As part of duct sealing process, I need to improve the air intake port show
in the photo so that it doesn't suck air from under the staircase:

https://dl.dropboxusercontent.com/u/...3/IMG_0341.JPG
The round port is 14 inch diameter. The grill cover is 15.5 inch x 25.5
inch. The white box on the upper right corner is a house alarm and can be
moved.

My initial thought is to get a 14-inch round to square vent boot like this
http://www.amazon.com/Speedi-Boot-SB.../dp/B0085UYOGS

and somehow attach it to the back of the grill cover, then connect this to
the floor vent with a 14 inch flex duct.

However, the edge of the floor vent is only 6 inches away from the grill
cover, so the back of the square to round boot will be over the floor vent,
so there is no room to connect the flex duct.

Could someone suggest a solution that works?

As part of duct sealing process, I need to improve the air intake port
show in the photo so that it doesn't suck air from under the staircase:

https://dl.dropboxusercontent.com/u/...3/IMG_0341.JPG
The round port is 14 inch diameter. The grill cover is 15.5 inch x 25.5
inch. The white box on the upper right corner is a house alarm and can be
moved.

My initial thought is to get a 14-inch round to square vent boot like this
http://www.amazon.com/Speedi-Boot-SB.../dp/B0085UYOGS

and somehow attach it to the back of the grill cover, then connect this to
the floor vent with a 14 inch flex duct.

However, the edge of the floor vent is only 6 inches away from the grill
cover, so the back of the square to round boot will be over the floor
vent, so there is no room to connect the flex duct.

Could someone suggest a solution that works?


*Go to a sheet metal shop and have a duct boot made to fit into the space.
You will need to give them a drawing with the dimensions. Make it a 1/8"
shorter on each side to slide in easily and have them add a 3/4" lip all
around so that you can secure it to the wall. You can have them add a duct
collar so that you can attach the flex directly to that. Ask them to make
the duct collar attachable from the inside so that you can remove it, slide
the boot in, pull the flex up, attach it to the collar and then drop the
collar into place.

I have seen this set up many times. The original installers are using the
wall cavity as a return plenum.

On Wednesday, October 16, 2013 7:46:28 AM UTC-4, John G wrote:
As part of duct sealing process, I need to improve the air intake port

show in the photo so that it doesn't suck air from under the staircase:



https://dl.dropboxusercontent.com/u/...3/IMG_0341.JPG

The round port is 14 inch diameter. The grill cover is 15.5 inch x 25.5

inch. The white box on the upper right corner is a house alarm and can be

moved.



My initial thought is to get a 14-inch round to square vent boot like this

http://www.amazon.com/Speedi-Boot-SB.../dp/B0085UYOGS



and somehow attach it to the back of the grill cover, then connect this to

the floor vent with a 14 inch flex duct.



However, the edge of the floor vent is only 6 inches away from the grill

cover, so the back of the square to round boot will be over the floor

vent, so there is no room to connect the flex duct.



Could someone suggest a solution that works?





*Go to a sheet metal shop and have a duct boot made to fit into the space.

You will need to give them a drawing with the dimensions. Make it a 1/8"

shorter on each side to slide in easily and have them add a 3/4" lip all

around so that you can secure it to the wall. You can have them add a duct

collar so that you can attach the flex directly to that. Ask them to make

the duct collar attachable from the inside so that you can remove it, slide

the boot in, pull the flex up, attach it to the collar and then drop the

collar into place.



I have seen this set up many times. The original installers are using the

wall cavity as a return plenum.



Which is typical. So before going to all that trouble,
how airtight is the area under the stairs and if any air
is getting in there, where is it coming from? If the
leakage is from heated inside air space, it doesn't
matter. It might be easier to seal up any leakage
that's coming into the cavity from the basement, etc.
instead of custom fitting sheet metal.

