Like Frankenstein’s Monster, Just Zap It With Electricity

Electricians are arrived at the house at about 8:00AM. Told me it’d be about four hours to install the 240-volt from the circuit breaker panel to the outdoor heat-pump. They were done a touch past 10:00AM.

I turned the Nest thermostat, which drives the oil burner, down to 58F and ran around setting the head-units to 66F. There was, of course, some smells because of them being new units. This caused a good deal of stress with various members of the house, which always has a cascade effect to take out everyone else. But, with the head-units running to get the “off-gassing” done with ASAP, all the windows were opened, and the air cleaners turned on. You can see that at the lowest point on the orange chart above. As the smell dissipated, the windows were closed and the air cleaners eventually throttled back to Auto. With all of that in mind, you can see that the electrical usage, now that we’ve baselined it a bit, is no different than before the mini-splits and heat-pump were powered up! LOVE IT! As an added bonus, because the oil heated baseboard heaters are not being used, I think the air is cleaner, which means less need for air cleaners! WINNING!!!!

Now, this is New England. While the heat-pump is rated down to 5F, I asked the installer what he thought was about the sweet spot for switching over to oil heat. 26F. Under that point and the heat-pump starts cycling into defrost mode, which negatively impacts the efficiency of the system. Seeing as we are in New England, it can get below 26F during the day, let alone at night while we are sleeping. There is no easy way to manage this switch-over to oil from the heat-pump. If only there was a way to have this switch-over point monitored and automated…

Well, there is. This would be something entirely easy for Home Assistant. I already have the outside temperature from the Accurite weather station. This isn’t Providence’s temperature, or Douglas, MA’s temperature, but rather the temperature in my actual backyard. If it goes below 27F, turn up the Nest thermostat to 66F. I could set that up right now. It would be simple, in fact. Once backyard temp goes 27 or above, turn the Nest thermostat down to 58F again. But, that would kind of leave the head-units to keep running while the furnace came up to temp. If only there were a way to tell the head-units to stop calling for heat…

Well, there are a few ways to do that. Unfortunately, they all involve WiFi. Even Mitsubishi’s own implementation involves installing a damn expensive WiFi module in each head-unit. After spending some time chasing this down the rabbit hole, I did eventually find the ESP8266 solution, which seamlessly blends into the Home Automation type stuff that I have been playing with for the last couple of months. Unfortunately, I’ve been asked to stop adding WiFi devices to the house. THAT is the challenge.