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View Full Version : Where are the biodiesel powered A/Cs?



star882
02-03-2006, 10:30 PM
It's known that used vegetable oil from restaurants can power diesel engines. Why hasn't anyone thought about making a central A/C that runs on used vegetable oil? That's particularly useful at the restaurants themselves, since they can just use their old vegetable oil instead of pouring it down the drain.

jockfrost
02-03-2006, 10:49 PM
why not get an old diesel engine and connect it to a belt driven compressor and set to idle at 1500rpm the approx speed of a four pole motor and fit unloading heads for cap. control

i wonder how efficient it would run

nova
19-03-2006, 11:43 AM
I quess it wouldn't run for long and for sure it'd be quite expensive with current diesel engines. B5 biodiesels are accepted to use in diesel engines w/o any modifications, but all above that will require lots of expensive modifications. For example using biodiesels above B5 in Thermo King Yanmar engines will shorten mainenance intervals from 3000 hours to 500 hours. Also injector inspections / cleanings are required in 500 hours intervals.


Regards,
Nova

Andy
19-03-2006, 12:04 PM
It's known that used vegetable oil from restaurants can power diesel engines. Why hasn't anyone thought about making a central A/C that runs on used vegetable oil? That's particularly useful at the restaurants themselves, since they can just use their old vegetable oil instead of pouring it down the drain.

Cost:) when electric becomes expensive enough the technology will be harnessed. Besides they would need alot more oil than one restaurants could produce to A/C it.

Kind Regards Andy:)

shiftless
24-07-2006, 04:06 PM
Hi guys, I beg to differ. A 6HP slow-speed Lister diesel can use as low as .15 gal/hr at full output. In addition they are quiet, and in a well insulated shack are basically noiseless. There are also 12HP or even 20HP engines of this design available, produced in India. There is no need to convert the fuel to biodiesel, just filter the waste vegetable oil and run it. Loop some coils of copper tubing in the fuel tank and use engine coolant to keep it nice and hot. The waste heat could be used for other purposes too, say heating in the winter. You could have some valves and a separate fuel tank for starting and stopping the engine on regular diesel, but for convenience I would just leave the thing running 24/7. It will use only a minuscule amount of fuel when not under load. IMO this is a very good idea, definately worth checking into.