Hi,

I want to place a piece of furniture in front of a cold air return vent. The vent is close to the floor. There would be a gap of at least 3 inches between the vent and the back of the furniture. Would this pose any problems with the vent being able to function effectively?

Thanks!

It's always not a good thing to do, but sometimes it's inevitable. Your not cutting off the air supply, so in that sense it's good.

The only real change might be creature comfort. The room may be cooler than it was before if we are talking the heating season.

If you have AC, hopefully you have hot air returns at the ceiling and have bothe such that they can be alternately closed/open depending on he season.

If you block an air vent ( feed or return ) one may not make too much of a difference to the operation of your furnace / AC but if two are blocked, you could be in big trouble with the AC coil freezing up and the main limit of the furnace tripping due to lack of PROPER air flow across the heat exchanger... AC systems need aprox 400 CFM per ton of cooling and a furnace has a "rise" spec. that is listed on the ID label that tells you the difference of air temp between the feed air and the return air temp should be with ALL feed and returns open and a clean air filter, for the unit to operate correctly... and to have comfort and long term heat exchanger life...