Author Topic: Lifespan of PC case fans in a weather station (?) Most durable fans for PWS (?)  (Read 2395 times)

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Offline elagache

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Dear WXForum weather station tinkerers,

Two years ago, I modified my Davis temperature/humidity probe to have it fan aspirated with a standard 3" PC case fan.  You can read about how I did this on this posting on the WeatherCat forum:

http://athena.trixology.com/index.php?topic=1865.0

The fan I selected was the Noctua NF-A8 PWM:

http://www.noctua.at/main.php?show=productview&products_id=100&lng=en

It was more expensive, but I hoped that would make more durable in the more difficult semi-outdoor environment.  Well, it is time for my annual station maintenance and I see that the fan has failed.  It seems to me that this isn't a particularly long run for such a fan.  Certainly indoors  a case fan can last many years and this temperature/humidity probe is mounted under a deck so it gets some protection.  Nonetheless I recognize that the outdoors can be an extremely harsh environment in other ways.  The winds are much stronger than anything a fan would experience indoors.  In addition, since this station is in Northern California, the fan was exposed to a prolonged period of extremely high humidity during the heavy rains of last year.

So I have two questions:

  • What is a reasonable life expectancy for a 3 PC case fan in aspiration service?
  • Which brands of PC case fans have proven to be the most durable in weather station service?

Thanks in advance for any thoughts "you-all" might have.

Cheers, Edouard

Offline CW2274

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Mine runs full power 24/7 and has been currently going for about 30 months and is rated at about a 7-8 year life span. I see yours is warrantied for 6 years, why not return it?
BTW, what does the wind have to do with fan life? :???:

Offline Bashy

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You are adding and internal fan to external conditions, you were prob lucky to get that out of it.

You need to look for  fan that has a reasonable IP rating, something that does not allow water or dust penetration

Myself, i aint fussed, i will just get another fan as and when needed, always handy to have a couple in stock :)
Kind regards
Bashy

Offline WA7FWF

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If you want a fan that will last a long time outdoors in dust and rain, search for a IP68 fan, one example is a Sanyo Denki  9WL0812P4G001 80mm 12vdc 3.6W rated for 180,000 hours of run time (about 20 years), but your not going to like the price, $93.

Offline Bashy

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I have seen plenty in the 15 dollar range that would more than suffice...
Kind regards
Bashy

Offline Old Tele man

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Considering the obvious aggravation factor, which is preferable:

1) Three-to-five cheap $15 fans at 2-3 year intervals, ie: $45-$75 in 10 years?
2) One expensive $75 fan once in 10 years, ie: $75 in 10 years?
« Last Edit: October 01, 2017, 08:45:17 PM by Old Tele man »
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
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Offline Bashy

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That's if they "only" last that long and that's if the expensive one last the full 10 years

Cheaper could last longer, dearer  could last less
It's a gamble, myself, i will stick with the 3 fans
At 2 to 3 years life span, you can do the maths on that one too ;)
Kind regards
Bashy

Offline elagache

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Thanks for the feedback (Re: Most durable fans for PWS (?) )
« Reply #7 on: October 01, 2017, 03:16:37 PM »
Dear WXForum DYI fan aspirated station experts,

Thanks for your comments.  I still haven't had a chance to actually take the temperature/humidity probe apart to see if I can assess why the fan failed.  Perhaps some debris was blown into the blades or something analogous.

If you want a fan that will last a long time outdoors in dust and rain, search for a IP68 fan, one example is a Sanyo Denki  9WL0812P4G001 80mm 12vdc 3.6W rated for 180,000 hours of run time (about 20 years), but your not going to like the price, $93.

That's an idea worth considering.  I'll check to see why my fan failed and if indeed it simply failed because it wasn't designed for outdoor conditions, I might be willing to pay extra for a fan that will last a good long time under those conditions.  It is a significant hassle for me to replace the fan and like most people, I don't have nearly enough time to deal with everything else in my life.  These days I'm willing to pay extra to save me some time.

