What is your favorite fan?

[NiHaoMike]

With a good sized radiator, there won't need to be much back pressure to get enough flow. And you'll try to use the existing vents for the radiator and fans if possible.

I have two 3000 RPM 120mm Deltas in my hybrid air conditioner/water heater project and they don't need to run anywhere near max speed in order to get the correct airflow even though the compressor is rated for 5000BTU/hr, which is about 1500W. In fact, I could have got away with one fan for airflow alone, though having two allows me to play tricks like speeding up the bottom fan and slowing down the top one to back some liquid refrigerant into the condenser and increase the subcooling.

 

[bing]

We've all barked up that tree already.
Supposedly its "proprietary" information that he can't share.

Any Google searches simply find him posting all over forums about them.

Damn, which party did I miss ?

Edit: Let's not get into another Cindy Wu or Lainey Schmidt discussion either.

Huh ?

 

[bing]

http://en.wikipedia.org/wiki/Vector_control_(motor)

Hmm...my mistake to ask it wrongly, let me rephrase my question ...

Which references like patent or chip manufacturer's white paper or technical/marketing resources "SPECIFICALLY" specifies this Sine Wave feature at dc fan ?

Or link to fan manufacturers that are using it, for sure those marketing dept from the manufacturers will not miss it to put these jargon in their marketing campaign if this feature is so cool and as an enabler to differentiate their product from competitors, am I right ?

As for the difference between sine waves and square waves, that's just basic electronics.

Thanks for confirming that.

Fyi, I've been using oscilloscope for > 20 years.

 

[NiHaoMike]

Here's an article that explains it better than I could:
http://www.ecnmag.com/articles/2012/04/end-sensored-bldc-control

For noise-sensitive applications like HVAC blowers, sine wave BLDC motor control, also referred to as Permanent Magnet Synchronous Motor (PMSM) control, is applied. For PMSM control there is no free running coil, but instead Field Orient Control (FOC) - also called Vector control - was applied using multiple shunt inputs in combination with DSPs

Here's a (very long and technical!) lecture explaining how FOC works:

 

[BruceUSA]

Come on If you are running it at full speed and non pwm version. yes you will be deaf, it s loud. But the beauty of pwm version fan, my sytem will not be at full speed all the time. If I got time, I will post a short video just to show you, it is not as loud as you would think. As I say above post. you can hardlly hear my system fans running at idle from 12 feets away.

3 Delta fan 252cfm each in action. Check em out see for youeself, noise level is acceptable to me.