I'm In Chicago area. Any input on this? I would appreciate . Thank You

The practice in my area (MD suburbs of DC) in two story homes is have a return in the upstairs hall, a return on the first floor, and possibly a return in the basement.

I believe that most two story homes have the upstairs bedroom doors wide open except in the evening in occupied bedrooms. This would make the small thru-the-wall grates generally of no use.

Where is the return for your upstairs area? The hallway?

The return is in the hallway upstairs, exactly like in the picture. The picture is from their model home.

I now see it in the ceiling.

Again, I don't see what value the see thru openings provide when the door is open. I really don't see any great value when the door is shut in the evening for like eight hours either.

YMMV

transfer grills above doors work best when the ceiling is
high enough to allow the transfer grills to be offset.
in hallway it would be to top of ceiling molding
in bedroom to top of door molding.

this allows the air from the room...when the door
is closed...to return to a centrally located return.

by offsetting them noise & light transfer is reduced.
put them back to back...both noise & light transfer.

if there isn't room above the door...the grills can be
set to side of door...as long as they are within the
same joist bay of the wall...and not blocked/covered
by furnishings.

another way to transfer the air is via jump ducts.
grill in ceiling of bedroom to hallway.
in attic...supply boxes for each grill & a duct
that 'jumps' from one to another.
more materials, more work inside attic than
involved in transfer grills.

the undercut of the door...just doesn't work for
return air pathway. put carpet on either floor
& it has less of a pathway. thus different
methods of return air pathway.

standard transfer grills are 6" wide by 12" length.
not huge, but enough to return air from bedroom
now in a master suite with 2 supplies in bedroom
2 in each closet & one in bath...you need to move
more air...jump duct with larger sized duct is used.

best of luck.

Thank You for your long post. It really helps a lot and thank you again for taking time to explain us how it works.

energy rater,

You said, "this allows the air from the room...when the door
is closed...to return to a centrally located return."

Am I simply missing something? I thought the OP said the grills above the doors simply passed air through the wall from the BR to the hallway. Additionally, she said the return was pictured in the ceiling of the hallway.

You seem to suggest this is not the situation?

The builder has predesigned houses and we cannot change duct work. I guess if you want a new home you have to get those grills unless you want to spend a lot for a house. I see that older homes donâÂÂt have any type of returns in bedrooms. Can I eliminate those grills or sue some type of magnetic tape to cover them?

no this is exactly as you describe it saltydawg.

transfer grills over doors to bedroom/office.
centrally located return air of which you can
see a portion of in picture posted.

when doors are open...the transfer grills
are passive as door opening is allowing air
to return...and is greater in size than transfer
grill. when doors are closed...the the transfer
grill becomes active to allow air supplied to
be returned.

op....why do you want to cover them?

Where I live it is rare to see HVAC equipment installed in an attic. Most houses have the equipment installed in the basemen, or first floor if there is no basement. It would be difficult to run separate returns from the basement to each second floor bedroom.

In my opinion the transfer ducts are unnecessary. I don't have them in my house and I don't notice a problem. If you set back the thermostat when you go to bed, then the furnace will not run unless you have a very cold night. Even if the furnace or AC is running, there is a gap under the door. If you make it one inch, you should have at least a 24 sq. inch opening. The door itself is not air tight, neither are the windows and the door to the closet. There are plenty of ways for the air to escape. I find it hard to believe the room air pressure will rise above one atmosphere.

You can ask the builder not to include the grills. It is less work for him and cheaper. If he does not want to cooperate then remove one grill and place 3.5 inch thick insulation in the wall and then replace the grille. Put a piece of black paper over the insulation if you can see it through the grille. You can always remove the insulation if you think there is an air pressure problem.

mike,

Exactly!

Saltidawg,

Having lived in submarines you have to be the forum expert on air pressures.

"Having lived in submarines you have to be the forum expert on air pressures."

lol

LOL

Yes Mike. The house has HVAC equipment installed in the basement. I let the builder do their design and later if we see a noise problem we can cover them as you said.

"op....why do you want to cover them? "

Noise/privacy

"op....why do you want to cover them? "
Noise/privacy

the ask for jump ducts instead of transfer
grills, unless you'll keep the doors open.
if you supply air to a room...it needs a
dedicated pathway to return to the return air.
otherwise in the summer the rooms will get hot
with a/c on & doors closed.

offsetting the grills will reduce noise transfer.

