Room Temperature Imbalance
Are some rooms colder or hotter than the others? This difference temperature is typically an easy of air and heat flow. Since heat migrates upwards, upstairs rooms tend to be hotter and downstairs room colder. Also, rooms furthest from the furnace and air conditioner get the least air flow.
Checking Comfort
For this article I’m going to assume it is the middle of summer and keeping the house cool is the main objective. Start the process by getting to know your cooling system. Start from the heart of the system (i.e. the air conditioner) and note how the ducts carry the air to the rest of the house. The registers distribute air to each room while the return vents feed air back to the air conditioner. Make sure all registers are set wide open and that all returns are free from obstruction. Also, make sure that the air conditioner has been properly maintained and the air filter replaced regularly.
Now carefully note over a couple of days, and at different times, the temperature of each room. While it isn’t a bad idea to take exact temperatures, just noting how comfortable each room is will suffice. I used a floor plan of my house to document the comfort level for each room, as shown below.
My house is an open split level layout so air flows freely between all rooms. The problem is cold air pools in the bottom level and warm air rises to the top. My SimpliSafe freeze monitor, located on the lower level, shows about 6°F temperature difference between the lower level and the upper level, where the thermostat is located.
