I’ve flown a 172 with aircon in Florida, which made a big difference on the ground in the summer, mainly due to reducing the humidity (you can open the windows for plain heat). It was a lump in the baggage compartment with a vent in the side of the fuselage, so it might have been the Kelly one already mentioned. It’s not in the POH, so must be aftermarket. The standard ventilation system is below, with the front floor vents offering cold and hot air but the rest of the vents cold only. Annoyingly I can’t remember which vents the conditioned air came from.
This is a pic from the back of a TB20 with the Kelly system. AFAIK the compressor is belt driven and on the engine.
Probably shifting the empty CG a few inches back
These pics were posted on a US user group for the TB20
There were no more but you can see there is a bolt-on “bump” on the front cowling, and quite a large one.
It’s a pity that aircon has not been incorporated better on GA aircraft. All the installations seem a horrible bodge.
And electric ones are difficult to do because of limited available power. A belt driven unit like above can consume say 2HP which is equivalent to 1500W which at 28V would be 53A. Good luck with that! The Cessna 400 / TTX had a large alternator for powering the thermal ice protection system and there was a load of trouble with that alternator because the belt drive was way too small for the torque. I don’t know if that was ever solved.
A belt driven unit like above can consume say 2HP which is equivalent to 1500W which at 28V would be 53A.
Some GA aircraft require AC OFF during takeoff, I wonder why?
Probably because doing so avoids doing an AFMS which details a loss of performance.
Such an AFMS is very difficult (almost impossible?) to get approved. That is why e.g. Socata did the GT as “Mod 151”.
My Warrior -161 had AC when new and much of it (less the engine driven pump) was still there when I first had the plane. Removing the remnants took 50 lb or so off the W&B. I’ve flown 172’s in truly suffocating heat in the Southern US and often wondered about this, but in the US 10,500’ (or 11,500’) is a comfortable crusing altitude and soon removes any longing for heavy and expensive AC!
The only AC I’ve ever flown with is in R44 helicopters. It is very nice on a hot summer day to have a blast of cold air. I guess helis need it more because there is so much glass (well, perspex).
I vividly remember a departure from KLAS many years ago in an SR20 when it was 115 F, and my wife wiping the sweat from my eyes so I could see to take off. Could have done with AC there. But never felt the need for it in normal Bay Area conditions.
