Title text:
It’s important for devices to have internet connectivity so the manufacturer can patch remote exploits.
Transcript:
[A store salesman, Hairy, is showing Cueball a dehumidifier, with a “SALE” label on it. Several other unidentified devices, possibly other dehumidifier models, are shown in the store as well.]
Salesman: This dehumidifier model features built-in WiFi for remote updates.
Cueball: Great! That will be really useful if they discover a new kind of water.
Source: https://xkcd.com/3109/
The built-in hygrometer’s not necessarily going to be as good as a well-designed home automation system, especially if the fan’s not running all the time, so it has to wait for damp air to diffuse into the machine. It also lets you do other things, like not bother turning the dehumidifier on if there are open windows if you’ve got some way to detect that, or report the humidity to something that will graph it. It’s not stuff that most consumers will care about, but a microcontroller with WiFi like the ESP8266 or ESP32-C3 costs less than an accurate hygrometer chip, so it doesn’t make much, if any, difference to the final price, particularly if the product was going to use a microcontroller anyway.
It’s ironic that you can implement all this cool automation for a device but in the end still have to manually lug water to it.
Well it’s a **de-**humidifier. You need to lug water from it. For the dehumidifier in my basement, we have it hooked up to a hose that takes the water right down the drain.
But I do take your point, it is pretty funny.
Like how every source of power is still steam since before the industrial revolution.
Just most sources of power. Photovoltaic, wind and hydro aren’t steam based.
And your moms power is hip based.
I’m not going to knock her putting them to good use! It’s done well by her so far. 👍
That’s the spirit!
Ok, two things.
First, the cost of the Wi-Fi chip is clearly not the issue here. The real expense/concern is the effort and software mechanisms needed to secure that network connection. Connecting to the Internet is easy, securing that connected device is hard.
Secondly, at some point you still need the hygrometer, there’s no way around that. Either your dehumidifier is tracking humidity, or your home automation system needs to track humidity. And you can’t like… get that data from the web somehow, you need a local sensor, and it will generally only make sense to have it in the same room as the dehumidifier (meaning not necessarily where other smart home components are set up).
You’re missing my point. It’s likely that the cheapest way to design and build a dehumidifier these days will already include a microcontroller interpreting results from a digital hygrometer because these components are cheap and easier to work with than purely electronic/electromechanical designs with no microcontroller. The cost of switching from a non-WiFi/Bluetooth/Zigbee microcontroller to one with one or more of these networks is negligible, and once you’ve got it, it’s not meaningfully more expensive to pay a software engineer to expose the on/off switch and hygrometer readings via that network and have the marketing people write Smart! Now with WiFi! than it is to skip it and pay the marketing people to come up with some other nonsense to put on the box. If you care about security as little as the average IoT vendor does, then it’s nearly free to turn a dumb device into a smart one, so if it makes a handful of extra people buy the device, manufacturers will make things smart. For a dehumidifier, there are reasons why a handful of people will prefer a smart one, so smart dehumidifiers get made.
Well this part is definitely not true. A microcontroller and Wi-Fi chip are definitely more expensive than a wire, a variable resistor and a knob, which is all a purely electro-mechanical system would need in addition to the hydrometer.
The fancy digital version wouldn’t be a lot more expensive, but it certainly wouldn’t be the cheapest way to go.
That said, I think you’re right that most companies will opt to go the fancy digital route to try to sell a “smart” product with more features. But then I expect there will also always be companies that manufacture simpler, cheaper products as well.
The cheapest hygrometers these days only have a digital output, and a wire and a potentiometer aren’t going to be able to query an i2c bus to ask the hygrometer what it’s measured without the help of a microcontroller (and the microcontroller might be cheaper than the potentiometer anyway depending on the specific model of each - have you actually looked at the 2025 prices of things before making assertions about what they cost?). The analogue component of a hygrometer that actually does the measurement gives fairly small changes to the resistance/capacitance (depending on the kind of hygrometer), so the results need amplifying. If you’re measuring on the same chip, you can get away with a simpler amplifier and digitally compensate for any nonlinearity, whereas to get a strong enough signal to make it to the rest of an analogue circuit without much degradation, you’d need an amplifier that ends up being more complicated than doing everything digitally.
