On Sun, 5 Jun 2016 08:00:55 -0700 (PDT), wrote:

On Friday, June 26, 2009 at 1:55:43 PM UTC-4, David Nebenzahl wrote:
On 6/26/2009 9:12 AM Christopher Nelson spake thus:

I have a room that never seems to get enough heat or AC. I have a
split level. The furnace is below the family room and the cold/hot
room is above the family room. You'd think that'd be a short-ish run
of duct work but it does bend a couple of times. I'm thinking of
putting a booster fan like http://www.comfortgurus.com/product_...roducts_id/563
in. Do they work? Any comments on the brand or model I should be
aware of? I'd rather walk into my h/w store or home center and go
home with one but I can't find one locally. Is that to be expected or
have I just looked in the wrong places?

Sounds like almost the exact problem one of my clients has: a room far
away from the furnace that doesn't get enough heat.

I was suggesting that they look into installing a booster fan in the
duct to that room, until I ran into a guy who seemed quite knowledgable
about these kinds of heating problems. After a long discussion, I came
to understand that while a booster fan *might* work, there are other
things that need to be considered:

o The duct itself may be part of the problem. The typical corrugated
type of duct can impede airflow; replacing it with duct that is smooth
internally can help, as well as eliminating unnecessary bends.

o The overall configuration of the furnace and ductwork is important.
Any furnace has a limit to how much air it can move, so the question is
whether the ducts, plenums and return vents are properly sized. If
they're not, that can contribute to the problem.

Unfortunately, in my case this puts this problem outside of my area of
expertise; my clients need to talk to a competent HVAC person to get
better answers. You might want to as well.


--
Found--the gene that causes belief in genetic determinism

I too am considering a booster fan for the the ductwork to an addition to the house. I don't think I would want to use it all the time and will install a switch to turn it off. Will a deactivated fan impede airflow?
yes