Just how loud is loud?

It's often difficult to know how loud an activity is.

The following table (sourced from here) lists common noises and tells you how loud they are.

190 dBA Heavy weapons, 10 m behind the weapon (maximum level)

180 dBA Toy pistol fired close to ear (maximum level)

170 dBA Slap on the ear, fire cracker explodes on shoulder, small arms at a distance of 50 cm (maximum level)

160 dBA Hammer stroke on brass tubing or steel plate at 1 m distance, airbag deployment very close at a distance of 30 cm (maximum level)

150 dBA Hammer stroke in a smithy at 5 m distance (maximum level)

130 dBA Loud hand clapping at 1 m distance (maximum level)

120 dBA Whistle at 1 m distance, test run of a jet at 15 m distance 

115 dBA Take-off sound of planes at 10 m distance

110 dBA Siren at 10 m distance, frequent sound level in discotheques and close to loudspeakers at rock concerts, violin close to the ear of an orchestra musicians (maximum level)

105 dBA Chain saw at 1 m distance, banging car door at 1 m distance (maximum level), racing car at 40 m distance, possible level with music head phones

100 dBA Frequent level with music via head phones, jack hammer at 10 m distance

95 dBA Loud crying, hand circular saw at 1 m distance

90 dBA Angle grinder outside at 1 m distance

85 dBA 2-stroke chain-saw at 10 m distance, loud WC flush at 1 m distance

80 dBA Very loud traffic noise of passing lorries at 7.5 m distance, high traffic on an expressway at 25 m distance

75 dBA Passing car at 7.5 m distance, un-silenced wood shredder at 10 m distance

70 dBA Level close to a main road by day, quiet hair dryer at 1 m distance to ear

65 dBA Bad risk of heart circulation disease at constant impact is possible

60 dBA Noisy lawn mower at 10 m distance

55 dBA Low volume of radio or TV at 1 m distance, noisy vacuum cleaner at 10 m distance

50 dBA Refrigerator at 1 m distance, bird twitter outside at 15 m distance

45 dBA Noise of normal living; talking, or radio in the background

40 dBA Distraction when learning or concentration is possible

35 dBA Very quiet room fan at low speed at 1 m distance

25 dBA Sound of breathing at 1 m distance

0 dBA Auditory threshold

So for instance the house in the picture with a frost fan 30m from it (opposite Fairhall school) will be experiencing a noise louder than a hairdryer at 1m. Try it. Then try to sleep.

Why do Wind Machines Operate in Autumn?

Well, first of all there was a limited number of frost machines active last night. not really too cold and I certainly saw no evidence of frost on the ground.

However, this leads to the question of why the frost fans will even start up in Autumn?

We know that Spring frosts will damage new growth and hinder development, but it's a different reason to beat the frost in the Autumn.

The grapes are on the vine and are still developing. As such the plant is continuing to provide nutrients and energy to the fruit via the chemical processes associated with photosynthesis (photosynthate). If the leave are damaged by frost they no longer provide nutrients to the grapes and the reverse can occur where the plant can try to draw goodness back from the grapes. This is undesirable and typically it is prudent to pick grapes as soon as practical from a vineyard that has suffered frost damage in the Autumn.

Additionally, there is a risk of the wood of the vine not becoming fully mature before a frost and the resultant injury causing an increased susceptibility to disease.

Just when you thought it couldn't get worse. If frost damages the leaves and they die and this is followed by rain, the machine harvesting of the grapes can be difficult because of the dead leaves clogging the harvesters.

So there you go. Frost protection is useful. Frost protection is good. Just pick the right type and keep the frost fans away from your neighbours!

First 'real' frost of '09 tonite?

In spite of a couple of 'jittery' fans starting up in a the last couple of days (how hard can it be to calibrate a thermocouple to within a degree or two?) the first real frost event could be on the cards for tonite.

It would be nice to see some action. Things have been quiet lately.

Too quiet.......

Does being anti frost fan mean being anti wine?

Silly question, but if it isn't answered, there will always be ignorant people who assume that being anti-frost fans means being anti wine.

Far from it.

Vineyard owners and wineries can be artisans that craft a product that appeals to many.

