Unitary AC

Can anyone tell me how to determine the age of a unitar AC unit?
The serial #: W0H9087299. I have never run acroos one of these units.

2009 This is the company that makes York

Position 2 & 4 of the serial number

Unitary manufactures several brands including York, Coleman, Luxaire, Guardian, Evcon, and more…

Chuck is correct… 2nd and 4th digits indicate year of manufacture.
http://www.buildingcenter.org/york (style 1)

Yes! I should have mentioned. This is an outstanding site for serial number to date conversions for many equipment manufacturers http://www.buildingcenter.org/

Good place to place a banner ad too.