Author Topic: Add Fan to stevenson screen  (Read 15735 times)

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Offline raedh

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Re: Add Fan to stevenson screen
« Reply #25 on: September 26, 2012, 08:10:43 AM »
weather1967  : With the sensor in the plastic tube you will see differents raedh

for now either without running the fan I;m getting a good readings the expected max for today is 29 , for now am getting 28.5 , waiting night readings :grin:

Offline raedh

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Re: Add Fan to stevenson screen
« Reply #26 on: September 27, 2012, 01:54:18 AM »
the modfications, the best i can do #-o





« Last Edit: September 27, 2012, 03:12:17 AM by raedh »

Offline weather1967

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Re: Add Fan to stevenson screen
« Reply #27 on: September 27, 2012, 11:47:19 AM »
Νice job  :-)
Raedhl The fan sucks air from the side of sensor out-temp -hum,and air flow go above on the roof,do not put air over the sensor ,i think but i am not sure your fan put air over the sensor

And the distance bettwen the above side at out remote sensor with the under side at fan it is 1-2 cm.
« Last Edit: September 27, 2012, 11:52:29 AM by weather1967 »
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Offline raedh

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Re: Add Fan to stevenson screen
« Reply #28 on: September 28, 2012, 04:11:05 AM »
oh! do you mean i have to flip the fan to other side to it suck the air out of tube and distance between fan and sensor is 1-2 cm? so what am doing i worng now

Offline weather1967

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Re: Add Fan to stevenson screen
« Reply #29 on: September 28, 2012, 11:16:15 AM »
oh! do you mean i have to flip the fan to other side to it suck the air out of tube and distance between fan and sensor is 1-2 cm? so what am doing i worng now

Yes Raedh you must turn the fan from the other side to suck the air out of the tube,and the distance down side fan with up side sensor is 1-2 cm

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Offline raedh

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Re: Add Fan to stevenson screen
« Reply #30 on: September 28, 2012, 04:07:58 PM »
done  :grin:,

Offline weather1967

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Re: Add Fan to stevenson screen
« Reply #31 on: September 29, 2012, 12:20:47 AM »
done  :grin:,

You make measurements day and night ,and tell us the results  =D>
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Offline raedh

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Re: Add Fan to stevenson screen
« Reply #32 on: September 30, 2012, 06:21:11 AM »
should I keep it the same when winter arrives , because our winter is cold and we have snow event in many times

Offline DanS

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Re: Add Fan to stevenson screen
« Reply #33 on: September 30, 2012, 06:30:49 AM »
That's a topic that some folks may disagree with but I say yes, keep it running year round. The air you draw in and across the sensor is what you want to read no matter what temperature it is. The fan won't make it any colder. If the fan is off with no air flowing then stagnant/still air readings can differ slightly from the outside ambient temperatures.
My feeling about an enclosed temp/hygro sensor.

Offline raedh

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Re: Add Fan to stevenson screen
« Reply #34 on: September 30, 2012, 07:04:47 AM »
do I need to run with lowest voltage ?

Offline DanS

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Re: Add Fan to stevenson screen
« Reply #35 on: September 30, 2012, 07:11:11 AM »
Probably a good idea to run a low voltage to extend the life of the fan.  All you really need is a slow steady flow of fresh outside air to pass over the sensor. Higher power that blasts the air in won't gain you anything but having to clean the sensor and fan blades more often. ;)

Offline weather1967

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Re: Add Fan to stevenson screen
« Reply #36 on: September 30, 2012, 07:51:58 AM »
should I keep it the same when winter arrives , because our winter is cold and we have snow event in many times

Yes you keep and the winter,it is necessary ,one example the cold nights with no cloud in the sky ,and no wind ,there is temperature inversion the cold air it will enclave in the tube and the temp sensor it show lowest temperature for the correct,for this reason it is necessary to work the fan with half speed at 6 volt ,for unenclave the colder air where it have enclave it the tube,and the temps it will increase.

If there are not temperature inversion the winter night you will see ,if you have open the fan ,and when closed the fan you do not see any differents at temperatures.

