# Dry ice special effects in a plane? **URL:** \ **Category:** Factual Questions\ **Created:** [April 3, 2003, 6:48am UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151 "2003-04-03T06:48:39Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![quarrossimo](https://avatars.discourse-cdn.com/v4/letter/q/22d042/32.png) [@quarrossimo](https://boards.straightdope.com/u/quarrossimo)\ **Post date:** [April 3, 2003, 6:48am UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151/1 "2003-04-03T06:48:39Z")
Recently, I travelled by an [ATR 72-500](http://www.luftfahrtmuseum.com/img/620/n331/33124.jpg) aircraft. While I was waiting for takeoff, what seemed to be dry ice special effects “smoke” started pouring from the vents. Not being a very frequent flier, I was, naturally, quite frightened. But I seemed to be the only person bothered, as all the others went on unconcernedly with whatever they were doing. This went on in fits and starts throughout the flight, even after takeoff. What was happening? 😕 ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [April 3, 2003, 6:52am UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151/2 "2003-04-03T06:52:38Z")
Could you smell it? If not, was probably condensation from the air conditioning system. Under certain conditions this has happened in several larger aircraft I have flown in and it once even happened in a car once. YMMV ---
**Author:** ![quarrossimo](https://avatars.discourse-cdn.com/v4/letter/q/22d042/32.png) [@quarrossimo](https://boards.straightdope.com/u/quarrossimo)\ **Post date:** [April 3, 2003, 7:08am UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151/3 "2003-04-03T07:08:57Z")
No smell. If it was condensation, should it not have stopped some way into the flight? It kept coming on and off. ---
**Author:** ![Dr.Lao](https://avatars.discourse-cdn.com/v4/letter/d/2bfe46/32.png) [@Dr.Lao](https://boards.straightdope.com/u/Dr.Lao)\ **Post date:** [April 3, 2003, 7:12am UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151/4 "2003-04-03T07:12:48Z")
You mean the air conditioning vents? It was probably just water vapor. When warm, moist air is cooled it is less able to hold water. It is supposed to condense in the air conditioning unit to be carried away. Some of it apparently condensed in the air and came out the vents as steam (or fog or whatever). ---
**Author:** ![quarrossimo](https://avatars.discourse-cdn.com/v4/letter/q/22d042/32.png) [@quarrossimo](https://boards.straightdope.com/u/quarrossimo)\ **Post date:** [April 3, 2003, 7:19am UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151/5 "2003-04-03T07:19:45Z")
Sounds good Dr.Lao 🙂 Does this happen often in airplanes? ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [April 3, 2003, 5:11pm UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151/6 "2003-04-03T17:11:29Z")
More often than you’ve noticed. Don’t worry. It’s perfectly benign and besides - a little more moisture in the air up there now and then would be appreciated! ---
**Author:** ![rsa](https://avatars.discourse-cdn.com/v4/letter/r/839c29/32.png) [@rsa](https://boards.straightdope.com/u/rsa)\ **Post date:** [April 3, 2003, 5:24pm UTC](https://boards.straightdope.com/t/dry-ice-special-effects-in-a-plane/166151/7 "2003-04-03T17:24:22Z")
This occurred on one charter flight that I was on to the Caribbean. The only harm was that some of the vapor would condense on the vents and droplets contaminated with rust would fall staining people’s clothes. The flight attendants handed out vouchers for dry cleaning for those people who got “rained on”.