The Texas heat is not letting up and I had to come up with a plan to get some relief. I wrote about the problems I was facing with just 30 amp service last week and the inability to run both roof top mounted air conditioning units simultaneously on only 30 amps.
The only option was to purchase a small window air conditioner – hoping it would operate on the existing 20 amp breaker that feeds all the ‘house’ circuits in the Old Girl. A Zenith 6500 btu unit was purchased at Home Depot for $149.00. The specification indicate it draws 6 amps when running. The next problem was where and how to mount it. Most RV’s are not window air conditioner friendly
About the only spot available to mount the small window AC unit was the large sliding window above the couch. I decided to build a wooden frame to support the unit for strength and to keep it off the metal frame of the window. I was worried about possible harmonic vibration . Materials used were pine 2×4, 1/4″ plywood to seal the space above the frame and 2 1/2″ deck screws to put it together. Cost was less than $25. The hardest part was getting the measurements exact and working with the curved frame of the window. The horizontal 2x4s brace against the inside of the window frame and prevent the window AC unit from tipping outward. The frame rests on the small lip on the inside of the metal frame and appears to be very secure. A snug fit helps in that respect.
It was a hot, muggy afternoon working up this installation. By the time I was ready to place the AC unit in the frame, the inside temps in the Old Girl had climbed to 89 degrees — with the rear roof top AC unit running wide open and the sweat was dripping off the brim of my hat. I cussed those Day/Night shades as I fought them to get the frame in place. The distinct thought crossed my mind that I would be really upset if the unit overloaded that 20 amp circuit and would not run. Yeah, I would be really pissed. So when it came time to plug it in, I did so with some trepidation. I turned off the roof top unit and fired up the window unit. It worked! I punched the EMS switch on the rear AC unit and it fired up as well! Well alrighty then. Looks like I was good to go. I went out and checked the readout on the Progressive EMS and it was showing 23-25 amps with both units and the TV system running. Not much cushion left but I knew it was going to be close.
I marveled at how quiet the window unit was compared to the old roof top units. It was possible to converse normally and watch TV at sane volume levels. Nice! Within 20 minutes, the inside of the Old Girl had cooled 5 degrees —- during the hottest part of the day. I can live with that.
UPDATE 5/2015 — I just installed a 5k btu window air conditioner in my current 32′ travel trailer. Much cleaner and more professional install AND it will run off of a Yamaha 2000 generator! Read it here