductless minisplit.
“The main challenge is the layout,” he writes. “It’s essentially a 16-foot hallway with four bedrooms off of it. Originally, we were quoted for a four-zone system, with a head in each bedroom. However, after further reading, it seems that design would be overkill… especially after getting a cooling load calculation of roughly 10,000 Btu/h for the entire upstairs!”
Efrusy assumes he would be running the minisplit continuously in order to keep the second floor dehumidified and between 72°F and 76°F. Bedroom doors could be left open during the day.
“So the question is, how well would a single 9,000 Btu/h minisplit be able to cover the upstairs of our house?” he asks. “My hope is that we wouldn’t need additional fans to push the air into bedrooms. Would there be enough cooling through convection and the internal walls to combat the heat entering through the external walls and windows? Each bedroom has two small double-paned windows, and we get enough shade to prevent much direct sunlight, except for early morning and late evening.”
Those questions are the basis of this Q&A Spotlight.
Flexibility will be key
Whether a minisplit of that size will be adequate depends in part on how flexible Efrusy’s family proves to be, says GBA senior editor Martin…