Likewise, owning and operating a frost fan does not necessarily make a person an arrogant financialist interested in their own greed.

Using a frost fan in an irresponsible manner that leads to neighbours being kept awake and having their health endangered is the evil that is done with a frost fan. Not making wine.

These are troubled times;

Growers being told to reduce production volumes.

Prices for grapes dropping.

Wineries are desperate to get rid of the excesses of last years crop without damaging the reputation of the 'up market' product.

Less money being proffered by banks for capital expenditure.

Rumours of high levels of Botryitis due to this years weather conditions.

Let's not forget that the real growers who have a passion for producing a quality crop realise that the growth process is a variable thing that allows a mixture of conditions that can produce a stellar wine one year and a mediocre one the next. 

The industrialisation of the process of growing and processing with its chemicals and mechanical beasts is a far cry from the grower that knows his land and knows that some years are good and some not so good.

They will see out these tougher times while those absentee owners interested in a fast buck will be nervously eyeing the bottom line. 

So support the artisan growers, they deserve it. After all they are far more likely to be the sort of people who get on with their neighbours and would rather let nature encourage their crop to demonstrate something unusual, something special. Far less likely to arrogantly annoy the district with excessive noise.

The absentee owner will be far more interested in shoring up the price of the wine. No matter the quality.

Let me make a prediction.

This years crop will be proclaimed an excellent year in spite of the troubles that beset it.

This is what is always proclaimed.

By who? People interested in selling wine for a high price.

Why? Because they want to make money.

Is it true? Sometimes it is. But sometimes the emperor has no clothes.

When was the last time the wine industry proclaimed the year as being pretty poor and didn't recommend it?

If you say it often enough, it must be true

The Defender frost fan has had another outing at the Terrior field day (see attached clipping from the Nelson-Marlborough Farming supplement (click on it to see a larger version)).

And so another day, another contradictory specification.

This time the machine has been touted as producing 51 decibels of noise at 300 metres. Now the observant amongst you will be saying "Isn't that different to the original press release of less than 50dB?". Well yes! it would be. 

Should you be concerned?

Nooo..... No need for that, because the measurement is meaningless.

You see there still doesn't appear to be any independent testing data released for the fan. 

So the claim about having no special audible characteristics?

Worthless.

Should you be concerned about the 'whop factor'?

Gosh no. The odds of the tips of the machine's blades exceeding the speed of sound like an Iroquois helicopter are slim.

Does that mean it doesn't have special audible characteristics?

Ha! They wish.

I REALLY hope this fan is as good as they say. I really do.

But the longer they keep repeating that the fan is quiet and that it doesn't have special audible characteristics, the more concern I have that they don't have the data to back up the claim. This could be snake oil, peddled by a firm hoping to repeat something often enough so that people believe it. How are we to know?

Independent testing. Let a respected acoustics firm/expert do the measurements. Publish them to prove your claim. Seems simple. If the measurements confirm it, the world should beat a path to your door. 

If they're not.... Well I suppose you shouldn't release them...

Hang on...

Terroir '09 pulls in the crowds.

The heading is more than a little unfair since I have no idea how many attended. 

However, if all I have to go on is a newspaper article that shows 8 people, I'm hoping that there would have been more. 

To be perfectly honest, I would also have liked it more if there had been a salivating crowd pushing to get closer to the Defender frost fan that is to the right of the picture (click on it to see a larger version). In my dream World they are waving huge fistfuls of cash demanding to have their noisy Amarillos replaced by the shiny new blade-du-jour.

The article appeared in the Nelson-Marlborough Farming newsletter thingy.

How ideal are smudge pots for frost protection?

I have deliberately chosen smudge pots (not to be confused with return stack burners) as the first frost protection method to be evaluated as they have some aspects of operation that are controversial (like being so bad that even local body Councils have banned their use).

How do they feature?

The Grower:

• It should be cost effective to install and run.                                  Very Cost effective
  
• It must be reliable.                                                                       The mechanism is simple, so failures are unlikely.
  
• It must protect the crop from frost.                                               Effective protection.
  
