EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: 24602 on April 13, 2021, 08:06:29 am
-
Hey All
Looking at replacing noisy fans in various devices. I have used many Noctua fans in the past and they're great, high quality, low noise but very expensive.
I can find alternatives made by sunon often beating noctua in terms of specifications but is hard to tell if acoustically they will be fine before I purchase.
Any time fans come up for discussion and absolute silence is required Noctua is referred as the only option but is that just community fanboying because its there known best.
There is a reassurance that if I purchase noctua I'm getting a product that is the quietest that it can possibly be.
But sunon maybe quieter in terms of db but there is no way of knowing what it will actually sound like ie whining or other noise that you won't find on a data sheet.
Has noctua just made a good brand for themselves making everything else seem perceivably bad choice or should I just get the Sunons?
Just putting on my bang for buck hat instead of my Noctua Fanboy hat.
-
This guy reckons that it depends on your preferred fan speed.
https://www.youtube.com/watch?v=QnBo9bTRsxk (https://www.youtube.com/watch?v=QnBo9bTRsxk)
-
Indeed Noctua seems to be the preferred brand for silent fans but, in my experience, the fan is just one factor - turbulence noise and vibration are other two major factors.
For turbulence there is not much to be done other than speed control, unless it is possible to rearrange components inside the case (easier on a desktop, harder or impossible on test gear or other non-modular equipment). Vibration is something I had very sensible improvements by using good quality fans (Delta, Sunon) floating in rubber washers - I did this on lots of test equipment.
-
Noctua is well-known low-noise leader. And I haven't heard Sunon ever competed in this competition.
Here in my country there are a lot of Sunons but hey are known like industrial type. Sunon itself doesn't position them as low-noise ones.
-
You can tell a fan's technology by closely looking at the blade design and number of blades etc. It's about the only secret sauce there is, the fluid dynamics and precision moulding of the rotor's plastic.
I find Noctua are excellent and worth the extra cost.
A common mistake is simply using the wrong fan in the first place. You actually can get higher airflow, quieter operation by using a fan suited to the operating pressure drop.
Running a high CFM fan at low speeds - verses a low CFM fan at higher speeds, is important to know the difference. Rated CFM as a figure of merit is not the entire picture.
A part of fan noise is their designed pressure drop. You have to look at "fan curves" as it shows the differences in flow, speed and pressure, something mechanical engineers are into.
-
Several types of Sunon which I used did not have any annoying motor noise. Which is very common for Delta fans, and because of which I hate Delta fans.
-
Before people like Noctua came on the scene I used a lot of the Sunon Maglev fans for low noise operation. They work well, and last a long time, but I'm not aware of new and improved generations of fan from Sunon. I think they concentrate on industrial applications now, where noise isn't the key issue.
dBs don't tell the whole story. Some fans score well on noise level, but the noise is a bearing whine that, even though faint, really grates on the nerves. Both Noctua and the Sunon Maglev fans do a good job there.