Air Conditioning - Air Return Question

Forgive me for my ignorance on the topic of central air conditioning. Are the air return units supposed to suck air in from the house? I have two air returns, one in the living room on the main floor and one at the top of the stairs on the second floor. I notice if I put a piece of paper on the one in the downstairs it sucks the paper to the air return. If I put one on the air return at the top of the stairs, it just falls away. Would this mean a problem with the upper air return?

Forgive me for my ignorance on the topic of central air conditioning. Are the air return units supposed to suck air in from the house? I have two air returns, one in the living room on the main floor and one at the top of the stairs on the second floor. I notice if I put a piece of paper on the one in the downstairs it sucks the paper to the air return. If I put one on the air return at the top of the stairs, it just falls away. Would this mean a problem with the upper air return?


There is not a problem with it but.

If you have one unit doing the entire house then cover some of the one on the bottom so you pull the air from the top. This will pull the hot air from the ceiling.

Sorry, I'm not quite understanding your reply. The air return on the top floor that isn't sucking in air. Is that the way it is supposed to be or is something wrong with it?
I'm having problems with cooling my house. The bottom floor gets cooled off a bit but not to the level I would expect. The top floor is much warmer. The master bedroom has two vents in the floor which seem to have hardly any air coming out. The two smaller bedrooms and bathroom upstairs each have one floor vent and are cooler than the master but not much. The only air return upstairs is at the top of the stairs. It is a small townhome (approx. 1200 sq ft).
The unit leaks freon and for the past two years has had to have small amount of freon replaced at the beginning of the cooling season. Both times the HVAC repairman has checked the system and found no other problems. I'm beginning to think they don't do much in the way of checking.
There is also water leaking from the handler in the basement. It wasn't there a month ago when the repairman was in but I just noticed it today.
I'm just trying to check various problems and that's why I asked about the air return upstairs -- to see if it could be causing part of the problem.

Just for kicks: If you put paper over the whole grill in the down stairs. Then does the one up stairs draw good??????? dont keep the paper over the down stairs grill. Lets find out if the top one will work

There is also water leaking from the handler in the basement. It wasn't there a month ago when the repairman was in but I just noticed it today.
Now you said freon leak??? why didnt they find it and fix it???? low on freon can cause this water. Also did they clean the drain line from the unit????. Check big copper line at outside unit should be cold and wet,little line warm when running. If not then unit is low on freon again.

ED;)

Sorry, I'm not quite understanding your reply. The air return on the top floor that isn't sucking in air. Is that the way it is supposed to be or is something wrong with it?
I'm having problems with cooling my house. The bottom floor gets cooled off a bit but not to the level I would expect. The top floor is much warmer. The master bedroom has two vents in the floor which seem to have hardly any air coming out. The two smaller bedrooms and bathroom upstairs each have one floor vent and are cooler than the master but not much. The only air return upstairs is at the top of the stairs. It is a small townhome (approx. 1200 sq ft).
The unit leaks freon and for the past two years has had to have small amount of freon replaced at the beginning of the cooling season. Both times the HVAC repairman has checked the system and found no other problems. I'm beginning to think they don't do much in the way of checking.
There is also water leaking from the handler in the basement. It wasn't there a month ago when the repairman was in but I just noticed it today.
I'm just trying to check various problems and that's why I asked about the air return upstairs -- to see if it could be causing part of the problem.

If you have a return down stairs and one upstairs take a peice of cardboard and cover the one down stairs (while the unit is running) then air should be being pulled through the upstairs return.

This is a normal set up BUT in the winter you have to open the bottom return and close the top return.

AS to the water leak it sounds like the condensate line is clogged. It should be a white tube comming out of the unit. If you put a shop vac on the end of it and suck it out it should be ok.

How long have you lived there and did it cool good last year?

As for the air in the bedroom close the down stairs registers alittle and see how that works.
Also check the filters. And did you have the indoor and out door coiles cleaned.

I covered the return downstairs and after doing so, the air return upstairs was sucking in air. When I remove the cover from downstairs, the one upstairs stops sucking in air.
I have lived in this house for 4 years. The first two years were fine. Last year we had problems with it not cooling at all. The repairman came out and said it was frozen inside from lack of freon. We turned it off to unfreeze the system and he added freon. I asked about the leak and he said it would be so hard to find we might as well buy a new unit or we could just add freon every cooling season. It worked fine that season with the exception that it never really seems to cool off the upstairs.
This year the same thing happened and they put 1 lb of freon in. They didn't do anything else. I asked him about the cooling problem upstairs and he said it was because they were farthest away from the handler. I don't think they cleaned anything or really checked anything that well. I know he looked inside the handler because when I checked it yesterday the filter was not in place properly. He must have removed it and then couldn't get in back in.
I did replace the filter a month ago but it is already very dirty.
I will bring a shop vac home from work and try sucking out the pipe mentioned in a previous message and see if that helps.
Thanks for your help so far.

I think you would be well served to get a different service company. A good tech could find a leak in no more than a 1/2 hour unless it was a pin hole and he should still be able to find the general area.

As for the return it was probably sized wrong to begin with and the air is just taking the path of least resistance and thats through the return closest to the air handler.

I covered the return downstairs and after doing so, the air return upstairs was sucking in air. When I remove the cover from downstairs, the one upstairs stops sucking in air.
I have lived in this house for 4 years. The first two years were fine. Last year we had problems with it not cooling at all. The repairman came out and said it was frozen inside from lack of freon. We turned it off to unfreeze the system and he added freon. I asked about the leak and he said it would be so hard to find we might as well buy a new unit or we could just add freon every cooling season. It worked fine that season with the exception that it never really seems to cool off the upstairs.
This year the same thing happened and they put 1 lb of freon in. They didn't do anything else. I asked him about the cooling problem upstairs and he said it was because they were farthest away from the handler. I don't think they cleaned anything or really checked anything that well. I know he looked inside the handler because when I checked it yesterday the filter was not in place properly. He must have removed it and then couldn't get in back in.
I did replace the filter a month ago but it is already very dirty.
I will bring a shop vac home from work and try sucking out the pipe mentioned in a previous message and see if that helps.
Thanks for your help so far.



I have run into the same problem you are having in million dollar houses

If you keep the bottom return covered during the summer (so it only pulls from the top return) then you should feel some difference.
Keep in mind in the summer heat rises (you want that out) so keep the top open, in the winter you want the cold out, so keep that one open.

The unit may not have needed freon. With the returns not operating properly the system is pulling cold air in and could freze the coil and send pressures all over the place.

As far as the upstairs and air flow. Try shutting down the down stairs register a little (not completly) and see if you get more air up there. If you do then the system needs to be balanced.

The filter should be changed once a month.

I think you should find an AC company that will clean the coils, indoor and out door.

I'm going to try a few things and see if anything changes. I covered up the return downstairs to see if that helps with the cooling/airflow problem. However, after several days in a row of 90 deg temps with high humidity, we have now gone into 80 deg temps with low humidity so naturally the house is cooler.
I will call another repair company and get them to check the system and clean the coils, etc.
Thanks for your help so far. I have learned a lot from browsing these forums.