Thread: Return air vent location

Our new office has the return air and ac register located right next to each other. Within 1 inch. Is this a problem?

Most certainly, as conditioned air will be pulled right back into the return, thus defeating the purpose of the A/C, and subsequently the room air will not be cooled efficiently and such a set up will most likely result in the A/C working harder in order to satisfy the thermostat.

Originally Posted by Jerry gallman

Our new office has the return air and ac register located right next to each other. Within 1 inch. Is this a problem?

The he contractor said the ac volume of flow will blow down and away from the return so it's not a problem. The vent doesn't blow down its sides are open to allow airflow across the room not toward the flloor.

Originally Posted by Jerry gallman

The he contractor said the ac volume of flow will blow down and away from the return so it's not a problem. The vent doesn't blow down its sides are open to allow airflow across the room not toward the flloor.

While this may be possible, I would have serious doubts. If there is more than one supply register then flow is divided between the ducts serving different locations. The air returning to the grille would be a fairly large volume (if this is the only return grille, the volume of air returning would be the capacity of the system minus any restrictions due to duct and so on) and would probably overcome any flow from that particular supply register.

If your office has a dropped ceiling, tiles hanging on a framework, one of the ducts can be moved to the other side of the room.

You could tell the building owner he is shortening the life of his AC unit by employing a goof, who is forcing it to run steady at the poorest possible efficiency.

I imagine that in Florida you will be able to answer this question for yourself very soon.

http://www.price-hvac.com/Catalog/Se.../SectionEG.pdf

Return
The return air inlet has very little effect on room air diffusion, regardless of inlet type or
location. However, return air inlets should be located a sufficient distance from the supply
outlet so that short‑circuiting of supply air does not occur. It may also be desirable to
locate the returns in the stagnant zone to remove unwanted warm or cool air. For cooling, a high sidewall or ceiling return will remove warm air from the space (Figure 1).
For heating a low sidewall return will remove warm stagnant air (Figure 2).

The office is 10x18 roughly. If it's cloudy out its fine. If it's all sun then it can get warm enough to notice. I'll try to post a pic

Originally Posted by Jerry gallman

Our new office has the return air and ac register located right next to each other. Within 1 inch. Is this a problem?

Originally Posted by Jerry gallman

The office is 10x18 roughly. If it's cloudy out its fine. If it's all sun then it can get warm enough to notice. I'll try to post a pic

Yep!! Problem.

*in the Summer you could try restricting 1/2 of the return on the supply side ( couple of pieces of paper should stick to the return when it's pulling air.)

Originally Posted by Jerry gallman

The office is 10x18 roughly. If it's cloudy out its fine. If it's all sun then it can get warm enough to notice. I'll try to post a pic

Although from the photo it looks like a bad situation, the picture doesn't tell all. I suspect that the OP may have asked the question as a self-help solution on how to fix an AC problem. We really don't know what the real problem is and do not have all the facts. The location of these two registers may not be the solution to his problem.

The picture indicates that the supply register may be a 4-way register and the return is larger and it is an egg crate type.

To answer the OP's question though, in general you should maintain some distance between supply and return. Distance can be achieved through physical separation or design characteristics of the registers or grilles. Supply registers should be designed to discharge air at a higher velocity than the return grilles and should be selected based on air velocity and throw distance. The return grille should be designed at a lower velocity than the supply.

With that said, the return register may effect the throw of the supply register somewhat, but it's capture velocity wouldn't be high enough to notice in this small sized room. The supply air velocity would overshoot the most of the effect of the return grille.

Bottom line - You should contact an HVAC professional for solutions to the problem.

The windows do not allow direct sun in. Front side looks out onto a covered service drive. Non ac. The other side to the inside of building. No direct sunlight. Thank you all for the replies.

Jerry

Why not get an independent assessment from another HVAC company?

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Jerry

Why not get an independent assessment from another HVAC company?

Originally Posted by Raymond Wand

Jerry

Why not get an independent assessment from another HVAC company?

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Jerry

Why not get an independent assessment from another HVAC company?

It's the mans office.
He has no control over the HVAC contractor.
Just trying to regulate his work environment.

Originally Posted by Billy Stephens

It's the mans office.
He has no control over the HVAC contractor.
Just trying to regulate his work environment.

Changing the distance between registers won't help.

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Originally Posted by Billy Stephens

It's the mans office.
He has no control over the HVAC contractor.
Just trying to regulate his work environment.

Changing the distance between registers won't help.