At 11:57 PM +1100 3/2/99, Jack Brooks wrote:
>Putting the fan in front of the radiator partially blocks the radiator,
>inhibiting the flow of air and cooling. A "puller" fan is superior in
>performance to a "pusher" in this respect.
A pusher fan will block the air flowing into the radiator whereas a tractor
(puller) fan will block the air coming out of the radiator. Is there
likely to be any great difference in efficiency? A pusher fan will disrupt
the flow of air through the radiator more than a tractor, but after it
comes through the grill it is likely to be fairly turbulent already.
In either case, electric fans normally windmill when travelling at any
significant speed and present much less obstruction to airflow than their
appearance would suggest.
An argument can be made that a pusher fan increases the pressure, density,
and heat transfer capacity of the air flowing through the radiator. A
tractor fan does the opposite. But I am not sure that any of these issues
count for much - space for the fan and simple convenient mounting points
could be more important.
>Since I am concerned about total
>amps used for a given amount of cooling, it makes the most sense to install
>the most efficient configuration, especially since I am getting rid of the
>mechanical fan altogether and have lots of room for a fully shrouded fan.
The electric fan will run when the car is stationary or moving slowly. In
these circumstances the fan is creating the airflow not blocking it. It
should not run very often and unless your electrical system is marginal it
should cope. What the generator/alternator cannot supply will come out of
the battery which will be replenished when the fan stops. Fans typically
draw about the same current as the lighting system, so the fan should
create no problems during the day. You could test it with the lights and
fan operating together to see how the electrical system copes.
Trevor Jordan
74 TR6 CF29281U
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