Look, I’ll be honest with you, I’ve never built a dehumidifier (I’m sure you’re shocked). I don’t know what exact components tend to be used. What I do know is that I have a fairly new dehumidifier and we have another one from probably the early 80s. Somehow they both work. Again, I’m not sure what components were used in the older model, but given the age I’d be very surprised if the electronics it uses would be more expensive to manufacture than the newer one.
Really, I think the idea I’m trying to get across is just that you can always aim lower. Sometimes the goal isn’t achieving perfect precision, but rather achieving something good enough. Take toasters for example, most toasters don’t have a timer at all. They have a little piece of metal almost touching a contact. When you turn the toaster on, that metal heats up and it bends until it touches that contact, ding toast is done. And when you turn the little dial from light to dark it just moves that piece of metal slightly further from the contact. My point is, it’s not exact, it won’t be the same on every toaster, and it will probably shift over time. It’s a low tech solution for something that could absolutely be done in a more modern, more precise, and still inexpensive way (a simple timer). But it’s cheaper and simpler to just do it the old way, and for many applications, that’s fine.
Hell, I’m certain there are dehumidifiers on the market that don’t have any kind of humidity sensor at all. Even simpler…
So, first off, smart devices shouldn’t need to connect to the internet, only the local network. I have everything connected to Home Assistant, and then for access outside the house I have HA connected to the internet, meaning I only have one point I need to secure.
On your second point, I think the poster above was talking about having both an in-built as well as wifi-accessible external sensor. It makes it possible to have a more powerful dehumidifier in one space, running to a lower humidity than needed based off what’s going on in other rooms. Then have that air circulated by other fans, etc.
And how does a well designed automation system measure how much moisture in the air? There must be some kind of measuring device that measures moisture, a moisture scope! Ooh wait let’s latinize it to make it sound more impressive and sophisticated a hygro…me…ter… oh… uh… this is embarrassing.
In the UK, it’s common for electric showers to be on a separate isolator that needs to be turned on before they’ll heat up, and it also activates an extractor fan, and most people turn it off again when they’re done showering. It’s pretty simple for a home automation hobbyist to swap the regular isolator switch for a smart one, and then their system can know when they’re about to shower and activate the dehumidifier immediately. This can be much better than waiting ten minutes for enough humidity to diffuse into the dehumidifier for the humidistat to activate then waiting another ten minutes for the cold side to cool enough for any dehumidification to start.
I didn’t say a home automation system would be measuring the humidity and reacting. The opportunity to do better comes from the potential to be more proactive if you can figure out a way to tell a computer about impending humidity.
No it doesn’t. Those micros go for $1-2 bulk, but capacitive hygrometers are 10x cheaper.
I can get a board from AliExpress with an ESP32-C3 on it with free shipping for £1.10, so I’m not inclined to believe the £0.765 unit cost for a 5000-part reel from Mouser is really the cheapest way to get them in bulk as the other parts on the same board and the shipping have to cost something.
The cheapest hygrometer that Mouser sell is £0.748 per unit for a 10,000-part reel, and its datasheet says not to leave it for more than 60 hours in greater than 80% relative humidity (which is a pretty likely scenario for a dehumidifier) as it’ll drift, and if it happens often, it’ll age faster. You need to spend more to get rid of that restriction. I’ll concede that the accuracy penalty if you cheap out isn’t as bad as I thought - I’d not actually looked at a datasheet to see how badly modern hygrometers would drift, I just knew that they did - so plenty of manufacturers wouldn’t care, but the parts are still comparable prices, not a factor of ten like you’re claiming.