Replacing some old duct work.


  #1  
Old 10-26-16, 08:50 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Replacing some old duct work.

Hello,

We recently got a new Bryant natural gas furnace and they replaced most of the duct work in the basement, however, they tied into the old stuff where it started going upstairs. I want to replace some of that stuff but I'm not sure what parts to get.

Some of the bedrooms upstairs aren't getting warm enough. The baby's bedroom gets really warm and everything's fine there, however, the master bedroom which is right next door, hardly any air coming out and I think I know why. I'm uploading some pictures to show you:

Name:  Master Bedroom 1.jpg
Views: 1380
Size:  16.3 KB

Name:  Master Bedroom 2.jpg
Views: 1271
Size:  19.7 KB

In these first two pictures, you can see there's some 90 degree bends. I'm thinking I can redo the duct work in such away where I can remove one of those elbows and I think that will help. If I can run it under that gas line, I shouldn't need one of the elbows I don't think.


Name:  Master Bedroom 3.jpg
Views: 1256
Size:  13.6 KB

Name:  Master Bedroom 4.jpg
Views: 1187
Size:  14.2 KB

These two pictures here I think are the biggest problems. The air is being forced downwards into that squarish box thing. I think that's where the main issue is and I want to remove that all together. I can pull that square piece off...it's not very long at all.

Name:  Master Bedroom 5.jpg
Views: 1029
Size:  17.7 KB

Name:  Master Bedroom 6.jpg
Views: 1126
Size:  23.4 KB

Name:  Master Bedroom 7.jpg
Views: 1156
Size:  15.3 KB

These last three pictures try and show how those 6" round duct works connect to what's in the wall. I tried my best to measure that rectangle piece that goes up through the floor and into the drywall. It measures around 3.25" x 10". It's old. I cannot tell if it was normally an oval piece and the original owners just made the square piece fit or what. If I could find a way to replace that piece in the drywall, things would be great, however, I don't think I can do that very easy like. So I was thinking of just leaving that piece in the floor but removing what's attached to it. You know, trying to find some 3.25" x 10" rectangle to 6" round duct work transition piece or something.

Do any of you experts have any suggestions on how I should proceed and what parts I might want to purchase to do this? I prefer buying stuff locally from Home Depot and Lowes if I can. Any thoughts?
 
  #2  
Old 10-27-16, 06:50 AM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,956
Received 721 Upvotes on 640 Posts
I'm not an expert. But perhaps these comment might help. When you say some of the up stairs rooms aren't getting warm I assume you mean a second story. Typically a second story level will not get very warm (or cool if A/C is used) by the very nature that it's far from the source and the air cools by the time it gets to the desired room. The exception is if the second floor room is in a direct vertical straight line above the furnace. Removing those bend and elbows will not help very much. Insulating any bear ducts will help. Replacing duct work in the walls is a major under taking and expensive, not to mention tearing apart wall. However, there might be a system that can be slipped into the existing ducts that will cut down the size but will be insulated.

Another option is to use a fan at the register of the cool rooms to help boost warm air flow. Some of these are thermostatically controlled and will kick in when the furnace go on. Or just use a manual fan at the register when the room is in use.

Another thing to check is the damper position on all the duct work in the basement. The contractors should've balanced them at time of installation to give a best results for all rooms. But that could change as the seasons change and you may need to adjust periodically.

One more thing. Is the furnace properly sized for the size and number of rooms in the home?
 
  #3  
Old 10-27-16, 12:24 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Norm201,

Thank you for the response. Where to start...okay, it is a 2 story house with a full basement (unfinished) and an attic. The upstairs bathroom wasn't getting much air at all out of the register. That was the damper though. The lever to turn it was missing so I can see how the installation people might have missed that one. I want to remove the dampers all together.

The furnace is the proper size. They did a j-manual. They also installed a cold air return upstairs. The baby's room's ductwork is ran almost perpendicular to the master bedroom.

If you look at the third picture there, I think that's the main reason the baby's room gets a lot of air coming out but the master bedroom doesn't get much. The guest bedroom is nice and toasty as well. It's just that master bedroom there. To me, in that third picture, the air is being forced downward and just hitting that square ductwork there. I think that drastically affects the flow. That square piece is nice and hot when the furnace is running, but if I reach my hand upward to where it connects to the piece that goes into the wall, it's not very warm at all.

I don't want to replace the ductwork in the wall. I just want to replace those weird adapter type things that connect the round ductwork to the square. The third pic one, I can easily remove that piece from the ductwork. I'm sure there's got to be some better option than that piece to transition from round to square. I wanted to try and find something like this:
https://www.lowes.com/pd/IMPERIAL-6-...t-Boot/3308806

It's just that I'm having trouble finding the right size there. From my measurements, it needs to be around 10" x 3.25". The third pic shows the transition piece, but where it connects to the piece that goes into the wall, I don't think the wall pieces were square. I'm thinking they were almost rounded and the previous owners somehow made it fit, if you know what I mean.

What do you think?

Thanks.
 