Thanks again,

Edouard

Offline CW2274

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Considering the obvious aggravation factor, which is preferable:

1) Three-to-five cheap $15 fans at 2-3 year intervals, ie: $45-$75 in 10 years?

2) One expensive $75 fan once in 10 years, ie: $75 in 10 years?
Way I look at it, no need buying an exorbitant fan that will probably outlast my PWS, as I will inevitably want to upgrade at some point. 15$ for one that gets me 3-5 years is completely acceptable in my book.

Offline Old Tele man

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Considering the obvious aggravation factor, which is preferable:

1) Three-to-five cheap $15 fans at 2-3 year intervals, ie: $45-$75 in 10 years?

2) One expensive $75 fan once in 10 years, ie: $75 in 10 years?
Way I look at it, no need buying an exorbitant fan that will probably outlast my PWS, as I will inevitably want to upgrade at some point. 15$ for one that gets me 3-5 years is completely acceptable in my book.
You cheated -- you jumped to 3-5 years -- I wrote 2-3 years (wink,wink)!
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
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CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline Bashy

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Funny ya say that, i could have sworn (at the time i was looking) that the ones i saw over in the US for about $15 were
good for 40,000 hrs, i cant find them now, well, i can find some but dont state lifespan, i am still very happy with my
few quids worth of fan, a normal PC fan used in this way in the UK climate should be good for at least 2 years.

Having said the above, gimmie a minute to check sommat...

Ok, i built a stevenson screen back on 2008, i added fans to it due to backing on to shrubs, these fans were normal 80mm
pc fans, they were shielded bit more from the main elements due to the size of the screen but from 2008 to 2013, only 1
fan fail and it would still run if i tapped it, when i was mentioning lifespans above, i was being very conservative cause i couldnt
remember what year i built the screen.

It is a gamble though, i do not believe many of these fans are meant to run 24/7 anyway, but as Edouard needs reliability then
spending extra will guarantee a bit longer, although, PS Edouard its the humidity that gets at the fans mostly that and pollutants
Kind regards
Bashy

Offline ct

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The fan I selected was the Noctua NF-A8 PWM:

In one of my experimental stations, I turned a passive shield into a fan aspirated shield using a Noctua NF-R8.  I chose this fan because it is very efficient, and I power it with solar and batteries.  The fan spins up at 4V, which is good for 5V boost converters.  Most other PC fans start of 7 or 8 volts.  I've had the same fan in continuous operation for 3.5 years so far.  I know it is still spinning because I monitor fan speed.

I once had a similar Noctua fan connected directly to a 12V solar panel that provided over 18V in full sun.  Even though the specification was 12V the Noctua fan handled the higher voltage and produced much higher RPMs at 18V that at 12V.  I let it run for 6 months before disconnecting it.

Offline Phil23

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Just looking at fans for my outdoor data enclosure & came across this at one of our Aussie Electronics suppliers.

Sunon are pretty well known. IP68, but not sure if it's ball bearing or sleeve as the listing says sleeve & the specs say ball.

 [ You are not allowed to view attachments ]

Connection: 320mm Flying Lead
Air Flow: 53CFM
Speed: 4200 RPM
Noise Level: 44.5dBA
Material: Thermoplastic
Size: 80 x 80 x 25mm
Bearing Type: Ball Bearing

$42.95AUD.

Cheers.

Edit: It is actually a ball bearing fan.

Spec sheet can be found here....

http://www.sunon.com/index2/uFiles/file/03_products/08-catalog%20download/Sunon%20IP56.68.GR487_(239-A).pdf

« Last Edit: October 02, 2017, 04:17:24 PM by Phil23 »

Offline Phil23

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Updated my post...

Offline Ian.

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I used a Noctua fan, this is the link to my blog page showing the swop out: https://www.chatteris.biz/blog/davis-fars-upgrade-monitored-pc-fan/.
CWOP - DW3371
PWS - ICAMBRID16
https://www.chatteris.biz

Offline elagache

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Selected a fan (Re: Most durable fans for PWS (?))
« Reply #15 on: October 02, 2017, 07:16:40 PM »
Dear WXForum fans of DYI fan aspirated stations.

