What is this thing in the return plenum box?

[David A. Andersen]

What's wrong, missing, not working?

[KEVIN WOOD]

NEW RETURN TRUNK DESIGN EXTENSION
I have never seen this in SSM On.
I think you are missing the return to some area not served on that direct return plenum.
Purhaps an office or addition added.

[Charley L. Bottger]

Not enough info

[David A. Andersen]

Charley, I don't want YOU spilling the beans!!!

OK, Hint...

Supply air pressure 97 pa. (97 pascal = 0.389 419 186 31 inch of water [4 °C])
Turn off 2nd floor thermostat and pressure goes to 179 pa.
179 pascal = 0.718 618 910 81 inch of water [4 °C]

75pa = .3" wg ; residential system design duct pressure (static).

[Brian A. MacNeish]

Originally Posted by dandersen

Charley, I don't want YOU spilling the beans!!!

OK, Hint...

Supply air pressure 97 pa. (97 pascal = 0.389 419 186 31 inch of water [4 °C])
Turn off 2nd floor thermostat and pressure goes to 179 pa.
179 pascal = 0.718 618 910 81 inch of water [4 °C]

75pa = .3" wg ; residential system design duct pressure (static).

Sounds like there is a zoned forced air supply system......which is quite a rare bird in residences.

What are you showing in the first picture other than a couple of
plenum/duct takeoffs? Still not a great picture in the second photo.....I'm thinking a duct damper control arm.....but in the return?

[Charley L. Bottger]

Originally Posted by Brian A. MacNeish

Sounds like there is a zoned forced air supply system......which is quite a rare bird in residences.

Pretty common here in residences over 35K

[Brian A. MacNeish]

Originally Posted by cbottger

Pretty common here in residences over 35K

Do you mean 35,000 ft2 or 3,500ft2?

I can see it being used in cooling climes.....need to get that cooling upstairs. Predominantly heating climate here- 95%+. I used to see it in larger 1950-1960's homes and in the odd other one......but we haven't had much cooling in houses here until the last 5-10 years......HP/AC units being seen more and more.

[Bob Elliott]

Hows the filter?

[David A. Andersen]

House is 2,563 sf.

[Bob Elliott]

Originally Posted by Brian A. MacNeish

Sounds like there is a zoned forced air supply system......which is quite a rare bird in residences.

What are you showing in the first picture other than a couple of
plenum/duct takeoffs? Still not a great picture in the second photo.....I'm thinking a duct damper control arm.....but in the return?

Had zoned HVAC in a 3 story townhouse last week.
Cat 4 with 3 thermostats.
Had a damper controlled vent to the garage to boot.

[Jeffrey R. Pope]

Originally Posted by belliott

Had a damper controlled vent to the garage to boot.

Was it listed as a fire-damper?

I find thermostatically controlled dampers in homes of all shapes and sizes. The dampers, however, usually include control boxes and balancers

[Bob Elliott]

Originally Posted by jpope

Was it listed as a fire-damper?

I find thermostatically controlled dampers in homes of all shapes and sizes. The dampers, however, usually include control boxes and balancers

I had this on the forum last week asking about it if it was OK in the heating section.
[ATTACH][ATTACH][/ATTACH][/ATTACH]

http://www.nachi.org/forum/f20/garage-question-60368/

[Charley L. Bottger]

[quote=Brian A. MacNeish;780005]Do you mean 35,000 ft2 or 3,500ft2?

/quote]

3500Sq Ft My Bad was in a hurry

[David A. Andersen]

Jeff & Bob, you both posted pics of the missing parts...

[Jeffrey R. Pope]

Originally Posted by belliott

I had this on the forum last week asking about it if it was OK in the heating section.

I don't recall that, but the duct to the garage would require a listed smoke-and-fire damper in my jurisdiction.