Last edited by Spork Schivago; 10-27-16 at 12:27 PM. Reason: added a link
  #4  
Old 10-27-16, 12:40 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,956
Received 721 Upvotes on 640 Posts
A sheet metal shop can virtually make any transition shape you want. Just provide accurate dimensions.

Have you ever taken that square piece off yet? Could there be an obstruction in that junction? I also see what looks like duct tape being used to seal connections. That's a no no. Use metal foil tape if you must.

Truth be told I'm having trouble seeing the pictures clearly. I can't seem to get the proper orientation. Perhaps a few more pics taken from a far so we can see a larger area in connection with the specific problem. If it is being forced downward why would it be piped that way. I really don't understand and I can't quite see it on the pics.
 
  #5  
Old 10-27-16, 02:09 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Norm201,

Thank you for the information about the metal shop. I fix electronics for a living and don't really know a lot about this kind of stuff. If I cannot find the piece I'm looking for at one of the local stores, I will definitely contact one of these metal shops.

I'm sorry for the poor pictures. It's very hard getting a good picture of the area because of how crowded it is down there. We have the direct venting from the furnace, the direct venting from the hot water tank and the gas lines. Because of where the furnace is, I cannot get any more zoomed out with our camera. I'm pretty much up against a wall. I've taken more pictures though that hopefully will help you get an idea of the orientation.

If you look at these pictures and then look a picture three again, you can hopefully see how the air is being forced down into that transition piece, instead of being forced upwards like it is in the other runs. I hope this helps.

Name:  Boot 1.jpg
Views: 1153
Size:  20.7 KB

Name:  Boot 2.jpg
Views: 1046
Size:  18.7 KB

If I could upload a video, I'd be able to show things much clearer.
 
  #6  
Old 10-27-16, 04:11 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
Spork, first, it would not be a good idea to remove the dampers as that is the only way to balance the system. It's only a thin piece of sheet metal and when fully open creates very little if any resistance but critical to system balance. Next, that duct in the wall is called wall stack and is a common piece of sheet metal and is made to fit between 2 x 4 studs in the wall. They make transitions from wall stack to round. Standard is 3 1/4" deep x whatever width you want.(8,10,12 etc.). Next, the elbows due make a difference, especially the way yours are installed. Every elbow is equivalent to 5ft. of straight pipe. If it's possible to go under the gas line and at least have the airflow going up. Those elbows have joints on them that are adjustable for different angles. It looks as if you could maybe remove one. You can also get flex duct but beware the resistance is a little different between the flex and the hard pipe but it may save you from using all those elbows.
Depending how the bottom of that wall stack is put together, sometimes it will be with a removable cap, you could put a 31/4 x 10 90 on there and then put a 31/4 x 10 to 6 straight adaptor or if you could find an angle. It looks like Home Depot sells what you need if Lowes doesn't.
I hope this helps a little.
 

Last edited by spott; 10-27-16 at 04:40 PM.
  #7  
Old 10-27-16, 05:22 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes on 30 Posts
I pretty much agree with what spott wrote, especially about NOT removing any balancing dampers. I think I would try to fit a 3-1/4 x 20 45 degree elbow in to bring the stack out straight and then make the transition to the round duct.

OR, try to run rectangular duct all the way back to the plenum. That 3-1/4 x 10 inch duct has a cross section area of about 32 square inches while the six inch round duct feeding it has only about 28 square inches cross sectional area. That means you are going from a smaller duct to a larger duct and when you do that the velocity of the air drops. You really need a larger supply duct from the plenum to the stack for best results, a 7 inch diameter round duct would make a significant difference.
 
  #8  
Old 10-27-16, 06:29 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Spott,

Thanks for the information, especially about the dampers. I'll keep them in place. I disconnected the 6" round ductwork from the square piece. I removed the square piece, and then I removed the "elbow" that was up in there to get a better look.

The stuff in the wall has an I.D. of 12" x 4". It's an oval piece of wall stack, but it doesn't look like it's made out of the same type of material, maybe it's just rusty.

The oval elbow I removed, that's in bad shape. I measured the angle and it's around 130 degrees. It's very odd and I cannot find one anywhere I look. At this point, I want to replace that 130 degree oval elbow with a new one and find a 12" oval to 6" round transition. Then that blasted square box will be completely out of the picture. All it is is a square box with a cap on one end, the other end open, and a whole someone cut in the middle of it. I don't think it's supposed to be there.
 
  #9  
Old 10-27-16, 06:32 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Furd,

I had mistakenly measured the beat up elbow the best I could before removing it. The measurements aren't right, either that or it's some sort of elbow / reducer. The wall stack definitely measures 12" x 4". I am definitely okay with running a bigger supply duct to the plenum. Not sure how to cut the bigger whole, but if I can find away now to tie back into the wall stack, proper like, I think the hard work will be done. That weird elbow I took out, it's really banged up. Not sure what it looked like brand new. Like the other odd ball pieces down there, it's got this cardboard like stuff attached to it. The Corning Appliance guys thought it was some early form of insulation. The house was built in 1940. We acquired it around a month ago.
 
