I was planning to have some AC coil cleaning service done next year. However, the AC guy told me the old refrigerant will phase out next year and would be expensive to refill. He advice me to have my coil cleaned this year instead. Should I listen to him or find someone else? Does it make sense to clean the coil this late in the season?

Do you have straight air conditioning or a heat pump? it would pay to have your coils cleaned if you have a heat pump, not if you have a straight air system. while R22 is not being manufactured after January, it will still be available for a good while- in fact, recycled R22 is easily available

I know almost nothing about AC so I don’t know the answer to your question. What I know is the the same gas furnace is used for AC and heat. Does that mean anything?

You most likely have a straight air conditioning system. in the summer, the furnace acts as an air handler to move the air thru the ac coil. be careful what is used on the coil; others have suggested using general purpose cleaners and dishwashing soap, but I shy away from this. today’s ac systems are being pushed hard to operate in an efficient manner, and the copper being used is very fragile. approved coil cleaner is made specifically for protecting the materials used to make the coils and will not damage your system. if you don’t feel confident, please call a professional- it will be worth the money!

Having your coils cleaned should have no impact on your refrigerant. Unless you mean having the Freon charge flushed and the Freon and new oil put into the system. Coil cleaning can easily be done by a DYI person. There are normally two cleaners used. One is simply a clean similar to any household cleaner sued
on the A coil in the furnace plenum. Hust spray it on and rinse letting if flow out of the condensate drain. The Exterior Coil cleaner is a much more aggressive. This is designed to not only remove dirt but to dissolve any dead bugs on the coils. Usually they contain fairly high levels of Lye (NaOH) or similar maaterials. These are sprayed on and allowed to sit for 15-30 min and then rinsed completely. These can be purchased at a heating/cooling supply house if you can find one that will sell to the public. If not a strong mixture of the detergent used in dishwashers will do a pretty good job with a power washer if you are careful not to damage the fins on the coils. Again spray it on and let it sit for awhile but not dry and spray it off.

The AC company that did my free inspection told me that my freon is a bit low and probably need about 1lb of refill. The coil that needs to be clean is in the attic. I know almost nothing about AC and not confident if I can or even should do it myself.