Comment by IMSAI8080 | Hacker News Reader

Comment by IMSAI8080 | Hacker News Reader

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I have some questions about your figures:

- You've included the fridge, that's not really "standby" power in the sense OP is meaning. That's active power consumption. Fridges don't have a standby mode. - As above you've included air conditioning. That looks like active power with a pump running, not standby power. I cannot envisage any way you could get that consumption in standby. I think you've made a mistake with that. - Why did you measure the Alexa with a toaster and a clock connected to it? The Alexa is 2W max. Is this toaster some kind of smart device? A normal toaster is either on or using zero power. Do clocks have a standby mode? I don't understand that. - What's the iMac power consumption mean? It uses 6.6W shutdown or in hibernate? That seems unlikely. - Are you sure you've switched these speakers into standby? That looks like they're switched on and active. - What are the lighting figures? Regular lights are zero switched off. Are these remote controlled or wi-fi lights maybe? - Your door bell is seriously using 10 watts? Are you sure? Do you mean is this actually a camera or something? - You've got eight devices involved with delivering your wi-fi and network (four access points, 2 switches, a router and a controller) . That's probably more than average and it's arguable whether that's really standby power as such in the sense OP means. - It was measured with some form of clamp meter. Have you checked that with a multimeter to see if that's really accurate? A consumer one may not be that good.

I would interpret these devices as being in a low-power usage mode where we wouldn't expect high power draws, rather than literally a 'standby mode'. A clock certainly falls in this category. A fridge if it hasn't been opened in hours and has good insulation could even fall here as well overnight, etc. Sure there are power spikes but the important thing is the amortized consumption.

But you cant turn off your fridge at the wall so what's the point in measuring it?

Measuring your fridge is important as it could point to a bad compressor or bad seals.

Your fridge compressor shouldn't be running 24/7, and it should mostly be on standby until temperature rises.

The point is measuring the consumption of a device while you do not need it and it is not performing any meaningful work.

Your fridge is never in that state. Even when the compressor is not working, the fridge is still functioning and performing work. It is sensing temperature and pressure and time and then making decisions based on those inputs.

Your laptop is not performing meaningful work when it is updating while you are away. It can do that in the background while you look at cat pictures.

> the fridge is still functioning and performing work. It is sensing temperature and pressure and time

I believe most fridges use bimetallic thermostats to control a relay to power the pump. And they don't sense pressure or keep track of time.

Have you ever tried to start a super old fridge or AC that you unplugged without waiting the full 3 minutes before plugging back in? It sounds like a diesel truck shutting off in your kitchen.

Modern fridges absolutely keep track of pressure and time.

No, I admit I've never powercycled a fridge nor ever seen a reason to.

Can you explain the mechanism by which a fridge unplugged then replugged a minute later sounds like a diesel truck? The compressor pumps aren't continuous duty, they spend most of the time powered off anyway.

edit: I did some web searching and the only mention of wait times before plugging in a fridge I can find is waiting a few hours before plugging in a fridge if it was stored on its side. Unless you're also flipping your fridge over when you power cycle it, I don't understand why there should be any problems.

It's not specific to fridges, you'll find more results looking for AC/compressors in general: https://skeptics.stackexchange.com/questions/4695/do-air-con...

Depends on whether or not you have a fancy 'smart' fridge, in which case it could very easily be in a state where it is consuming power without performing any meaningful work. A lot of these IoT devices, while low power vs a traditional PC, are not efficient.

Measuring standby power matters where the alternate option would be to unplug the device or use an extension cord with a power switch instead of relying on an active but low-power state.

Sure, for things that you have the option to do that with and you don't mind the hassle. In cases where that isn't an option (i.e. in the case of a smart fridge) or you're not going to do that, it's still useful to know how much idle/sleep power a device consumes as you might want to either modify the device, replace or get rid of it.

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