  #10  
Old 10-27-16, 06:40 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Here's some pictures of the elbow. I think the whole in it might be why I felt so much hot air blowing out up there when I had my hand up in that area.

Name:  Elbow 1.jpg
Views: 1065
Size:  26.2 KB

Name:  Elbow 2.jpg
Views: 1116
Size:  27.2 KB

Name:  Elbow 3.jpg
Views: 1109
Size:  21.5 KB

Name:  Elbow 4.jpg
Views: 1115
Size:  21.1 KB

Name:  Elbow 5.jpg
Views: 1087
Size:  25.0 KB

There's another run downstairs that has the same type of elbow I believe. Have you guys ever seen one like that? Any idea what I'd search for or where I could find one? Home Depot and Lowes does not have anything like that. Lowes had some oval pieces, but only 6" (although with my tape measure, they measured closer to 8"). I wonder if I'm not supposed to measure to the curve, but just the straight piece for the size. I don't want to put that old piece back in if I could help it. I'd really like to purchase a new version of one of those.
 
  #11  
Old 10-27-16, 07:05 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
I might have used the angle finder incorrectly. This might be a 45 degree angled piece. What do you guys think?
 
  #12  
Old 10-27-16, 08:08 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
Spork, that is an oval 45. What is it you are trying to do now that you have it out. I'm not sure what a 6 in. oval measures across but I will look tomorrow and get back to you. It sounds funny but it goes by cfm's and a 6in. oval measures different than a 6in. round but carries the same amt. of air. You might want to see if you have a sheet metal store or a heating supply house where you are. They make everything you're looking for but the box stores carry a limited amount of stock because basically these are areas the DIYers don't get into so it's not worth it to stock everything.
If you google SHEET METAL DUCT FITTINGS you will see what is actually available without being custom made
Can you take more pics of the wall stack now you that you have that piece removed.
 
  #13  
Old 10-27-16, 09:15 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
I will take more pictures of the wall stack but it will be hard to see because it's up in the ceiling in the basement. I want that really old beatup 45 degree elbow replaced. I want to tie the new elbow into the furnace the most efficient way possible. I don't want that dang square box with the whole cut into it. I want to some how go from the oval elbow to either 6" round duct or replace the 6" with a 7" and just cut a bigger whole in the plenum somehow for the 7" piece to fit.

Then, I think we'll get a lot of hot air in the master bedroom, like we get in the other rooms on the 2nd floor. I think Corning Appliance should have fixed this, personally. The 6" round ductwork was just blowing downward into that box. All we were getting up in the master was radiant heat, more or less. With all the other vents in the other rooms, you could actually feel the air blowing out.

Lowes said something about a company called HEP which isn't too far from here. I haven't heard of them before but they're in Elmira and I contacted them via e-mail asking about the part. On their site, they said if they didn't stock a part, they could order the part. I think that's good news. The wall stack physically measures 12" x 4" but I don't think it's a 12" wall stack. I think the physical dimensions are different than the nominal dimensions and when someone says 12", they might be talking nominal, not physical. So maybe these are something like 8" or 10" wall stacks and not 12"?
 
  #14  
Old 10-27-16, 09:32 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Here's the pics, I'm sorry it's so dark. We haven't found the big flashlight yet. It's still packed away in a box. This was probably the worst time to purchase a house! Everything was good until the baby was born and now we get very little sleep and very little work done! But I guess the joys of being a parent are worth it.

I'll try to post brighter pictures tomorrow.

Name:  Wallstack 1.jpg
Views: 1071
Size:  18.1 KB

Name:  Wallstack 2.jpg
Views: 1063
Size:  9.7 KB

Name:  Wallstack 3.jpg
Views: 1049
Size:  15.1 KB

Name:  Old square thing.jpg
Views: 1005
Size:  16.3 KB

It's hard to tell from the pictures there, but that piece in the cellar's ceiling, the oval wall stack that measures 12" x 4", that goes straight up. Someone notched out the load bearing beam though at a 45 degree angle and was using that 45 degree oval elbow. In the fourth picture there, that's the square thing they were using to adapt the elbow to the duct work.

I just want the square gone, I want a brand new elbow that doesn't have holes in it and then I want a way to go from oval to round. I think if I can find the right size 45 degree oval elbows, finding the transition piece won't be that hard. The same site would probably have it. So far, I cannot find any oval elbows over something like 8" (maybe it was 7".) 6" seems to be the most popular size.
 
  #15  
Old 10-28-16, 05:27 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
Spork, I found this site so you can at least see what's out there and it gives you measurements of the oval and wall stack. Maybe you can see what you want. I'll check back.
I'm getting confused looking at your pics.

Ductwork | Ductwork Supplies | Sheet Metal Ductwork
 
  #16  
Old 10-28-16, 07:13 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
I just need a 45 degree oval vertical elbow that physically measures around 12" x 4" and then a transition piece that has an oval on one end that measures around 12" x 4" and a 6" round end on the other. I want to hook the oval elbow up to the wall stack and then hook the transition piece into the elbow, then hook the 6" duct into the transition piece.

