Avionics Excessive Heat

[kjmorris2023]

I have an A-36TC with a Dynon Installation including AP. The Avionics generate quite a bit of heat. Legs get very warm even at altitude. I thought about putting Lonestar 3 port or greater in there to move air. I hear and read that the Skyview HDX and the IFD 440 have their own fans. My mechanic looked under the glareshield and did not see attachment points for the hoses but my avionics guy said the IFD is the only one. My mechanic even suggested a 24V computer fan at the next annual to help move air. I live in Phoenix with obviously hot weather. I'm concerned more about the equipment that I've paid to install 80K having it's life shortened.

In commercial aircraft that have powerful fans that move air throughout the cockpit equipment and E&E compartments constantly and have redundancy and warnings.

Comments?

 

[Rhino]

The installation manual requires a minimum 1 inch space for the heat sinks and fans to operate properly. I assume yours has that. But the install manual also states forced cooling air may be required in hot climates. Assuming you lived in Phoenix at the time of the original install, this should have been addressed at that time. I would definitely pursue the fan idea, and I might not even wait for the annual to do it. It shouldn't be too difficult to put a temperature probe in temporarily just to be sure. If the operating temperature of the HDX ever exceeds 140 degrees, you need extra cooling. Temperature limits for all components are listed starting on page 2-7 of the installation manual.

https://www.dynonavionics.com/includes/guides/SkyView_System_Installation_Guide-Rev_AL_v16.pdf

 

[kjmorris2023]

My installer said he only does on the Mooney's must be that 1 inch space that's tight on that airplane. Now I have Air Conditioning installed on my Bonanza and at least on body parts up high not near the floor we're pretty comfortable. I've started to direct at least one outlet toward the avionics. I probably could open those side floor outlets to help dissipate the heat near the floor. And this is with firewall air shut off. The Avidyne audio panel is so hot you wouldn't want to hold it for long. And honestly it's the same at 15,000. I would doubt it ever gets to 140 but wouldn't hurt to put a probe up there.

Thanks Rhino

 

[Rhino]

I'm not completely sure if the 140 degree limit is internal or ambient, though it seems to suggest ambient. That would probably be a good question to ask Dynon via their support links. If you ask that question, please post the answer here so it will be available for others to reference.

If you get over 140 ambient, it's probably much hotter inside the units. However, the HDX has alerts to warn you of excessive internal temperatures within the EFIS, so this is likely just a general, ambient air issue.

Good luck. Hope you find a good solution that's not drastic or too expensive.