Cooling fan in instrument module.
Not sure whos plane this is, but thanks for pic.
Y10-02-21
Bud Yerly:
As a weight and power Zealot I see your points, however the fastest way to kill electronics is heat.
My panel only draws a few amps, and the manufacturers do not require cooling fans, but without the fan cooling, the slow steady increase in heat makes the inside of my vented panel rise to over 100 degrees even on a cloudy day. The Europa panel is made for ease of installation and removal for maintenance. However, the novice does not notice that the panel can be built almost air tight. Many put extensions and iso mounts to allow air flow, but still it is a hot box.
In winter I wanted some warmth and vented my panel from the passenger side footwell ( a fan blowing up on my radios over to the pilot side footwell which has a tube sucking air from the top of the Blue Mountain Lite down and out the left rear of the panel), my thinking was that it would keep my feet warm. I am here to tell you, it got hot. The steady stream of 90 F air on my feet became annoying. I will vent back to a vent in the top of the panel onto the windscreen very soon.
Our experience at Custom Flight has seen the Dynon Flight Deck 180 or D100s go blank on a 90 F summer day. The Dynon is working but the screen video goes near blank. The panel interior temperature was about 100 on the outside but the local component inside was hotter causing the blanking. As far as the newer avionics we all can't live without, if you hold your hand to the back of the new Garmin G3X (2.75amps -35to +70C), or Dynon Skyview (3.5 amps -40 to +60C), the case is actually very warm (hot), and although neither needs direct fan cooling, the manufacturers require space and air movement, which to me means, I need a fan. Grand Rapids Sport is a very low power system however they warn:
"The GRT Horizon EFIS does not require external cooling. However, as with all electronic equipment, lower operating temperatures extend equipment life. Units in an avionics stack heat each other through radiation, convection and sometimes by direct conduction. Even a stand- alone unit operates at a highertemperature in still air than in moving air. Fans or some other means of moving air around electronic equipment are usually worthwhile. Be certain that cooling air does not contain water ? a problem often encountered when using external forced air cooling air.
The Horizon HX contains in internal cooling fan. Be sure that there is adequate air available so that it can cool the display unit. Although the microprocessors don't use much power, they do need heat dissapation."
As for venting the windshield, I couldn't agree more, that a pleasant 85 degree Zephyr bathing the windscreen should work on a coolish day and modest humidity, but on those rainy days such as when we left Sunday after Sun 'n Fun, the only way to keep the windscreen clear was a rag, a Zephyr doesn't hack it. Like the car, the windscreen needs a pretty stout blast of very warm air if it is to clear effectively in high humidity conditions and those high speed descents from 10 grand back into the hot sticky airports of Florida.
The open panel metal airplanes get enough air to get by because of their hangy downey wires from their open panels and drafty metal construction. We have a neat and tidy panel package that alas, can cook our avionics. Bottom line is, fans or outside ducted air are a good thing for the life of avionics.
Just my opinion,
Bud Yerly erly:
Y10-04-23
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