Buying guide for best dimmable light bulbs
Dimmable lighting has always been popular for its ability to quickly change the atmosphere in a room. It can be bright when you need clarity for working, then soft and warm when you want relaxation or romance.
LEDs offer numerous benefits over traditional incandescent bulbs, lasting longer and using less energy, but standard LEDs don’t work with dimmer switches – for that you need special dimmable LEDs. Fortunately, there are plenty available. However, they’re actually quite a complex device, which can lead to confusion when buying.
BestReviews was created to find solutions to precisely this kind of challenge. We’ve been looking at both the technology and practical applications. Our recommendations represent a broad range of alternatives, and the following buying guide should answer any technical questions about dimmable light bulbs.
Key considerations
How dimmable light bulbs work
Dimming an incandescent bulb is simple: you just reduce the voltage supplied. LED light bulbs don’t work the same way. In fact an LED isn’t a bulb, it’s an electrical circuit (called a driver) and a light-emitting diode made from thin slices of semiconductor. LEDs don’t dim in the same way that incandescent bulbs do, but they can be made to look like they do.
Analog: One way is to use analog dimming – reducing the current so the LED doesn’t light fully. This kind of LED can work better with an incandescent dimmer switch, but the results are unpredictable. Flicker can be a problem, and some LEDs may not light at all.
PWM: The better method is pulse width modulation (PWM), which works by switching the LED on and off, thousands of times per second. The effect works because the very clever human brain is happy to take an average of what’s going on. So if the LED is on 20% of the time and off 80% of the time, what you actually see is something that’s one-fifth as bright as usual. These bulbs deliver way more reliable performance, but depend on an LED-compatible switch, called a trailing-edge dimmer.
Smart bulbs: There’s another alternative, which doesn’t rely on a dimmer switch at all: the smart WiFi dimmable LED. Given that LEDs are a kind of semiconductor – in essence, similar to the things you find at the heart of a computer – it should be no surprise that some manufacturers have taken the idea further than just the ability to adjust brightness.
The result is “smart” dimmable bulbs, which can be controlled by home hubs and virtual assistants (like Alexa), and smartphones or tablets. They can be voice activated, programmed to turn on and off at specific times, or controlled by phone even if you’re hundreds of miles away. Some can also display different colors – up to 256 million of them.
Most are controlled by WiFi. The best work with all common household routers, but not all. It’s important to check compatibility, and whether a “bridge” (a wireless device used to connect networks) is necessary. In areas where internet coverage is poor, Z-Wave is a popular alternative (a low-power radio network), and several Z-Wave smart dimmable LEDs are available.
Brightness
The brightness of incandescent bulbs has historically been measured in watts, but this is actually wrong because watts are a unit of energy consumption. Brightness should be measured in lumens. Bulbs marked like this are becoming more common, but it can be confusing. As a result, LED bulbs in particular are frequently marked as “100W equivalent,” “60W equivalent,” and so on. But their actual power consumption is a lot less. A 60W equivalent LED typically uses only 7 or 8 watts to generate that amount of brightness. A 100W equivalent uses just 12 or 13 watts. This illustrates why LEDs offer such impressive energy savings.
Dimmable light bulb features
Choosing a dimmable LED bulb is pretty straightforward. There’s the obvious physical size, the fitting (screw or bayonet), and the initial (or maximum) brightness you expect – the “equivalents” mentioned above. But there is one other thing to consider – LED color (because white isn’t just white).
Color
The whiteness of a bulb is actually called the “color temperature” and is rated in kelvins (K). At the lower end of the scale you’ll find what’s called “soft” white, at around 2700K. ‘Warm white’ is around 3500 K. Although they can reach 8000K (used for vehicle headlights), the highest number you’ll see for household use is 5000K, called “daylight” LEDs.
Dimmable light bulb prices
There is an enormous range of brightness, color, and size options available, and an equally wide range of prices.
Inexpensive
Candle-style bulbs are only a couple of bucks apiece (though you usually need to buy a half dozen minimum) and ordinary household bulbs are between $3 and $5 each, when bought as a multipack. Large bulbs and specialist shapes get more expensive, and the sheer variety makes it impossible to give price guidance here.
Expensive
Smart dimmable bulbs are another thing entirely. These run from around $20 to over $40 each for color-changing models. All of which can seem expensive when you look at the price of old-fashioned incandescents. However, the greater life expectancy and lower energy consumption mean that eventually most dimmable LED bulbs deliver a modest savings.
Tips for disposing of old light bulbs
When you’re upgrading to dimmable LEDs, you probably have old bulbs to throw away. Several recycling options are available from stores and local recycling centers, and this is always the preferred option. However, most can go in the trash if necessary.
FAQ
Q. Aren’t all light bulbs dimmable?
A. Standard incandescent and halogen bulbs should work with any dimming light circuit. Standard LEDs will not. Dimmable LEDs can be unpredictable with older dimmer switches because of the different circuitry. A specific LED-ready dimmer switch is a much better solution. CFLs (compact fluorescents) also need to be the dimmable type. Note that smart LED dimmer bulbs should never be used with dimmer switches of either kind – they don’t work together.
Q. Why do my dimmable bulbs buzz?
A. All bulbs are prone to buzzing, not just dimmable LEDs. The tungsten filament in incandescent bulbs is known to vibrate. With LEDs, the problem comes from the rapid on-off switching used to dim the bulb, which can cause components of the bulb to vibrate. It’s at its worst when dimmable LEDs are used in incandescent dimmer switches, but it happens with LED switches, too. In fact, all dimmable LEDs vibrate to some extent, but with good ones it’s not at a level you’d notice. After testing, we found that cheap switches and bulbs are the worst culprits. The simple solution is to invest in quality. Alternatively, choose smart dimmable LEDs. They don’t rely on switch control, so they don’t have the problem.
Q. Can I use non-dimmable LEDs on a dimming circuit?
A. No. Even if you run out of dimmable LEDs temporarily and just want normal light without using the dimmer. You risk damaging the bulb or the lighting circuit itself. However, it’s perfectly safe to use dimmable LEDs in a non-dimming light fitting.
