Yes it is a good Q how it would be plumbed into the cockpit. Presumably same way as the existing engine driven systems.
For a retrofit system, it could go into the rear cavity and just blow the cold air in from there. GA cockpits are small enough.
An electrically driven compressor has the big advantage that it can be driven from a variable speed (3 phase brushless, nowadays) motor, so you can get exactly the amount you need and don’t get the issues with varying engine RPM.
Interesting video. Shows no system detail but it sounds like they did what I am proposing 
They blow the cold air in via vents in the headliner, which makes for a much easier installation than connecting into the existing air outlets. 50A is a LOT though. They show some C172s – no way can you find 50A on those.
You can even find 70A in a 28V Cessna with upgraded wiring and a PlanePower AL-series alternator.
I installed a 200 amp alternator on the TIO-520 in a Cessna 207 to power survey equipment, it can be done. But it’s a big job, with lots of rewiring. There’s a special belt required for the high power alternators. Still, I worry about the starter adapters doing that. The 207 didn’t last long enough for the adapter to be a problem, the survey pilot oopsed into a mountain with it. It was amusing during my testing, to consume all of the electricity the plane was making (which was converted to household 110 VAC by inverters) I ran a household radiant heater on the right side of the cabin in flight. Happily, that was winter testing, so the ample heat was very welcomed!
From my AC work on the larger planes, I can tell you that the space requirements and weight of an AC system make them pretty impractical for GA planes. I think Piper offered AC as an option on some Cherokees (and probably larger types), but I have never seen one, not too popular – at least in Canada.
When I did the testing of one of the Twin Otter AC systems, it was a Maldavian Twin Otter on floats (so a bit of extra testing regarding possible splash water effects). It was in the high 30C’s each day, so we really appreciated the AC. That said, the system pumped the cool air into the cabin from the back, so further back in the cabin was cooler. There was little effect in the cockpit. Since then, I have amended the approval to include ducting of cool air to the cockpit. The Twin Otter has just enough room for ceiling ducting, GA planes, not so much!
My very low cost solution for my modest C 150 (and a 172 taildragger I borrow from time to time) is to take a door off for local flights. Lots of circulating air!
Did that belt go onto the existing engine pulley?
You can even find 70A in a 28V Cessna with upgraded wiring and a PlanePower AL-series alternator.
Sure you can get 70A alternators – I have one too – but the plane itself will draw something. A typical load analysis for a well equipped SEP comes to quite a lot.
Diamond IFR certified all-systems on G1000 + GFC 700 setup adds up to 28 amps on 28 V or alternatively 23A with the KAP140 autopilot. So difficult but not impossible.
Or maybe these guys are just plain-out lying who knows.
28A for aircon is very doable on a C172 and above class of SEP.
But 50A+ as discussed earlier would need an unusual alternator, not the normal 70A size which is widespread in GA, right up to the “IO540/550” level.
There is the ALT-FLX which is 150A, which is pretty amazing, but there is zero field data on whether anybody has installed it. I expect it would need a field approval, although if one was doing an aircon STC that would include installing that.
I’ve just seen pics of a Swiss based TB20 with the Kelly aircon. It looked quite a neat installation. Ducts everywhere
Just seen this thread… I’ve flown several R44s with A/C. Factory built-in of course, but still they must find room for it somewhere. An R44 isn’t exactly spacious.
johnh wrote:
An R44 isn’t exactly spacious.
Nor is it a payload champion.
