How much clearance in front of return?

[eialfonso]

What is the minimum clearance that should be left in front of the return?

We are bulinding a built in bookshelf and we have a return up against one of the boohshelf's side and were wondering if we can get real close to the return (2-6in) or if we should move the return?

Thanks

[mjr]

You should move either the return or the shelf. 2-6" isn't going to be enough.

[cem-bsee]

I disagree -- 6" would be ok -- air can go around corners -- 2" might work -- depends upon how much of the return is being blocked, eg: how wide the shelf side is -- the size of the return -- to prove this point, one could measure the static pressure drop thru the return with a board in the proposed place at various distances from the return. One might measure the blower motor amperage, accurately, and watch for any change -- pressure will probably be more accurate.

Evidentally the filter is not inside this grill?

[marauderx]

Are you looking to snuggle up to the whole return or only part of it? 2-6" for the whole return is too little, as your velocity around the shelf will need to increase, gathering more dust and crap around it since it is now adding to your system pressure. If it is only partial (10-20% blocked) the air will be able to flow freely by the shelf, and not be a major cause of concern nor make your fan struggle any more than normal. You have any pictures you can post up? They help considerably in most cases.

[Reliant Air]

Will the bookshelf cover the rntire return or just part of it? Also, is this the only return in the house? What size is it?

[docholiday]

Move the return and build your bookshelf all the way to the wall. Who wants to vaccuum a 2-6" nook between the bookshelf and the wall?

[contactor]

It really depends on the return size and application to other returns. I would design the bookcase with an open back if possible to accomodate access. If you have a return air grill( 6X14) say in a 2x4 wall,16" on center, You have 50 sq." of inside air space of the cavity of the 2x4 wall.Thats all it will draw. Perimeter of a 6x14 grill at 1" clearance is only 40 sq. " . Back it up to 2' ,youll be OK. If its your only return, thats another story.

[eialfonso]

Thank You for all the replies, I belive I have anough info to make an informed decsion or at least to ask the contractor the right questions.

[pstu]

Has anyone thought through the subject of filters? Is this going to be the kind of return where you have to move the bookcase in order to change the filters? If it is, there seems no other choice but to install one of those "rock-stopper" filters which never does a whole lot, but lasts forever.

Best of luck -- P.Student