Jim & Geri's Home Page

Our HVAC system consists of a small air conditioner and a gas furnace. A single zone covers the whole house. There are 12 supply registers and four return registers.


The graph above shows temperatures at three locations. The outside and office temperatures are taken at 30 minute intervals by a Davis Vantage Vue weather station. The bedroom  temperature is logged by a Raspberry Pi on the hour and half-hour plus anytime there is a change of at least one degree. These graphs are updated shortly after each hour.


This graph shows the temperature at the supply register in the computer room which happens to be the register closest to the furnace. The temperature at the supply registers rises rapidly when the heater fan starts to run. Timing starts when the temperature rises more than five degrees and stops when the temperature falls more then one degree. Register temperatures are captured once a minute with an Adafruit MCP9808 Breakout Board connected to a Raspberry Pi via the I2C bus.