Air Breeze and my apology

I'm thinking of an Air Breeze to go up the mizzen, so this thread is now getting quite interesting.

I have just seen the following on a (largely) USA group:

"If you want to allocate a certain amount of money to 'green' charging, spent it all on solar panels and skip the wind generator. They only work in strong winds, so they are a bit of a luxury. If you do get a wind generator, please PLEASE don't let it be an Air-X Marine. They are the most efficient, but make a horrible noise. I have a recurring dream, of going round the anchorage in my dinghy, with a Remington pump-action shotgun, and blasting each and every Air-X. Boom! There's another one gone. Boom! and another...."
 
oldvarnish said:
I'm thinking of an Air Breeze to go up the mizzen, so this thread is now getting quite interesting.
"If you do get a wind generator, please PLEASE don't let it be an Air-X Marine. They are the most efficient, but make a horrible noise."
Click to expand...
I have contributed to many threads on this subject but anything before the fora change seem impossible to find.

When I first fitted my Air-X I had read that the blade moulding marks were a major cause of the noise and so I sanded mine to a smooth, polished finish. The unit was still somewhat noisy but not exceptionally so and against the noise of the wind in the rigging and neighbours' slapping halyards in the marina or anchorage, quite bearable.

The manufacturer claimed just before I bought mine five years ago that new models were much quieter and I think that was true with the one I bought. The blades of mine were probably stiffer than earlier ones but there is a limit to what can be achieved by that shape, where the tips taper off to a fine point almost.

This is because I believe that the major noise is a result of tip flutter; the aerodynamic shape of the blades' tapered tip is too thin for adequate support and they flex slightly at speed. This was supported by a poster describing how someone had quietened their Air-X by shortening the blades and this is borne out by the Air Breeze (and the Portuguese version) having thicker blade tips.
 
I purchased one of the 'new' Air X shortly after they came out in 2003. Yes they are noisy with the standard blades, especially when the regulator does not bring it under load or switch it off in gusty conditions and the blades are effectively free wheeling. Turning off and back on usually gets it charging again. Even in steady winds around 20 knots and charging the blade noise can be heard a long way off. I used to hear mine if I had inadvertantly left it switched on (or others) before I entered the marina. Usually, I turn the AirX off when near occupied boats.

Two possibilities - from what I have read the Breeze is designed to be quieter but has only 50% of the output, but starts charging in lower wind speeds.

Or you can have the high output of the Air X without the wind noise. Look up Air X Noise on the US, SSCA forum and read what they say about the 'silent' blades from Portugal (or Spain in some posts). As a result I purchased a set after damaging my standard blades and they really do make a tremendous difference. In 15 - 20 knots I asked a neighbour if he could here that? "Hear what?" was the reply. We were 4 boats down the pontoon and he was very surprised as he knows full well the noise my AirX used to make.
Have no connection with the company http://www.silentwindgenerator.com/

Have described the blades in earlier posts in this thread.

Hope this helps.
 
thanks SRM - very helpful. So am I right in thinking that there seem to be two options:


1 buy an Air Breeze which has a lower output, but quieter operation. Can the Breeze be fitted with the Portuguese blades.

2 buy an Air X and fit it with Portuguese blades

Is there anything to factor in that I have forgotten?
 
oldvarnish said:
thanks SRM - very helpful. So am I right in thinking that there seem to be two options:


1 buy an Air Breeze which has a lower output, but quieter operation. Can the Breeze be fitted with the Portuguese blades.

2 buy an Air X and fit it with Portuguese blades

Is there anything to factor in that I have forgotten?
Click to expand...

It all depends on where you will be based. From my experience of 5 years in the Adriatic with an Air-X, I would buy the Air Breeze, hoping that the lower load resistance would keep it turning and charging in the typically Mediterranean wind pattern of too often little wind.

I think that the Air-X has been withdrawn, being replaced by the Air Breeze. You may well find some old stock somewhere if you decide that is what you want.

As I wrote in another post above, the Air Breeze uses a different foil with thicker tips to avoid the flutter effect so perhaps the Portuguese blades may not be necessary. You can see a video here where the microphone wind noise is louder than the Air Breeze.
 
