On Monday, January 21, 2013 12:35:37 PM UTC-5, 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

I'm pretty sure the supply ran in the basement and was probably added after the two halves were assembled. With the furnace on it got warm and if it was insulated I'm not sure the basement would freeze here in Pa, just seemed like wasted money. The owner was a older women who for 5 years had no problems but only now in her sixth season complained of cold, almost seemed like she was complaining of air currents. All the windows were "closed" but some were not latched properly. She had had several heat contractors out to try and solve her problem. One installed a new larger central duct(uninsulated) in the basement but that did not seem to solve her problems, that did not make sense to me as the house worked fine in its original configuration. I'm pretty sure that the house acts as the return to the furnace. The homeowner said she cleaned the filter regularly. I guess its time for another heating contractor.

I will advise the home owner, thank you for your help!