how many cold air eturns chould one furnace have? and how long should a cold air return be? and can a cold air return be in the same room as the furnace? i am really stuck i amremodeling my basement bathroom and the cold air return runs right thru the bathroom making the ceiling about 5' tall and would like to move but eed the questions first. if any one can i appreciate it. thank you
A return can not be within 10' (in the same room) of a gas furnace or water heater. If both are electric then it can be right on the return drop if you want.
How many returns depends on alot of factors like static pressure, size of system,size of duct, length of duct including equivalant length of all fittings and size and more.
Easiest way to find out where that duct in the bathroom can move is call a local HVAC contractor. They will provide you with a plan on how to do it right and a bid to do the job. Do it yourself with their plan if you choose to. Consulting fee is cheap.