Control an HVAC register with a servo to improve room comfort throughout the day
Like most US homes, our 1000sqft house is heated and cooled by forced air in a single zone. There is one thermostat which turns the system on or off, and all areas are fed hot or cold air at the same time.
Ideally, with the airflow to all rooms balanced, every room would reach the temperature set on the thermostat, but this can’t work at all times of the day. In summer, the sun’s varying angle in the sky means that the east side of the house is heated more in the morning, the south walls receive most at midday, then the west walls in the late afternoon. This heat concentration means rooms facing the sun at a given time of the day will be hottest.
To counteract this effect, zones can be incorporated into the ductwork. These are areas that can receive different airflow to provide greater heating/cooling. So a south facing room could get more cool air in the middle of the day, and less in the morning and evening. In a new installation, zones are created using sections of ductwork with electrically operated dampers, and a thermostat/timer to manage the additional zones.
For my project, I wanted to create a basic, low cost zoning system for warm months. It would keep most of the cool air in the main living areas during the day, and then direct more of it into my west-facing bedroom to provide extra cooling in the evening. As well as balancing the extra heat load of that room, this would bring the bedroom to a cooler sleeping temperature without having to cool the rest of the house quite as much.”


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