homebrewed aspiration fan for Davis Vantage Pro

[mikeym]

Has anyone homebrewed a daytime aspiration fan for the Davis Vantage Pro> Davis doesn't sell it any more and they few that are out there are $$$. Just curious if a fan of the proper size and a solar panel would do the job ??

Thanks in advance.

 

Cheers

MikeyM

[faulknjc1]

This is just a stab in the dark, but I wonder if you could use one of those computer cooling fans - I think you can get them at Radio Shack or Fry's or stores like that that sell computer parts - pretty cheap I imagine.

Just an idea . . . good luck.

Jason

[JaxWeather]

I don't have a Davis so have nothing to compare directly with and searching the web i have been unable to find any specs on the davis fans however here is a solar powered fan that seems to be something worth considering...

"the length of the wire (2 meters) can be adjusted to affixed it where it can receive maximum sunlight.
The Solar Air Vent moves air at 32 cfm's."
General Specifications
Length    5 1/2"
Width    3"
Height    5 1/2"
Solar Panel    5 1/2” x 2 1/2” x 5/16”
http://www.4lots.com/index.asp?PageAction=VIEWPROD&ProdID=357

-Bob

[carterlake]

You kidding me?

Piece of cake. $10 even. Buy 2 or 3.

Or buy this one and cut it out of the hat

[iww]

Now that our American friends have cracked the 1-wire lightning detector, does this mean the start of homemade FARS?

Do you have scrap heap challenge on the TV in the US?

[carterlake]

Do you have scrap heap challenge on the TV in the US?

Junk Yard Wars? I love that show.... I don't think TLC shows it on TV anymore...sadly.

My fan blowing on my sensors is a 12V computer fan but I have it wired since it's in the shade.... very inexpensive... less than $10.

[iww]

With your enthusiasm, and eyes always on the $$$$, you ought to start selling your modified kit to us over the pond.

We buy anything over here, working or in some cases, not working!!

[JaxWeather]

Ok now you guys have gone and done it again

I just ordered the Solar Powered fan i linked above, figure it will be easier to mount with a square shape and also the solar panel can be moved around a bit... 

Don't know why I did it as last weekend I just redid my station to get my temp sensor completely in the shade and it has been reading spot on ever since  LOL

Will let you all know how the fan works when i get it...

-Bob

- But Honey it was Their fault... they started it... -

[iww]

Here is what you do:-

Build a homebrewed aspiration fan for Davis Vantage Pro in the US for say $10, then sell it to us over here for say, $90.00.

Then blame the high price on the exchange rate, price of crude oil, fuel surcharges etc. just like all the other manufacturers of weather monitoring equipment seem to.

[niko]

But we would need an exclusive distributor to complete the picture, are you up for that?

[iww]

I would be interested if we could have the rights to carterlakes boltek calibration tool as well!

I could shift the first consignment to the Isle Of Wight users alone!

[yagigain]

I am trying to build in a FARS into my V Pro2.   Would it be better to have the fan blowing on the sensor or trying to suck air through the sensor.   It seems to be much more effective blowing air accross the sensor, but when I look at the real Davis FARS it sucks (not sux .. well the price sux). 

Any ideas .. anyone done this ?

[niko]

I am trying to build in a FARS into my V Pro2.   Would it be better to have the fan blowing on the sensor or trying to suck air through the sensor.   It seems to be much more effective blowing air accross the sensor, but when I look at the real Davis FARS it sucks (not sux .. well the price sux). 

Any ideas .. anyone done this ?

Theoretically it would be better to design the system so that air at ambient temperature from outside the system is pulled over the sensors, rather than air being blown on the sensors that has been heated by passing the fan motor and by the increase in pressure due to the fan. In practice both effects should be very small so it probably makes no difference.

[yagigain]

Thanks, I didn't think of that.  I did some experiments and I couldn't see any noticable difference with blowing the air accross the sensor.   That makes things much easier becuase I have the little 12V fan that is only about 35mm accross and it fits inside the standard shield easily and blows air from one side of the shield accross the sensor and out the other side.   It seems to work well so far, but time will tell.

[yagigain]

I should update this.  I've setup everything and done some more testing in 'the field' and it looks like there IS a temperature spike each time my blowing fan runs.  I tested at night and the spike is .5 C in 8C windless conditions.  During daytime, under cloudcover at 10.6C the spike was .4C.   

I guess I could run it as a 24 hour fars with a gel cell battery and then adjust the error out via calibration on the console, but that is messy.

I've yet to try in warm-hot, sunny weather, perhaps the error will be less  during those conditions.

Does anyone know if I can move the Temp sensor on the VP2 using a extension lead, like I did with my wind sensor ?   Then I could simpy move it into a shady, breezy area and forget about fars.