Topic: Using Davis solar powered aspiration fan in the winter

[onedart]

I have a Davis 6153 unit which has a solar powered aspirated fan unit for drawing air up through the sensor chamber. Now it is winter, i do not get enough light to enable the unit to power the fan and as the sensor chamber is tripled sheilded to protect the sensor from solar radiation i obviously have issues getting a proper airflow through the chamber, the effect is not getting a low temperatures during the night and not getting as high temperatures during the day and the temperature takes longer to react than other stations locally(i.e slower temperature movement) . I thought about getting the 7747 unit for the winter which is just the baffles with no fan so as i could get a constant airflow to the sensor, does anyone have any other suggestions with regards a solution to this problem.

[NiceBill]

Why do you compare your station with other stations around you?   How do you know they are correct?  You can't do that!   Your station should work just fine unless you are living in total darkness for the winter.

Bill.>>>>>>>>>>>>>>>>>

[Sigdigit]

I have the same unit.  The fan aspiration is really only critical when you have high solar radiation in a breeze free environment.  As you mentioned, you are not getting enough solar radiation to power your fan.  Therefore, the solar radiation is probably not enough to influence your readings.  Although there are additional radiation shields on your unit, the unit should function fine as a "passive" radiation shield, allowing plenty of airflow.  These shields will not insulate the sensors, other than from solar influence.  I am in a valley, with very few other PWS's nearby with similar topography.  This morning I registered a low temp of 16 deg. F.  Using "Weather Exchange", I could see I registered the coldest temp in a 30 mile radius.  Therefore, I don't believe the shielding is preventing accurate sampling of the ambient temperatures/humidity levels.