If you go here: Browsing OVAL

Can you explain the measurements? I see the 7" oval. It shows above it that it measures 9 1/8". Then, under it, it shows 3-1/4" x 12". What's that 3-1/4" x 12"?

I took the old elbow into a place that specializes in heating. When I called, they said if they didn't have what I needed, they could order it. But when I took it in, they said they couldn't get anything that big and said my only bet would be a metal shop. Then I called another place, HEP in Elmira. They said the biggest size they go up to is 10". He told me though that their pieces measure whatever they call them. For example, a 10" actually measures 10" across.

I called a metal shop and left a message. I'm waiting on an answer.
 
  #17  
Old 10-28-16, 07:34 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Here's a picture of me looking at it straight on. I'm standing back, the cameras pointed right at it, just high up, by the floor joists. There's a load bearing beam where they notched into it so they 45 degree elbow would fit. Above that notch is the wall stack.

Name:  DSC01816.jpg
Views: 1054
Size:  23.9 KB



Here's a picture of me standing under it, pointing the camera straight up.
You can see the load bearing beam that they notched into at the bottom. You can see the first floor 1x4 subfloor in the top of the picture. You can see the floor joists and where they're starting to separate from that load bearing beam in the left of the image and a very little of a floor joist to the right. In the center of the picture, you can see a little bit of drywall and you can see the oval wall stack, that physically measures around 12" long by 4" wide.

Name:  DSC01817.jpg
Views: 1067
Size:  23.0 KB

Is that any better for you? If you're still having trouble, I'll create a video and upload it to a private server for you to view.
 
  #18  
Old 10-28-16, 09:06 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
In the bottom pic it looks like I can see oval pipe inside the rectangle, if I'm looking at it right. It looks like it was mickey moussed it. I think I see what you're up against.
If you can reach up in that hole and feel that piece of pipe see if you can feel ridges on it. If you can the have the pipe going the wrong way. On ductwork there is a male and female side. The male side goes into the female and always in the direction of the airflow to cut down on resistance. To get a piece on that pipe now you will not be able to slide it in unless you can crimp it real good. You're going to have to try to fit the next piece over that fitting if I'm looking at it right and continue from there. If you can get something on that piece and into the bay the rest won't be bad.
Can you trim that sheetrock and expose more of the duct?
 
  #19  
Old 10-29-16, 03:16 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes on 30 Posts
Sorry to be late in getting back to you. That oval "duct" looks more like flue pipe, for products of combustion, than it looks like air duct. It appears to me to be some old crap that was pressed into service rather than getting the proper materials.

If the duct is really 4 x 12 (I'm not doubting your word) then it means the house construction is likely prior to 1950, maybe as old as the 1930s. I say this because it has been a long, long time since 2x4s really were four inches wide. At any rate that duct would then have a cross-sectional area of 48 square inches or approximately 35% larger than the six-inch round duct feeding it. No wonder you didn't get much heat from it. If you want to use round duct you will need to go to eight-inch diameter which has an area of about 50 square inches, just a bit over the rectangular duct. The alternative might be to keep it all rectangular with both 45 and 90 degree elbows and then rectangular 4 x 12 duct back to the plenum. Anything else will be a compromise.

Also, I am in agreement with spott, it IS a Mickey Mouse installation...or worse.
 
  #20  
Old 10-29-16, 07:34 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Spott,

Just so we're clear, there's only the oval ductwork in the wall there. They just cut a "square" out of the load bearing beam, because the wall stack just happened to end up on one. Cutting the drywall probably isn't something I can easily do. It's very hard to get up in there. It's hard to tell from the picture, but the load bearing beamed is notched, for the elbow to sit on, at about a 45 degree angle, and then the pipe is above the load bearing beam. So I gotta reach back there on the notched beam and then curve my arm upwards.

There's no rigids on the oval wall stack there, but there are rigids on the broken elbow where it attached to the wall stack. So that wall stack piece is a female piece. Because it's female, I won't have to worry about an crimping if I could find the correct elbow, right? I'd only have trouble if that wall stack end was male, right? Or am I going to have to find away to cut the drywall regardless? It's going to be real hard to cut the drywall the way it is.
 
  #21  
Old 10-29-16, 07:42 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Furd,

You're both right about it being a mickey mouse installation. Someone just jerry rigged some parts to tie the "newer" furnace into the older ductwork.

The house was built in 1940. Back then, we believe they had a gravity fed coal furnace. Then, about 40 years ago, a natural gas forced air furnace was installed. Then a few weeks back, a high energy efficient furnace we had installed. The people who looked at the old furnace said it was probably from the 70's. They said it didn't have any fail safes in it and if the electric went out, the furnace had to be turned off or the gas would still come out or something. We just said heck with it and paid for a new one.

The 4" I'm not 100% sure on, because it's flexible. I really don't want to remove this ductwork and add something else. It's going to cost a lot of money to tear down the drywall and do it "proper" using the 6" wall stacks. There's another run, in the guest bedroom, that's exactly the same. There's a run the baby's bedroom but it runs upside the chimney and that's square, but probably not the right piece either.

