I bought a Honda 2000 in January and it would start and run my 11,000 btu a/c. Everything was fine this spring using it on weekends, etc. Then, this past weekend we ventured further away from home. At 3000' elevation, the little 2000 just wouldn't start the a/c. Returning home, it started up again. I live at 600' elevation. I knew I was running on the fringe but the altitude put it over the load limit for the little 2000. So, I guess the little 2000 will be getting a brother in the near future.