I am designing and building my own house. I am very interested in automatizing several devices as blinders and lights.

In general, I am thinking in using Zigbee (Xiaomi and Aqara), RF and IR devices. The latter two will be controlled by a RF + IR controller.

Each device itself won't probably consume too much. However, imagine all my switches are connected and my blinders are always waiting for an RF signal to activate them. All those devices needs then to work with DC, which makes them, at least, need the use of an AC/DC converter.

How much could this devices consume? Is it relevant? Should I worry about it and try to reduce or optimice the number of connected devices?

Thank you so much,


  • 1
    It really depends on the size of the power supplies and how efficient they are and how many of them you will have. The devices themselves don't draw very much power usually a few milliamps but one thing I tell folks is to put your hand on the supply if it feels warm there is power being consumed to provide the voltage needed and heat is generated this may be many times the usage of the device itself. With that said 10-15 small power supplies consume less than a 100w lightbulb running 24x7. – Ed Beal Sep 14 '18 at 13:16

If having your devices connected means you'll pay more attention slash automate your device usage -- dimming the lights, having them automatically turn off when no one is in the room -- then the sips of energy the connected devices use is certainly worth it.

For example, the Philips 458141 dimmer switch uses Zigbee and is battery powered (CR2450), with a minimum battery life of 3 years.

Philips 458141

On the other side of the coin, if you install tons of connected gadgets yet don't reduce your energy consumption (or worse -- you use more energy) then the vampire power draw can hurt.

Bottom line: install these devices and take advantage of them. If you install them and don't use them, then you're wasting money up-front and continuously.

  • From what I know, most components in IOT are DC powered. For this reason, the comparaison of the consumption of that switch is not fair (batteries are DC also and doesn't need converter). I agree with what you say in the first paragraph. Probably trying to save from wasteful devices is the point (bulbs don't consume much). – riqui Sep 20 '18 at 5:52

First, this would be a fantastic question for the Internet Of Things (iot) StackExchange.

Opinion here: If your system runs on DC, then I say wire your house with DC. Any self-respecting house in this day and age, especially a geek designed house, should have an auxiliary low voltage system fed by solar and batteries.

Or should I say a primary low voltage system, as this is the system that will work in the ice storm/hurricane/earthquake. If one really wanted to take it to limits, one could build a house where heating and refrigeration worked, usable lighting worked, Internet worked, and you could stream Netflix on a tablet indefinitely. But that's well beyond the scope of this conversation.

Anyway, yes, there will be vampire load. Less the device itself, and more the numerous conversion penalties of converting 120V into low voltage at every device, as the converter must be sized for the device's max possible draw. You'd have to consult the manufacturers for exactly how much, as the amount would be too small to measure with a Kill-a-Watt.

  • Interesting answer... Apparently, building a DC net for home would be interesting (and even more if it is solar powered!). However, I guess, cable sections (and resistances) could become very big is the power requirements are not too small. Am I wrong? – riqui Sep 20 '18 at 5:54

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