Solar Air Conditioner
Okay for all boondockers needing to run air conditioning, gotta love ingenuity! :B Solar Air Conditioner
Forum Discussion
Jimindenver, that is definitely a cheap way to go if you only need 5,000 BTUs of cooling. It's similar to the AC in my Aliner which I run with a 1,200/1,500 watt geny. However it only has an EER of 11.2, not bad as far as window ac's go, as many this size are only in the 9.5-10.5 EER range. The AC I linked to however has an EER of almost 21.5 meaning it will produce roughly twice the cooling power from same wattage draw. So if you truly only need 5,000 BTUs of cooling most of the time it will only be drawing around 250 watts with it's variable speed compressor and scalable power draw/output. Plus, being a native DC device you don't have any inverter loss, making it roughly 10% more efficient than converting from DC to AC power that a window unit AC would require. Remember that 3.9 amps is at 120v which will convert to a about 43 amps at 12v (assuming a 90% efficient inverter.) 720 watts of solar panels might keep up at peak sun, but just barely.
A better comparison is to an Arctic Breeze 12v truck AC. It draws 600 watts, making 8,000 BTUs, but like most ACs it must cycle (turn off and on)to reduce its cooling output. 8,000 BTUs should easily be enough to cool a single RV bedroom if you have decent insulation. My Aliner barely gets by with a 5,000 BTU AC, but it is tiny, (less than 100 sq. ft.) only slightly larger than an big RV bedroom, though it is well insulated. This unit draws 45 amps at 12 volts, but it will probably be running only 60% of the time, meaning that your average wattage draw would be about 30, making it much easier for your solar to "keep up" when not in peak sun. Still, 3-4 8-d batteries would give a much more comfortable buffer, and wouldn't be stressing your battery bank as much from the Peukert effect of such a high current draw from a single battery when the sun isn't cooperating.
http://www.arcticbreeze-truckac.com/content/arcticbreezeintro.html
Chip
A better comparison is to an Arctic Breeze 12v truck AC. It draws 600 watts, making 8,000 BTUs, but like most ACs it must cycle (turn off and on)to reduce its cooling output. 8,000 BTUs should easily be enough to cool a single RV bedroom if you have decent insulation. My Aliner barely gets by with a 5,000 BTU AC, but it is tiny, (less than 100 sq. ft.) only slightly larger than an big RV bedroom, though it is well insulated. This unit draws 45 amps at 12 volts, but it will probably be running only 60% of the time, meaning that your average wattage draw would be about 30, making it much easier for your solar to "keep up" when not in peak sun. Still, 3-4 8-d batteries would give a much more comfortable buffer, and wouldn't be stressing your battery bank as much from the Peukert effect of such a high current draw from a single battery when the sun isn't cooperating.
http://www.arcticbreeze-truckac.com/content/arcticbreezeintro.html
Chip
