Did an overhaul of my ductwork last week. House was built in the early 50s. All of the supply registers were located in the center walls of the house, returns on the outer walls. With the thermostat located on a center wall, the furnace would run, immediately satisfy the thermostat and turn off, leaving an overall feeling of cold throughout the house.
Not only was the layout an issue, but the existing trunks and round pipe were way too large and not setup correctly, resulting in no static pressure and little supply to the 2nd floor. The plan was to reduce the trunk sizes and run new 6” round pipe to the outer walls as new supply vents, and use the existing supply registers as the new cold air returns. As the HVAC people will know, this will help the overall feeling throughout the house and result in slightly longer run times for the system. (Instead of on/off on/off every 5 minutes)
While taking it all down, you wouldn’t believe the amount of dust in the return vents. It literally rolled off the panning in sheets as it came down. I’ve only been in the house 3 years but I can imagine there’s never been a ductwork cleaning performed.
Decided to go with floor registers as opposed to the old wall spots, as I prefer the look of them. Used an old sears jigsaw with a handful of reverse cut blades that seemed to do the trick nicely. A little hesitant at first drilling through my hardwoods but after the 3rd one I was making record time.
Overall I’m happy with how it all came out. I’ve spray foamed the existing wall cavities (old returns)and closed them up from the basement. The house definitely feels different now, and I find myself going downstairs just to look at the new shiny duckwork.
I’m working on the drywall and replacing the moulding throughout the house now.
Overall Time: about a week of evenings and 1 full weekend day
Overall price: about $550 (got most parts at or around cost)