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Hello All,
Are most MH heating duct trunks made of rigid fiberglass board? I believe that is how mine are constructed, unless they are sheet metal lined with rigid fiberglass. I'm thinking of attempting to reseal the duct boots to the main trunk but I'm unsure what products use. Will mastic adhere to the fiberglass lining? I'm sure there is no tape that will work adequately. BTW, those fiberglasas ducts are also very difficult to clean without damaging the fiberglass. Luckily I have no water or structural damage to the duct interior and they appear to be serviceable after nearly 30 years.
Thanks for any ideas/experience on this matter.
-Steve in Maine

The one's that I have seen are metal (OK thick tin foil). I have seen metal wrapped with fiberglass, But I don't recall seeing an actual duct made out of fiberglass.

Greg

Greg wrote:The one's that I have seen are metal (OK thick tin foil). I have seen metal wrapped with fiberglass, But I don't recall seeing an actual duct made out of fiberglass.

Greg

Hi Greg,
The ducts in my home have the insulation on the inside, but I'm unsure of the outer material...I don't really want to tear into the belly just to find out, but I also see wood at the ends of the trunkline. I guess there are as many types of ducts as there are mobile home brands, anything goes!
The internal fiberglass probably helps with thermal retention and cuts down on noise, but is awfully hard to clean. Thanks for your input.
Steve

Some are metal some are fiberglass. Guess you found out. Mastic would work fine to reseal the boots just use the high velocity kind or the hvac grade whatever they label it as now. As far as duct cleaning I wouldn't unless you had like a animal or spilled food or toys etc down in there. The EPA even recommends that you do not clean your duct work. If you are seeing mold and or really bad dirty ducts its should just be replaced. Most particles settle and almost form like a blanket to the duct and won't be disturbed unless you start trying to clean it. You can really do more harm than good. My 2 cents on duct cleaning.

Good advice, thank you.
I was thinking along the same lines about not disturbing the fiberglass duct interior too much...last thing I want is to breathe in airborne fiberglass, I'll just remove the larger detritus beneath the room registers. Not sure how much heat loss there is around boots, but some mastic sealant can't hurt, esp. with Kerosene prices nowadays.
Steve

They have small filters that slip under the register. I have never used them so I can't say if they work or not or how much they would cut the air flow.

Greg

My neighbor uses those slip in filters. As long as there not too fine they don't affect the air flow that much.