Tag Archives: led lighting

A possible solution to slow or unresponsive Hue lights

They used to say that there are two ‘internet of things’ systems that ‘just work’ out of the box: the Sonos sound system, and Philips Hue lighting. I’m fortunate enough to own both of them, and I would add the Honeywell Evohome heating system (though one of my friends has had a few complications with an unusually large installation).

When we moved house recently, though, my previously-faultless Hue system seemed to become a bit less reliable. Admittedly, we have rather more bulbs now (33 and counting), but that’s nowhere close to the limit it can handle. Our bulbs are always powered, so the cunning mesh networking should make sure that nothing is out of signal range. Yet sometimes lights weren’t obeying their commands promptly, switch presses needed to be repeated, and things generally seemed, well, a bit sluggish. I was beginning to think it might be time to wipe the configuration off my bridge and start again from scratch. It probably does have a lot of accumulated junk on there…

And then I did a little research and realised something that I should have thought about earlier.

Zigbee (the wireless networking used by Hue and a variety of other systems) runs at approx 2.4Ghz: the same frequency range as Wifi. Like Wifi, it has a number of channels, and if your wifi router and your Zigbee hub have overlapping channels, they can interfere with each other. I found this useful diagram online (apologies for not knowing its creator):

‘802.11b/g’, in case you don’t know it, is part of the technical standard popularly known as Wifi, so the green labels show Wifi channels, and the blue bars show Zigbee.

The number and availability of channels vary depending on your country, but they will be similar to the above. Although Wifi has about a dozen channels, the nearby ones overlap substantially, so most installations only use 1, 6 or 11: if both you and your neighbour are using Wifi channel 1, you won’t make much difference by switching to 2 or 3; you need to go at least as far as 6. Go much further than 6, and you’ll start interfering with your other neighbour on channel 11. Usually, these days, wifi routers are pretty good at picking their channel by finding the least congested space, though you may need to reboot them from time to time to encourage them to do so.

Anyway, one thing that had changed in my new house was the Wifi. And when I looked, sure enough, my Wifi router was on channel 11 and my Hue hub was on a Zigbee channel that was rather too close for comfort. By going into the Hue app and looking at the settings for my Bridge, I was able to change the Zigbee channel to number 15, and things are going a lot more swimmingly now!

Hope that might help someone else…

Often is his gold complexion dimmed…

Zetalux 7W light bulbA package arrived today; a small but heavy one, containing my first LED lightbulbs. No, not the little ones that go in torches, but big ones designed to replace the 240v tungsten bulbs in my ceiling light fixtures. Michael had found a good UK supplier, and I wanted to experiment with what I’m sure will be the way we all light our homes five to ten years from now.

As I’ve written before, I don’t really like the CFL (compact fluorescent lamp) bulbs that have been the only real low-energy option in the past. You know, the ones that look like some sort of lower intestine curled up where the bulb should be? Firstly, they’re a nasty colour, though much improved now. Secondly, they take a while to warm up to full brightness. Thirdly, they may use less power but they contain nasty chemicals which leads some people to question how environmentally friendly they are overall, and lastly, you can’t use them with dimmer switches, which rules them out for about half of the rooms in my house. Not just dimmers, either, some other electronic switches (like electronic timers) also don’t work. I’ve put a couple of these bulbs in, and I’ve sort of become used to them, but it’s really a case of how much I’m willing to sacrifice for my moral obligations, rather than something I do with joy.

LED-based bulbs, on the other hand, use even less power, are probably more environmentally friendly to manufacture, supposedly last for somewhere between twenty and forty years, and are available in dimmable form. It was time to try them, so I ordered three different ones, even though they cost £25-£35 each. So, after a quick try, what’s the verdict?

Well, the good news is that the brightness is really quite impressive. Anything over about 4W is a viable replacement for a 50-60W bulb, so, yes, they use about 10% of the power of a conventional bulb, and about half that of a CFL. These are also well-made, as they should be for that price. In five years’ time, when we’re buying cheap LED bulbs for a few quid, we’ll be amazed at the robust construction techniques used today. They hit full brightness immediately and the dimmable one worked nicely with my dimmers. All good so far.

However, I’m not sure that any of them will find a permanent home in my light fixtures yet.

Firstly, they’re too white. They don’t have the bluey-green tint of some CFLs, but they are still very white. This may be something I’ll get used to over time, but if you’re thinking of buying any, be aware that those labelled ‘warm white’ are still not nearly as warm as a tungsten bulb. They’re fine if you’re keen to simulate daylight in your sub-basement, but not if you’re after that cozy, welcome-you-home-on-a-cold-winter’s-night look. Particularly if you mix LEDs and traditional bulbs in the same room, you’ll notice the difference. Fortunately, manufacturers and suppliers are starting to publish the colour temperatures – don’t trust anything described as ‘warm’ if its temperature is over 2800K, and even 2800K leaves something to be desired.

But that’s not the main issue. The main issue is that, while a glowing filament emits light in all directions, LEDs are very directional. They therefore make good spotlights, which is why LED bulbs have chiefly been sold with GU10 connectors, as used by the little spotlights that have been embedded in everyone’s ceilings in recent years. There, I can imagine they work well, and are worthwhile because, charming as those lights are, they’re not a very efficient way to light a room. When my existing GU10 bulbs give up the ghost, I’ll replace them with LEDs. But most of my house has light fixtures – some of them antique – which make it rather obvious if only the top half of the bulb is emitting light and most of that light goes in one direction. The very unexciting paper globe shade above me, which I’ve been planning to replace for about 7 years, if fitted with an LED, does a very good job of lighting the floor in the middle of my small study but leaves the periphery in shadow. The main glass fitting in the centre of the dining room has two bulbs, side by side, mounted horizontally. With LED bulbs, this lights up the walls but not, to any great degree, the table. It looks very strange.

Until this is sorted, I’d need two or three times as many lights in every room to get reasonable coverage, which undoes some of the benefits. CFLs are better, but I can’t use those because of my dimmer switches. And the 7W bulb pictured above, which was intended to go in an Ikea R80 spotlight fitting at about eye-level on the kitchen wall, is a good, bright bulb but I can’t use it because it’s the wrong shape: the dome of the bulb extends beyond the lampshade and so is dazzling. Ironically, the one good spotlight-based experiment fails because the bulb sends light in directions I don’t want it to go!

So, my advice is, if you’re willing to pay a lot, these bulbs are starting to become quite good. But unless you’re planning to use them as ceiling-recessed spots, you may need to budget for new light fittings as well. Still, look on the, ahem, bright side. At least the fittings may cost you less than your lightbulbs!

© Copyright Quentin Stafford-Fraser