Glare shield defrost fans

[Aerosport1]

I was wondering what size fans most people are using for the wind screen defrost fans? The 4" fans seem a little large in diameter. Any thoughts

Geoff

 

[Lycosaurus]

None

I was considering using a defog fan, since I plan to fly in winter. After some thought, I did not want the permanent magnets in the fan to affect my compass reading, and decided against it.

Now that I am flying the plane, I find that I have not needed it yet (25 hours). A couple of times the windscreen fogged up as I entered and closed the canopy (slider). Once engine started, it did not take long to clear up (a minute or two), and I could taxi safely.

I do have dual mufflers with heat muffed plugged in series, which provides loads of heat. Temperatures flown were from 0 F to 20 F.

 

[kevinh]

Now that I am flying the plane, I find that I have not needed it yet (25 hours). A couple of times the windscreen fogged up as I entered and closed the canopy (slider). Once engine started, it did not take long to clear up (a minute or two), and I could taxi safely.

Yep! Same here - I did run two of the van's 3/4" plastic ducts up from the heater air inlet at the bottom of the firewall to blow on the left and right sides of the canopy. Weighs/costs virtually nothing.