Topic: Barani: too good to be true...

[Jasper3012]

The data doesn’t lie, does it… I invite you to have another look at both my and gvdb111’s comparison sheet.

[Meteorology fan]

Do an annual comparison of Stevenson Screnn (even a full-size one like from Metspec) vs Barani Meteoshield Pro III. You will then see that there will be days when Stevenson's superiority in maximum temperatures will be apparent. Yes, most days there will be no significant differences, but the Barani Gen III in my opinion has more disadvantages than advantages.

In a climate like Poland, it was the disadvantages of the Barani Gen III that were highlighted more than those of Belgium. It is inconceivable that meteorological services would use this cover on temperature measurements to assess climate change. It's the product of a great marketer and it doesn't work, it's just as he describes.

[mauro63]

I cannot understand the intent of this debate which remains an end in itself
On the other hand, the solution appears simple in my eyes, in Poland the Barani works badly, ok will they use something else, in Belgium does it work slightly better? they'll see what to do, in Italy it works well, ok

Have you ever heard of the site-specificity of an air temperature detection system?

otherwise the post has no way out and does not arouse any interest, everyone remains on their positions and counters those of others, and I don't think anyone here has time to waste

NO ONE, I will repeat it as long as it is necessary, knows the truth, everyone expresses views and opinions, all of which can be shared or not

M.

[Meteorology fan]

Of course, I have heard about the specifics of the air temperature sensing system. My opinion is simple, that in harsh conditions in low wind a radiation shield with a fan is a must, and here no marketing spiral of Barani will help. This shield works only as it blows, it is enough that it starts to blow weakly or not at all and we have a big problem.

There will be more days in Poland where the Barani will strongly overestimate the temperature compared to the Apogee TS100 and Davis FARS24H than in Belgium, where wind speeds are generally higher than in Poland, except in the Baltic region. Therefore, a better solution than the Barani Gen III is a cage, even one like the MetSpec plastic one.

It is well known that the Barani has a problem measuring air temperature correctly when we have the sun low above the horizon. In autumn and winter this will affect daily averages and maxima on sunny days.  In Poland, Barani suffers more from this than in Belgium, and it will be more than 2-3 days a year. Interestingly, Barani thought it had solved the problem, and here you go Apogee TS100 and Davis FARS24H reveal that the problem still exists. Could Apogee be wrong in this situation? We saw the same thing with the Stevenson Screnn screnn and the Barani Ms Pro III.

Only that Barani's marketers cleverly hid this fact in a thicket of marketing platitudes and are selling us a product with a hidden defect that few people will detect. This is a dishonest act, because they should write under what conditions the shield has defects and what the overheating values might be. This is what MetSpec, for example, does.

https://metspec.net/radiation-shields/

[mauro63]

Of course, I have heard about the specifics of the air temperature sensing system. My opinion is simple, that in harsh conditions in low wind a radiation shield with a fan is a must, and here no marketing spiral of Barani will help. This shield works only as it blows, it is enough that it starts to blow weakly or not at all and we have a big problem.

There will be more days in Poland where the Barani will strongly overestimate the temperature compared to the Apogee TS100 and Davis FARS24H than in Belgium, where wind speeds are generally higher than in Poland, except in the Baltic region. Therefore, a better solution than the Barani Gen III is a cage, even one like the MetSpec plastic one.

It is well known that the Barani has a problem measuring air temperature correctly when we have the sun low above the horizon. In autumn and winter this will affect daily averages and maxima on sunny days.  In Poland, Barani suffers more from this than in Belgium, and it will be more than 2-3 days a year. Interestingly, Barani thought it had solved the problem, and here you go Apogee TS100 and Davis FARS24H reveal that the problem still exists. Could Apogee be wrong in this situation? We saw the same thing with the Stevenson Screnn screnn and the Barani Ms Pro III.

