foxontherun wrote:Below is a snip from when I did an initial test using shore power; you are pretty much on the money if I did my calc correctly. I thought I had some data from where it ran for long periods but can't find it at the moment.
Harry
Re: Window Air Conditioner Intake/Exhaust
Post by foxontherun » Tue Jul 07, 2020 9:42 pm
I have completed the construction of the AC test and ran the initial 6 hour test today. Temp in trailer at start was 93 degrees with 48% humidity; west side of trailer in the sun all afternoon. AC is temporarily built into the side door on the east side of trailer which receives sun until early afternoon. Test was from 2 PM to 8 PM. AC used 3.35 KWH, startup was 4.3 amps if I read meter correctly. The interior temperature was 64 degrees 45% humidity at the end of the test. I was impressed with how cold it was in the trailer. I didn't think it would get that cold in such a short time with the trailer in the sun all afternoon.
Just a caution: 3.35 kWhr = 3350 Watt*hours. Divide that by 6 hours and you have 558 Watts, which sounds like it's in the ballpark. Divide that by 120 vac and you have 4.65 amps, so the 4.3 amps sounds about right. But if you run that on a 12 volt battery, the battery will have to supply ten times that much, about 46.5 amps, ignoring the inefficiencies of the inverter. Can the battery even supply that much? How big is your battery and how long do you want to run the AC? I didn't look closely at the rest of the thread, but be sure your wiring and interfaces up to the inverter can handle that current!
Generally, folks have done the calculations and decided it's not practical to run a conventional AC off of the size batteries most of us have in our teardrops. (Bruce has a van built around his electrical system, so that's different.)
Don't want to sound discouraging, but don't want you to get into dangerous or costly trouble either.
Tom
