Opinions on mask fans. Worthwhile? Noisy gimmick?

[Altec]

Bunch of my team mates ran homemade fan setups. A couple sub-30mm fans ziptied to the vents with a small battery pack and switch. Worked better than any off the shelf option. Not for cooling, simply to keep fogging at bay in the muggy MD summers.

[lew]

My fan in my JT Spectra works well, but that noise is a problem. Out here, where the humidity is low, it is better to move your head often and introduce airflow. Back in the Midwest, I never had a problem with fogging on a thermal lens.

[JonM]

Let me just say that when I got my ExFog setup, I tested it by wearing it and my mask during a 20 minute workout on my elliptical. By the end, my foam was completely soaked in sweat, yet my glasses and lens were completely fog free. I even turned it off a couple times to make them fog and turning it back on again cleared them both almost instantly.

[nerdcore]

I don't use fans now, but back when I wore glasses under the mask, it was necessary. My glasses always fogged but my mask lenses never did. I never used them to keep cool.

I only used homemade ones similar to those Fanz kits.