Aplication - Small split HVAC systems 1 1/2 ton to 5 ton, residential houses and apartment complex. Closet and attic instalations.
I have seen 3 ways a p-trap has been installed in air handlers, just a p-trap by itself, a vent after the drain pan but before the p-trap and a vent after the p-trap.
Question - What are the determining factors regaurding which p-trap constuction is required?
I have my own common sence ideas but would like to hear other opinions.