Thread: Ghost vents

Hello!

Are ghost vents required in new construction. If so, then when?


Thanks in advance,

Jim Murphy

Similar Threads:

• PVC VENTS?
• From gable vents to Ridge & Gable Vents
• Fun with WH vents!
• Are mechanical vents allowed on island kitchen sink vents in Florida
• Ghost?

Originally Posted by JIM MURPHY

Hello! Are ghost vents required in new construction. If so, then when? Thanks in advance, Jim Murphy

Ok, I'll bite. What the heck is a ghost vent?

Originally Posted by Gunnar Alquist

Ok, I'll bite. What the heck is a ghost vent?

It is a vent found in bedrooms and adjoining hallways that allows ventilation into the room when the door is closed.

They also keep the door from slamming when the HVAC is on.

But they do defeat the purpose of any soundproofing, it's like having an open window to the hallway.

They are transfer ducts (better practice) or just transfer vents back to back (cheapest practice).

They equalize the pressure between conditioned space which have doors and can be closed off.

in order to put air in, air has to be allowed out.

Yea colleagues, but who ya gonna call?
ghost busters.JPG

Originally Posted by ROBERT YOUNG

Yea colleagues, but who ya gonna call?
ghost busters.JPG

Ghost Vent Busters....of course!

Jim, I hope you are not offended by my post.
I apologise profusely if you are.

In hindsight, which can be 20/20 when realized, I apologise profusely.
I meant the statement as a means of jocularity between colleagues.
Again, I hope you are not offended.

Best regards.

I have never heard that term before.

Jim,

To not answer your question, I have rarely seen these. The exceptions would be in manufactured homes, a few homes built in the '50s and commercial office buildings.

transfer grills are as common as the folks around here

http://buildingscience.com/file/5861...token=suIytP6L

RR-0005: Transfer Grille Sizing | Building Science Corporation

for those who worry about noise transfer
many of use grew up with these at bedrooms without too much emotional scarring
91376d1431761294-talk-cheap-builder-interior-door-and-transom.jpg

Barry,
Thanks for the post.

I wanted to reply pretty much the same as you and Jerry but lost my nerve thinking I might have upset Jim with my dam thoughtless Tomfoolery.

Transfers ducts.
All over the apparent building were I reside.
Stabilize pressure in a habitable environment and allow combustion air.

Hope all is well.
Best regards.

Thanks to all for the replies and Tomfoolery!

Jim

- - - Updated - - -

Thanks to all for the replies and Tomfoolery!

Jim

- - - Updated - - -

Thanks to all for the replies and Tomfoolery!

Jim

- - - Updated - - -

Thanks to all for the replies and Tomfoolery!

Jim

Originally Posted by JIM MURPHY

It is a vent found in bedrooms and adjoining hallways that allows ventilation into the room when the door is closed.

Typical construction in most of Canada is simply known as an undercut door. This is where the bottom of the door can be "undercut" somewhere between 1/2 to 1 inch above the floor line. This also allows for air and heat transfer.

Here's another POV from Building Science -http://buildingscience.com/documents/information-sheets/information-sheet-wrong-undercutting-doors

Down hearyah ... south of that border ... the ICC codes require the transfer ducts/grills.

You'd probably have to undercut a door 4 inches ... and that would mean repairing the door where you cut the bottom rail out of the door.

1/2" carpet pad
1-1/2" carpet
2-1/2" undercut
________________

4-1/2" undercut

Originally Posted by Jerry Peck

Down hearyah ... south of that border ... the ICC codes require the transfer ducts/grills.

You'd probably have to undercut a door 4 inches ... and that would mean repairing the door where you cut the bottom rail out of the door.

1/2" carpet pad
1-1/2" carpet
2-1/2" undercut
________________

4-1/2" undercut

1-1/2" carpet. As they say here in the south, "You can't hide money!"

It is very common in my area to have what we call 'jump ducts'. They look like a furnace supply vent, but they 'jump' out to the hall. Sometimes the jump ducts from 3 different bedrooms come out in a single large vent/register in the hall, often located near the return air vent. I have never heard them called anything but jump ducts, but this is AZ.

Almost every manufactured home I've inspected has what I call 'transom vents' over the door to accomplish the same thing but without near as much privacy. I don't know if I made up that name or if I heard it somewhere.

