Please Help! Returns & Ducting Problems - HVAC - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 07-30-2012, 10:57 AM   #1
Join Date: Jul 2012
Posts: 2
Rewards Points: 10

Please Help! Returns & Ducting Problems

Hello Folks!

Hoping for a little help here

We have a 1600sf single level home, part flat roof and part very high ceilings w/ very small attic space.

Our AC is a Trane XR12, our heating system is a Trane XL80.

We have 2 returns in the house: the one located closest to the heating unit is a 10in return from here 8in ducting is used and leads to a 8in return located in the hallway.

1. The first problem we have are that the noise level is crazy when we run

2. The second problem is that we get a musty smell when the unit is

We had a HVAC guy come out and he suggested changing both the returns and the connective duct to 16in. He said this should take care of the noise and of course the new ducting won't allow the attic air to be pulled into the new system. Funny thing is that when we go into the attic it doesn't smell like the musty air that the unit puts out.

Another HVAC guy we know says to go with 14in returns.

3. Third problem : I also asked him if he could change the size of the metal
box on the first return because the mouth is a odd size (8 X 22) and we
can't find Filtrete filters to fit it but he said that that is a major job and
he'd had to tear up the wall to that that.

We know nothing about HVAC at all so any guidance would be much appreciated!! Hope I provided enough info and sorry if I provided too much!


DIYMOM2012 is offline   Reply With Quote
Old 07-30-2012, 12:46 PM   #2
I'm Your Huckleberry
Join Date: Mar 2011
Posts: 5,884
Rewards Points: 2,270

I charge $350.00-$400.00 to add/change a return filter grill. Not that big of a deal in any way. You shouldn't even need any sheetrock repair.

All it is is removing the existing filter grill, unframing it and re-framing to the size of the new one. Cut a bit of sheetrock so the base of the grill fits into the new framing, screw grill into framing and done. There's about a one inch lip all the way around the grill that covers the cut sheetrock so again, no need for any repairs. Hopefully the grill has a duct board backing but it's nothing at all to add a piece to the back, cut a hole in the backing for the new and bigger collar (for the new and bigger 14" or 16" return duct), seal it all with mastik and done deal.

25 x 20 is a common return grill size.

Entire job may take two, possibly three hours including new duct run.

Yes, your return air ducts (and grills) might be too small if the noise is too loud to bare. If those filters are sucking up into the grill really hard it's another tell tale sign of needing to increase return ducts.

Think of it like sucking as hard as you can through a tiny coffee straw. Your system is not receiving enough air to satisfy proper heat extraction with too small return ducts. Have that taken care of and not only will the noise be reduced but you'll notice a difference in comfort.


Doc Holliday is offline   Reply With Quote
Old 07-30-2012, 02:20 PM   #3
Join Date: Jul 2011
Posts: 615
Rewards Points: 500

Since you dfidn't tell us what size a/c you have or what part of the country you are living in,we can't suggest what size duct you need.
All I can say is what you have now is way way too small and that too big is a very rare installation.Its much better to be too big especially if you have flex duct.
Quality homes have a return in every room except the kitchen and bathrooms.This gives you the quality comfort in each room.
What you have if sized right will give your equipment the right amount of air flow but you will notice a bit of discomfort in every room.
Ther low bidder for the equipment in your house did not do your house any favors.All they did was save themselves some labor .
REP is offline   Reply With Quote
Old 07-30-2012, 05:04 PM   #4
Join Date: Jul 2012
Location: MD
Posts: 272
Rewards Points: 250

14"= up to 2.5 tons
16"= close to 4 tons

does not mater where you live.
turnermech is offline   Reply With Quote
Old 07-30-2012, 11:52 PM   #5
Join Date: Jul 2012
Posts: 2
Rewards Points: 10

My AC is 4 tons.

Thank you all for your input so far.
DIYMOM2012 is offline   Reply With Quote
Old 07-31-2012, 06:25 AM   #6
HVAC Contractor
Join Date: Jun 2012
Location: Augusta, GA
Posts: 412
Rewards Points: 336

If your measurements are accurate, your returns are waaaaay too small. As others have suggested, 16" would be much preferred over 14". With returns, bigger is always better.

I too agree that changing a filter grill is generally no big issue, but if the return is metal duct to the return box, and the return grill fits that duct exactly (which is the way it sounds) then changing the filter grill size can be a bit of a challenge. Might be easier and cheaper to just buy filters from the local HVAC supply house - they would be able to source 8 X 22 filters (which is an odd size) for you, I'd assume.


scottmcd9999 is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Basement air coming up through vents and returns glsmith HVAC 7 09-05-2016 12:07 AM
Cooling delivery problems in my home need help? DaveFL HVAC 2 07-20-2012 08:22 AM
rerouting HVAC ducting for an upflow furnace joregon3597 HVAC 2 05-03-2012 07:08 PM
Are you having ice problems? Grumpy Roofing/Siding 27 02-17-2008 03:51 PM
Water in Furnace Ducting sdoca HVAC 3 09-14-2007 06:54 AM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1