Installed in 91. 1700 hours on engine. I have owned the boat for seven years use the refrigeration daily for 3 or four months here in the Pacific Northwest, but 1/3 of that time is on the 110v backup. Typical run time on the ED is 1 hour or less per day to keep food cold and meat frozen. My valve is on the outside in the engine compartment. Other than the belt, I have done no maintenance and have never had a problem.