bryton ratcliffWe decided to write an article to explain about light condensation as PrismBeam gets condensation feedbacks from time to time. Today, we're going to tell what is condensation, when it's normal, when it's a trouble needs support from PrismBeam.
What is Condensation?
Condensation is the result when moisture get into lights and turn into tiny droplets or fog on the inner lens surface cause air vents are designed no matter it is aftermarket lights or stock.
How Vents Work and Why They're Important?
How Air Moves Through light Vents in Different Environments
Gas Movement in Humid Environment
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Humid outside air enters the light through the vent to balance pressure.
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If the internal lens surface is cooler than the incoming humid air, vapor condenses into fog.
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As heat from the LED/HID source warms the lamp, water evaporates again.
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Ventilation gradually pushes humid air out and brings in drier air (once ambient humidity decreases).
Gas Movement in Cold Weather
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Cold air is denser and moves into the lamp more easily as internal pressure drops.
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Warm air generated by the bulb rises and exits through the vent, carrying moisture with it.
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When the car is turned off, cooling air may bring new humid air back inside, causing mild fog.
Gas Movement After Car-Washing or Heavy Rain
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Vents do not let liquid water in, but they allow humid air to pass.
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Pressure changes move humid air in/out more frequently during washing.
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Once the lamp heats up again, vapor evaporates and leaves through the vent.
Gas Movement-Temperature Difference
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When the temperature inside the light differs from the outside temperature, the internal air pressure changes.
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Warm air expands and naturally pushes outward through the vents.
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Cooler air contracts and pulls fresh outside air back into the housing.
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This in-and-out airflow lets moisture-laden air escape.
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As the air cycles, the light gradually balances its internal humidity level.
Why Air Vents are Important?
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They regulate air pressure:
Without vents, the light becomes a sealed “pressure box.” Temperature changes would force pressure to build up inside, easily stressing seals and causing cracks or leaks. -
They control humidity inside the housing:
Vents allow moist air to escape and drier air to enter. This keeps the internal humidity at a stable level and reduces the chance of persistent condensation. -
They support the condensation–evaporation cycle:
Small amounts of fog can form naturally, but vents ensure that the moisture can leave the system. No vents = no escape path. -
They prevent water accumulation:
When vents work properly, moisture evaporates and circulates out instead of turning into droplets or pooling at the bottom. -
They protect electronic components:
Modern lights have LEDs, ballasts, DRL modules, and internal wiring. Proper ventilation helps keep the environment dry, which reduces the risk of corrosion or electrical failure. -
They extend the lifespan of the light:
Balanced air pressure + controlled humidity = healthy seals, stable optics, and better long-term performance.
What is Normal Condensation?
A small amount of fog inside a light can be completely normal. Modern lights are not airtight; they use ventilation ports to breathe. Because of this, moisture in the air can temporarily collect on the inner surface of the lens when temperature or humidity conditions change.
How Normal Condensation Behaves?
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It appears as a light, even fog and tiny droplets—not water pooling.
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It gradually decreases over time as the light warms up and air flows through the vents.
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It eventually disappears without forming beads of water or running marks.
How Long It Takes to Clear?
Different light types heat up at different speeds, so the evaporation time varies:
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LED lights:
Fog clears slowly—anywhere from a few hours to longer—because LEDs produce less heat. Most of our lights are LED. -
HID/Xenon lights:
Fog clears within 1–12 hours, depending on usage and ambient temperature. -
Halogen lights:
Fog often clears the fastest—within minutes to a few hours—because halogens generate strong heat quickly.
Environmental Impact
Weather plays a major role:
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High humidity slows evaporation.
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Cold or damp weather slows it even more.
In these conditions, light fog may take several hours or even most of a day to disappear.
The Golden Rule
Condensation is normal when:
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It slowly decreases over time, and
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It eventually dries out on its own, and
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It never turns into big droplets, streaks, or visible water accumulation.
If the fog gets worse, forms water beads, or doesn’t improve, then it is not normal and indicates an issue.
What is Trouble Condensation?
If the fog does not decrease or you notice big droplets or pooling, there may be an issue.
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Risk: Excess moisture can damage the electrical components inside the light.
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Solution: Contact support@prismbeam.com with your situation. PrismBeam will provide assistance.
Possible Causes Trouble Condensation
1. Blocked Vent
Lights have small vents to balance temperature and pressure, allowing moisture to escape.
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If vents are clogged with dust, dirt, or debris, fog can build up inside.
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Tip: Vents are usually located at the bottom or back of the light.
2. Worn or Damaged Seal
Lights have rubber seals to prevent moisture from entering.
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If the seal is cracked, old, or detached, water can seep inside, causing persistent fog or pooling.
3. Housing Damage
Cracks or other damage in the housing allow water to enter directly, which cannot evaporate.
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This may require repair or replacement to prevent damage to bulbs or LED control units.
Summary
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Normal: Fog gradually decreases and disappears over time, even if it takes hours depending on lamp type and weather.
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Abnormal: Fog increases, forms droplets, or pools.
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PrismBeam is here to help: contact support@prismbeam.com for assistance.
(Unauthorized disassembly of the light unit will void the warranty)
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