I would say, Yes. As window air conditioners are basically an entire heating and cooling unit in a single box, they tend to weight from 40 pounds to even 80 pounds. Thought there are units below 40 pounds, it would take a good amount of research to find. But this systems come with precise instructions on how to install and secure them. Hence the weight on the system should be a concern once they leave your hands and latch onto to the window.