Only that Barani's marketers cleverly hid this fact in a thicket of marketing platitudes and are selling us a product with a hidden defect that few people will detect. This is a dishonest act, because they should write under what conditions the shield has defects and what the overheating values might be. This is what MetSpec, for example, does.

https://metspec.net/radiation-shields/

Very good,

the basic mistake, in my opinion, are these insights of a commercial nature aimed at discrediting a product, they which can be harmful or annoying.

Everyone makes their own assessments based on their own experience without the need to transform them into public slogans.

In comparisons carried out in the professional field, I invite you to read the WMO reports on the matter, you will NEVER read that screen A is better than screen B and screen C is the worst, you will always read that, in certain conditions, screen A returns a value colder or warmer than B or C, not more accurate or truer.

It goes without saying that the experience of those who analyze that data allows them to easily understand that if on a day of strong radiation, and in the absence of wind, screen B records temperatures higher than 2 degrees vs A screen for hours we are in the presence of an evident radiative error.


M.

[bianconero57]

  question to the expert speakers but why do you never talk about psychrometric effects by sublimation in Poland or others in these comparisons ??

[Jasper3012]

I cannot understand the intent of this debate which remains an end in itself
On the other hand, the solution appears simple in my eyes, in Poland the Barani works badly, ok will they use something else, in Belgium does it work slightly better? they'll see what to do, in Italy it works well, ok

Have you ever heard of the site-specificity of an air temperature detection system?

otherwise the post has no way out and does not arouse any interest, everyone remains on their positions and counters those of others, and I don't think anyone here has time to waste

NO ONE, I will repeat it as long as it is necessary, knows the truth, everyone expresses views and opinions, all of which can be shared or not

M.

I think the point of the thread is clear? To compare the Barani MS Pro with the Davis FARS 24/7. I’m just following the data in this thread and so far, the data points to the Barani being an excellent choice. For sure there will be moments where it performs poorly but these moments seem to be very limited in both frequency and duration.

[mauro63]

I cannot understand the intent of this debate which remains an end in itself
On the other hand, the solution appears simple in my eyes, in Poland the Barani works badly, ok will they use something else, in Belgium does it work slightly better? they'll see what to do, in Italy it works well, ok

Have you ever heard of the site-specificity of an air temperature detection system?

otherwise the post has no way out and does not arouse any interest, everyone remains on their positions and counters those of others, and I don't think anyone here has time to waste

NO ONE, I will repeat it as long as it is necessary, knows the truth, everyone expresses views and opinions, all of which can be shared or not

M.

I think the point of the thread is clear? To compare the Barani MS Pro with the Davis FARS 24/7. I’m just following the data in this thread and so far, the data points to the Barani being an excellent choice. For sure there will be moments where it performs poorly but these moments seem to be very limited in both frequency and duration.

My message was not aimed at you, your approach is correct from what I have read but, probably, my terrible English helped me to misunderstand my words and, if so, I apologize

PS from an happy Pro's user

M.

[tobyportugal]

Hello,

With Jan Barani's help, I'm going to put a series of instruments into operation:
Pro3
FARS (new version)
MeteoHelix IoT (new firmware)
MeteoRain 200 Pro (new version)
MeteoRain IoT Pro (new version)
MeteoWind IoT (new version in about 1.5 months)
They will be installed in Belgium (on the outskirts of Gembloux), initially the Pro3/FARS will be equipped with "simple" SHT35.
The garden with lawn has 2 places without shade during the day and without big thermal obstacle. I need to test the 2 possibilities before making my choice.
As soon as my in-laws' situation allows me to make a return trip to Portugal, they will switch to my SHT45s, and my Lambrecht rain gauge will be repatriated to Belgium.
Unfortunately I can't afford to buy back the other shelters I have in Portugal.
When the time comes, I'll open a dedicated post in the hope that the discussions will be constructive and exclusively technical with a concern for rigour.

PS: I am a simple enthusiast paid by nobody.

[Meteorology fan]

@tobyportugal - I am curious about these comparisons. You should use the Apogee TS100 as a reference instrument with a smart pyranometer for correct comparisons of the Barani Gen III shield.

