I have a gas forced air furnace and an under insulated older home

[likesmountains 52]

Can anyone explain to me if closing off the vents in unused rooms will really force more of the heated air in to the occupied rooms? I just can't figure out how the air gets back down in the duct and find its way to the open vent...can anyone explain it to me? Thanks!

[NMDemDist2]

1. the air is forced to go "somewhere" if you close off it's exits it will

be forced to go to the only opening available and since it's not being bled off in several spots, you get the majority of the heat in the open vent

and to help with the lack of insulation, check out this thread in the frugal group

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=353x418

[likesmountains 52]

3. Thanks, the bubble wrap looks like an easy step. See my reply below/

[Stinky The Clown]

2. Shutting heat outlets in unused rooms is a tried and true way to save $$

In every tip sheet one ever sees about saving on energy costs, that tip is included. AZDD6s post about the 'why' is correct.

[likesmountains 52]

4. I know it is supposed to work, but in my mind I see the air blasting

up through the ducts, finding one blocked and trying to go someplace else to escape, but it "runs into" all the other hot air still being forced up and....well I just imagine all the hot air tumbling around in the ducts work. Maybe it's just me! I did go ahead and close off the empty room vents though. Thanks, Cathy

[Stinky The Clown]

5. Think of it another way .......

Air goes down a closed duct ...... and just stays there. It cools and that's that. The warm air that floows will just not go down that duct, instead following the path of least resistance .... to an open duct.