HVAC Requirements when Buying

[Taylor Hendricks]

When looking for rental properties, it seems most of the HVAC systems are relatively old that I come across. Do you have certain requirements for these systems for you to buy the property? (Certain age, seller replace them, etc) Or do you just factor this in as an initial cost to replace them right away? 

Definitely a larger expense but also one of the most important, so I'm interested in seeing how experienced investors handle this. Any help is appreciated!