Frans, Ira and others...
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
higher
temperature 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
----- Original Message -----
From: Frans Veldman<mailto:frans@privatepilots.nl>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Friday, April 23, 2010 7:06 PM
Subject: Re: Europa-List: Re: Instrument module cooling/demisting
fans.
<frans@privatepilots.nl<mailto:frans@privatepilots.nl>>
On 04/23/2010 06:39 PM, rparigoris wrote:
> Hi Ira Thx. for the reply. How are you cooling your radio,
> transponder and EFIS?
Instrument cooling????
My Garmin SL-30 consumes less than 1 Amp max during receive. If it
were
to convert this current totally into heat (efficiency zero), it could
only produce 14 Watts of heat.
My transponder consumes approximately 250mA. With this current it can
not produce more than 3 Watts of heat (again with a worst case
efficiency of 0). That's about the same as an annunciater light, and
that doesn't need cooling either. I have no EFIS, but if such a beast
is not a powerhog, it can not produce much heat as well.
Modern avionics is very efficient and does't produce as much heat as
the
older style equipment, and hence doesn't need cooling at all.
Have you actually tested how much "heat" your equipment produces?
If there is no heat production in the instrument module, there is no
need to remove it. ;-)
Frans
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