How often should you change filter in home air conditioner?

My a/c tech says twice a year. Fall, so you're ready for heating season and Spring so you're ready for cooling season. Those are the 2 times a year he comes to change ours and we have the special allergy system.

Every 2 months is sufficient. My husband is an air conditioning/heating service man for 5 yrs. Leaving a filter gooked up with junk doesnt allow your system to circulate properly...and your breathing all that junk it. It goes into your duct work.

Every 2 months, for people with allergies, personally I don't change mine but once every like 3-4 months

The rule of thumb is change them every 3 months, but I would check/change them monthly or each time you get a bill. Better to over-change them than pay for repairs or high utility bills.

how often do change any filter. conditions vary. the best way is to plan and simply check it once a month then you can determine your conditions for replacement. if you live in a dusty area check it more often. opinions vary so eyeball it.

I own an A/C company and I change mine every month. They are a dollar each, whats the issue ?

Clean monthly my window units.

every month, & clean the outside housing.