07-23-2014, 02:30 PM
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#1 (permalink)
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Not bad for a machine
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Electric fan when the engine is off or on?
What is more efficient? What is better at cooling? What uses more electric? When should I use my electric fan?
I have it hooked up to a switch on the dash so I can turn it on and off when needed. Just thinking when the best time to use it is.
Does it not make a difference? Hmmm...
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07-23-2014, 02:45 PM
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#2 (permalink)
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It's all about Diesel
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It's not unusual for electric fans to remain running for a while after the engine is shut off, but it might be not necessary at all since the engine won't be generating more heat when it's off.
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07-23-2014, 02:46 PM
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#3 (permalink)
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Not bad for a machine
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Sorry I was talking about during EOC.
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07-23-2014, 02:50 PM
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#4 (permalink)
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It's all about Diesel
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Quote:
Originally Posted by dirtydave
Sorry I was talking about during EOC.
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If the engine is off, I guess it's better to keep the fan off too anyway. Since you'd be coasting, could rely on the air flow  |
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07-23-2014, 03:16 PM
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#5 (permalink)
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Not bad for a machine
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Quote:
Originally Posted by cRiPpLe_rOoStEr
If the engine is off, I guess it's better to keep the fan off too anyway. Since you'd be coasting, could rely on the air flow |
Or have the fan on for extreme cooling?!
No extra load when the engine is running...
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07-23-2014, 06:09 PM
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#6 (permalink)
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Just cruisin’ along
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I'd also say off while coasting. You get plenty of cooling while gliding and once you restart that cool water gets pumped back into the engine.
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07-23-2014, 07:55 PM
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#7 (permalink)
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It's all about Diesel
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Quote:
Originally Posted by dirtydave
Or have the fan on for extreme cooling?!
No extra load when the engine is running...
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Under a low load it would probably not worth the "extreme" cooling, since it would still impose a little load on the electrical system. |
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07-23-2014, 08:15 PM
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#8 (permalink)
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Cyborg ECU
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An electric fan runs off the battery, not directly from the engine. So its load is rarely or never borne directly by the engine at the moment of the fan's use. At least it is not easily predictable when the electric load will bring on the alternator to charge the battery. Run it during EOC or during engine-on pulses and I am not sure it will make a difference.
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See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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07-23-2014, 09:03 PM
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#9 (permalink)
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Human Environmentalist
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Running the fan with the engine off (alternator off) is the least efficient way to run. The lead acid battery is extremely inefficient at charge/discharge, so running the fan from the alternator output is better.
Regardless, the fan should not be manually controlled. It needs to come on when the engine is too hot, and switch off when temperatures are ideal. The driver should not be distracted with trying to control temperature when the thermostat does an excellent job of this already.
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07-24-2014, 02:29 PM
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#10 (permalink)
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It's all about Diesel
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IIRC he was considering an alternator delete.
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