Do you close the registers in rooms that do not need cool air during the summer?
It may sound intuitive – if a room doesn’t need cool air, why waste the energy dollars trying to keep that room cool? However, it’s not that straightforward. Heating and cooling equipment is complicated. Sometimes what you think is a good idea, may not be.
It is not a good idea to control the temperatures of your rooms by closing registers. Why is that? Well, your HVAC system is designed to heat and cool a certain amount of space. When you start messing with the registers, it affects that amount of space. Closing registers has the same affect that a dirty filter has; it raises the pressure in your system.
If you have a variable-speed motor, this can cause it to operate at a higher capacity for longer periods of time – essentially negating any of the efficiency benefits gained by investing in variable-speed equipment. If you have a single-speed motor, it may not be able to maintain proper airflow. Low airflow = low comfort levels.
And, those are just the problems that occur at the surface. The increased pressure also has additional consequences for other parts of your HVAC system. It could increase duct leakage – lowering comfort and raising utility bills. Or, even worse, you could wind up with a frozen coil or a broken compressor – two CRUCIAL cooling components.
All is not lost though. There are intuitive heating and air conditioning systems that do allow you to control comfort from room to room. It’s called a zoning system. Make sure you ask your HVAC contractor about your zoning options.