When I tore out the subfloor in the baby's room and put down the plywood, there where 1x4's for the subfloor. Under that, 2x8's that measured 2x8, not 1 1/2 x 7 1/2 or whatever a 2x8 measures now. I just thought they were rough cut.

What do you mean about the alternative? Keep it all rectangular? Can I somehow mix that oval wall stack with a rectangular piece? If I did the 4 x 12 at the plenum, I'd have to cap off the 6" whole somehow and cut out some 4x12, which I wouldn't mind doing. I just can't find any elbows large enough for the wall stack. I contacted a guy but he didn't pick up. I left a message. He makes custom ductwork.

Too bad there wasn't away to sneak some 6" piece up through the 12" x 4", you know? Just feed it right up there (or down there) and just have the 12" x 4" act as a sleeve and the 6" carry the heat...
 
  #22  
Old 10-29-16, 08:35 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
I was just thinking a bit more. It's a bit hard because we have the newborn and I don't have long time stretches to work on this, just little bits of time. Anyway, the wall stack in the basement starts (or ends) at the load bearing beam, right? Then it runs up through the wall in the den on the first floor, and then up the wall in the baby's room wall / master bedroom closet. The closet I think was added afterwards. There's this really big odd shaped really beat up roundish piece in the closet that goes to a really cool looking wall register. We definitely want to keep the register. But the closet, that's still got lathe and plaster. My wife wouldn't care so much if I ripped that lathe and plaster out.

If I ripped that lathe and plaster out, could I pull that wall stack out and just slip a 6" one down in there? Do you guys think the 12" x 4" is in sections? Does the new ones come in sections? I have 8 foot of lathe and plaster. So if I did that, I could remove that 12", even if I had to cut it every 6 foot or so, and then just slide down new proper wall stacks in sections. Would that work and if so, what would I want for the new wall stack and how much money are we looking at for the proper parts?

Thanks.
 

Last edited by Spork Schivago; 10-29-16 at 08:56 PM.
  #23  
Old 10-29-16, 08:49 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
What those measurements refer to as it states is the comparison of the two pieces. Another words the equivalent of a 7" oval pipe is a 31/4 x 12 piece of rectangular wall stack. The 7" oval delivers the same CFM's as the 31/4 x 12.
Your pipe could be 4 x 12 because back then a 2 x 4 was a 2 x 4 and not 11/2 x 31/2 and all ductwork was most likely custom made. I doubt if pieces were mass produced for sale to the public. Your liable to run into all sorts of things that seem strange to us but that's how they did things back then. I lived in a house with old ductwork that was soldered before they began crimping fittings together. You can have what they call a transition piece made if you have to attach to the 4 x 12 to whatever size to need to get back to the trunk line. Also, the piece in the wall not being crimped is a good thing. The piece you get will have the crimped end going inside the existing piece.
When I mentioned the sheetrock I was just wondering about trimming the piece off that seemed to be hanging down below the beam it front of the sheet metal to give you more access. Maybe it was just the pic that looked different than what it was.
Don't give up. It's not as bad as it seems. It's just hard sometimes trying to explain if you've never worked with it before, especially long distance.
 
  #24  
Old 10-29-16, 09:03 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
Wall stack or any sheet metal is generally fastened to the studs along the way to keep everything in place. You will never get a 6" round pipe into the wall cavity because the space is only 4" deep. That's why they make oval or wall stack. They come in different lengths. In my area I can get oval up to 108". Wall stack generally comes in increments of 2 ft. That is 2, 6, 8 etc. Don't know what is available in your area and I wouldn't begin to guess the cost knowing nothing of the area.
 
  #25  
Old 10-29-16, 09:09 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks Spott,

Yeah, it is hard because I don't really know all the terms, I'm slowly learning, but that's a problem, and on top of that, with the chimney and venting for the furnace and hot water tank in the way, it's really hard to get a good pic. You can't really tell easily from the picture that the whole is a good ways back.

Is getting a custom made piece still a good idea with it being 12" x 4" oval? If a 7" oval delivers the same FM's as the 12" x 3 1/4" square piece, just think how much a 12" oval would deliver....I think that's what Furd was saying. And even if I get a custom piece and a transition piece to go from the 12" oval elbow to maybe an 8" round ductwork piece, wouldn't that affect the amount of air that goes to the other rooms? Wouldn't it be best to keep the round ductwork at 6" and just try to pull that 12" oval one out and replace it with a smaller wall stack? Something that I could more easily hook to a 6" round ductwork?
 
  #26  
Old 10-29-16, 09:23 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
First off you have to attach to what is there unless you remove it for something new. Next bigger isn't always better when figuring ductwork size There are other factors such as furnace size, plenum size, trunk size, blower size. They all have a capacity to the amount of air they can carry. If that is oval in the wall it can't be 4 x 12. What does that oval piece you pulled out measure. I looks like the same stuff in the wall. I'm confused where the wall stack comes into play.
 
