Closing off duct work

cnoheltyJune 30, 2012

We have a system that is about 350 sq. ft too small for our house. We have lots of 98 degree days or more and it just doesnt keep up. We have gotten a few estimates but it is a 10000 or more change. One guy suggested we close off the duct work that supplies our finished room over the garage because the duct work is too big for it anyway an we have to use a window unit to cool it anyway, but he didn't say how to do it. Anyone k ow what that entails ?

Thank you for reporting this comment. Undo
energy_rater_la

what size duct serves the room over the garage?
what is the capacity of the hvac system?
can the ducts in use handle the additional
air flow or are they undersized for more air flow?

there is more to it than just disconneting
a duct.

the guy that suggested this..he is hvac guy?

best of luck.

    Bookmark   June 30, 2012 at 6:55PM
Thank you for reporting this comment. Undo
mike_home

You could do it by simply blocking the registers in the room. If the duct feeding the room as a damper control you could close it to block the air.

Have you looked into adding more insulation to your attic? The increase in insulation would lower the heat load and allow the AC to keep up.

    Bookmark   June 30, 2012 at 7:14PM
Thank you for reporting this comment. Undo
energy_rater_la

if the damper is at the plenum you would be
putting the addtional air back into the plenum
to be distributed through other ducts.
which may not be sized to handle additional air.

just shutting the register doesn't put the
air back into the plenum. it does little
to distribute the air throughout the house.

there is a reason that there are manuals for
both duct design and sizing.

adding insulation on the attic floor does nothing
to the heat gain through the walls.

putting foam/foil sheathing on exterior of walls
shared with attic will stop both air leakage
and heat transfer.

foam sheathing will air seal when installed and caulked
in place. foil facing into the attic will reflect
heat back into the attic and out of the walls of the
room.

rooms over garages are surrounded by hot attic
air. this air gets to 140 degrees in summer.
air sealing the walls works. otherwise you
are just pumping air into a room with extreme
temps.

best of luck.

    Bookmark   July 1, 2012 at 11:30AM
Sign Up to comment
More Discussions
Thoughts on proposed HVAC system?
To start: my house is two-level (main plus upper)...
gbleeker
Bad TXV valves (2 in a row) on brand new unit
Just got a XR15 Trane HVAC unit installed last week....
dhome
Is this HVAC system OK?
Replacing original old ~9 seer unit. House is 2001...
thereloader
Moving floor vent to toekick area
Hello. We are renovating our kitchen as well as baths...
cathy725
Blown in insulation vs spray foam
I am looking for advice. I have a home built in 2000...
mkrafczyk
Sponsored Products
Greenson Quilt
Grandin Road
30" Bates Vanity - Walnut
Signature Hardware
Stylish Shoe-Rack with 3 Folding Double-Depth Doors
TheBathOutlet
Cayman Game Chair
$599.00 | FRONTGATE
The Finer Things II Wall Art
Grandin Road
Wyndham Collection Bathroom Centra 48 in. Vanity in Espresso with Marble Vanity
Home Depot
Thomas & Friends Close-Up Personalized Canvas
$19.99 | zulily
23 Inch Glossy White Bathroom Vanity Set
TheBathOutlet
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™