When I reset my Sense near the start of Aug, I decided to try an interesting experiement from two perspectives. My thermostats allow the option of running the furnace fan for a minimum amount of time each hour so I set both units to run for a minimum of 5 minutes each hour. I wanted to to see two things:
- Did this help with energy consumption (mostly AC this time of year) ?
- Does Sense learn to separate the furnace fans from the AC compressor, or will Sense detect the blended AC/furnace fan combination as a single device ?
So far, here’s what I have learned.
- I do use less energy when the furnace fan is turned on regularly every hour, even with the same thermostat settings. Our situation may be somewhat unique, but we typically have cool nights (60s) and warm (75-80) days during summer, but the upstairs heats up late in the day due to stucco and roof heating from the sun (even with heavy insulation). We can open some windows / doors during the day when the outside temp is below the set point (74), but it’s painful to open windows in some of the rooms due to blinds/furniture, etc. The fans do a fair amount of mixing throughout the house, plus between the cooler downstairs and warmer upstairs, postponing the onset of AC.
- Sense has learned both furnace fans and has learned the upstairs AC so far. It meticulously detects the standalone fan every time, plus picks a few stray AC activations as “Furnace Fan”. But most of the time it detects the AC compresser plus furnace fan together.