On 10/16/13 3:05 AM, bob wrote:
As part of duct sealing process, I need to improve the air intake port
show in the photo so that it doesn't suck air from under the staircase:

https://dl.dropboxusercontent.com/u/...3/IMG_0341.JPG
The round port is 14 inch diameter. The grill cover is 15.5 inch x
25.5 inch. The white box on the upper right corner is a house alarm
and can be moved.

My initial thought is to get a 14-inch round to square vent boot like
this
http://www.amazon.com/Speedi-Boot-SB.../dp/B0085UYOGS


and somehow attach it to the back of the grill cover, then connect
this to the floor vent with a 14 inch flex duct.

However, the edge of the floor vent is only 6 inches away from the
grill cover, so the back of the square to round boot will be over the
floor vent, so there is no room to connect the flex duct.

Could someone suggest a solution that works?

Assuming the round pipe is not meant to also pull air down the wall
cavity from an upper level, consider "boxing in" the space behind the
vent cover with something like 1/4" plywood. Cut 3 sides and a top.
Use 1x2 to glue and screw together and to sub-floor behind vent.

On Wednesday, October 16, 2013 2:05:51 AM UTC-5, bob wrote:
As part of duct sealing process, I need to improve the air intake port show in the photo so that it doesn't suck air from under the staircase: https://dl.dropboxusercontent.com/u/...3/IMG_0341.JPG The round port is 14 inch diameter. The grill cover is 15.5 inch x 25.5 inch. The white box on the upper right corner is a house alarm and can be moved. My initial thought is to get a 14-inch round to square vent boot like this http://www.amazon.com/Speedi-Boot-SB.../dp/B0085UYOGS and somehow attach it to the back of the grill cover, then connect this to the floor vent with a 14 inch flex duct. However, the edge of the floor vent is only 6 inches away from the grill cover, so the back of the square to round boot will be over the floor vent, so there is no room to connect the flex duct. Could someone suggest a solution that works?

What is wrong with sucking air from that location? Too dusty?? Are thre other cold air returns on that floor level? What registoers will be allowing return air to flow if you close that one off. Is it also drawing air from the floor above, using the wall space as a plenum as another poster questioned?

"Retired" wrote in message
...
On 10/16/13 3:05 AM, bob wrote:
As part of duct sealing process, I need to improve the air intake port
show in the photo so that it doesn't suck air from under the staircase:

https://dl.dropboxusercontent.com/u/...3/IMG_0341.JPG
The round port is 14 inch diameter. The grill cover is 15.5 inch x
25.5 inch. The white box on the upper right corner is a house alarm
and can be moved.

My initial thought is to get a 14-inch round to square vent boot like
this
http://www.amazon.com/Speedi-Boot-SB.../dp/B0085UYOGS


and somehow attach it to the back of the grill cover, then connect
this to the floor vent with a 14 inch flex duct.

However, the edge of the floor vent is only 6 inches away from the
grill cover, so the back of the square to round boot will be over the
floor vent, so there is no room to connect the flex duct.

Could someone suggest a solution that works?

Assuming the round pipe is not meant to also pull air down the wall cavity
from an upper level, consider "boxing in" the space behind the vent cover
with something like 1/4" plywood. Cut 3 sides and a top. Use 1x2 to glue
and screw together and to sub-floor behind vent.


That would be my vote too, But, as mentioned, only if the round pipe is not
also meant to pull air down the wall cavity from an upper level.

Assuming the round pipe is not meant to also pull air down the wall
cavity from an upper level, consider "boxing in" the space behind the
vent cover with something like 1/4" plywood. Cut 3 sides and a top. Use
1x2 to glue and screw together and to sub-floor behind vent.

Good point about the upper level. However there is no opening anywhere else
in the wall cavity.

Building a box is probably easiest for me since I have the necessary tools.
The trickest part is probably sealing the box against the drywall opening.

As to why I need to do this, it's because I'm thinking of getting the ducts
"Aeroseal"ed and the contractor recommended I do this first.