Where are you come from ?
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Offline raedh

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Re: Add Fan to stevenson screen
« Reply #37 on: September 30, 2012, 09:06:59 AM »
Jordan-Amman, I'd really like to know the purpose of running the fan with 6v instead of 12v
« Last Edit: September 30, 2012, 09:11:30 AM by raedh »

Offline DanS

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Re: Add Fan to stevenson screen
« Reply #38 on: September 30, 2012, 09:59:16 AM »
Amman you say?  Some of the best Shawarma's in the world there! Almost everyday for lunch while I was working there. Couldn't get enough. :-P

edit: oooops, don't want to steer this thread off course but my stomach started growling when I saw Amman. Back to Stevenson fan now.
« Last Edit: September 30, 2012, 10:01:42 AM by DanS »

Offline weather1967

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Re: Add Fan to stevenson screen
« Reply #39 on: September 30, 2012, 10:18:46 AM »
Jordan-Amman, I'd really like to know the purpose of running the fan with 6v instead of 12v

The day we want the foul power for this use 12 volt,the night it do not necessary the foul power air blow  for this use 6 volt.

Dans he wrote correct why we use 6 volt at night

Probably a good idea to run a low voltage to extend the life of the fan.  All you really need is a slow steady flow of fresh outside air to pass over the sensor. Higher power that blasts the air in won't gain you anything but having to clean the sensor and fan blades more often. ;)

Ps : Dan and here to Greece we have nice foods  :lol:
« Last Edit: September 30, 2012, 10:21:16 AM by weather1967 »
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Offline DanS

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Re: Add Fan to stevenson screen
« Reply #40 on: September 30, 2012, 11:08:38 AM »
Jordan-Amman, I'd really like to know the purpose of running the fan with 6v instead of 12v

The day we want the foul power for this use 12 volt,the night it do not necessary the foul power air blow  for this use 6 volt.


If you're handy with a soldering iron this would be easy to make (and cheap) to control 12v in the day and 6v in the night for the fan.


p.s. Dimitris, Ive heard a lot of good things about the food in Greece from former colleagues. Unfortunately that is one of the countries I haven't visited. :-)
« Last Edit: September 30, 2012, 11:16:17 AM by DanS »

Offline raedh

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Re: Add Fan to stevenson screen
« Reply #41 on: September 30, 2012, 12:15:14 PM »
You're all welcome here guys feel it as your second country ,  for now am running the fan with 6v all day and night that because the daytime we have here where I live a steady breaze 17-25 km/ hr so since made the modification I'm getting good readings . And much thanks to weather1967 and DanS

Offline weather1967

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Re: Add Fan to stevenson screen
« Reply #42 on: September 30, 2012, 12:31:06 PM »
Ι added the numbers at electronic components Dan electronic circuit
I added a diode 1N4001 at relay for protection
The resistor 82 οhm - 1 watt it decrease the voltage at 6 volts
Relay 12 volts
Transistor 2N2222
Variable resistor 0-100 Kohm (it needed for to tuning exactly at point to darkness to open)
Photoresistor 2O kohm
Resistor 10K between base transistor and photodiode

Dan i hope some day you come at Athens,and we meeting for Greek food :-)

« Last Edit: September 30, 2012, 03:22:37 PM by weather1967 »
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Offline DanS

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Re: Add Fan to stevenson screen
« Reply #43 on: September 30, 2012, 12:42:26 PM »
Sounds good Dimitris and thanks! (thanks also for the 1n4001 addition. I have a bad habit of forgetting those in the drawings #-o). :-)

Offline weather1967

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Re: Add Fan to stevenson screen
« Reply #44 on: September 30, 2012, 12:58:42 PM »
You're all welcome here guys feel it as your second country ,  for now am running the fan with 6v all day and night that because the daytime we have here where I live a steady breaze 17-25 km/ hr so since made the modification I'm getting good readings . And much thanks to weather1967 and DanS

My pleasure Raedhl,i see from WU two days after you will have thunderstorm there,the fan you can have at 6 volt if you have clouds all day,but 3-4 October i see sun and max temps 31-28 ,this days you must have fan at 12 volt.

http://www.wunderground.com/weather-forecast/JD/Amman.html


Sounds good Dimitris and thanks! (thanks also for the 1n4001 addition. I have a bad habit of forgetting those in the drawings #-o). :-)

No problem Dan,nice to talk with you.

« Last Edit: September 30, 2012, 01:01:36 PM by weather1967 »
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Offline raedh

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Re: Add Fan to stevenson screen
« Reply #45 on: September 30, 2012, 01:56:37 PM »
yes that's why for now its running on 6v as you suggested and readings are better than ambient SRSLX100 reading
, thanks again weather1967, it is a good fealing when you the station give a good and stable readings  :grin:

 

anything