Closing 2nd Floor Vents? - http://www.hvacmechanic.com/ Forums

Original message

George P

216.127.248.2

"Closing 2nd Floor Vents?" , posted Wed 5 Mar 07:11

My parents live in a 2 story home but have a bedroom on the first floor. They are using the first floor bedroom exclusively since it is getting hard for them to climb the stairs. My question is can I shut all the vents (forced air heat) on the second floor to reduce energy costs or will that cause any damage to the system?

Thanks!

Replies:

amech

69.243.161.150

"Re(1):Closing 2nd Floor Vents?" , posted Wed 5 Mar 09:13

Trapping to much of the heat in the ductwork will possibly cause your furnace to fail on your high limit switch.

Freon

70.157.177.45

"Re(2):Closing 2nd Floor Vents?" , posted Wed 5 Mar 11:33

Without the correct flow of air through the furnace, it will run hotter than designed. That usually leads to failure of the heat exchanger.

You MAY be able to do what you propose BUT you need to take simple measurements to be sure the furnace is running as designed.

On the front of the furnace should be a label with make, model etc. On that label will be listed "Temperature Range" or "Temperaure Rise". This range (30 to 50 degrees, for example) tells you how hot the air leaving the furnace can be.

For example, if the house air entering the furnace is 70 degrees and the Temperature Rise range is 30 to 50 degrees, then the warm air as it exits the furnace should be between 100 and 120 degrees. If, after you start closing ducts you see your air as it leaves the furnace approaching 130 degrees, then you know you have closed off too much air flow.

Your air temperature may still be below the high limit safety but higher than the allowable design range. So you need to make those two temperature measurements to know what's going on as you close off air flow.