it's just bigger stuff with more expensive parts if you smoke one out. it will intimidate you, but you'll get used to it. ... the one brand I don't understand is trane.... never get how that thing works. the basic principal is the same. as built unit will jog your brain a lot more, but it's just similar. I work with a lot of packaged rooftop, which is just a glorified 80% furnace with AC coil.... you will run into alot of junky one that needs to get going just for one more season for the last 20 years....

oh don't puncture the roof, they really hate that. or if you do make sure you hide it really well.... lol