I have a 1978 Shult (I think) 14x60. It has a Miller oil/hot air furnace with the main duct running down the middle front to back. This is awkward, since the registers intrude into traffic areas, especially the kitchen/dining area. It makes furniture placement difficult, plus, it's full of "who knows what" after 30 years of service. If I remember right, it looks like it's made of insulation board run between floor joists, rather than metal ductwork.
![Shocked :shock:](./images/smilies/icon_eek.gif)
I would like to know if it's possible to clean this main duct, replace it, and/or move it to the outside wall with registers under the windows? It's my understanding this location provides more efficient heating. I also have a 30x14 attached addition harboring several rooms with flexible insulated ducts, which run off the main duct. Any help or guidance would be appreciated!
![Smile :)](./images/smilies/icon_smile.gif)
PS- I tried the shop vac with long hoses and found it to be pretty much useless.