Eletric Kite Inflation

[spork]

n is the number of moles present

I should add that I mean moles of gas (a number proportional to the number of molecules present), not small burrowing mammals.

I'm not sure how to take that - was the jacket on or off?

This also assumes that air is an ideal gas, which it isn't.

Agreed, but I don't calibrate my speedometer for relativistic effects for the same reason I don't worry about how much air at 22 PSIA differs from an ideal gas.

However [takes sports jacket off] I'm not about to try to calculate the significance of this because this is a thread about pumping up kites, FFS.

Well considered.

[ronnie]

The CO2 inflator.

I'm left wondering

How do you know when enough is enough?

[Kamikuza]

Got there in the end - thanks Weetabix, that makes more sense than the reasons I've seen on the interweb. And thanks to Spork, for reinforcing my point despite the poorly understood or explained erm explanation

I don't calibrate my speedometer for relativistic effects for the same reason I don't worry about how much air at 22 PSIA differs from an ideal gas.

How much difference it would make at 8psi in a LE? Probably not a whole lot ...

So anyway ... what was decided - little compressed bottles a good idea or not?

[edt]

Got there in the end - thanks Weetabix, that makes more sense than the reasons I've seen on the interweb. And thanks to Spork, for reinforcing my point despite the poorly understood or explained erm explanation

I don't calibrate my speedometer for relativistic effects for the same reason I don't worry about how much air at 22 PSIA differs from an ideal gas.

How much difference it would make at 8psi in a LE? Probably not a whole lot ...

So anyway ... what was decided - little compressed bottles a good idea or not?

it's cool but seriously expensive, you can buy the little co2 containers for $100 and get them refilled at $25 every 3 or 4 sessions by a welding supply store or beverage dealer, or you can buy a high pressure (3,000 psi) system for $3,000 or $4,000 and refill them with air, or you can design a low pressure system (100 psi or less) for about $300, which unfortunately will be tied to your car since if you are using only low pressure air, you would need a container as big as a keg of beer, no good for setting up on the beach. If you use a compressed air system the air will be cold coming out, just something to watch out for, not necessarily a problem.

Battery pump systems on the other hand that get up to 10psi range from $100 to $300 are easy to use and portable, watch out for the lower priced "high pressure" inflators since some of the are for mattresses and only get up to 3psi.

This thread left it right about there, didn't get far in comparing all the battery powered electric inflators, that would be a good topic for another thread.

Oh and nitrogen only air systems are a just a scan designed by companies. They like to pretend there is a noticeable difference between ordinary air which is mostly nitrogen and 100% nitrogen. There is a thread over at the car forums about how nobody could tell if their tires had nitrogen or ordinary air unless you told them ahead of time.

[BrisKites]

[spork]

I went to your website to check out prices on your super-awesome kitepump. Couldn't find it. Must be too new. I'd like to rep this innovative new product in the U.S. - is that a possibility?

[BrisKites]

[robertovillate]

Oh and nitrogen only air systems are a just a scan designed by companies. They like to pretend there is a noticeable difference between ordinary air which is mostly nitrogen and 100% nitrogen. There is a thread over at the car forums about how nobody could tell if their tires had nitrogen or ordinary air unless you told them ahead of time.

For "most" day to day drivers they may never notice the difference between "air" and nitrogen - until they make the connection that their air-filled tires require fairly constant attention for proper inflation pressure.. However, almost everyone who races cars uses nitrogen. Even if you just have a nice production car with expensive tires on it Nitrogen is beneficial, for a couple reasons already mentioned: pressure stability and rubber protection. When you are running tires at 150-200mph the temperature of the tires is very hot and regular "air" changes pressure while nitrogen will not. This makes a huge difference in handling and safety.

If you have nice tires on your car and bought them thru a good supplier they will put nitrogen in them for you. It's a nice thing to have nitrogen in your tires if you don't drive the car a lot and don't want to inflate to proper pressure every time your drive. It's not a scam between the bottled gas supplier and tire companies. It works.

Back to original subject: Yes it would be great to know more about & see more product options/prices/suppliers for an effective kite pump.

I did not see a price list for the electric pump the mentioned a few pages back (from Boats to Go in Miami)? Looks very similar to the Scoprega, but maybe less expensive (?). And then again you don't know how well a product like this performs (reliability) until you have a few years of use on it.

The "Volo" refillable bottle is an interesting concept, but the cost and practicality of refilling it make it a non-option for me. The last thing I want to do is start paying $10 to fill my kite PLUS the hassle of running to the gas supplier to fill it for me.

I figure my Scoprega has averaged less than $0.30 per kite inflation over several years so that's worth it to me.

[spork]

It seems pretty silly to compare moist air with dry Nitrogen, and then tell us Nitrogen maintains a more stable pressure. Let's compare apples and apples. How do you think dry air compares with dry Nitrogen for pressure stability?

[edt]

When you are running tires at 150-200mph the temperature of the tires is very hot and regular "air" changes pressure while nitrogen will not. This makes a huge difference in handling and safety.

no. regular air and nitrogen give you the same performance. race cars use nitrogen for the same reason that aircraft use nitrogen. Their tires can reach temperatures of 250 so the tires can catch on fire inside the tire tho they dont say that they say the tires can "oxidize". nitrogen for performance is just another scam that regular people shouldnt bother with.

you can use boyles law and calculate the performance of nitrogen vs air and the characteristics are indentical in terms of performance even for race car drivers but of course they will tell you it is better for all sorts of other reasons they dont understand (they dont know physics after all), but the real reason is so the tires dont catch fire from the inside.