Computer Fan - Really Loud?

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alexbrand

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Why not just wire the fan in so that it switches on and off with your compressor?

If you have the thermostat probe towards the top of the fridge it should in theory be the warmest place inside it. When the compressor cuts in so does the fan. This way it only works when its needed.
IMHO it's needed all the time, as long as you want the temperature really 'controlled'. Imagine a bottom fermentic yeast close to the fridge's bottom. It might besome degrees colder than at the top where the thermostat probe is.
In the moment the compressor (and the fan) stops the cold air will fall down to the bottom. But the fridge keeps on cooling for a short period longer than it really runs. So why not let the fan run all the time and let it try to get a homogen tempered enviroment?

Alex
 

pokolbinguy

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I wonder what it costs to run a 6.5v fan at 500mA a day... would be interesting.... Anyone know how to work it out???

Pok
 

scrogster

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Nearly $30 for a computer fan? Don't you guys have annual hard rubbish collection out your way? Walking up and down the street stripping bits from abandoned computers should yield you a load of perfectly good computer fans for nix.
 

alexbrand

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I wonder what it costs to run a 6.5v fan at 500mA a day... would be interesting.... Anyone know how to work it out???
Well, in theory your fan "needs" 78 watts per 24 hours (P = U * I --> 6.5V * 0,5A = 3,25VA --> 3,25VA * 24h = 78watts/day).
How much do you pay for 1 kWh?

Alex
 

pokolbinguy

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Nearly $30 for a computer fan? Don't you guys have annual hard rubbish collection out your way? Walking up and down the street stripping bits from abandoned computers should yield you a load of perfectly good computer fans for nix.

Not when you live in the country.

Pok
 

Ross

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For best performance, you want the fan running all the time; they cost bugger all to run. I'm amazed more guys don't rig them up in there regular fridges as well, they make a huge difference to getting a consistant temperature & speed up chilling of kegs, fermenters etc. I think it's Bonj who's got his rigged to switch off when the lid is opened; this would be the perfect senario, as you don't want to be disturbing the air when the lids open.

Cheers Ross
 
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Just rigged up mine yesterday after seeing the interest in this thread. 12 volt 80mm fan from my old computer cost nothing and the guys at Jaycar in Frankston sold me a 12 volt 500 mah power pack for $16 and threw in a connector as well. Kegs are now happy at 3-5 degrees in freezer. I even managed to adjust the thermostat up a degree or two. :D
 

fixa

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I got a 240 volt fan from Dick Smith, can't remember how much, around $25 i think. Plugs straight into a timer, and i run it 10 mins on, 10 mins off. dunno why, i just do. It's not too noisy, not as noisy as the font pump anyway. Saves messing around with transformers though..
 
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bindi

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I run a computer fan that cost bugger all and run it on 7.5v :)

Fan_web.jpg
 

Screwtop

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Well, in theory your fan "needs" 78 watts per 24 hours (P = U * I --> 6.5V * 0,5A = 3,25VA --> 3,25VA * 24h = 78watts/day).
How much do you pay for 1 kWh?

Alex
But the strain of pushing all that heavy cold air up to the top could make it as high as 80w/day. With domestic Tariff 20 here in Qld at 21.516c per kWh for the first 100kWh that could end up costing as much as 1.72c per day. Better shut off the fan. ;)
 

newguy

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With domestic Tariff 20 here in Qld at 21.516c per kWh for the first 100kWh that could end up costing as much as 1.72c per day. Better shut off the fan. ;)
:huh:

Folks around here are complaining about a kWh being increased to 8c from 7c. I can't imagine what would happen if we were charged 21c. :eek:
 

alexbrand

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But the strain of pushing all that heavy cold air up to the top could make it as high as 80w/day. With domestic Tariff 20 here in Qld at 21.516c per kWh for the first 100kWh that could end up costing as much as 1.72c per day. Better shut off the fan. ;)
Damn I forgot to calculate with these parameters! ;)
May be in the cold enviroment is also consumes more power because the air density is higher and so more power is needed to stirr the air?? Or a higher humidity?

