On Mon, 21 Jan 2013 09:35:37 -0800, Paul Drahn
wrote:

On 1/21/2013 5:52 AM, andyeverett wrote:
A manufactured home has a compact oil fired forced air furnace in one
corner oc a 40x28 manufactured home. A large central duct runs down
the middle of an unfinished basement and perpendicular ducts run in
the joist spaces. The joist spaces in the basement are insulated with
faced fiberglass. The home is in south eastern PA. Seemed like a lot
of heat was wasted because the central duct was not insulated. The
owner of the home complained of cold and one heating contractor
installed a larger central duct (slows down flow further increasing
heat loss?)

Should the duct work be insulated and if so roughly how many years to
payback?

Thank you for any help!
My triple-wide mfg. home has two ducts going the full length of the
house. One for each of the long sections. floor vents connect each room
to the full length duct. The third house section has a flexible,
insulated duct going under the floor from the exchanger to a single vent
in an office space.

Are you SURE of the arrangement of the heat ducts? The central duct you
see must have been added after the house was built and in place.

The heat system must have an air return path free of obstructions. That
includes leaving room doors open as much as possible. Is the heat duct
metal? Should always be insulated. Hot or cold.

Paul in Central Oregon
Insulated heat ducts in basements are almost unheard of up here in
"the great white north" - but our basements are insulated (and heated)