It seems fair to say that Dyson sits at the intersection of impressive engineering and borderline ridiculous products. The Dyson Airblade 9KJ hand dryer that [ElectrArc240] recently took to bits would definitely seem to fall under the latter, combining an incredible amount of engineering all for the simple task of drying wet hands.
These hand dryers are rated for a cool 900 Watts, with an 0.5 W standby power consumption, though you can also switch it to a 650 W ‘eco mode’ when installing it. The air that gets sucked into the dryer first passes through a HEPA filter before it hits the heating element and then gets blown out of the handles onto one’s hands.
Both of these handles come with a presence sensor in the form of an ST VL53L3CX time-of-flight sensor, along with a path for the heated air towards the thin slits. Returning to the section just past the HEPA filter is the compressor, with a rather fancy airflow path that involves various stacked meshes. As can be seen in the video, where you’d expect basically a simple blower motor or so, there is a truly astounding amount of parts as the teardown progresses.
The motor disassembly is the first part where some desoldering and breaking of glue bonds is really necessary, but it gives full access to the driver board. The circuit used here is your typical IGBT-based gate driver, though with a mystery PIC MCU to do things. Following this the tear-down turns fully destructive, giving access to the motor internals.
Following an analysis of these internals we marvel at the carbon-fiber rotor that keeps the single magnet in one piece. This is another engineering choice that serves to justify the 1,000 quid price tag. All so that rest room visitors do not have to suffer the humility of using paper towels.
You can complain at the price tag, but I think we would agree most hand dryers suck rather than blow. Would be nice to see a well made and cost optimized version. Say using off the shelf brushless motors and commodity turbine wheels.
From the video: “…this HEPA filter which seems a little bit unnecessary for a hand dryer in a bathroom”
Well, without the filter a hand dryer is just a germ cannon. :/
How well do you think your average fuel station is going to maintain that filter?
The concept of jugaad says “no.”
They’re a gem cannon anyway, it gets blown off your manky paws into the air.
It’s a public bathroom. It’s already chock full of floating particles of other people’s poop.
Yes, but does it blow the water back at you like the older ones that you stick your hands down into? Have they solved the problem of it being so loud that children scream and run away?
The only hot air hand dryer that I have ever encountered that worked well was one of the old school ones (1970s) in Arizona where the humidity was about 10%
Bathroom design is nuts. I think it’s kept in a perpetually bad state because it is taboo to change how people poo.
One of the best bathroom designs I every encountered was in an 1800s building. It was designed to be hands-free to reduce germ transmission. All without any electronics. Everything was peddle-operated (toilet flush, faucet, trash can lid, etc). And the door swung both ways so you could kick it open to go in and to go out.
Never understood the need for inward exterior doors in the toilets – even more so double inward doors!
Thought it ironic when a hospital worker emerged from a cubicle whilst I was in there relieving myself. He proceeded straight from the cubicle to pulling the inward door and left. Clean hands in a hospital are so last decade.
Eh? Never had one blow back at me. And are kids easily spooked where you are?