Rapid Air Unit with vav boxs

[honesttech88]

Has anyone ever seen a Rapid Air 4000 series hooked up to ductwork and 10 vav boxes and a bypass and seen it work correctly

[heatingman]

NO. Ive never seen a rapid fire unit in an application where there was any ductwork to speak of. I'd venture to say, that this set up is not at all approved. How can you regulate the air flow, when the combustion air is the same air stream? I'd guess you're makin CO and lots of it, and might just kill someone, or the burner just wont fire.
Unless Im thinking of a differant Rapid Fire unit, there is no heat exchanger and you rely on the airflow to bring in fresh combustion air.

[union boy]

He did say with bypass. but still it would be the first for me also.
usally they are for makeup air?

[maxpower]

If your unit is constantly bringing in all O.A. and your by-pass is vented to the outside also. I don't see why it wouldn't work.