We have one in our 5th wheel and it's the best thing EVER! It cools infinitely more efficient than a roof top unit. You can run it on a 2k watt Generator. It's dead silent(I always hated how loud the rooftop units are), so you don't even know it's running. We took 2 different trips to Las Vegas in August at 106 degree weather outside, but it's in the 60's inside (so cold I use a blanket). It took my husband and our son in law about 3 hours to install and within 30 minutes of setup at the campsite the RV is at a comfortable temperature. The only thing we do extra is use a fan to move the air around more evenly.