The Washington Post
The downside of heat pumps
The July 23 Economy & Business article “An overlooked tool as Europe boils” touted the effectiveness of heat pumps and asked why they aren’t used more.
Well, here is why: because of their flawed design. Heat pumps use a liquid coolant to lower the temperature of outdoor air that is then recirculated into the house or building. This system works great between about 35 to 85 degrees, but, unfortunately, in my experience, it does not work well beyond these points. This is because the air gets harder to cool the hotter it already is. This causes the liquid coolant to take more time to burn off the heat, slowing down its ability to cool the house. And this is not just some theoretical limitation; the other day, when it was nearing 100 degrees, my house’s thermostat was going up, not down like it should have been.
So, if you consider buying a house where the temperature regularly exceeds these limits, I would make sure you aren’t getting a heat pump.
Ethan Stearns, Bethesda