  #27  
Old 10-30-16, 12:13 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes on 30 Posts
Just a few observations and then I am bowing out of this discussion.

The original questions were concerning rooms on the upper floor having uneven heating. Upon further discussion it is discovered that a new furnace was installed but mostly using the old ductwork. It was not mentioned if the problem of uneven heating was existent prior to the new furnace, or if it was, I missed it.

The original poster correctly determined that the problem had to do with the duct design and installation. Further discussion pointed out that various parts of the installation were likely made with used materials and in a less-than-stellar method.

So far the fix has been centered on repairing/reworking some of the more obvious duct defects but I am wondering if it is not time to start from the beginning. That beginning would be to ascertain, via a heat loss calculation, the true needs of the room(s) that are deficient of heat and then calculate if the installed ductwork in the walls is adequate to heat the room(s) IF the supply ducts in the basement were properly sized and connected. Obviously changing the ductwork already in the walls is a HUGE undertaking but if it is inadequate for the job then it must be done or else other means of adding heat to this room will need to be explored.

IF the existing wall duct is proven to be adequate then different methods to get the heat from the furnace plenum to the base of the duct need to be explored. If the duct is NOT adequate then something else needs to be discussed.
 
  #28  
Old 10-30-16, 01:00 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Spott,

Here's some pictures of what I've been calling the wall stack, with a tape measure there so you can see that it's 12" x roughly 4".

Name:  DSC01819.jpg
Views: 1113
Size:  31.8 KB

Name:  DSC01820.jpg
Views: 977
Size:  36.3 KB

Here's a hand drawn picture of what I've been calling the wall stack, with measurements.

Name:  measurements and shape.jpg
Views: 1037
Size:  6.4 KB

I've been calling it a wall stack because I thought you said the ductwork in the walls was called a wall stack. I've been calling it oval because when I go to Home Depot or Lowes, pieces that have the rounded corners like that are listed as oval.

I have a 6" round ductwork coming off the plenum that is currently unhooked. Before, it was attached to this 12" x 4" "oval wall stack". That 12" x 4" runs straight up from the basement, up through the den (in between the drywall) and up into the baby's room. At the baby's room, there's a 90 degree elbow of one sort or another that runs it into the closet. I can't see the elbow because there's lathe and plaster.

Here's a picture of where it comes out of the closet. Some how they went from oval to round, no idea how. I can remove the lathe and plaster and see....

Name:  DSC01822.jpg
Views: 1034
Size:  18.6 KB


Here's a picture on the other end of the closet, where it's connecting to the register....
Name:  DSC01823.jpg
Views: 1028
Size:  24.6 KB

And here's a picture of the actual register...
Name:  DSC01824.jpg
Views: 978
Size:  23.2 KB

I didn't want to upgrade any sizes. I'm just under the impression that 12" x 4" piece that runs from the basement to the master bedroom is just way to big. I thought I could rip that lathe and plaster out (we're going to anyway, because we want drywall in there). And once it's ripped out, slowly pull that 12" x 4" out, if it's not attached to anything. Once it's out, slowly slip in a smaller piece, either square or oval. Then, down in the basement, instead of having to connect the 6" round ductwork that comes from the plenum to the 12" x 4", I could just connect the 6" round ductwork that's already coming from the plenum to the new "wall stack" that I put in.

Would that not work at all? Even if I have a custom made 45 degree elbow that measures roughly 12" x 4", and I have a custom made transition piece that allows me to go from that custom made 12" x 4" 45 degree elbow to 6" round ductwork, I was under the impression that the 12" x 4" is just too big and not enough air will come out.

I can try measuring the elbow I removed, but it's the wrong size. The previous owners used padding on the sized to block the air flow that was leaking out. My guess is it was about 2" too small.

We already teared some of the lathe and plaster out in the closet when we were running cat 6, rg6u, and cat 3 to the babies room. It wouldn't be very hard to tear the rest out.
 
  #29  
Old 10-30-16, 01:04 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Furd,

We never tried the old furnace. We hadn't lived here long enough and just wanted it replaced before winter came, however, the previous owners had double pane windows installed and insulated the rooms, so I'd imagine they had issues with heat as well upstairs.

I've tried doing the heat loss calculation but no matter how much I read, I just can't figure out what the heck they're asking, it's kinda greek to me. I can provide information on the furnace, the size, the make, the model, etc, if that'd help at all. I think at this point, tying into that old ductwork in the wall is just a bad idea. I think it needs to be replaced. But I agree, I don't want to just throw any random sized piece in there. I want to figure out exactly what size I need and go from there. If I could get the old 12" x 4" out, I don't think putting a new smaller piece in would be a problem. It's a straight shot from the basement there up to the closet.
 