I have lived all over the US during my Military service and afterwards. I have NEVER seen a pass through set up such as described and shone here.

I am not arguing against their value, just saying that apparently there are many of us that leave the bedroom doors open when unoccupied and some leave them open when occupied. As someone earlier described, there is leakage under and around the door, via windows, etc, such that much if not most of the USA does not include these "vents."

I cannot believe a builder, in order to close a sale, would not agree to leave them off (and save himself some labor and material costs.)

YMMV

This post was edited by saltidawg on Wed, Jun 19, 13 at 20:25

Be sure to consider the privacy implications of these type of vents.

If balance is required, I prefer jumper ducts to a common area and or a transfer grill that is low on one side and high on the other.

"it needs a dedicated pathway to return to the return air.
otherwise in the summer the rooms will get hot with a/c on & doors closed."

Energy Rater,

Why would the rooms get hot if the door is closed? Are saying the room has a perfect seal and no cold air can enter the space?

If the OP were to install a jump duct in the attic, how much energy loss would you expect if R8 duct work were to be used? Wouldn't there be a net loss of energy compared with not cutting holes in the ceiling and removing the typical R38 insulation?

"it needs a dedicated pathway to return to the return air.
otherwise in the summer the rooms will get hot with a/c on & doors closed."

Energy Rater,

Why would the rooms get hot if the door is closed? Are saying the room has a perfect seal and no cold air can enter the space?

If the OP were to install a jump duct in the attic, how much energy loss would you expect if R8 duct work were to be used? Wouldn't there be a net loss of energy compared with not cutting holes in the ceiling and removing the typical R38 insulation?

I live in 1 story 60 years old house now and we donâÂÂt have any returns in bedrooms. Before we lived in townhouse and furnace was on the second floor but no return in bedrooms. I asked a co worker that has a 30 years 2 story house and he said he has return in bedrooms back to the furnace. From here my questions.

So my NJ house actually has something GOOD about the hvac? Each of the 4 upstairs bedrooms has its own return. They are not cut through to the hall. The mbr one goes up onto the attic as does the hall one (I think) and they must join up together to go down to the basement. I think 2 of the br are back to back and go down to join up with one from the dining room, which seems to line up with one br. Not sure where the other one br return goes. Now you have me wondering. I have pretty high door undercuts. I never knew there was a reason for that. I thought it was poor workmanship with measuring!

I though poor air return was leading to humidity in my house. I have been Having high humidity in the house, might be because it's not hot enough for the ac to run for long. I've been running it to try to lower the humidity. I think my air sealing is part of the problem (though it helped with humidity in the winter!). He checked the return flow this week by drilling a hole and sticking some measurement tube in. I think he said it was a 2 (?) but that it could be higher.

Anyway, I have never noticed the return vents the op showed. I will have to pay attention to homes I visit because now I am curious.

Cindy,

Making the house tighter by sealing it keeps the humidity from entering in the summer, and leaving in the winter.

The door clearances are made to be high enough to handle the highest pile of carpet or hardwood floor. Doors with already assembled in the door frame. The carpenters are not worrying about air flow.

Having the returns in each room are a good thing. However having a return connected to an uninsulated duct in the attic is not a good thing in my opinion.

Have you ever noticed cold air coming out of the return in the winter, or hot air in the summer?

return air leakage contributes to high RH in the home.
investing in the mastic seal of ducts & returns is
monies well spent.

for any one in any climate.

best of luck.

Mike, they are big black soft looking returns. I think they say r-8 on them. There are just 2 of them.

Sometimes it is higher humidity inside than out. I have two temp and humidity units. I once calibrated them ( with salt and water in a baggie)and one was accurate and one is 8% offf, but it is consistent. They are Oregon scientific weather stations. Maybe I'll buy a different kind to double check them.

I'll stop posting about this and start a new thread if my humidity continues once the ac runs longer when it's hotter out. Thanks.

Mike, they are big black soft looking returns. I think they say r-8 on them. There are just 2 of them.

Sometimes it is higher humidity inside than out. I have two temp and humidity units. I once calibrated them ( with salt and water in a baggie)and one was accurate and one is 8% offf, but it is consistent. They are Oregon scientific weather stations. Maybe I'll buy a different kind to double check them.

I'll stop posting about this and start a new thread if my humidity continues once the ac runs longer when it's hotter out. Thanks.