My opinion is that if someone gets the equipment for free for testing, he can't talk about its defects and these tests are not fully objective. He will only speak in superlatives. It is different when he spends his own and hard-earned money. I have friends who work in large corporations in high positions, and I know what it is like for ambassadors of various brands, and I know what stipulations there are in contracts. It is clearly emphasized what they are not allowed to talk about in public, because they won't get anything for testing again.

[Jasper3012]

Latest sheets from both me and Geert. Barani looking like the better option so far, largely in line with the Stevenson screen and cooler than the Davis FARS.

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[JCA433]

The Davis FARS performs better with stronger ventilation than can be provided with the low powered stock fan.  In another thread I compared the Davis 7714 shield with insides painted black with the Davis FARS with 12 Volt DC fan and found in conditions clear skies and average wind speed less than 1 knots to calm ,the Davis FARS average temperature was as much as 1.8 F cooler.   The largest difference in September last year was about 3.6 F.   However, these large differences ended in mid October  and since that time there are no days with a average difference more than 1 degree F.  In fact only 14 days  total since August 10 last year  was the FARS average afternoon temperature more than 1 degree F lower.

I also compared the Davis FARS with stock fan with Davis FARS with much more powerful 12 Volt DC fan and found that the FARS with the more powerful fan averaged about 0.4 F lower in the afternoon.   I know this may surprise some people but the largest differences were not in sunny windy conditions.  The largest differences up to 1 degree F occurred with sunny condition and calm winds.  Actually, the smallest differences 0.2F to 0.4F, occurred during higher wind speeds and sunny conditions.

I think we have enough data to know the Barani Pro shield is definitely NOT a marketing gimmick.  I believe it is among the best if not the best passive shield in the world.  It is made of very high-quality durable plastic that should last many years and ,yes, I do recommend it

[CW2274]

I also compared the Davis FARS with stock fan with Davis FARS with much more powerful 12 Volt DC fan and found that the FARS with the more powerful fan averaged about 0.4 F lower in the afternoon.   

No surprise. One of two reason I switched to a 60 CFM fan is simply because I'm in a place that averages about 70 days per year over 100F. The other just as important, if not more, reliability. Win, win.

[Jasper3012]

A 0.4F improvement would actually nearly completely get rid of the error I’ve been seeing with the FARS compared to the MS Pro… It’s been running 0.2-0.3C warmer during afternoon sunshine as you can see on my sheet. Problem is my station is in the middle of nowhere so I can’t get a wired power supply, so I’d need a much bigger panel to support a 12V fan. Would a 12V fan even run at night with the standard 1.2V batteries?

[CW2274]

Would a 12V fan even run at night with the standard 1.2V batteries?

Not even close.

[Jasper3012]

What would you need then for it to spin at roughly the same speed as the stock fan does at night?

[CW2274]

No idea. Too many variables. Just know that the stock batteries will never work to power a 12 volt fan.

[tobyportugal]

What would you need then for it to spin at roughly the same speed as the stock fan does at night?

There is generally a rule for motors WITHOUT a variable speed drive that below 60% of its rated voltage it will not turn.
What is the amperage of your motor?

[Jasper3012]

I’ve got no idea about the specifics for the Davis stock fan.

[JCA433]

I am using a Cooler Guys 80mm 12 volt DC fan.  The minimum voltage required for it to spin is 4 volts if I remember correctly.

[tobyportugal]

Solar panels + charge controller with USB output + powerbank 20000mah and a 1-6v motor 
https://www.jameco.com/c/DC-Direct-Drive-Motors.html

[TheBushPilot]

Assuming the fan is 12 V, and you know the amperage, you can figure 80% usable capacity of a sealed lead-acid battery:

LATITUDE	RESERVE TIME
0° to 30° (N or S)	144 to 168 hr
30° to 50° (N or S)	288 to 336 hr
50° to 60° (N or S)	432 hr

You can pretty much figure the capacity of battery required based on this rule of thumb.

