Six Answers to Your Lighting FAQs

Many of us want to replace our old, inefficient lighting with energy-saving alternatives, such as ENERGY STAR® certified LEDs. But with lighting aisles filled with dozens of bulb types, and even more options available online, figuring out which bulbs to purchase can be confusing. To make this process easier, we’ve answered six frequently asked questions about LEDs. Check out the answers below, and be sure to stay tuned for Part II of this blog series, which will answer common questions regarding energy-efficient appliances.

1. What do I look for if I’m trying to find an LED to replace an incandescent bulb?

We’re used to looking at wattage to find a bulb with the desired brightness, but wattage actually indicates energy use, not how bright a bulb is. Because LEDs use over 80% less energy than incandescent bulbs, they require significantly fewer watts to provide the same brightness. To make it easier for shoppers to find an LED that is equally bright, LED bulb packaging will often have the equivalent incandescent wattage listed on the front; however, the true measure of brightness is indicated by the lumens number. A typical 60W incandescent bulb provides 800 lumens of light, and so, too, will its 9W LED replacement.

In addition to checking brightness, make sure the LED has a similar color temperature as your incandescent bulb. Look for a bulb with a soft white light appearance, indicated by a color temperature of 2700K – 3000K. Finally, check that the LED is ENERGY STAR certified, meaning it has undergone third-party testing to ensure high performance.

2. What do the different color temperatures of LED bulbs indicate?

Color temperature, measured in Kelvin, indicates a bulb’s light appearance. This feature can range from warm, yellowish light (2700K-3000K) to cool, white light (3500K-4100K) to crisp, bluer daylight (5000K-6500K). Which color temperature to select will depend on your home’s interior design and the desired ambiance. Warm, yellow light is often used to create more comfortable living and dining rooms, whereas whiter light is typically preferred in bathrooms.

3. How can I tell if an LED bulb is suitable for outdoor use?

For bulbs that are appropriate for outdoor use, the package will indicate “wet-rated” or “damp-rated.” Wet-rated bulbs are designed for direct exposure to rain or snow, making them the best bulb choice for floodlights, landscaping lighting, and other fixtures that are not shielded from precipitation. Damp-rated bulbs are more appropriate for fixtures protected from the elements, such as lanterns and covered porch lights.

4. What do the abbreviations on bulb packages, like “BR30”, “A19”, and “PAR38”, mean?

The first half of the acronym indicates the style of bulb: for instance, “BR” stands for bulged reflector, “PAR” stands for parabolic aluminized reflector, and “A” stands for A-line bulb. This means the first two bulbs are reflectors, typically used for floodlights and recessed lighting, whereas the latter is a traditionally shaped bulb, often used in indoor lamps. The numbers in the second half of the abbreviation indicate the bulb’s diameter, in eighths of an inch: for example, “30” in BR30 means the bulb is 30/8 (or 3.75) inches in diameter.

5. Are LEDs compatible with dimmer switches?

Many LEDs are dimmable, and will be marked as such on their packaging. However, it’s important to also check whether a particular dimmer switch is compatible with the LEDs you’d like to purchase. Otherwise, you may experience unwanted flickering. You can determine compatibility by checking the product details for a particular bulb or dimmer. Fortunately, many manufacturers also produce universal dimmer switches, which are compatible with incandescent bulbs and LEDs alike.

6. Can LEDs be used in fully enclosed fixtures?

When LEDs are used in enclosed fixtures, heat released from the bulbs becomes trapped. With LEDs that aren’t specifically designed for these fixtures, the heat affects their performance and shortens their lifespan. On the bulb package or in the product specifications, you will find a label along the lines of “suitable for fully enclosed fixtures” or “not recommended for fully enclosed fixtures.” To ensure optimal performance, be sure to purchase LEDs that are designed for the fixtures in which they will be used.

Got more lighting questions? Share them with us via Facebook or Twitter, and we’ll do our best to provide answers. And when you’re ready to shop, don’t forget to take advantage of price discounts on ENERGY STAR certified LEDs at retailers across Massachusetts and through our online storefront, made possible through support from the Mass Save^® sponsors. You can also check out the Mass Save Lighting Guide for even more tips on what to look for when shopping for energy-efficient bulbs.