Shade is not necessary. The length of the required lineset will matter. So no, is the answer, it just needs to be within the range of distance specified; not too close, not too far. Don't coil it either to take up lengths. As for sizing, size it correctly. All over sizing does is cause short-cycling which can cause it's own issues and in the long term does not do you any favors.anyone have knowledge of mini splits? planning to add one to my detached garage/shop. I found the one I wanna go with based on research, senville 18000btu and I have the electrician that can install, does the location of the outside unit (condenser) play a big part? the best inside location is a west wall and that leaves the unit outside in direct afternoon sunlight, I can shade it with a fence or something I suppose but didn't know if that's necessary.