In most motorcycle helmets, the rider gets very hot, and the human head produces a lot of heat and humidity, that builds up inside the helmet, causing fogging on the upper half of the inside of the lens. By utilizing the space already carved out for the DVS internal drop down mechanism, and making new brow vents that open and close at just the right spot, we created vents that are designed to allow trapped heat and moisture to leak out from simple convection during riding, using laminar flow to pull out the hot air.
This was very tricky, because it has a high probability to create a lot of noise when the air moves over the opening, similar to blowing air over the open top of a bottle. To eliminate the noise, we refined the vents by hand, while riding on the freeway, until the helmet was quiet. The results were immediate. A fully fogged shield may be cleared in seconds, even on a rainy day.
