# Why are bouncy castles constantly inflated? **URL:** \ **Category:** Factual Questions\ **Created:** [July 9, 2013, 7:03pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069 "2013-07-09T19:03:55Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [July 9, 2013, 7:03pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/1 "2013-07-09T19:03:55Z")
Bouncy castles at fairgrounds etc always seem to have a noisy compressor constantly pumping air into them, which leaks out through the seams, or, in many cases, through open flaps in the sides. Why is this? It seems rather wasteful to have a generator running constantly to keep the air going. Surely it’s not beyond inflatable technology to build a leakproof castle that you can just inflate and leave up, reinflating occasionally if it has lost air - often they are only in place for a day or so at a time, anyway. ---
**Author:** ![Prof.Pepperwinkle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/prof.pepperwinkle/32/13627_2.png) [@Prof.Pepperwinkle](https://boards.straightdope.com/u/Prof.Pepperwinkle)\ **Post date:** [July 9, 2013, 7:12pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/2 "2013-07-09T19:12:13Z")
My guess is: you jump on a leakproof balloon, it’s gonna pop. A whole buncha kids jumping with the energy of their youth is going to keep pushing out the stored air, so it needs to be continuously restored. Of course, I could be wrong. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [July 9, 2013, 7:15pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/3 "2013-07-09T19:15:06Z")
> [@Prof.Pepperwinkle](#): > > My guess is: you jump on a leakproof balloon, it’s gonna pop. A whole buncha kids jumping with the energy of their youth is going to keep pushing out the stored air, so it needs to be continuously restored. Of course, I could be wrong. I’d be surprised if a few kids bouncing up and down on a castle produces more of a battering than an inflatable boat (RIB) doing 40 knots over a choppy sea, and they manage to stay inflated OK. ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [July 9, 2013, 7:23pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/4 "2013-07-09T19:23:03Z")
I always thought that they were designed to be very leaky so that any number of people could jump in it and it would maintain the same pressure (as determined by the blower). The ones that I have rented would deflate substantially in just a few seconds if you turned the blower off and it could re inflate fully in seconds once you turned it back on even if people were still inside of it. In short, the bouncy castle doesn’t regulate the pressure on its own, the blower does. I realize the question is asking why that is but I think it is because the blower combined with a leaky structure can regulate the pressure better than just inflating it once and letting any random number of people jump around in it at any given time. You also don’t have to worry about smaller punctures affecting the operation of it using that design as opposed to a ‘fill it and forget it’ one. ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [July 9, 2013, 8:03pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/5 "2013-07-09T20:03:55Z")
> [@Colophon](#): > > I’d be surprised if a few kids bouncing up and down on a castle produces more of a battering than an inflatable boat (RIB) doing 40 knots over a choppy sea, and they manage to stay inflated OK. But the part of the RIB that hits the water is the rigid hull, not the inflatable tubes. And you don’t deflate and fold the tubes on a daily basis. It’s probably a combination of cost and liability. Making a huge inflatable castle, meant to be deflated and folded up routinely, completely leakproof would cost a fortune. Much cheaper to design it to be leaky and just run the fan continuously. Two 15 amp fans cost about 40 cents an hour. Plus with the fans going even a huge blowout would still lead to a slow deflation, instead of an immediate collapse and small kids falling 20 feet. I’ve got a home inflatable slide, like [this one](http://www.ebay.com/itm/Banzai-Sidewinder-Falls-Bounce-House-water-Slide-Inflatable-Water-Park-/111060110176?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DMRU-220%252BUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D21%26pmod%3D181123318380%26ps%3D54). Last weekend, a seam opened up a 2 foot hole and started venting air. The thing didn’t even collapse, just got softer. ---
**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\ **Post date:** [July 9, 2013, 8:15pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/6 "2013-07-09T20:15:56Z")
> [@Prof.Pepperwinkle](#): > > My guess is: you jump on a leakproof balloon, it’s gonna pop. A whole buncha kids jumping with the energy of their youth is going to keep pushing out the stored air, so it needs to be continuously restored. Of course, I could be wrong. This makes sense. They appear to be designed to allow air to escape in a controlled way when there is a lot of weight on them, rather than uncontrolled and more damaging (at the seams). ---
**Author:** ![Buck\_Godot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/buck_godot/32/6573_2.png) [@Buck\_Godot](https://boards.straightdope.com/u/Buck_Godot)\ **Post date:** [July 9, 2013, 8:52pm UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/7 "2013-07-09T20:52:17Z")
I would imagine the kids being the conniving little devils that they are would consistently find ways to puncture a bouncy castle. Rather then have to find and patch the holes that the buggers put in after each use it’s presumably better to just accept the existence of holes in the design. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [July 10, 2013, 12:49am UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/8 "2013-07-10T00:49:42Z")
Cost. To make them leak proof would make them more expensive. Plus it a small whole were punched in it a repair would have to be made on the spot, and would have to be air tight. The bigger ones have more than one section. The sections are Velcro together. ---
**Author:** ![Ottoerotic](https://avatars.discourse-cdn.com/v4/letter/o/6de8d8/32.png) [@Ottoerotic](https://boards.straightdope.com/u/Ottoerotic)\ **Post date:** [July 10, 2013, 3:54am UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/9 "2013-07-10T03:54:39Z")
> [@Shagnasty](#): > > The ones that I have rented would deflate substantially in just a few seconds if you turned the blower off and it could re inflate fully in seconds once you turned it back on even if people were still inside of it. I think this is a huge factor. Have you ever tried to completely deflate an inner tube? It takes forever. Huge castles can be taken up or down quickly without special equipment which saves on labor costs. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [July 10, 2013, 4:22am UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/10 "2013-07-10T04:22:36Z")
I wonder if a sealed bouncy castle would be _too_ elastic and bouncy, to the point of being dangerous. Air escaping from a hole would add some damping. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [July 10, 2013, 4:24am UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/11 "2013-07-10T04:24:26Z")
> [@Ottoerotic](#): > > Huge castles can be taken up or down quickly without special equipment which saves on labor costs. If that were the only factor, they could easily connect the pump backwards and forcefully deflate it. ---
**Author:** ![Terr](https://avatars.discourse-cdn.com/v4/letter/t/839c29/32.png) [@Terr](https://boards.straightdope.com/u/Terr)\ **Post date:** [July 10, 2013, 4:30am UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/12 "2013-07-10T04:30:54Z")
If you put your hand next to any seam in a bouncy castle, you will feel escaping air. The program (I think it was “How it’s made”) I watched on manufacture of these explained that this is very much on purpose, and without it the strains on the seams as the kids are bouncing would be much higher and would make the product prohibitively expensive, and the bouncing would be much “harder” which would reduce safety of the product. In fact the program credited the inventor of the idea of on-purpose-leaking-seams with creating the industry. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [July 10, 2013, 8:00am UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/13 "2013-07-10T08:00:32Z")
Searching for the inevitable leaks in a “leak proof” bouncy castle would also (probably) be a lot more expensive than running the pumps constantly. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [July 10, 2013, 8:38am UTC](https://boards.straightdope.com/t/why-are-bouncy-castles-constantly-inflated/663069/14 "2013-07-10T08:38:41Z")
> [@naita](#): > > Searching for the inevitable leaks in a “leak proof” bouncy castle would also (probably) be a lot more expensive than running the pumps constantly. Nah, you’d just use a _big_ bucket of water. 🙂 Thanks for the answers, all. It does make sense.