Cold air return

[daklem]

Hi. The cold air returns in my second story are at the top of the walls. Can I move a return down to the lower part of the wall, like they are on the first floor, in one of the rooms without changing the system's efficiency?

[Hube]

You can cut a low opening in a few inches above the floor (just above the baseboard). I assume your unit is on a lower level (basement..
Locate this new return air opening in the SAME STUD SPACE. Install the low opening grille with a damper in it. This way when the low one is closed (cooling season),the top one will be drawing air.
When the low grille is open,(heating season) the top one will not be able to draw any air because of the damper's leaf blade will block of the space in the stud.
You now have a HIGH/LOW return. Use one or the other when needed. Low for Heating season
High for cooling season

If by chance your unit is located above(attic area) do the same as described, but install the damper upside down in the high opening. Remove any mid - height girt that may exist in this stud space. Good luck...Hube

[daklem]

Thanks for the answer, Hube.

It is a basement system. I want to close off the old top vent and only use the lower vent. I assume there isn't any problem if electrical conduit is running across the stud bay where I want to locate the return, right?

[Hube]

It should be no problem , it was drawing air ok from the high opening in this same space with the conduit in it before, was'nt it?

[daklem]

Yes it was. I just didnt know if there was some weird building code issue, but I guess that shouldn't matter as it was there before just couldn't see it.

[ajg93]

Hube...how necessary or helpful is the damper. I have done exactly what you have suggested however I simply block the high return with sheet metal behind the grill (in the heating season). Is this ok or will having a damper on the lower grill provide some benefit?

Thanks,
Adam

[Hube]

Ajg93; Having a operable damper only in the lower grille and none in the top one, allows you to convert from the cooling to the heating seasons (and vice/versa) very easily at the flip of this lower damper. No need for any sheet metal block off in the top grille at all....NOTE: A normal heating register with an attached leaf type damper is all that is required, perhaps 6x12 or 8x14 ,etc.or larger as required.
For heating season,open this lower damper, thus blocking off the top.
For cooling season, close this lower damper, thus opening up the top. Obviously both openings have to be in the same stud space.
savvy ??? If still not clear, just post back and we will try and explain more if need be. Hube

[imeduc]

Make sure you get a heat register for this not a grill. Also ask for the cheap cheap register the have the full damper like on the back. You need a 6"X14".So like Hube said it will close off the stud space.

ED

My mistakes dont define me they inform me.

[ajg93]

Hube...I understand how the system works and your comments. What my question was meant to address was whether my current setup (having the upper grill blocked with sheet metal and the lower grill open) achieves the same thing as a lower grill w/ a damper. I was wondering if the damper provides any advantage other than ease of use?

Thanks,
Adam

[Hube]

AJG93; If your going to keep this high blocked one off, then there is no need for a damper in this lower return because you want to keep it open so it can draw in return air. No harm whatsoever.
Drawing air from the low grille will be the best for the heating mode as cold air is at the floor level and it should be drawn back to the unit to be heated and sent out via the supply ducts. Low wall locations for r/a are ok for heating, but high wall locations are best for cooling mode.
And the beauty of a high/ low system is that it can be switched to whatever mode the unit is operating in , it can be switched at the flip of a damper.
Obviously, if you don,t have cooling, you only need the low wall return with no damper. Your system depends on return air in order to function properly. Hube