If jump ducts or door trimming is needed I have a great way to demonstrate it. With the blower on I close the bedroom door almost all the way and hold a piece of surveyors tape at the opening. At a master bedroom with multiple supply vents I can get the tape waving like a flag.

Originally Posted by Claude Lawrenson

Typical construction in most of Canada is simply known as an undercut door. This is where the bottom of the door can be "undercut" somewhere between 1/2 to 1 inch above the floor line. This also allows for air and heat transfer.

Here's another POV from Building Science -http://buildingscience.com/documents/information-sheets/information-sheet-wrong-undercutting-doors

Claude, I did not know that. Thanks!

I do find the "air and heat transfer" statement a bit disingenuous.
I was taught heat rises. Unless they are referring to the coolest heat, or the heat with lowest over all heat performance. Or the heat not as hot as the upper heat.
The guys and gals writing this home sciences stuff might refer to the air movement as "overall air exchange." Be a safer narrative IMO.

Originally Posted by JIM MURPHY

Thanks to all for the replies and Tomfoolery!

Jim

Jim, your a good sport and I concur. Thanks everyone for your replies.

Originally Posted by ROBERT YOUNG

Claude, I did not know that. Thanks!

I do find the "air and heat transfer" statement a bit disingenuous.
I was taught heat rises. Unless they are referring to the coolest heat, or the heat with lowest over all heat performance. Or the heat not as hot as the upper heat.
The guys and gals writing this home sciences stuff might refer to the air movement as "overall air exchange." Be a safer narrative IMO.

Robert,

"
I do find the "air and heat transfer" statement a bit disingenuous.
I was taught heat rises. Unless they are referring to the coolest heat, or the heat with lowest over all heat performance. Or the heat not as hot as the upper heat.
"

You are referring to when there is not air movement, heat will rise ... but when there is a fan blowing the air through ducts and out supply vents, the heat will go in the direction it is blown, as will cold air (which is just air with 'less heat' in it).

Trying to blow air from a furnace or air conditioner into a room is like trying to blow up a balloon - except the room will not expand, so unless there is a means to allow as much air out as is being blown in ... the room will pressurize (not much, but to the point that no more air can be blown in than is being leaked out someplace).

Undercutting doors is the old way, very inefficient and lacking (unless one likes wearing knickers, then ... it's a match ).

They are called transfer grills. It's the cheap way of getting around installing cold air returns thru out the home. Builders will have a central cold air return on the 1st and 2nd floor and use transfer grills and also under cut doors in order to move air. This eliminates the need for return duct work in the basements. Around here (buffalo N.Y. area ) they use 2 flex ducts down thru a chase and hook right to cold air drop at the furnace.

Originally Posted by Jerry Peck

Robert,

"
I do find the "air and heat transfer" statement a bit disingenuous.
I was taught heat rises. Unless they are referring to the coolest heat, or the heat with lowest over all heat performance. Or the heat not as hot as the upper heat.
"

You are referring to when there is not air movement, heat will rise ... but when there is a fan blowing the air through ducts and out supply vents, the heat will go in the direction it is blown, as will cold air (which is just air with 'less heat' in it).

Trying to blow air from a furnace or air conditioner into a room is like trying to blow up a balloon - except the room will not expand, so unless there is a means to allow as much air out as is being blown in ... the room will pressurize (not much, but to the point that no more air can be blown in than is being leaked out someplace).

Undercutting doors is the old way, very inefficient and lacking (unless one likes wearing knickers, then ... it's a match ).

Jerry, home sciences is a subject I have been away from to long.
Happy Claude brought it up.

My disingenuous statement was from my view, and yes a limited one at that.

When is air not in movement? Good question, but how much air movement is enough movement?
Objects can block or redirect air movement as well.
Window Curtains play a major roll is limiting the transfer of air, heat to warm a cool an object.
In my neck of the woods, air movement and dew point condensation are misunderstood by the average home owner.

Circulation occurs with the use of a mechanical system, like forced air HVAC or air exchangers/HRV, ect...
Baseboards, ceramic wall panel heaters and hot water radiators on the other hand, and for the most part, rely on convection as a means to transfer conditioned air. Movement is restricted/limited to convection and the amount of whole house circulation. The undercuts doing less as compared to forced air.

Happy you saw so fun in my post.
More happy you are back safe wrapped in everyone's prayers.