Air condtioner/duct work question

Question

I need help figuring out how my duct work is laid out under my house. I live in a 1999 manufactured home. All of the vents on one side of my home have quit blowing, so I figured that there is a main duct that supplies all of the vents on one side of the house loose or un-attatched. The problem is under this house all of the duct work is up in the insulation and then covered with a thick plastic material. If there is any way to know WHERE I should pull the insulation down from before I start, it would save a lot of time and money! All of the vents on the other side of the house work great. The furnace is Intertherm brand.

Please help if you can!

Thank you.

Answer 1

Find the air handler in the house and get an approx measurement.



Underneath the duct should split to go to both sides fairly close to the bottom of the air handler.

Before starting to cut into the insulation and plastic listen for air blowing and feel for cold air movement.

Answer 2

Did you try something like a stud finder or maybe a prod?

Answer 3

If there is a fire damper installed at the point where the duct was connected from one side of the house to the other, this is where I would start my search. It should be obvious where they connected the supply duct. This is insulated, and the return is not.

Answer 4

Some homes use a jumper duct, visable from below that attaches the two sides.

Others have a tee in the trunkline that connects the two above the membrane and insulation.

There would be a repair in the membrane where the home installers would have made the connection.

I have seen many that were not done properly.

Answer 5

Take a long drill bit or small oak dowel rod 3' or longer. Take off a floor register cover and sharpen end of dowel rod. Drive it down through the bottom of the metal ductwork and into the insulation and also through the cardboard type lining. You can put pc. of duct tape over the hole in ductwork when finished. This will tell you where under the home to cut into liner.

If no ducts work i would start right under where furnace is and work your way away from the furnace.

I lived in a mobile home once and did this to let hot air under trailer to keeps pipes from freezing between floor and liner panel, it worked great