Say for example your fan is 12 V, 0.2 A. Since Portugal's latitude is around 40° N, you would aim to have a usable capacity of between 288 and 336 hours.

Multiply the reserve time by the current drain divided by 0.8 (80%) and you get the required battery Ah for your setup.

(0.2 A * 288 hr) / 0.8 = 72 Ah

And for any other configuration not just a fan you can plug in the numbers and arrive at that value. Hope this helps.


Cheers

[Jasper3012]

So I'd have to get a 12V fan, higher voltage solar panel, higher voltage battery and a higher capacity on the battery to get through the winter... My knowledge on the technical side is very limited so I'll leave that to someone else haha. For now, I'll just be continuing the comparison between the Davis stock FARS and Barani MS Pro.

[tobyportugal]

Assuming the fan is 12 V, and you know the amperage, you can figure 80% usable capacity of a sealed lead-acid battery:

LATITUDE	RESERVE TIME
0° to 30° (N or S)	144 to 168 hr
30° to 50° (N or S)	288 to 336 hr
50° to 60° (N or S)	432 hr

You can pretty much figure the capacity of battery required based on this rule of thumb.

Say for example your fan is 12 V, 0.2 A. Since Portugal's latitude is around 40° N, you would aim to have a usable capacity of between 288 and 336 hours.

Multiply the reserve time by the current drain divided by 0.8 (80%) and you get the required battery Ah for your setup.

(0.2 A * 288 hr) / 0.8 = 72 Ah

And for any other configuration not just a fan you can plug in the numbers and arrive at that value. Hope this helps.


Cheers

Your calculation is not entirely correct:
A 72ah 12v battery with 0.2a (2.4w) of current required gives 288h (with coefficient 0. for a complete discharge.
For a 50% discharge: 144h, i.e. 6 days without any solar charge.
A 20w solar panel will produce 1.12a of charge current, from which we subtract 0.2a to run the motor and 0.006a absorbed by the charge controller. So we have +/- 0.8a of available charging current. With a 40w panel we have a balance of 2a of charge current. In this case a 72ah battery is greatly oversized. A 72ah 12v battery weighs 20kg and costs +/- 190€.
But I could be wrong.

[TheBushPilot]

Assuming the fan is 12 V, and you know the amperage, you can figure 80% usable capacity of a sealed lead-acid battery:

LATITUDE	RESERVE TIME
0° to 30° (N or S)	144 to 168 hr
30° to 50° (N or S)	288 to 336 hr
50° to 60° (N or S)	432 hr

You can pretty much figure the capacity of battery required based on this rule of thumb.

Say for example your fan is 12 V, 0.2 A. Since Portugal's latitude is around 40° N, you would aim to have a usable capacity of between 288 and 336 hours.

Multiply the reserve time by the current drain divided by 0.8 (80%) and you get the required battery Ah for your setup.

(0.2 A * 288 hr) / 0.8 = 72 Ah

And for any other configuration not just a fan you can plug in the numbers and arrive at that value. Hope this helps.


Cheers

Your calculation is not entirely correct:
A 72ah 12v battery with 0.2a (2.4w) of current required gives 288h (with coefficient 0. for a complete discharge.
For a 50% discharge: 144h, i.e. 6 days without any solar charge.
A 20w solar panel will produce 1.12a of charge current, from which we subtract 0.2a to run the motor and 0.006a absorbed by the charge controller. So we have +/- 0.8a of available charging current. With a 40w panel we have a balance of 2a of charge current. In this case a 72ah battery is greatly oversized. A 72ah 12v battery weighs 20kg and costs +/- 190€.
But I could be wrong.

Rule of thumb is 2 weeks of reserve so you eliminate any possibility of lost power especially during the winter when you’ve got sometimes weekly cloud decks and the charge efficiency of only10-15%. But that’s more so rule of thumb for legit automated weather station sites.


Cheers