Saturday, December 8, 2018

The right / best way to control a light. It depends.

Given all the flame wars over smart bulbs vs smart switches it seems time to make a post to use in replies. One guy even suggested using both to avoid:

  • People turning off the switch. It should be obvious that even if the switch is smart, if it is off it is off and you can't control the light till you turn the switch on. Covering the switch with something like the Magnetic Switch & Outlett Cover for Toggle Switches ought to make people a think before flipping the switch.
  • Smart bulbs coming on after an outage (they only do this after an outage not a flash). To avoid the power on after an outage all you need to do is put a bulb in an unneeded location and create an event to turn off all or some of your lights if it comes on. Note too the reason these lights come on if the power is cut for about a second is so you can manually override them if other control is lost. Some do have a hidden parameter to turn this off if you really think you need to. Google it. Personally even though I live in the country and have all my computers and AV and network equipment on UPS to handle the flaky electric I've only had the lights get triggered by this a couple times in over a year now so I don't see it as much of an issue.

There really is no point in chaining smart devices and in fact is can cause issues if the smart bulb is Z-Wave or Zigbee in that these are mesh devices and removing power from them means the mesh is regularly disrupted. In the best case this causes lag and in some cases might cause devices to miss commands. Depending on the WiFi bulb it may cause connection issues as well since most of them work via a cloud interface of some sort and disconnecting them will require them to establish a new connection to that cloud to receive commands. Then there is the whole bit about updates which would only be able to install while the the light ia powered. Bottom line these devices are designed to be always on so powering them off for extended times at your own risk.

As for the "right way" to control a light. First off it would depend on the best fit for the env.
Other than a bed room:

  • I would use a motion detector as the primary trigger with voice backup
  • As a secondary I would the dumb switch (with a magnetic cover to avoid accidents) and a timer that shuts off the light after X minutes of it being turned on and/or no motion detected. In many cases this also tied to turn off other devices in the room like a TV.
  • I might use a wall switch or a smart bulb generally dependent on the level of control required. As in a smart bulb if I want to control the bulbs singularly or a smart switch to control a group of bulbs in a room. Just do the math. Which is cheaper to replace the bulb(s) on this circuit or the switch(s). Factor in if dimming or color changing is required of course.
  • If a dimmer is wanted with a single bulb the Hue and Lightify dimmers work great for that and is pretty cheap too. Note the Hue dimmer with bulb bundle is generally a good bit cheaper than the two separately.


For a bedroom or other place where you want more manual control a smart switch is used without a motion detector.

Simple right? Like most of this stuff there is not general "right answer". The best fit is on a case by case basis. Though let me repeat again always try and get devices that work with multiple hubs because it is pretty much a given at some point you will want to move to a new one. Whether is a shutdown like Resolve or Lowes' Iris or issues like SmartThings has been having or incompatibility between version of hubs like Lowes Iris' and SmartThings' V1s and V2s or you just need a feature some other hub has and your current one does not.

Want a second opinion?

Note some of these are a bit one sided and a couple get into Rube Goldberg style options. 

FAQ: Philips Hue and Other Smart Bulbs - What sort of light switches to use with them? (Long FAQ)
Proper way to use both a smart wall switch and smart bulb to control same ceiling light fixture (multi-part question)
5 things to consider before installing smart light switches
Smart Switches vs Smart Lights: Which is best solution?
Which is Smarter: Smart Switches or Smart Bulbs?
Smart Switch vs Smart Bulb: Which Is Best for Your Smart Home

No comments:

Post a Comment