Installing new return air grill


  #1  
Old 10-21-09, 11:35 AM
A
Member
Thread Starter
Join Date: Jul 2002
Location: Ca
Posts: 748
Received 0 Votes on 0 Posts
Installing new return air grill

Hi,

I have an attic central air system with a ceiling mounted return air grill. I would like to change the return air grill size (due to a conflict with some remodeling) and I need to verify the parts required since I probably have to get these online. The sales guy verified my part list but I don't fully trust him.

The filter area will remain the same as the current filter. My central air system has a 16" flex duct for the return air. I will have to move one 2"x4" brace in the attic a few inches to accomodate the new return air box. Position of air box will only move a few inches (closer to ca unit).

1. Hart & Cooley 673 18" x 24" return air grill.

2. Sherer manufacturing 18"x24" R6 return air box

3. Sherer manufacturing 616-16 Ductboard tab collar 16"


Will these parts all work together and do I need to fabricate any other parts (I have very limited fab capability)?

It's not clear to me how the tab collar attaches to the air box. Do you cut a hole in the air box or do you have to attach sheet metal with a hole to the air box?

Also, I believe mastic is used to seal the tab collar to the box.

The Sherer website has very little info on these products.

http://www.sherermfg.com/Return-Air%20Boxes.pdf

http://www.sherermfg.com/Tab%20Collar-one.pdf


Thanks for any info.
 
  #2  
Old 11-02-09, 05:23 AM
GRIMKNOTME's Avatar
Member
Join Date: Nov 2009
Location: N.C. USA
Posts: 120
Received 0 Votes on 0 Posts
**First of all DO NOT GO DOWN IN SIZE if possible go up to the next size unless the box you have now is insulated .**

These parts will work (BUT i see no need for a scoop thats used in supply not return) Your flex should still reach , if it has a 90 degree elbow reuse it.
That looks like a ductboard collar which will work with that box since it should have 2 inch insulation in it , but 1 inch will get you by.

You will have to do this below you are correct , lay the straight collar in the center use a black permanent marker mark the outside of the tabbed side , then lay it aside , then lay a flathead screw drive at a 45 angle (holding box between legs unless installed ) strike with a hammer at flathead end to get a hole started hold screwdriver straight up strike at bottom get you a long slice in it then go to work with the snipes cutting out side edge of black mark , cut out insulation with knife , stick collar ,(may have to trim a lil more to get a good fit ) push collar tru bend tabs back on insulation and mastic around top of collar , let dry , you have it pull the liner of the flex duct tape it and zip tie it , then pull insulation and outer liner over it , all the way to box , zip tie it , seal with mastic at all joints

Its not clear to me how the tab collar attaches to the air box. Do you cut a hole in the air box or do you have to attach sheet metal with a hole to the air box?


And I would get a gallon of mastic to seal lt and use the rest to go over any other joints . It will wash off your hand but not your clothes

Hope this helps.
 
  #3  
Old 11-02-09, 08:07 AM
A
Member
Thread Starter
Join Date: Jul 2002
Location: Ca
Posts: 748
Received 0 Votes on 0 Posts
Thanks a lot Grim,

Parts arrive today so your post is just in time.

The vendor only sold the mastic in large tubs so I did not order any.

Can the correct mastic be found at the home centers?
I know it's sometimes used for tile installs but don't know if it's the same thing.
 
  #4  
Old 11-02-09, 02:53 PM
GRIMKNOTME's Avatar
Member
Join Date: Nov 2009
Location: N.C. USA
Posts: 120
Received 0 Votes on 0 Posts
Originally Posted by AlexH View Post
Thanks a lot Grim,

Parts arrive today so your post is just in time.

The vendor only sold the mastic in large tubs so I did not order any.

Can the correct mastic be found at the home centers?
I know it's sometimes used for tile installs but don't know if it's the same thing.
Maybe at lowes or home depot if not try noland supply they normally sell to public I dont think tile grout is same as sealing mastic really .
 
  #5  
Old 12-02-09, 12:41 PM
A
Member
Thread Starter
Join Date: Jul 2002
Location: Ca
Posts: 748
Received 0 Votes on 0 Posts
Got everything installed however I noticed that my Hart and Cooley 18"x 24" return air grill makes quite a bit of noise.

When I lower the grill with the filter in place I can barely hear anything but with the the grill in place there's quite a bit of air noise. The filter is a BoAir electrostatic.

I think the previous setup (14"x30") may not have made as noise because the electrostatic filter was more restrictive and reduced airflow. When the unit turned on, the filter would get sucked up to the grill frame very forcefully but the current BoAir has to be held in place with some foam.

It's not a big deal but I'm wondering if installers get a lot of complaints on air noise from the return air.

P.S. Homedepot does carry mastic in half quart tubs
 
 

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