Yes, Massachusetts. I have a dual fuel heat pump with natural gas backup installed in 2020, so it’s a newer system. And I have one heat pump mini split in the least energy efficient, but most used room in my house (large, high ceilings, exterior walls on three sides, and a skylight).

The first couple of years I noticed when it got just below freezing, the central heat pump seemed to struggle to keep up. Then this year I replaced my windows and got new wall insulation in both of the main bedrooms and bathrooms (previous insulation was original from the 1960s and shredded to bits with huge gaps.)

After those improvements, I’ve been running my heat pump down to 20⁰F/-7⁰C so far without any issues at all. I’m excited to see how cold we can get and this system still keep up. I am still supplementing my one large room with the mini split, but that’s mostly because all my plants are in here, so I keep this room warmer than 68⁰F/20⁰C.