kjpro @ usenet.com wrote:

Problem is, most return ducting won't allow a customer to drop in a pleated
filter and still have the required CFM's for the system to operate
efficiently and without shortening the life of the equipment.




I'm afraid I don't understand the problem here. Most
filters are in the return air plenum. Most modern
systems are designed for pleated filters. So why would
there be a problem with putting pleated filters in the
return?

With my old system I kept on using the old fashioned
(and cheap) fiberglass filters, but it was designed for
them and I didn't want to take a chance on messing up
the system.

Bill Gill