Replies

1. 
   Greg_Brown | Jun 13, 2001 06:53am | #1

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   I'm bidding a wall unit that will be installed over a return air register. Homeowners wanted to go with louvered doors to allow air to register, I told them there are other ways. First thought was to duct down to toe kick area & install wood grill across toe kick, I don't think the area is big enough. then I thought I could put a wood register on side of cabinet,& duct to that. now I'm wondering if I can get away with making the cabinets shallower & shimming them 3-4 inches away from wall? the register is 32 x 18- haven't been to jobsite so I don't know size of duct behind register- cabinet that will cover register is 45 wide 84 tall- is it the size of duct behind register (area or displacement or whatever) that I have to provide?

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   Ralph_Wicklund | Jun 13, 2001 08:39am | #2

   *Is this the type of return unit that has the filter carrier built in to it? If so then there must be access to change the filter. Perhaps a removeable panel in the rear of the unit.Is this air return in a partition wall? If so, how thick is the wall? Sometimes the stud space is used as the air return duct and is not lined in any way. Even if it is lined, the cross section would only be about 100+ sq. in. in a standard 3 1/2" stud wall. If that is the case you are free? to use your imagination and design one or more decorative/functional features to allow air to reach the return and still have a built-in look to the unit.If you use the plan to hold the unit off the wall 3-4", with a corresponding decrease in depth, your side panels could incorporate verticle louvers running the entire height of the rear 3-4" of the panel - on BOTH sides - and leave the top completely open behind the unit. Just leaving the top open would give you enough air space without the louvers but it would be a nice decorative touch.Knowing the duct size will give you an idea as to the louver size you need. A 4" x 45" toe kick is about 180 sq. in.,before covering with a louver device and a taller kick, say 6", is 270 sq. in. All you have to do is calculate the louver gap size you need and build accordingly. You could also forgo a covered kick and suspend the unit from the wall, leaving of course a 3-4" space BEHIND the lower portion of the unit to expose the air return grill. The lower portion of the unit at the grill would have the shallow depth shelf and the remaining could be full depth. The air would return from under the entire suspended cabinet.

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   piffin_ | Jun 14, 2001 01:21am | #3

   *After getting your facts about sizing of existing ducts, talk to a heating engineeer, preferably the one that did their house.A starved heating system will not only fail to heat but in trying too hard could overwork itself into an early grave or run into high maintainance costs. With the cost of energy already going up who wants to spend more than they need to.as a general rule - every elbow bend cuts airflow by 15% so size of opening isn't the only concern you have. An inline fan booster can over come one problem and add to noise complaints.I feel for you 'cause I'm sure your customers arre much like some of mine. "I don't care. My wife wants it. You figure it out"

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   Greg_Brown | Jun 14, 2001 01:21am | #4

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   see first post pleeze