• It should not be labour intensive.                                                  There is a medium to high requirement for attention during operation
  
• It must be safe to operate.                                                           Probably about medium
  

The Crop:

• It must not affect the normal growth / development of the plant.   No problem
  
• It should not introduce any foreign contaminants.                          Probably a low to medium risk here.
  
• The quality of the fruit should be unchanged.                                Probably low to medium again
  

The Environment:

• It should not deplete a natural resource.                                      It burnt oxygen, but this hasn't been identified yet as a resource depletion issue.
  
• It should not make any physical impact other than on the crop.    The physical impact was high with huge palls of smoke covering large areas and soot accompanying it.
  
• It should not introduce any pollutant to the environment.             Very high with considerable pollutants released into the atmosphere.
  

The Neighbour:

• Its operation mustn’t affect their health.                                   Medium risk with smoke pollution exposure
  
• Its operation shouldn’t degrade their property values.                Property values relatively unaffected unless it was during a frost season (so low)
  
• It shouldn’t degrade their enjoyment of their own property.        During times of use, enjoyment would drop considerably.
  

What can we read from this?

Well with features that were important to the grower and relatively benign affect on the crop, the technique was popular in the day. In spite of a significant impact on the environment and neighbours. However as consciousness was raised to the health risks and pollution impact, regulations were enacted to limit, prevent or alter the activity.Parallels can be drawn with frost fans in the sense that what little regulations are in place are not well structured or not followed and this has allowed the wild west mentality to take hold. Now as the impact of the devices has begun to be felt by more and more people, their use is being viewed less favorably.

What’s the ideal form of frost protection?

There are a number of different individual features to consider and there are a number of separate interest groups with stakes in the method.

Interest groups:

• The Grower
  
• The Crop
  
• The Environment
  
• The Neighbours
  

The Grower:
Features that are important to the grower are things like;

• It should be cost effective to install and run.
  
• It must be reliable.
  
• It must protect the crop from frost.
  
• It should not be labour intensive.
  
• It must be safe to operate.
  

The Crop:
Features that are important to the crop are things like;

• It must not affect the normal growth / development of the plant.
  
• It should not introduce any foreign contaminants.
  
• The quality of the fruit should be unchanged.
  

The Environment:
Features that are important to the environment are things like;

• It should not deplete a natural resource.
  
• It should not make any physical impact other than on the crop.
  
• It should not introduce any pollutant to the environment.
  

The Neighbour:
Features that are important to the neighbour are things like;

• Its operation mustn’t affect their health.
  
• Its operation shouldn’t degrade their property values.
  
• It shouldn’t degrade their enjoyment of their own property.
  

Now I am sure that there are other features and possibly other interest groups in the wider scheme of things, but this is a fair start.
Of course the list provides an opportunity to evaluate different methods on their appropriateness, but because each interest group has a different agenda, there will always be conflicting drivers for what constitutes an ideal method.
That said, there is merit in evaluating the methods and comparing them, simply because it highlights the disparity between the different groups, promotes debate and perhaps arrives at resolutions / compromises.

Just how much are grapes worth?

A good question and one that varies.

The most common sale sees a grower using a contract or the spot market. 

With a contract there is an agreed upon price for the grapes set early in the season. If a grower is willing to gamble that the market is going to be short (and therefore demand high) they can sell on the spot to try and maximise their profit.

Both ways have their benefits and pitfalls. There are a certain number who are experiencing difficulty this year as the market adjusts to selecting a lower yield but higher quality crop because of the oversupply last year and the impact of the current economic market.

Ultimately there will always be a market and the shrewd grower will continue to produce quality grapes that will be in demand.

The yield for vineyards will vary depending on the growing conditions during the year. Last year saw tonnages approaching 18 tonnes per hectare. This year with a concentration on lower volume and quality it is anticipated to see yields of approximately 12 tonnes per hectare.

In 2008 growers could receive approximately $2400 per tonne (although this was variable depending on the variety and quality). This year prices are expected to average around $1700 per tonne (this year is expected to see a much larger variation in prices because of the wineries being a little more selective).

All in all a grower could anticipate approximately $20,000 per hectare this year if all goes according to plan.

To put that into perspective a little, a 1/4 acre section (if that is typical any more) could grow $2500 worth of grapes a year.