REFLECTOR: GRT Displays overheating - Anyone else see this?

[Mark Magee]

Hi Brett,
You guys all laughed at me and my longings toward cabin A/C... We closed out that thread. I agree with GRT on the vents except I'd consider some 12V pc power supply fans, one port one starboard, blowing up on the windscreen. This would double as winter defogger/deicer. With the doors open until after run-up you should be getting a fresh flow of 100F air on a hotter day. If you can get aloft into cooler air I'd think you'd have a shot at keeping the Glass out of over temp. Pretty simple fix, two holesaw cuts on your glare shield and mount the fans and grab 12V from same circuit powering the GRT's: those fans pull very little power.
Frankly I'd even consider laying a Blue Ice pack or two below my Glass displays secured somehow for summer work until this confounded La Nina weather pattern subsides.
Or install A/C: I'm game!
My $.02 USD.

Mark B. Magee
N34XL
Sent from IPhone 4

On Jul 8, 2012, at 9:36 PM, "Brett Ferrell" <reflector at velocityxl.com> wrote:

> We've had quite a string of hot weather here in SW Ohio as of late, and on the last couple of flights we've had issues with our GRT HX screens overheating and shutting down in flight.  We've got backup dial gauges, but needless to say, it's disappointing when you lose the fancy readouts, and though we've been planning to fly to Airventure we will likely won't if we can't quickly find a solution to the issue.  Has anyone else seen this behavior?  If so, how did you resolve it?
>  
> GRT tell me that the screens should run 'about 30 degrees' above ambient.  They will shut down at 160 F, and you can see the internal temperature by going to setup menu (Display Maint, Analog Input page).  It's been right at 100 F here for the last few days, and I can confirm that on the ground they warm right up to 130.  We went around the pattern and in less than two passes they were shutting down!  I went to the setup page, and sure enough, they were reporting in the mid 150s.
>  
> GRT believes that if I add vents to my glaresheild the issue will resolve itself, but I have already tried a large (68 cfm) computer fan aimed at the back of the displays, which only relieved about 1 degree F of temperature, and tried routing cooling air from the nose fresh air vent to the back of the displays to no effect (the screens still shutdown in flight).  I believe my situation is unique because I mounted a second oil cooler in the nose for winter recirculating air usage (rather than  cold outside air), and have checked this cooler is, in fact, getting quite hot.  On my last flight it was over 200 F even though the one on the nose NACA was below 180, so I think this cooler is just filling the nose area with hot air.  Net, I'm going to pull that cooler, and at some point put vents in the glaresheild, but that's a fair amount of effort the way I have it mounted.
> 
> Brett
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