A Guide to Damp and Wet Location-Rated Lighting

Lighting has been developed for nearly every environment known to man, including settings where water is a constant hazard. Both damp and wet location-rated fixtures can work in applications where moisture is present, but there are differences between the two and it’s important to know what they are before installing new fixtures.

What are Damp and Wet Location-Rated Lights?

Not all lights are right for every environment, which is why some are location-rated. The location rating lets the installer know where the fixture can be safely placed, and some of those fixtures come with damp or wet ratings. Here’s what each mean:

Damp-rated fixtures

If a fixture is rated for a damp environment, that means it can withstand indirect contact with water. Damp-rated fixtures aren’t built with the same waterproof seals that wet-rated fixtures are, but they can handle moisture better than dry-rated fixtures.

Condensation and excess humidity are common examples of indirect exposure to water, so damp-rated fixtures are ideal for high humidity environments. Locker rooms, natatoriums, food processing facilities, cold storage facilities, bathrooms and kitchens are all settings where damp-rated fixtures make sense.

Damp-rated fixtures can also be installed in some outdoor applications, as long as they are not exposed to rain, snow or ice. For example, exterior canopy lighting is typically damp-rated, as are fixtures installed under overhangs and awnings. Damp-rated fixtures are even found inside active mines, though dust is a greater concern here.

Wet-rated fixtures

Wet-rated fixtures are even better protected from water and can hold up well in humid environments and settings where direct contact with water is expected. Wet-rated fixtures are engineered with watertight enclosures that keep the lamp shielded from water even if the fixture is submerged.

With their waterproof design, wet-rated fixtures are the standard choice for exterior applications such as parking lots, highways, pathways, and stadium lighting. Wet-rated fixtures are also a must for swimming pools and hot tubs. They also have many commercial and industrial applications, including car wash and offshore oil rig lighting.

Why Is It Important To Match Lighting To Their Rated Environment?

Damp-rated fixtures are sufficient for indirect water contact and wet-rated fixtures are needed when direct contact with water will occur. It’s extremely important to keep this in mind when selecting fixtures, especially if your project includes exterior lighting. There a few reasons for this caution, including:

  1. Safety – Water is an active electrical conductor and even brief, incidental contact is enough to produce an electrocution hazard. It’s always worth considering if water will be a problem for a particular project and to respond accordingly by selecting the proper fixtures. If water does intrude into the lamp enclosure, it can result in an unregulated discharge, which could lead to fire or severe injury.
  2. Fixture lifespan – Fixtures that are mismatched to their environment will usually fail early. Sometimes, this failure can be sudden if water manages to reach the lamp. This can be a costly mistake to make, especially if you’re switching out a lot of lights or expensive commercial fixtures.
  3. Performance – If you’re not getting optimal performance from your new lights, then you’ve spent a lot of money for little impact. Water intrusion is one reason why some lights experience performance issues, even if only a small amount of moisture is affecting the lamp. Keep the lights dry and they’ll produce crisper, more brilliant illumination.

Are There Damp And Wet Location-rated LED Lights?

LED lighting technology has been adapted for nearly every environment and application, including applications that involve contact with water. It’s now easy to find LED lights that are IP-rated against dust and water intrusion, and LEDs that can handle submersion in water. Since LED lights are highly controllable, it’s popular to attach dimmers or color filters to LED fixtures that are installed in pools or fountains. This can create a dramatic effect that only wet-rated fixtures can deliver.

Damp and wet location-rated fixtures are also available in an impressive array of designs, including vintage, modern and industrial styles. Form and function can both be considered when selecting damp and wet-rated lights.

What Does A Fixture’s IP Rating Refer To?

Lighting fixtures are reviewed by the Underwriters Laboratory (UL) for safety reasons. Specifically, UL considers the fixture’s engineering and how well it is protected against intrusion against solid material and water. Every fixture is given an IP rating, and this rating specifies the level of protection.

Each IP rating consists of two single digital numbers. The first number refers to the fixture’s protection against solid material (typically dust) and the second number refers to the fixture’s water protection. The first number scales from zero to six, while the second number scales from zero to eight. The higher the number, the better the protection. To be considered a wet-rated fixture, the light’s IP rating should include at least a five in the second column, though you’ll need an IPX7 or IPX8-rated fixture if it will be submerged for any length of time.

What If I’m Not Sure If A Fixture Is Damp Or Wet-rated?

Lighting fixtures come with safety labels that detail whether the light can handle damp or wet conditions. If the light is location-rated, you may see “suitable for damp locations” or “suitable for wet locations” on this label. The IP rating should also be listed somewhere on the label. If the second number is a five or higher, then it should be safe for most exterior applications as long as the fixtures will not be submerged.

To avoid any confusion, it’s best to consult with a lighting expert to determine which option is best for a particular space. Experienced lighting manufacturers and installers can provide valuable insight into what a fixture is rated for. In addition, a lighting expert can recommend location-rated fixtures for a particular project, ensuring you get the best performance and lifespan out of your lights.