Let me fill everybody in on my final decision as far as a replacement fan.  First off, I was finally able to make a more careful inspection.  First I double-checked that the power supply was still working.  Then I opened up the temperature/humidity radiation shield to look at the fan itself.  It didn't look too bad really:



I've seen dusty fans inside computers that were still working fine.  So losing this fan after 2 years wasn't a satisfactory life-span in my opinion.

Thanks to advice here, I decided to look into the possible choices in fans with an IP68 rating.  User wa6fwf suggested this fan: Sanyo Denki  9WL0812P4G001 fan.  Here are its specifications:

http://www.mouser.com/ds/2/471/San_Ace_80WL25_E-541667.pdf

It is certainly a rugged fan and Mouser electronics had them in stock.  However, honestly 20 year life-span seems like over-kill.  My station is already 8 years old.  It is likely to have something else break long before this fan would break.  I wasn't very successful in locating many other IP68 fans.  I only found one other model that was in stock in the United States and I could get any information about the fan's durability.  However, I did find a Chinese vendor on eBay that had this Sanyo Denki fan. 

http://www.ebay.com/itm/172120113322

Mouser has the specs but alas no inventory:

http://www.mouser.com/ds/2/471/San_Ace_80WP25_E-534043.pdf

The fan has very similar specifications but it is expected life-span was only 4-1/2 to just under 7 years depending on conditions.  Still that's more than double what my first fan was able to do and hopefully it will be closer to 7 years in the mild California conditions.  I went ahead and purchased it on eBay.  Now I just need to wait for it to make its way across the Pacific!

Thanks again for all the helpful advice!

Cheers, Edouard

Offline CW2274

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I may be completely wrong here, but if I were a betting man, I'd say the failure was due to lack of flow because the whole fan is sitting on top of the sensor chamber instead of resting inside it, as it's sits too close to the plate directly above it. Any fan without proper flow will fail prematurely without "flowing" as designed, it backs up, causing the motor to simply work harder than designed. Either way, I'd sure as all get-out rest that new fan casing into the chamber to breathe more properly and not tax the motor as much.

Offline Bashy

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I would say moisture plays a big part, PC fans are designed to be in a case inside,
there is no IP rating on the fan he used therefore ingress of dust and moisture will have worked its way in.

I see the lifespan is 6 years, i bet that does not include being outside

The new Sanyo fan, the, just under 7 years lifespan is at 60C, why that i dont know
is it the optimum temp for the oil in the bearing/s? if its thicker then perhaps it will put more
pressure on the motor? and same with thinner, not enough pressure, i dont know, just guessing,
but please, do not expect 7 years again, another thought, is the high temp of 60C pretty much
the same for most PC fans as an optimum running temp?
Kind regards
Bashy

Offline Phil23

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I may be completely wrong here, but if I were a betting man, I'd say the failure was due to lack of flow because the whole fan is sitting on top......

Don't really think so,

Seen so many PC's over the past 30 years where fans have failed early in the most pristinely clean machines,
while others where the grilles are all blocked, blades covered in crap, yet the fan still runs as quite as a mouse.

I can never pick them. Maybe it's just quality control that's a bit too relaxed.

Offline AWL

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Been running this fan which is rated IP55 for a couple of months.

Offline weatherc

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I would say moisture plays a big part, PC fans are designed to be in a case inside,
there is no IP rating on the fan he used therefore ingress of dust and moisture will have worked its way in.

I agree here, its the moisture whats may be the problem. In time when i had 1-wire did i see bits totally rusted off in just a few months if they not was properly sealed.

I use, like Bashy, the cheapest found fan for my shield, cost less than 10, and they have all lasted at least one year in our climate...So when it fails is just to replace it and it still gets lots cheaper than IP-rated fans, not to talk about Davis own fans...

Offline pfletch101

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another thought, is the high temp of 60C pretty much
the same for most PC fans as an optimum running temp?

That sounds very high, particularly if you are talking about the fan temperature. 60C is reasonable (if a bit on the high side) for a PC CPU chip under load, but a PC fan should be running well below that.
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