"Can the Breeze be fitted with the Portuguese blades."

I am only going on what I have read on the net recently while trying to source replacement blades for my Air X. The Breeze uses quite different blades to the X and more to the point the breeze Blades are held by one bolt while the X have two. So the short answer is No.

I did come across a post where someone tested a Breeze with the Portugese blades by using an X hub to carry them. However, they stopped it from running in stronger winds as they were concerned about overdriving the Breeze's 200 watt output. The X hits peak output of around 400 watts in just under 30 knots wind then drops the output to almost zero by regulating blade speed - I don't know what the Breeze limits are but can imagine that more powerful blades may cause problems such as overheated components.

Incidentally, am not sure if you have read my earlier posts but my Portugese blades are not totally silent, there is a little wind noise at higher speeds plus bearing hum that can be heard on board. But then no wind turbine can be totally silent close up.

Basically, you will have to decide based on your typical wind speeds and power requirements. In a lower wind speed environment the Breeze may well give more power over time as it starts charging earlier.

Not so sure that the X has been withdrawn SWWindpower had it on their site along with the Breeze when I looked but some dealers were saying only Breeze available.

Hope this helps.
 
>I was wondering how the trim of the boat was affected by having a 'fan' up the mizzen mast.

We have ours on the mizzen, with no trim issues at all (we also have radar on the mizzen). But we are a heavy displacement boat with a lot of hull stability and I guess it may depend on the type of boat you have.
 
I'm surprised to hear that you've had a bad experience with their customer service srm. I called them up to order a new nose cone (small rattle, actually has stopped now) and they sent one out pretty much immediately.

Did you try calling them?
 
In this day and age most well run businesses answer emails within one working day, so no I did not phone given time differences etc. Also, their web site specifically said the email address could be used to order parts. Same problem when the mild steel yaw bearings seized up full of rust a couple of years ago. No response to my email. That time I went to our local agricultural engineer who looked at the remains of the bearing, measured it, gave it a number, went into his store and came back with a replacement so I bought two. Anyhow, their silence did me a big favour as I now have a much better set of blades at similar cost to that quoted by UK distributors and a nice quiet AirX thats so much nicer to live with.
 
>I was wondering how the trim of the boat was affected by having a 'fan' up the mizzen mast.

As a comment of mine started this perhaps I can clarify what I was thinking. The weight will have very little effect so trim should not be effected. (though depending on height of the turbine there will be a very slight reduction in stability, but unless your boat is an ultra ultra light displacement not enough to think about) However, there is a wind load exerted by the fan which has to be absorbed by the mast and rig. I was thinking that if AirX turbines are working up a mast (and I have seen one at the top of a tall mizzen)then the Breeze with only half the power output should be fine as it will not put as much load on the mast and rig.
Appologies for not explaining clearly to start with.
 
Yes srm, that's clear.

Out of interest, I'd be curious to know what that sideways force would be in a, say, 20 knot wind.

Any aeronautical engineers tuned in?
 
oldvarnish said:
Out of interest, I'd be curious to know what that sideways force would be in a, say, 20 knot wind.

Any aeronautical engineers tuned in?
Click to expand...

My intuitive response is near enough the same as a solid disc the same diameter secured across the wind. That assumes the blades absorb 100% of the energy so perhaps a bit less. Its the same argument thats used when discussing drag of fixed and freewheeling props while sailing.

Area swept by blades x force exerted per unit area for a given wind speed and air density.

Am happy to be corrected on this - as I said, an intuitive response.

Found the question interesting so went away and did a bit of googling;

Area swept by Air X blades = 11.54 sq ft.

Force exerted by wind at 25 mph = 3.07 lb / sq ft

Horizontal load due to turbine blades = 35 lb.

Provided that my basic assumption is correct, and I could be very wrong here as the speed of rotation may have an influence.
 
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I don't know how to post a link to previous threads but there is some info in a thread I started earlier this year about the "silent blades for the air X. You can get t it by looking at my posts (there aren't that many).

I've just ordered these and with p & p they cost 214 euros which was £192 (ouch!)

I hope they are worth it. Boat is in the Caribbean so wont fit until January. Will report on how good (or not) they perform.
 
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