Accounting for rentals

Hi, we are considering to offer the option to rent our equipment to distributors. Currently they have to buy a demo system outright. I need to try and understand how this will affect our turnover, but unsure how to model this in. Say 10% of our current sales will be on rental basis. Minimum rental term is 6 months. It will take 3 years of renting to get our money back on 1 system. Will there be a COS? any help or your own experience with rentals will be greatly appreciated! thank you