Timeline for What powers the air-conditioning on commercial planes?
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
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| Oct 24, 2020 at 12:26 | comment | added | John K | They are using the same hot bleed air, being tapped off the engine compressor (or APU), for either. As I said, some of the hot bleed air is bypassed around the pack and mixed downstream with cooled air to get the final temperature going to the distribution system. If cooling the cabin, more is going through the ACM to be chilled, if heating, most is being bypassed. | |
| Oct 24, 2020 at 4:18 | comment | added | Keith McClary | Airliners at cruising altitude need cabin heating, not cooling. Can they use waste heat from the engines, like smaller aircraft or (fossil fueled) cars? Is this worth another Question? | |
| Oct 2, 2020 at 0:10 | comment | added | John K | @JWalters Ok ok...you think too hard lol. | |
| Oct 2, 2020 at 0:01 | comment | added | J W | Neither "airline" nor "airliners" are defined terms. Many airlines use piston or turboprop powered aircraft, including the Cessna 402 and 208, Beech 1900, etc. | |
| Oct 1, 2020 at 23:54 | comment | added | user22445 | Excellent answer @john K | |
| Oct 1, 2020 at 14:27 | comment | added | John K | Although I thought the reference to "airliners" at the top of the post covered it, I added some additional text. | |
| Oct 1, 2020 at 14:26 | history | edited | John K | CC BY-SA 4.0 |
text added in response to comment
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| Oct 1, 2020 at 13:25 | comment | added | J W | If you were speaking narrowly of only a subset of large jets then you should edit your post accordingly. The aircraft I referenced are by definition Large Turbine Powered Aircraft. Moreover, the Citation V/Ultra does have wing boots (which are effective) in combination with heated leading edges, but later iterations in that model and similar designs have complete heated leading edges. Likewise some varients do not have the VCM, and only use the ACM, which is fully powered by the engine bleed air. Your assertions that these engines do not produce sufficient bleed air are erroneous. | |
| Sep 28, 2020 at 17:06 | comment | added | John K | Well those are what I referenced in my comment above. They use vapour cycle because the engines can't produce the bleed flow. The Citation V has boots for the same reason, which are a terrible alternative to heated LEs and are only used because there is no alternative. My post is about airplanes like Regionals and heavies, say 50000 lbs and up. | |
| Sep 28, 2020 at 10:53 | comment | added | J W | The CE-560 (a §25 large transport category) uses a closed vapor cycle machine using freon to supplement the ACM. See also the CE-525 series, the CE-550, etc. I'm just throwing out examples that I am familiar with. Part of the rational with this design is that the vapor cycle machine can produce very effective air conditioning from EPU electrical power alone. | |
| Sep 27, 2020 at 16:04 | comment | added | John K | I'd be interested in an example of a large aircraft using a refrigerant in a closed system, which is what vapour cycle refers to.Even the bleedless 787 uses electric compressors to provide the hot high pressure air in place of bleed. Cooling is still by a bootstrap Air Cycle Machine, compressing air to get it hot, taking away the heat, then letting the pressure drop. Small corporate airplanes,especially turboprops, may use vapour cycle refrigeration systems because their engines can't produce the bleed volume. The earlier Citations had to use boots on the wings for deice for the same reason. | |
| Sep 27, 2020 at 15:51 | comment | added | Bianfable | @JWalters "Many large turbine (jet) aircraft use vapor cycle machines": really? I've only ever seen PACKs (Pneumatic Air Cycle Kits) on jets, I've never heard of one with vapor cycle. Can you give an example? | |
| Sep 27, 2020 at 15:32 | vote | accept | blacksmith37 | ||
| Sep 27, 2020 at 11:57 | comment | added | J W | This answer provides incorrect information regarding vapor cycle machines on jet aircraft. Many large turbine (jet) aircraft use vapor cycle machines in the air conditioning process. | |
| Sep 27, 2020 at 1:06 | history | answered | John K | CC BY-SA 4.0 |