2004 alfa sun air conditioner
Good reply DL. Since Gary doesn't say where he is or how large the RV is, we can only guess about the problem. Does the RV have dual pane galss in the windows? Is it well insulated? If the "291" means that it is 29' long, it is a lot of RV for one air conditioner, at best. And if he is in an area with temperatures well above 90 degrees, he probably will never win. I have two air conditioners in my 35' motorhome and dual pane glass. In 95 degree heat the front unit probably runs about 70% of the time and the rear one around 50%. And that is with a fan blowing part of the air from the bedroom into the front to balance the load. When we were in 105 degrees, the front unit would run from 9am to 9pm each day.
There is a way that you can check the unit to see if it is working properly, quite easily. Just get a dial thermometer and tape, or some other way attach it to the grill where the air enters into the a/c unit. Give it five or ten minutes and then check the temperature and move it to the outlet of the a/c. The differential temperature should be at least 18 degrees. If you a/c lowers the temperature through it by 18 degrees or more, it is working properly. The rest of the story is, how well insulated is your RV, how large, and how air tight?