# Making a vent smaller



## beenthere (Oct 11, 2008)

Needs to be cover with a piece of metal, and the metal then cut to needed size.


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## alexlacelle (Feb 27, 2012)

beenthere said:


> Needs to be cover with a piece of metal, and the metal then cut to needed size.


Ok so I can just cover it with sheet metal, seal it properly with hvac tape and cut out the size I want?

Thanks!

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## mako1 (Jan 7, 2014)

Not a hvac guy but :What makes you think you can just make the intake and outtake smaller?Why are you doing this?


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## alexlacelle (Feb 27, 2012)

mako1 said:


> Not a hvac guy but :What makes you think you can just make the intake and outtake smaller?Why are you doing this?


For starters when I started the Reno the vent was blocked completely without causing any issues with the furnace. I had a problem with the furnace overheating when I bought the house due to not enough cold air returns and fixed that as well so I know that won't be a problem.

I'm making it smaller so that it can accommodate a standard sized grill, also, it's a very small room and doesn't require the 12" by 12" opening that is there.

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## Bob Sanders (Nov 10, 2013)

Lemkie said:


> I'm making it smaller so that it can accommodate a standard sized grill, also, it's a very small room and doesn't require the 12" by 12" opening that is there.


From the pic it's clear that it's already been done in the room on the opposite side. Nothing wrong with that, (I have the same old style venting systems in my house as well) but I would at least take that grille off and finish the drywall edge so you're not blowing bits of drywall into the air for the next 20 years.

The problem that you might run into with this is that the vent cover is actually a combination floor/wall vent. The feeding duct comes from both the floor AND the wall, so you can't go with a simple wall grille as you have done on the other side otherwise you will end up cutting a substantial amount of feeding duct out of the picture... and you have to remember you're heating 2 rooms with that duct. Now they do sell smaller, lower profile floor/wall vents, but you have already got a flat wall grille on the other side so heating won't be that even. You'll get less heat in the room on the other side so you may have to balance that off by slightly closing the new vent.


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## alexlacelle (Feb 27, 2012)

Bob Sanders said:


> From the pic it's clear that it's already been done in the room on the opposite side. Nothing wrong with that, (I have the same old style venting systems in my house as well) but I would at least take that grille off and finish the drywall edge so you're not blowing bits of drywall into the air for the next 20 years. The problem that you might run into with this is that the vent cover is actually a combination floor/wall vent. The feeding duct comes from both the floor AND the wall, so you can't go with a simple wall grille as you have done on the other side otherwise you will end up cutting a substantial amount of feeding duct out of the picture... and you have to remember you're heating 2 rooms with that duct. Now they do sell smaller, lower profile floor/wall vents, but you have already got a flat wall grille on the other side so heating won't be that even. You'll get less heat in the room on the other side so you may have to balance that off by slightly closing the new vent.


Thanks for the information this is quite helpful. When you talk about finishing the drywall behind the vent do you mean just a coat of plaster on the edges or is there a better way?

Also, I see why you say it's a combination vent as part of the floor is cut out in this room. It it not the case on the other side however. The edge of the box is lined up with the wall, so only a wall vent is possible there. 

Should I just stick to a wall vent in this room as well since that's the case?

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## alexlacelle (Feb 27, 2012)

Lemkie said:


> Thanks for the information this is quite helpful. When you talk about finishing the drywall behind the vent do you mean just a coat of plaster on the edges or is there a better way? Also, I see why you say it's a combination vent as part of the floor is cut out in this room. It it not the case on the other side however. The edge of the box is lined up with the wall, so only a wall vent is possible there. Should I just stick to a wall vent in this room as well since that's the case? Sent from my iPhone using DIY Forum


I was just thinking. What if I add a triangular piece of tin to the top of the box to help guide the air out to the walls, would that help at all?

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## Bob Sanders (Nov 10, 2013)

Lemkie said:


> Thanks for the information this is quite helpful. When you talk about finishing the drywall behind the vent do you mean just a coat of plaster on the edges or is there a better way?


 The edges. I wouldn't go to town with anything expensive or time consuming. Pick up a roll of aluminum foil tape (used for duct work) and tape the edges.



> Also, I see why you say it's a combination vent as part of the floor is cut out in this room. It it not the case on the other side however. The edge of the box is lined up with the wall, so only a wall vent is possible there.


 Yup. Clearly some one has added a wall there or at least done some work because the vent on the other side USED to be the same as the one you're working on right now.



> What if I add a triangular piece of tin to the top of the box to help guide the air out to the walls, would that help at all?


I would hang on until you decide what vent you want to use. If you pick up something like the one below, it has a built in damper so you can adjust airflow and balance things out.


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## bobinphx (Nov 25, 2011)

what is the white material between the sheet metal and the wall. Looks like asbestos to me. Might want to have that checked or removed. 
Just a thought.


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