The waterproof breathable cap can effectively prevent the formation of condensation on the headlights

With the advent of winter, the gradually widening temperature difference between day and night often causes the headlights to fog up, which not only affects the light transmittance of the car headlights, weakens the lighting effect at night, and brings hidden dangers to driving safety at night, but also Affect the service life of the relevant electrical components in the lamp.
Generally speaking, there are two methods that can be used to remove moisture and achieve headlight ventilation: convection and diffusion, and two methods have obvious advantages and disadvantages.
Convection means open, cross ventilation and working with at least two vents to remove external moisture through air circulation. This process is triggered by pressure differences when the temperature rises (for example, when the headlights are turned on) or when the car is moving. These pressure differences create drafts with outside moist air. Ambient air is sucked in through the lower opening and out again through the upper opening.

However, the disadvantage of this open waterproof and breathable solution is that dust, dirt particles, insects, etc. will also enter the headlights along with the inhaled air. And, convection only works when the car is moving or the headlights are on. Adding to this is the fact that the air is often not able to circulate to the desired area around the headlights due to the large number of components piled up in the engine bay, which is also a problem.

The more effective way to remove moisture from headlights is actually to diffuse. The main reason is that diffuse ventilation does not need to be activated by driving the car, it is an effective way to continue. In addition, with the use of high-quality waterproof and breathable caps, the headlights can prevent dust particles from invading the lights during the long-term effective diffusion of water vapor. While protecting the lights, it also reduces the possibility of water molecules condensing into water droplets .

Vent tubes can effectively reduce condensation when the car is running through the convective effect, but they cannot ensure that the headlights are not affected by dust, dirt, sediment or water; products like vent caps can provide effective protection from foreign objects such as dirt , but it only provides a very limited diffusion effect and cannot reduce the condensation well.