John,

 

Maybe so, but I have.  There are many ways to cause the canopy to mist up.  Get in a forward hinged canopy Lancair while it's raining and there will be plenty of moisture in the cockpit with rain cooling the canopy - interior condensation will form.  Another is when taxiing on a cold but sunny day in October and the sunny side of the canopy can be quite clear whilst the other side has frosted up with exhalation condensation (this problem is exacerbated by carrying a breathing passenger).  There are other ways - and all these are usually cleared in flight by incoming vent air.

 

I do have a Radio Shack blower on the pilot side that can clear a small porthole sized area just above the glare shield that has been useful.  Except, it is not as beneficial when taking off VFR into scattered clouds accompanied by a high overcast --- everything is the same shade of gray whether looking out thru the porthole or trying to see through the rest of the misted over canopy.  BTW, this is even more difficult whilst flying as a wingman and it is why I have curb feelers on the wingtips.

 

Grayhawk

 

PS How do I get to "learn" from "experiences" over and over again?   ;<{))

 

PPS Yes, "{" is my mustache. ;<{O

 

Larry -

That would be OK if you want to have the cabin heat up high enough to where it would cool the stack and then defrost. The defrost pattern would probably be only a couple of small circles before the flow cooled to where it was colder than the windscreen. You really do need to defrost a wider portion of the windscreen, and only the plenum would do this. If one needs more defrost air, a fan in the duct feeding the heat/defrost valve would be one solution.

Question for all on this list: When has anyone had to use defrost while flying their Lancair?

IMHO there are not many :-))

Cheers,

John

On Wed, 30 May 2012 16:05:22 -0400, <larry.eversmeyer@faa.gov> wrote:

Question
Wouldn't putting these fans in blowing up help with the defrost.  It seems that at OSH I was talking to a 360 guy that did this with great results.  This is what I have been planning on using instead of the defrost plenum that the legacy is design with.  Any thoughts?

Thanks
LarryE

From:	"John Schroeder" <jgschroeder2@windstream.net>
To:	lml@lancaironline.net
Date:	05/30/2012 12:05 PM
Subject:	[LML] Re: glare shield fan
Sent by:	"Lancair Mailing List" <lml@lancaironline.net>

---

Addendum:

The bezels on our avionics boxes with this fan setup are cool to the  
touch. I believe that it is best to blow air down from the glare shield  
vents, rather than up. We don't notice any heat increase on our feet.

The fans noted below can also be had in 24 volts. I believe the mfg part #  
is 3324

Cheers,

John


On Wed, 30 May 2012 11:59:14 -0400, John Schroeder  
<jgschroeder2@windstream.net> wrote:

> Dan -
>
> We have two fans mounted on the glare shield that suck air down from the  
> cabin air vents and over the avionics stack. We had one before but  
> decided to add the second one because the stack avionics were still  
> running hotter that we felt was comfortable. They are small "muffin"  
> fans we got from Allied Electric. http://www.alliedelec.com/  Papst  
> Fan:  Mfr's Part #: 3312 12V
> Allied Stk #: 70105405
>
> John
>
>
>
>
> On Tue, 29 May 2012 13:09:41 -0400, Dan Ballin <dballin@gmail.com> wrote:
>
>> Anyone have experience thoughts on using a fan in the glare shield on
>> a Legacy to cool the avionics.  I am concerned about pulling air out
>> towards the canopy and onto the plexiglass, but I believe this would
>> result in better cooling.  I do have a avionics fan, but it still gets
>> mighty hot behind the panel.
>>
>> Thanks
>> Dan Ballin
>> N386DM
>>
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