n700jl

n700jl

Well Known Member
Yes it is hot this summer but we have had a couple of inflight shut downs on our EFIS. I think that this is caused by the EFIS over heating then doing a reboot. I am going to try to run some cooling air from the avionics fan to the EFIS. Any Thoughts on this? the EFIs is right next to the radio stack. This is why they call it experimental!
 
Where did you get thoe fan covers

Thom,

Im putting a computer fan in the glare shield this weekend. Where did you get the cool looking screen cover?
 
I haven't run any cooling fans (other than what is internal to my GRT HX displays and the Garmin 430) in all th hours I have put on the Val - most on the gulf coast. Remember than in the -8, you have a natural insulation between the panel and the firewall known as a baggage compartment! My neighbor just added a computer cooling fan to the avionics stack in his F1, since he gets a lot of heat soak back after shutdown. I don't think he's used it enough to tell if it will solve the high temps he sees - he had a LOT of heat-related troubles with his BMA gear before he swapped it all out for GRT this winter.

Paul
 
I don't have any cooling fan to the GRT, only to my Garmin stack that have a cooling port. I have never had any heating issues with the GRT EIFS so far.
 
I have 2 GRT Horizon HX 8.4" screens. Radio Shack cooling fans maybe an option. I do have 1 spare port on my avionics cooling fan. I did not remember reading anything about external fans needed in the installation manual?
 
Just a comment here from a EFIS manufacturer- Over the years we have had a very small number of customers see overheat warnings on our D10A/D100 products (these products tell you on the screen when they get warm).

Every time we see this, it means the whole area behind the panel is 150+ degrees F, which means ALL your avionics are roasting, even if they aren't warning you. It was never that our EFIS was particularly sensitive, it's just that none of your other avionics warn you. Your $7,000 Garmin 430 is suffering too. We got a kick out of a few customers that complained we were sensitive to heat because of the warning on the screen yet they also mentioned that their XXX won't even turn on until it cools off.

We mostly found that just getting some sort of passive vent hole at the top of the panel fixed this. Usually this happened to an aircraft like a glasair that had a really well sealed avionics hood, which just meant all the air stagnated and heated up. Putting some small vent hole worked wonders.

It could also work to just get a fan that exchanged air out of this area in general. Any airflow makes a huge difference.

If your EFIS has a ARHS inside the EFIS like our D10/D100's do, please talk to your manufacturer before you point a fan right at the unit. AHRS units have complex temperature calibrations, and having a fan blowing at one side will cause hot/cold spots that could affect attitude performance.
 
The test I use is to reach behind the panel and touch the avionics/EFIS. If it is uncomfortable to keep fingers on it, it is too hot.

In the F1, this was often the case after shutting down for lunch on a hot summer ramp - even with insulation on both sides of the firewall and a vent slot in the glareshield, the heat from the engine would radiate back into the avionics and make the BMA EFIS do funny things on takeoff.

The GRT EFIS has not had the same problem, but having spent a bunch of money on a new EFIS, I was keen to ensure it stayed cool and happy during the summer.

About a dozen flights ago, a 2 amp-hr battery was wired into the line to the computer fan, isolated with a rectifier. This allows the battery to charge up while the Master is on, and to run for a few hours when the Master is shut off. The fan sits in a shroud made from a hardware store ABS pipe reducer and is plumbed in line with a NACA duct on the side of the fuselage. It draws approx. 1/4 amp. In flight, ram air blows harder than the fan alone, but on the ground, the fan continues pulling in outside air.

Not surprisingly, this setup lasted for about a dozen flights before the battery gave out - perhaps it didn't like being fully run down between charges. A solid state 1-hour timer is waiting to be installed which will hopefully keep the new battery happier.

In the limited testing so far, the avionics were never hotter than warm to the touch, even after the lunch-hour ramp shutdown at 90 F OAT.
 
Put a fan in

I have an RV-7A and I wish I had put a fan in when built. I also wish it was a defogging thing as I have seen condensation one morning after overnight camping. A couple of week?s age we had some sun here in Seattle and it got hot. Over 100 degrees. Anyway the Dynon came up black screen with a message saying to the effect that it was overheating after sitting on the ramp for an hour:eek:. I shut it off because it was sunny and who cares. After flying for 15-20 minutes I turned it back on and everything was merry. It must be getting hot back there.

My advice... Put a cooling fan in if you are in Arizona, or even Seattle.
 
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