Solar Air Conditioner
Okay for all boondockers needing to run air conditioning, gotta love ingenuity! :B Solar Air Conditioner
Forum Discussion
Reed, since you are already at 48v it seems that adding a high efficiency 12,000 BTU mini-split 48v DC heat pump (actually an AC and an efficient heater) that uses only 1/3rd the wattage of your conventional rooftop ac unit at only $1,800 would be more cost effective than adding enough LFP batteries to triple your roof unit's runtime.
Does the KWH rating of PFP batteries reflect total KWH, or usable (available) KWH (70% of total capacity)? Also, did you have to get a special solar controller or was the Morningstar folks able to reprogram your controller with LFP voltage curves?
Almot, I see your point that their minimal system might provide 10 hours of cooling on day one (as you are starting with full batteries), but what about day two, (as you are starting day two with depleted batteries)? You would definately need more battery capacity and more solar power than that for continuous 10hr/day usage. Perhaps they are counting on the AC's 500w draw being reduced significantly as the inside temperature drops during the evening hours and the AC compressor scales back its output - to say 6,000 BTU or lower. I'm sure that a lot would depend on the load placed on the AC (which will vary widely) to determine its actual current draw and battery run time.
Chip
Does the KWH rating of PFP batteries reflect total KWH, or usable (available) KWH (70% of total capacity)? Also, did you have to get a special solar controller or was the Morningstar folks able to reprogram your controller with LFP voltage curves?
Almot, I see your point that their minimal system might provide 10 hours of cooling on day one (as you are starting with full batteries), but what about day two, (as you are starting day two with depleted batteries)? You would definately need more battery capacity and more solar power than that for continuous 10hr/day usage. Perhaps they are counting on the AC's 500w draw being reduced significantly as the inside temperature drops during the evening hours and the AC compressor scales back its output - to say 6,000 BTU or lower. I'm sure that a lot would depend on the load placed on the AC (which will vary widely) to determine its actual current draw and battery run time.
Chip
