When you install a lot of heating and a/cs for a living, you honestly get used to how you do things! However when you end up getting something odd thrown at you, things can tend to get a little confusing.
This is how it was for me when I worked for this one heating and air conditioner company as one of their most certified heating and air conditioner specialists and had to install a rooftop Heating, Ventilation and A/C system.
This was something I was totally not used to and had only done one time. Installing a rooftop heating and air conditioner device is nothing like installing a proper central heating and a/c. It takes a lot of skill to learn the difference and it is not something they were teaching in heating and air conditioner university back when I went. Because at that time rooftop heating and a/cs were not really common, so they thought to not waste time teaching about them. I ended up learning about installing rooftop heating and a/cs all by myself on my own time through trial and error over the years. I also had a little bit of assistance from the really first heating and air conditioner company I worked for many years ago. They helped me learn the differentials in installing rooftop heating and a/cs verses residential or respected commercial heating and a/cs. But once you learn, you can do it with glee and flying colors. It will all toil out for the best!