would not recomend it if your talking in the mechanical room. Now if your furnace is in a mechanical room and you can come off the drop locating the return regester outside the room ....... I'm all for it.
Preffer not having a return where it could possibly pull flu gases down a hot water heater flu or furnace flu if its not power vented or low on combustion air. There are all differant positive and negatives just depending on the installation.
I do like pulling cold air off basement flloor winter and summer as long as I can do it safely. Helps in heating and cooling being both times a year you don't need a cold basement floor
That is a good point given the fact that the drop is close to my water heater. I did have it on my old sytem for many years (15) and it never presented a problem, where all still alive, no CO issues. My utility area is well ventilated, but again it is worth more research. My basement is always cool in the summer and warm in the winter, very dry and finished as a laundry, rec room and workshop. Hopefully I will get more posts on my thread along with some more input.