Screwtop, I think we really should shut off all out fans to prevent the earth from further global warming? BTW: if I look through the window at the moment I really would appreciate global warming... ;)

Alex
 

Fatgodzilla

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Damn I forgot to calculate with these parameters! ;)
May be in the cold enviroment is also consumes more power because the air density is higher and so more power is needed to stirr the air?? Or a higher humidity?

Screwtop, I think we really should shut off all out fans to prevent the earth from further global warming? BTW: if I look through the window at the moment I really would appreciate global warming... ;)

Alex
34 degrees Celcius here on the south coast of NSW - is this what they call global warming ................................................................................
................................................................................
........... wait, the southerly has just come in. 19 degrees celcius now - we have been saved. Thanks you Al Gore !!!!!!!!!!!!!!!!!!!
 

clintmo

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I ordered 4 of these fans from pccasegear.com which were on special at the time for $6 each... they are now $11. Incedently i have a camper and i was putting them in there for those hot nights over summer. They are very silent
At the lowest speed setting this model operates at a silent 10dBA. At maximum speed the noise level is still barely audible at 24.5dBA, yet moves an impressive 34CFM.
. I have mine running straight off a 12v battery and they are really silent. If you are after a silent fan get the audible rating... after getting them i read the voltage / amps usage because power consumption is an issue for a campervan. 12v / 0.14 a = 1.73 W which is nothing really considering a light bulb is 75W (in some cases). Im also running a flouro in my van which is 18W, so basically i could run around 10 fans for the same amount of power as the flouro.

so instead of stopping that fan... turn off you lights :)

EDIT "Arctic Cooling 92mm Fan AF9225 PWM" is the fan http://www.pccasegear.com/category320_1.htm
No affiliation yadayada just happy with a product :)
 

milpod

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Thought a few guys may be interested in cheap pc fans,fans
I installed one today,for the hot weather due,but my freezer is cycling more then once a hour now.

Before installation it cycled once a hour at most.

Am I missing something here?Seems to forcing cold out,as opposed to just circulating it.

Yes seals are airtight.Any ideas?

Cheers
 

newguy

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Thought a few guys may be interested in cheap pc fans,fans
I installed one today,for the hot weather due,but my freezer is cycling more then once a hour now.

Before installation it cycled once a hour at most.

Am I missing something here?Seems to forcing cold out,as opposed to just circulating it.

Yes seals are airtight.Any ideas?

Cheers
Before the addition of the fan, the air in your freezer was stratifying - cold air at the bottom, warm air at the top. As time goes by, the layer of warm air grows thicker until it contacts the temperature sensor. That process used to take an hour. Now that you added a fan to stir the air, there is no stratification anymore. The compressor will thus cycle a little more frequently. Nothing to worry about.

The thing to consider is that with the fan installed, the entire contents of the freezer are at a consistent temperature and the temperature swings within it will be much less than without the fan.
 

SJW

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I have a spare phone charger that I want to hook up to a computer fan. The specs on the back say:

Input 240v/50Hz/21mA/5VA
Output: 3.7v/355mA/1.3VA

Would this be suitable to hook up to a 80m comp. fan?

Steve
 

Jye

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I have a spare phone charger that I want to hook up to a computer fan. The specs on the back say:

Input 240v/50Hz/21mA/5VA
Output: 3.7v/355mA/1.3VA

Would this be suitable to hook up to a 80m comp. fan?

Steve
The voltage is a bit low and probably wont even turn the fan and if it does the fan may not be fast enough to provide good circulation. Look for about 8-9v minimum.
 

kevnlis

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Most fans should have a voltage rating on them of the minimum voltage required to start the fan. 7v is pretty commonly required, but some can go with as little as 5v!
 

SJW

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I found another one and it says:

INPUT: AC100-240V/180mA. 50-60Hz
OUTPUT: DC 10V 740 mA

As u can see I dont do electronics

Steve
 

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