How do I find out how old the A/C unit is by the model/serial # and what Seer it is? The unit # is RACB-042JAS. Buying a house and need to determine if A/C is still any good.
Thanks

I would contact a home inspector and pay the few $$ so they can check the entire house out. I would call a HVAC company and have haye the equipment checked out.

It makes no difference how old it is. The condition is what matters.

This series started in

RACB-042JAS / Mfg Date: 1983

But I do not know the end of the run date which could have been for a few years.

The middle numbers in the serial number is the date. Ex. 5D302 M2398 12323
Date code is 23rd week of 1998