Quote:
Originally Posted by mysocal911
Always good to do some basic calculations:
1. Typical A/C compressor power demand - 4 hp = 3,000 watts
2. Typical battery/alternator current; 3,000 / 12 = 250 amps, which results in R* I^2 losses in the wiring most don't consider.
The alternator's current output at near idle RPM needs to support over 100-150 amps for acceptable A/C performance, e.g. @ traffic light.
Converting to a DC compressor @ 12V laughable!
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'Typical' numbers are just that.
You agree that high voltage electric AC compressors work in electric vehicles, yes?
The Toyota Prius uses a 20cc compressor. It uses between 1000 and 1500W of input power and delivers between 2000 and 3kW of cooling depending on where you set the dial.
We are using an 18cc compressor which we usually run with an input current of 75A, giving an input power of around 1000W and a cooling capacity of 2600W. So, we are not far off the Prius but the 911 has a much smaller cabin.