On Wednesday, October 16, 2013 3:26:25 PM UTC-4, wrote:
On Wednesday, October 16, 2013 2:05:51 AM UTC-5, bob wrote:

As part of duct sealing process, I need to improve the air intake port show in the photo so that it doesn't suck air from under the staircase: https://dl.dropboxusercontent.com/u/...3/IMG_0341.JPG The round port is 14 inch diameter. The grill cover is 15.5 inch x 25.5 inch. The white box on the upper right corner is a house alarm and can be moved. My initial thought is to get a 14-inch round to square vent boot like this http://www.amazon..com/Speedi-Boot-S.../dp/B0085UYOGS and somehow attach it to the back of the grill cover, then connect this to the floor vent with a 14 inch flex duct. However, the edge of the floor vent is only 6 inches away from the grill cover, so the back of the square to round boot will be over the floor vent, so there is no room to connect the flex duct.. Could someone suggest a solution that works?



What is wrong with sucking air from that location? Too dusty?? Are thre other cold air returns on that floor level? What registoers will be allowing return air to flow if you close that one off. Is it also drawing air from the floor above, using the wall space as a plenum as another poster questioned?

He's not trying to close it off. He wants to make it so it
can only pull air through the vent grill. It's a triangular
space below stairs and the way it is right now, it can pull
air anywhere from the cavity. Probably 95% or so is coming
from the open front. But, I earlier raised the question of
what is on the other sides of this enclosed little space?
If it's all interior space, basement below, then the only
unheated air issue would be from an unheated basement.
In that case, if he can, he could just seal the bottom.
If there is an outside wall on one side, then it's a different
story.

Per his last post, the "aeroseal" contractor told him to
get it done. I'm wondering why an aeroseal contractor,
who's in the business of sealing up duct systems,
isn't capable of fixing this for the customer, since
he's the one saying it needs to be fixed. As someone
else pointed out, all that's needed is a custom made
sheet metal boot. You would think this would come up
all the time. It's a very typical duct situation and
if it's your business to seal up ducts..... I mean
what's more professional, to offer that service to
your customers or leave them to go find another contractor,
or find a duct fabricator, take measurements, etc.
If the contractor did it, they measure it, have the
fabricator they do business with make it, put it in,
add it to the bill, make more money. As a customer,
I'd sure prefer that instead of leaving me to figure
it out.

But if it were my house, no exterior wall, and I could
see inside that there are no holes to the basement,
I'd just leave it be. Or if there are a couple holes,
then I'd seal them. Or better yet have aeroseal, seal
them. IMO, the difference in any possible energy savings
beyond that isn't worth all the trouble. At some point
you can get carried away beyond the point of reasonable
return.

On 10/17/13 1:33 AM, bob wrote:
Assuming the round pipe is not meant to also pull air down the wall
cavity from an upper level, consider "boxing in" the space behind
the vent cover with something like 1/4" plywood. Cut 3 sides and a
top. Use 1x2 to glue and screw together and to sub-floor behind vent.

Good point about the upper level. However there is no opening anywhere
else in the wall cavity.

Building a box is probably easiest for me since I have the necessary
tools. The trickest part is probably sealing the box against the
drywall opening.

As to why I need to do this, it's because I'm thinking of getting the
ducts "Aeroseal"ed and the contractor recommended I do this first.


Consider caulking, or foam weatherstripping

from the open front. But, I earlier raised the question of
what is on the other sides of this enclosed little space?
If it's all interior space, basement below, then the only

Two sides of the space is outside walls, below the floor is crawlspace.

The aeroseal contractor did offer to build a box for $450.
I think it's way too high so I'm doing it myself.

On Thursday, October 17, 2013 1:57:04 PM UTC-4, bob wrote:
from the open front. But, I earlier raised the question of

what is on the other sides of this enclosed little space?

If it's all interior space, basement below, then the only



Two sides of the space is outside walls, below the floor is crawlspace.



The aeroseal contractor did offer to build a box for $450.

I think it's way too high so I'm doing it myself.

I agree, that's a lot of money. In that case either getting
a sheet metal boot fabricated or building a wood enclosure
around it and sealing it with duct sealant sounds like the way to go.