# Compressed air motors



## NaeKid (Oct 17, 2008)

An Aussie has been playing with compressed air to spin motors that power vehicles. The story goes that one motor with some compressed air will allow a motorcycle to travel around 60 miles .. or a firetruck with six of his motors will allow the truck to get where it needs to go, virtually silent.

According to Wikipedia: http://en.wikipedia.org/wiki/Compressed-air_vehicle

Compressed-air has been used to move vehicles as large as trains, planes and submarines as early as 1863 ...

http://www.motorcycle-usa.com/360/5406/Motorcycle-Article/Green-Speed-Air-Motorcycle.aspx

http://www.drive.com.au/motor-news/the-motorbike-that-runs-on-air-20111103-1mwq2.html


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## Viking (Mar 16, 2009)

I seem to remember reading about a car being built in India that was to be ran by a compressed air motor. The thing I wondered about was the cost of running a compressor and maybe having to carry a small engine driven compressor along to get you home in case of running out of compressed air.


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## LincTex (Apr 1, 2011)

I want to see some energy/efficiency numbers. 

My experience with compressed air motors has been with Gast motors, diesel engine air starters (LOUD!!!!!!!) various air tools (drills, etc..) and other industrial applications. I notice many Amish also use compressed air motors to avoid grid-tied electricity.

I have observed that compressed air motors are inexpensive to manufacture and very long-lasting, but really NOT all that "energy efficient".


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## labotomi (Feb 14, 2010)

Compressed air is one of the most inefficient forms of energy storage and transfer. Every industrial facility I've worked in was always trying to minimize the use of compressed air due to the high cost of operation.


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## cowboyhermit (Nov 10, 2012)

LincTex said:


> I want to see some energy/efficiency numbers.
> 
> My experience with compressed air motors has been with Gast motors, diesel engine air starters (LOUD!!!!!!!) various air tools (drills, etc..) and other industrial applications. I notice many Amish also use compressed air motors to avoid grid-tied electricity.
> 
> I have observed that compressed air motors are inexpensive to manufacture and very long-lasting, but really NOT all that "energy efficient".


Most air motors are incredibly inefficient, due to design not due to the air itself, they are capable of putting out a tremendous amount of torque for their size and weight but this comes at the cost of any real efficiency. Piston motors run on air can be VERY efficient, much better than internal combustion.

The motors that are showing the most promise (and that these guys are using) are a new rotary style that is well into the 90% range of efficiency If you look up "Di Pietro motors" there is some technical data out there. Of course that isn't taking into account compressing the air in the first place, just like electrical motor efficiency doesn't count the generation.

Efficient air motors could be really useful in certain applications, the real problem is the fact that compressed air has a very low energy density


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## OldCootHillbilly (Jul 9, 2010)

I've seen old steam engines run on compressed air before. Seen a big ol scoop shovel what was left way back in the woods brought out that way cause they didn't know ifin the boiler were still any good. Ifin memory serves, it were one a the shovels used on the Panama canal an they wanted ta restore it.

Biggest problem bein, it takes a fair amounta energy ta make compressed air. Now it would be mighty clean though! 

I thin it would be more efficient ta go back ta steam. But then again, I be a old steam boiler man an sorta got a soft spot fer it.


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## Tirediron (Jul 12, 2010)

Steam power came to my mind as I read this thread too, and maybe a combination of the 2 would work well for remote area applications, a large steam powered compressor with a big tank and use air as a far safer remote.


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