Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Old Home-Bad Duct Design

GSE Member Posts: 9
<strong>More like no duct design...  Hi Guys-Quick back ground of what I'm dealing with:

Purchased an older home with a new addition almost 2 years ago.  The original home is early 1900s while the addition is 5 years old.  During the addition, a new high efficiency furnace was installed and the installers modified the existing duct "work".  Here are my issues:

1-Return in Kitchen

2-Returns in completely packed closets

1-Return in laundry/slop sink room

1-6"x12" Return in dining room

1-6"x12" Return in master bedroom

1-4"x24" Return in new addition (which is a closeable diffuser type)

1- 6"x 12" Return in new addition upstairs

Some how the 4"x24" (96 sq in) RA is supposed to provide enough air to the 5-4"x15" (300 sq in) diffusers in the surrounding area.  The other supplies in the home have ducting that are exposed to the attic air (I live in WI BTW) or are placed away from windows and cool spots.  A majority of those RAs use the outside wall stud spaces as the duct work, which aren't even close to being sealed and they have both high and low voltage wiring running parallel and perpendicular in them.  Even more mind boggling is the lower portion of the new addition has no RA/SA ducts to it so in summer we have mildew growing on our furniture (yes i started dehumidifying down there).

4/6 RAs are out of code in more than 1 way.  They are not modifiable because of the old wall make ups without major renovation involving a ton of lead containing debris.  Nor is there enough of them to supply the SAs with air without taking air in of the wall cavities.

5/12 SAs are in terrible spots or exposed to unconditioned space.

Even my thermostat is in the south room with the most windows.

I'm angry that "heating professionals" such as these still function and get good reviews even through all of their stupidity.  Luckily I am a solar installer/designer and have a decent handle on hydronics/new ducting.

My end all question is:  Should I just abandon the heating system, sell the furnace, install low temp hydronics, and go with whole home controlled ventilation?  I'd much rather.  Piping is much easier to balance and install in a home such as this.

PS no flack for not seeing this before purchasing the home.  Every home in this local/price range either has this kind of poor duct design/remodeling or had a 1920 steam boiler with 4000 lbs of asbestos wrapped pipes.




  • icesailor
    icesailor Member Posts: 7,265
    Returning Air:


    Consider yourself with all those returns that don't work. Where I work, I've seen a multitude of new $1,000,000 + homes with a supply in every room and a great big square return over the furnace with a 16" or larger return stuck in the back. I've seen I've seen 8" flex duct run in cathedral ceilings with 2" X 10" rafters and run up and over to the other side of the room (yes, they cut through the ridge beam) and the AC air in winter would be perfect in the Summer only the summer air would be perfect for the winter. Because they never cut the bottom of the doors off, the doors get sucked shut when the AC or heat is on.  I've had bathrooms on second floors freeze up with the heat running because the air handler in the attic and ducts were so cold that cold air was blowing out of the registers in the ceiling.

    Air handlers are a wonderful thing.
  • GSE
    GSE Member Posts: 9
    No air to return

    Well yea didn't you know furnaces create their own air?  Better yet, they actually convert the nat gas/propane into breathable air and put it in your ducts!

    That's terrible though, what did you tell those customers?  I've actually seen things like that myself in the solar world.  A lot of the fly by night air heating contractors wouldn't actually install a return duct-they would literally fasten a duct boot from the suction side of the fan to the top plate of a wall in the attic!  Those calls are typically for burned out fans and I get the tell the customer why :(

    You still don't make me feel any better about my situation though lol
  • GSE
    GSE Member Posts: 9

    35 views and no takers???
  • lchmb
    lchmb Member Posts: 2,997

    the option is there for a hydronic system that would be my option in a heart beat.
  • GSE
    GSE Member Posts: 9
    Is it right?

    I certainly agree with that.  But am I abandoning hope too soon on this air system?  Am I doing something overkill by just going to hydronics and full home ventilation?
  • don_9
    don_9 Member Posts: 395

    Well at least his intention were good with a return in every room.To be fair often time back in the old day many of Joice spaces were used for return path.not the best way to do it but some home old and new do not allow a for a proper distribution system.

    I would do away with what you have and go with wet heat.not bc i think wetheat is better then force air,it bc your home will not lend itself to a low pressure distribution system.

    Sound like a home where ductless ac would be a better match.After all if you have the funds to separate the heat from the ac even better for comfort all year long.
  • GSE
    GSE Member Posts: 9

    Thank you for the info Don
  • BillW
    BillW Member Posts: 198
    Sorry it took so long...

    Bad ductwork is a question that is unfortunately, all too common.  You find it everywhere, and it's sad to see that there is so little understanding of how important this is.  It is very difficult, messy and expensive to remedy.  Find a reputable pro in your area, and have it evaluated.  Maybe a zoning system will help, or maybe you can convert to panel radiators and a hi-efficiency boiler for heat, but you still will need the ductwork for A/C, unless you want to use several "splits"; splits being ductless AC units that are often used in second homes.  They consist of a condensing unit outside, a 2" hole in the wall for the electric supply and refrigerant lines, and an indoor coil with a fan for cooling.  Some can be heat pumps, and offer supplemental heating as well.  They are easy to install.
This discussion has been closed.