  #30  
Old 10-30-16, 01:34 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
This is the furnace we have:
Bryant® Preferred 96% AFUE 80,000 Btuh 4-Way Multipoise Condensing Gas Furnace, 2 Stage, Variable Speed

It's an 80,000 btu 96% efficient furnace. The make and model is Bryant 926TA48080V17A-B. I can't figure out how to tell what size blower it has, but I remember the guy saying it was a two stage, if that makes sense. This is what the paperwork says on it:

AFUE: 96.2%
Output Heating Capacity: 78 MBTUH

The following data is for reference only and is not certified by AHRI:
Input: 80 MBTUH
Ef: 79.7 MMBTU/yr
Eae: 472 kWh/yr
PE: 37 Watts
Furnace Type: Non-Weatherized
Config: Upflow, Downflow, Horizontal
Fuel Type: Natural Gas, Propane Gas

Advanced Main Air Circulating Fan
"e" Electrically Efficient Furnace


It's equipped with an Electronically Commutated Motor (ECM). It's direct vent.


The plenum has six 6" round ducts supply lines coming off of it and then a square supply duct that has 4 more 6" round ducts coming off of it.

The room itself measures 11' 6" x 13' 3" x 8' tall. There's two double paned windows. One measures 3' 7" x 5'. He other measures 2' 3" x 5'. The closet measures 6' 4" x 2' 2" x 8' tall. The ceiling has that yellow fiberglass insulation. The floor is hardwood with 1x4 (pine?) subfloor. There was no insulation under the baby's room subfloor so I don't think there's insulation under the master bedroom's floor, however, all the walls are insulated. Even the closet has pink fiberglass insulation. The studs and floor joists are 16" on center.

Would that be enough information to figure out if the current ductwork is too big for this? I can't see going from 6" round to that 12" x 4" being right. I want to do this right, even if it means a lot of work. It's our house now and I don't want to cut any corners, even if it's going to cost some money.

If it was the right size, I was thinking of trying to use something like this between the drywall:

https://www.lowes.com/pd/IMPERIAL-6-...-Pipe/50385544

If that'd work, I mean....

I can do drywall, I'm not that good at it, but I have a friend who used to do it for a living for a year or two. He'd help if I absolutely asked him too, he's just real busy.


I know I've asked a lot of questions and I want to say that I really appreciate all the help all of you have provided. It's frustrating but it's nice to know there's people willing to help me, complete strangers, for free. Thank you guys. I can provide any information you guys need, if you want more information or need to know something else...
 

Last edited by Spork Schivago; 10-30-16 at 02:17 PM.
  #31  
Old 10-30-16, 03:28 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
First off the terminology. WALLSTACK is rectangular and OVAL is OVAL. Different animals but both made to fit in wall a cavity between studs. You have OVAL in the wall. You measured 12" across. you need a piece that will fit inside of that. If you go to your "Browsing Oval" sight you will see an 8" OVAL fitting measures 10 1/2" across and looks like the closest you are going to come with off the self stock. Depending on the room you have to screw it or tape it, run strapping under it to keep it attached.
On that sight on the OVAL page if you click fittings and you'll see options. Click on ELBOWS. this will bring you to 90'S and 45's. Then you will see an option that says OVAL to ROUND and you will see your options available. An OVAL 90 might not be your best bet when trying to attach to the piece in the wall because it might bring you to close to the ceiling when you go from OVAL to ROUND. You might want to get 2 45's which would give you more room for the round pipe. On that same sight you will see the OVAL to ROUND options.
What I'm thinking is if you can get the first piece in the wall and then everything is off the self stock that you can do yourself.
Stock: 2) 8" 45's, 1) 8" oval to round adaptor, 1) 8" to 6" reducer, then whatever 6" pipe you need to get back to the plenum.
I know the reducer was never mentioned before but it is a common piece that the box stores should carry.
All fastened with zip or self tapping screws and aluminum tape if you want.
Just a suggestion unless I'm missing something. By the way, FYI, that white cardboard on the old pipe in the closet is ASBESTOES covering. If not disturbed not a problem but you can put tin foil around it if you want to encapsulate it if you feel more comfortable.
 
  #32  
Old 10-30-16, 04:06 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Spott,

I feel like we're making progress now. For some reason, earlier on, I thought someone said the stuff in the walls was called wall stack and that's why I had been referring to it as a wall stack. I cannot get a 90 degree elbow on that 12" oval in the wall, it just cannot happen. To do that, I'd have to chop a lot of load bearing beam out of the way. I need the 45 degree one.

I can get a custom oval elbow made that will attach to the 12" oval in the wall, and I can get a custom made piece that will connect the 12" oval elbow to the 6" round ductwork that goes to the plenum, but is that the way to go? Will we get the air flow we need or is that 12" oval in the wall just too big?

Thank you so much for pointing out that was asbestos. I want to remove that as well, but for now, I'd just like to get air coming back into the bedroom.

You've been a great deal of help. You and Furd have taught me a lot. The first place I called, HEP in Elmira, they said the biggest oval elbow they had was 10". If an 8" oval measures 10 1/2" across, would a 10" oval measure around 12" across?
 
