Need to create air duct returns in house

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Old 06-15-10, 12:50 PM
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Need to create air duct returns in house

I live in a cape cod house and I am having trouble cooling the upstairs of the house and need to add an air return back to the a/c unit.

My question is can I have two vents linked into the same duct that goes downstairs into my unit? Meaning a vent in the hallway and a vent in the bedroom (same wall) using the same duct. Will this effect the pull of the air? Will it reduce the pull? Is it better to have two separate runs?

Thanks
 
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Old 06-15-10, 02:07 PM
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I have quite a few returns using the same duct

Can you add vents upstairs?
 
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Old 06-15-10, 06:52 PM
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Returns will not do it you have supply duct issues.
 
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Old 06-15-10, 09:01 PM
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Your supply duct design could be the problem. It is a challenge to get a single unit (I assume that is what we are talking about?) to evenly cool or heat a two story home. I have had the same problem for many years on my own 2 story house and I just totally reworked all my supply ductwork in my crawlspace due to recent flooding. I still only have one return and it is downstairs. When I replaced the flooded supply ductwork I built a Y joint and split the ductwork into 2 lines and zoned the upstairs and downstairs (I did not buy the zone kits since they were very expensive I just bought and installed the dampers with manual locking hand quadrants on them, it was a cost savings measure) Right now I am VERY pleased with the results. I have made some small adjustments to the flow on each side and the temps are nice and even now. I had as much as 10 to 12f difference between upstairs and downstairs before especially on very hot sunny days but now I am only seeing a max 2f which I think is exceptional. I am saving up to buy the actual zoning controls (maybe next year) but may not even need them, is 2f really worth 1000 bones?. I will have to say that the ductwork replacement project has been very expensive and I would NEVER EVER have done the rework had it not been for having to replace the ductwork anyway due to the flood. If I were you I would be making myself a a drawing of what is there as far as ductwork to see if it is anywhere close to the manual D recommendations you may find that you just had a poor system installed originally that is what I had no doubt. Maybe yours will be easier than mine was to rework. good luck
 
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Old 06-16-10, 05:30 AM
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I don't think there is an issue with the supply ducts. My downstairs is very comfortable but as you walk to the second floor you feel the temperature rising. As of now there is no returns on the second floor circulating the air. This cape cod style house has a second floor but the ceiling is right on the roof line, so it takes a beating from the sun all day. There is a small crawl space above the upstairs ceiling.

Having zoning controls is not an option for me. I need my single unit in the basement to be sufficient. I can add vents but I am worried that the run to the basement will be too far. I want to cut a vent in the ceiling on the upstairs landing and have it piped down to the basement. Is it better to use the wall as a return or an actual duct? How far is to far when running a duct for a return? Do I need a return box behind the grill?
 
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Old 06-16-10, 06:08 AM
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Again the return is not the issue! You have to have the supply air going to the 2nd floor before you can return it to the unit. You might only need some dampers installed in the duct. Most likely the duct work is under sized to get the required air flow needed to cool the 2nd floor. I would do a manual J before you start doing anything.
 
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Old 06-16-10, 08:05 AM
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There is supply going to the second floor. I have two bedrooms and one full bath each with its on supply. The air flow out of those registers seem adequate enough to cool those rooms.

What do you mean by manual J and what are dampers?

Thanks
 
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Old 06-16-10, 09:08 AM
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Do you have any problems heating this floor in the winter?

If not, I would look at putting the new return vents as high up as possible so you're removing warmer air instead of cooler air
 
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Old 06-16-10, 11:06 AM
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I just moved into the house in April so I can't tell if I'll have issues heating the upstairs. I think your right in that I need to install vents on the ceiling to pull the hot air out.

To install the return, is a single duct attached to a register and piped into the main return in the basement all I need?
 
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Old 11-29-10, 07:43 PM
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I know it's been a while since you posted so I'm curious if this worked. I have the same problem with a different style house. We have one return air at the top of the stairs but it's on the floor. The smaller rooms seem to cool fine but our master bedroom isn't cool enough so we've used window units or fans. We know an HVAC guy and he suggested adding return air on the ceiling above the one we have and closing the lower one in the winter. We've completely gutted our bedroom so I want to make sure I do this right before I close everything back up

Should I add another return air someplace?

Will return air work if duct isn't in the wall? Can I simply put in a grill and let the wall act as a duct?

I'd be interest in comments from not only the original post but anyone else who might know
 
 

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