Electric AC?

[giantpune]

That's a fraction - 0.9hp

1 hp = 745 watts

Fox Mustangs had a WOT AC cutoff switch, I'm sure others did as well.

According to these 2 links, its around 3.5HP required to run, which still isn't terrible.
https://www.zena.net/htdocs/alternators/alt_inf2.shtml
https://www.thecalculatorsite.com/conversions/common/watts-amps.php

If using a gasoline engine instead of a diesel, with a slightly lower 2 to 2.5:1 drive ratio, figure on a requirement of about 1 hp per 15 amps of output power

600w @ 12v is 50amp. Divide by their 15, and I got 3.5HP (ish).

 

[TheDude]

These get their power from the battery, and the battery gets its power from the alternator. When you increase electrical load of 12v thingies on a car, the alternator puts more load on the engine to generate more power.

So unless their kit has some sort of switch that gets pressed when you hit WOT, I'm not understanding how the AC compressor is not robbing the energy that you would rather use to push the car faster.

Yeah I don't know and I get what you're saying because well .. it's true. My assumption was that this uses less power than a mechanical model and at times when the alternator isn't making enough power, it'll use the battery as a buffer.

Obviously there's other issues with that, just trying to make sense of what the claims are. I think this really boils down to this compressor is less powerful than the mechanical models and uses less energy as a result. Of course that also means it also won't cool as well.

FWIW - From what I've seen they don't really market this as a replacement for OEM ACs and something we should all be running to. It's marketed more as auxiliary ACs for larger vehicles and for specialty installs like project cars and hot rods.

 

[MikeGriese]

This will make more sense when cars start running 48V or higher power.

 

[rcadd1ct]

Do these kits have some mechanism to turn off the AC compressor when you stomp on the gas pedal? That 10hp they require doesn't matter as much when you're cruising around only using 50HP anyways. But you put your foot down and go WOT, you probably care more about the car going as fast as it can, so you want the AC to be disabled.


View attachment 91931

My termX stealth 4150 has AC kill at over 60% throttle (user adjustable). Also has AC kick to bump the throttle when AC is on at idle.

 

[Don C]

I've been going to do this for a while, this discussion finally got me motivated. I wanted to see what size alternator I'm going to need when my build is finished. This is a snip of the spreadsheet, if anyone wants a copy of the spreadsheet let me know and I'll post it.

 

[Cleveland Crush]

I've been going to do this for a while, this discussion finally got me motivated. I wanted to see what size alternator I'm going to need when my build is finished. This is a snip of the spreadsheet, if anyone wants a copy of the spreadsheet let me know and I'll post it.
View attachment 91988

Please post the entire spreadsheet, I'd like to see it. Thanks.

 

[Don C]

Please post the entire spreadsheet, I'd like to see it. Thanks.

The spreadsheet is attached