AC or DC fan

[leochngyh]

I am currently using a AC 6" fan to cool my tank but the noise is too loud.

Seeing lot of people using DC fan and getting a good cooling result. Should I change to DC fan? Isnt more powerful AC will get better cooling than DC?

[nakazoru]

I am currently using a AC 6" fan to cool my tank but the noise is too loud.

Seeing lot of people using DC fan and getting a good cooling result. Should I change to DC fan? Isnt more powerful AC will get better cooling than DC?

Depending on the noise that the fan generates. It is really not the AC or DC that determines the noise.

I have 4 small DC fan and 2 120mm DC fan 12 V. The 120mm is almost noiseless but the 4 small on really noisy. Good fan manufacture has the noise express in db, when you buy so look for those low noise one. More expensive I think.

[cci[RR]us]

The faster the blades spin, the larger the blades are, the faster they oscillate, leading to a higher frequency of the sound produced (high pitch vs. low humming) as well as higher amplitude (louder). Hence, the sound is more related to the size and speed of the fan blades, rather than the energy source.

[leochngyh]

But is the DC fan have same cooling result with AC? Conside same size on 12VDC and 220VAC. My AC fan now cooling my tank around 2-3°C, if the DC fan can do the same result, I might be changing to DC fan. At least less noise.

[ervine]

my DC one seems to move more air.. only problem is the adapter to the DC one kept on blowing for some reason... in the end gave up on it...

[leochngyh]

so can I say DC and AC is almost getting same result? Then I maybe getting a DC fan, less power and less noise. Anyone can confirm?

[Oceandeep]

agree.. I use a number of fans ..

DC.. is still better... and safer

[nakazoru]

One point to add when DIY Fan, it is good to also fix a filter to it from salt water from being splash to the moving parts of the fan. two of my DC fan fail after 6 months.

Now I attach air filter to it and water stays out of it.

[May&Bruce]

The noise mostly relates to the fan blades moving through the air, so an AC or DC fan of the same size, rotating at the same speed, will have a similar noise and the same cooling effect.

Some fans are designed to be more quiet - but this relates to the design of the blades and casing.

AC fans rotate at one speed only - based on the AC frequency. DC fans can be made to rotate at different speeds by varying the voltage to the fan.

In regard to is one more efficient than the other (efficient in terms of cooling) as I said before if the fan design is similar (blade shape and diameter, and speed of rotation) then the cooling effect will be the same. Basically, in order to increase the cooling effect you need to either have bigger blades or the fan needs to rotate faster.