Slow down a fan speed.

[Mike Coonrod]

Electrial experts,
I have a hot dawg heater and would like to slow down the very powerful
fan that clicks on after the burn chamber gets hot, it is too loud in my
garage, drowns' out the football game. I looked at the heater itself
and I can NOT select any other options on the control board to set the
speed. Also, the fan on the back of the heater that I want to slow down
has a start capaciter, and I don't know is that is important but it may
be. Can I just look at the amp rating on the fan and add a reostat in
line with the feed to the motor? (I took two years of electronic backin
the 80's but don't use in day in and day out)

I have a call into Modine, the makers of the heater, but they do not
seem that user friendly. Thanks in advance.

Mike in cold Minnesota.

 

[Pop]

There are ways to control inductive motor speeds, but
unfortunately a resistive solution isn't one of them. As you
decrease the current to a motor, the current increases sometimes
to the point of catastrophy. More likely the temp would rise
until an internal winding temperature sensor shuts the fan down.
Sometimes they are self resetting, sometimes not.
Check into motor controllers for a better solution.
Pop
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..
: Electrial experts,
: I have a hot dawg heater and would like to slow down the very
powerful
: fan that clicks on after the burn chamber gets hot, it is too
loud in my
: garage, drowns' out the football game. I looked at the heater
itself
: and I can NOT select any other options on the control board to
set the
: speed. Also, the fan on the back of the heater that I want to
slow down
: has a start capaciter, and I don't know is that is important
but it may
: be. Can I just look at the amp rating on the fan and add a
reostat in
: line with the feed to the motor? (I took two years of
electronic backin
: the 80's but don't use in day in and day out)
:
: I have a call into Modine, the makers of the heater, but they
do not
: seem that user friendly. Thanks in advance.
:
: Mike in cold Minnesota.
:

 

[sQuick]

Electrial experts,
I have a hot dawg heater and would like to slow down the very powerful fan
that clicks on after the burn chamber gets hot, it is too loud in my
garage, drowns' out the football game. I looked at the heater itself and
I can NOT select any other options on the control board to set the speed.
Also, the fan on the back of the heater that I want to slow down has a
start capaciter, and I don't know is that is important but it may be. Can
I just look at the amp rating on the fan and add a reostat in line with
the feed to the motor? (I took two years of electronic backin the 80's
but don't use in day in and day out)

I have a call into Modine, the makers of the heater, but they do not seem
that user friendly. Thanks in advance.

Mike in cold Minnesota.

I wouldn't recommend slowing it down. The fan was designed to run at
that speed for a reason.

Maybe look at replacing the fan with a quieter one of the same speed.

sQuick..

 

[operator jay]

I wouldn't recommend slowing it down. The fan was designed to run at
that speed for a reason.

I agree, and to elaborate for the OP, slowing down the fan may allow the
unit to overheat.

 

[Bud--]

I agree, and to elaborate for the OP, slowing down the fan may allow the
unit to overheat.

If it is gas fired yes.

Old Modine units were a hot water/steam radiator with fan forced air
through it. If it is one of these reducing the air flow shouldn't be a
problem.

Noise, air flow and power consumed fall off rapidly with lower speed,
What I remember is square law for air flow and power vs. RPM.

Do you get a lot more heat than you need - you will loose capacity fast
with lower speed.

Lower speed motor (which can be lower power).
Dual speed motor.
Different fan blade.

bud--