After running for a few days with the fan off, I’m no longer convinced the fan is the whole problem.\u00a0 The temperature reading still doesn’t always make sense.\u00a0 I received the new fan, and I plan to install it tomorrow.\u00a0 I’m also going to increase the distance between the flower pot sections from 1 inch to 2.\u00a0 This to allow for more air flow.\u00a0 I’m thinking in addition to the fan getting hot from the over voltage, that I’m just not getting the air movement through the housing that is required.\u00a0 The flower pots are a fairly tight fit when they aren’t spaced far enough apart.\u00a0 Hopefully these two changes will achieve the desired result.\u00a0 I’ll post an update after I make the changes, and again after I let things settle for a few days.<\/p>\n
Update:<\/strong> I installed the new fan this morning and it works fine.\u00a0 The rating on this fan is 3700 rpm at 24VDC.\u00a0 The old fan was rated for 12VDC, but the power supply feeding it is rated for 20VDC.\u00a0 This caused the fan to spin a lot faster than it did at 12VDC, and that was what led me to believe it may have been running hot.\u00a0 The new fan is actually rated for more voltage than the 20VDC I’m feeding it, so over-voltage shouldn’t be a problem.\u00a0 The other concern is whether 20VDC is sufficient for the motor to start.\u00a0 I tested it with a variable power supply on my bench before installing it and it took about 15VDC to start spinning. So 20VDC should be plenty of voltage to run the fan.<\/p>\n I also spaced the sections of the FARS farther apart to help the airflow.\u00a0 I created some 2 inch spacers to replace the 1 inch ones I had been using.\u00a0 The extra length required me to remove several sections that weren’t essential for it working correctly.\u00a0 Then I mounted everything back on the pole outside.<\/p>\n Initial comparisons with my other outside thermometer and nearby stations on Weather Underground look great so far, with little or no solar heating taking place.\u00a0 I need to let it run for several days to see how things perform over time, as other changes I made in the past appeared to be working at first.\u00a0 That could have been caused by my opening the FARS up and releasing any warm air that had built up inside of it.\u00a0 Over time the warm air would build back up again due to poor ventilation.\u00a0 Maybe I really got it right this time.\u00a0 I’ll know better after a few days.<\/p>\n","protected":false},"excerpt":{"rendered":" After running for a few days with the fan off, I’m no longer convinced the fan is the whole problem.\u00a0 The temperature reading still doesn’t always make sense.\u00a0 I received the new fan, and I plan to install it tomorrow.\u00a0 … Continue reading