Keeping cool (and warm) again

The whole replacement HVAC thing happened pretty fast, with it dying again Tuesday night and replaced by late Friday afternoon. Fortunately, I had litigated the pros and cons of various options when it died last year, so I kinda knew what to look for and what I was likely to want.

I knew we probably wanted to go up a half-ton in capacity, and our vendor confirmed that was the right thing given our square footage. Neighbors who have upgraded concurred, so we went from 3 to 3.5 tons. You don't want to go too big, because if it's running in short bursts, it's not good for the equipment, and does a poorer job at reducing humidity. The other option was to consider single or two stage, or variable speed. These operate how the names imply. Single stage works at one speed, two works at two speeds, and variable everywhere in between. Each is more expensive than the previous. Sort of. If we're only gonna be in this house another five to eight years, there's no universe where we ever make up the cost in energy savings. So despite my hippy energy efficiency fetish, variable speed was not gonna happen. Two was a little more expensive, but because it qualifies for a $2,000 tax credit, it was actually the least expensive option. Basically, when it only needs to cool or heat a degree or two, it runs at about 60% normal speed, which is more efficient. It's a lot quieter, too. So that's where we landed.

The physical differences in the equipment are interesting. The heat pump is taller and wider, with way more coil surface area than the old one. The air handler coil has three faces instead of two, and is taller. All of that makes sense given the difference in capacity, but I expected the size difference to be more subtle. The installer did a great job routing the pipes, in a cleaner way compared to what was there.

The one bummer was that my now very old Nest thermostat couldn't control two-stage heat and AC, you had to choose one or the other. Meh, whatever, I just bought the newer one. After being in for this much ($8,600), it is what it is. I wanted to stick with Nest so I could still control both from the same place, and their ability to use a remote sensor is necessary. Our upstairs thermostat is in the hallway near the two-story open area around our living room, so all of the downstairs heat lands there, and so it's not the same temperature as the bedrooms. I don't know why they didn't put the thermostat in the primary bedroom. We use the remote sensor in our room, which is as much as two or three degrees cooler in summer. The same phenomenon happens downstairs in my office, but I only use the sensor when I'm working, other wise the rest of the downstairs is too cold.