On Wednesday, January 27, 2016 at 10:52:15 AM UTC-5, Arnie Goetchius wrote:
Arnie Goetchius wrote:
A local Plumbing contractor says the following:

"In the case of a central heating and air conditioning system, closing off vents
has the same effect as a dirty air filter. It simply restricts airflow. Heating
systems are designed to heat the whole home and are sized accordingly. Shutting
off a section of airflow increases the air pressure in the system, in turn
increasing the amount of duct work leakage."

"A more energy efficient way to control individual temperatures in unused rooms
is by using a ductless heating and cooling mini split systems that are mounted
on the wall and wired using a simple wiring process to an outdoor unit. No ducts
are used so installation doesn't take much time at all. Ductless heating and
cooling mini split systems are a flexible solution."

My question: Is closing the ducts to three unused bedrooms and an unused
bathroom a bad idea and it won't save any money on the gas bill?


Thanks for all of your comments. It looks like the next step is to block off the
returns in the unheated rooms. I found a "Magnetic Vent Cover" here that I will try:

http://www.lowes.com/pd_73204-34146-...d=3260659&pl=1

Do you actually have returns in all rooms? I don't, I have one return in the hallway, and the room doors are undercut to allow air return.

If you do, where is your return filter?

At any rate, it doesn't really matter.

The heat loss in that room is less when the room is cold than when it is heated. So the return air you pull back has lost less heat with the supply ducts closed.