ChineseWindGeneratorNoiseLevels?

[doubledipsoon]

Anyone out there running a 1kw-2kw Exmork, Zonhan, or Huaya Turbine wind generator? I'm wondering about the noise levels on these machines. Since their rated rpms with their 2.8-3.2 meter rotor/blade diameters are about 300-400, and since they are "fixed blade" units, I'm questioning whether they are annoying to listen to or not. Any input would be greatly appreciated!

[kitestrings]

You might want to ask the same question on the Back Shed forum.  There's a gent there, Philm, that is using them, I think with GO222 blades of his making.

[SparWeb]

I had a neighbour who had an Exmork.  Ran for 1 year.  Blades exploded in a storm that mine easily survived.
PS.  The Exmork was not shipped with a proper controller, so it sat on the pole doing nothing for a year before the installer could  set it up properly.
After it failed, it took 6 months before the installer could replace it.  With a much smaller turbine.
My neighbour was not happy.

When it was working, it was not too noisy.

[SparWeb]

Aleko -  maybe another brand name on the same ( or similar) chinese made machine.

[doubledipsoon]

"when it was running it was not too noisy" sounds like good news to me. The Exmork, Aleko, Zonhan clones, all made at the HuayaTurbine factory, have the option of a "manual shutdown" (like the old Jakes), by Oz Engineering, so if a bad storm arrives you shut it down, to avoid the obvious. Oz also sells aluminum airfoils that supposedly work to lower rotor blade rpm and thus wind blade noise. I mean, these machines are heavy duty but need fine tuning. And, you are correct, their electronic suck, so go with another charge controller. So if you want to save a few thousand dollars.....

[SparWeb]

His Exmork did not fail in a storm one would normally associate with needing to "shut down".
You would spend a lot of time babysitting an inert wind turbine, if your strategy is to always shut it down.
The tail is supposed to furl.

[doubledipsoon]

You're probably right.  Sounds like a good question for OZ Engineering- why would they spend all their time upgrading a chinese wind generator?  So what wind machine do you run?

[SparWeb]

The Exmork I saw did not appear to be very durable.  After the blades exploded, my neighbour invited me over to look.  I took photos.  The foam filler inside the fiberglass had air pockets in it, and the edges had defects, possibly as a result of uneven trimming by hand at the factory.

Mine, I built myself:  www.sparweb.ca
My blades are also hand-made, but in a completely different way; using wood.  Durable for 10 years so far, and despite the current lot of damage they're sustained, are not stopping yet.  A new set is in progress.

[doubledipsoon]

The verdict is in- don't bother with a Chinese wind generator. After listening to many youtube videos on Huayas, Aleko's, and Zonhans, they all make a whinny, whistley noise that changes pitch and will sooner or later drive you nuts, and make for edgy neighbors. To be brutally truthful, I've never heard a "pleasant" wind generator other than the old Jakes- 240 rpm with a blade-actuated governor.  A set of blades that feather and low rpm is indispensible for low noise levels, period. I'd like to thank all the chinese wind generator fans for saving me plenty of time, labor, and money for convincing me to say "NO" to  getting another noise-maker. And Sparweb, I'm impressed with your creativity, but how noisy is it.....really?

[SparWeb]

Ah, you really want to know.  It's not quiet, but it's not annoying. 

There are a few different noises. 
1) blade tips - swish noise - intensity increases with RPM
2) generator vibration - harsh hum noise - intensity varies, peaking at RPMs resonant with the tower
3) tower guy wires - whoosh noise - intensity increases with wind speed
4) shaft bearings - screech noise - when they wear out

Currently the loudest is the tower's guy-wires, not the turbine.  The turbine is quieter than it used to be through erosion of the wood, because the blades are old and worn by hail storms.  Now it simply doesn't run as fast and strong as it used to when the blades were new.  The new blades had a "swish" from the tips but the furling would be kicking in if you ever heard the sound from the house and it would stop right away.  There was a time, many years ago, when I didn't have vibration isolation on the generator mounts, and that communicated a vibration from the generator (magnet poles) to the tower.  I put it on isolators in 2010 and that completely went away.

I'm making new blades and while it's down for blade replacement I will probably replace the bearings and the isolator mounts.

[doubledipsoon]

I read a very interesting gov't report (don't remember what it was called) on wind generator noises- they concluded that it is the "changing pitches" that are annoying- as the rotor and blades speed up and slow down due to changing wind speeds, the pitches and frequencies incessantly change and can make you "notice" the noise more. This is why a large heavier machine 6-7 foot wooden blades with plenty of "momentum" can be more resistant to gusts and wind variables, and have a more steady noise and unchanging noise level, and thus, less noticable compared to a higher rpm lighter wind machine that changes tones more frequently.