  #33  
Old 10-31-16, 12:13 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
Spork,
I do not know what a 10" oval measures. You can ask the guy you contacted. If you get the 10" what's you plan after that. It's going to be too big for anything unless you want a laundry shoot. You are beginning to over think this thing. We're not curing cancer, you just want heat to that room.
What it boils down to is you either tie into what you have or you rip out what's in the wall and go all new 6" or 7" if you want. Connecting to what you have is done all the time and works fine for the most part. More important than that oval in the wall is how the rest of your duct is set up. I'm not a big fan of running supply's right off the plenum. Unless you have just a few close runs you should use a trunk line but that's another story. How much air you get depends on how the ductwork is setup as a whole. There is no way to tell if it will work until it's in and balanced since we are not there. On paper it should work is all I can tell you. Your other rooms are fed with the 6" and are tied into most likely the same stuff in the wall that you have in your room. If they are heating fine then go with it.
Get the 8" oval 45's and the 8 x 6 reducer and tie into the 6" you have. At the most you can go with 7". Don't worry about so much what's in the wall as long as you can connect to it.
Do you have any other rooms that are the roughly the same size that are being fed with 6". How are they heating. That should help you decide.
 
  #34  
Old 10-31-16, 01:07 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Spott,

Thanks again for the advice. I don't want to overthink it. Only the master bedroom has the 12" x 4" oval. The bathroom upstairs just has a 6" round ductwork. The previous owners ran it up through the kitchen and built a box around it. The baby's bedroom has a square 12" x 3 1/2" square ductwork that runs up along side the no-longer used chimney. The guest bedroom has the oval, but it measures 10" x something.

All of them seem to get adequate heating. For the guest bedroom, the vent also heats the hallway. If we close off the hallway, the guest bedroom gets nice and warm. The upstairs bathroom wasn't getting much heat but then we realized that plate in the ductwork down in the basement was closed. Once we opened that, it started heating up.

We'll go try and buy a 45 degree oval at HEP. If they don't have the right size, we'll contact the company that makes custom ductwork again. If tying into that 12x4 doesn't provide enough heat, then I guess I'll take the drywall down and put a smaller piece in. Thanks for the help.
 
  #35  
Old 10-31-16, 01:45 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
You will be fine. The 8" oval will slip in and reduce from there. If you want to reduce to 7" round if you have room on your plenum that will be OK. You should install a damper just in case.
Let me know how you make out.
 
  #36  
Old 11-01-16, 11:34 AM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Spott,

How did you want me to tie the 8" oval into the 12" oval that I have? Just that custom made elbow, right? Or was you thinking of me replacing the stuff in the wall with a smaller piece? I thought I understood what we were doing. I was having a customer 12" x 4" 45 degree elbow made and then a transition piece to go from the elbow to the 6" duct that was ran to the previous home made contraption. Where does the 8" come into play?
 
  #37  
Old 11-01-16, 02:20 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
That's fine if you can get those parts. You may need 2 45's to level off your pipe to connect into the 6". Remember the 45 will leave you pointing downward which is fine if that's what you want.
Sorry for the confusion.
 
  #38  
Old 11-01-16, 05:21 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks Spott, We're going to another machine shop tomorrow. If they can't do it, we're just going to run new smaller ductwork through the walls. This is taking too much time.

It wouldn't be hard at all to just run a new smaller size piece. The first machine shop we took it too was a waste, the guy couldn't make anything that big he said. Thanks for the help.
 
  #39  
Old 11-01-16, 06:42 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,768
Received 141 Upvotes on 133 Posts
Whatever your comfortable with but before you rip everything out you don't think it might be worth it to get just an 8" oval 45 and see how it fits. It's real short money and if that guy you called has it he may let you return it if you don't like the fit and it would save you a ton of work and it will work fine but if your comfortable with it do what you think. I'll check back to see how you're doing in case of questions.
Bear in mind though that if you run new ductwork you'll most likely need some sheet metal tools such as tin snips, crimpers etc. Just something to think about.
 
  #40  
Old 11-02-16, 01:19 PM
S
Member
Thread Starter
Join Date: May 2016
Location: United States
Posts: 145
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks Spott,

I took the piece to a new machine shop today, a local one. At first the guy said he couldn't make it, then he went and talked to someone and said one of his guys might be able to make it but it'd cost lots of money. He couldn't give us a quote today but said he'd quote us tomorrow. He said the piece looks like it was made by hand a long time ago. He said the reason it failed was because it was crimped and it should have been one piece. He said it could take more than half a day to make it. He had a really big shop with really fancy equipment that looked like it costed over 100,000$ for certain ones.

Tomorrow, we'll get a quote from him. If it's too much, we'll try the 8" but I know we tried a 6" and it was just way to small. We'll give an 8" a shot though. I know I took a 10" 45 degree square elbow I found and that was way to small. I thought if I could just bend the ends down a bit, maybe it'd equal the 2" I needed, but that didn't work at all.

If it comes down to running new ductwork, what would you suggest? We'd still want to hook into the 6" round ductwork that's already ran from the plenum...would you just run 6" oval and then find a 6" oval to 6" round transition piece or something?
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: