Guys, I've kinda inherited a house -- the house my wife grew up in we moved into when we got married last year.

Just looking at the markings on the furnace it says it's a Chrysler Airtemp. The model # looks to be CU20-30. Says it "produces 1200" and "CFM at .35". None of the numbers make sense to me and I can't find anything on the web to even tell me the age of this unit. I know it's electric (100 amp power is run to it in #2 wire)

I'm assuming it's pretty old but any idea ?

We're remodelling an addition and want to connect it to the central air unit but the furnace is already having trouble heating the home on the below 30 days so I hate to make it worse. Plus dirt in the crawlspace had slowly crumbled over time and piled itself up on two sides of the furnace. I dug it that out back down to the concrete pad it's installed on but there is some rust at the base of the unit on those two sides.

Just looking for opinions.....time to replace the whole unit or can something be done to get more out of it ? The whole house with addition is only 1500 square feet.

Thanks for any thoughts on the subject.