DIY Hot Air Hand Dryer – An OCD Sufferer’s Best Friend


[haqnmaq] admits that he suffers from Obsessive Compulsive Disorder and on occasion, can be found washing his hands up to 20 times an hour. Very distrustful of cloth towels, he exclusively uses paper towels to dry his hands, to the tune of 2-3 rolls a day. In an effort to lessen the impact his OCD has on the environment and his wallet, he decided to build an automated hot air hand dryer using a 555 timer, which doubles as his entry in the 555 Design Contest.

The concept behind his project is to use a hair dryer as a hot air source, relying on a phototransistor and a pair of IR LEDs to detect when hands are placed under the dryer. When a pair of hands are detected, a relay is triggered and the hair dryer is turned on. Once the dryer has run for a pre-determined but adjustable time, the relay is opened, and the hair dryer turns off.

It’s a pretty simple project, but one that is quite useful, whether you suffer from OCD or not. The only thing he might want to watch out for is the restricted air flow to the dryer, since it is mounted in a sealed plastic container – a few seconds with a hole saw should remedy the problem quite easily.

Want to see the hand dryer in action? Keep reading for a short video demonstration.

[Thanks Ryan]


38 thoughts on “DIY Hot Air Hand Dryer – An OCD Sufferer’s Best Friend

  1. Never understood that. Power that is made by coal or a renewable resource such as trees? I was in the timber business for a while and that used to drive me crazy. Save the trees? About as green as you can get for the money until solar and wind prices come down.

  2. Please keep in mind that the production of paper towels is very hard on the environment. Paper production not only uses wood, but vast amounts of water, along with bleaching agents that make fish very sad.

    I personally find it admirable that this person is able to recognize and logically deal with a condition that can cause severe problems in individuals.

    I just wipe my hands on my pants, but we are all different aren’t we?

  3. Uranium derived power has very little impact. Esp compared to coal. — I won’t comment or argue on paper vs coal.

    That said, 20 times an hour? Get a psychiatrist or get prescribed SSRI’s. My hands wouldn’t survive 20 times an hour, they already suffer at 2-3 times an hour at work.

  4. Trees regrow and when they do, they take CO2 out of the air. Protip: trees get probably half of their mass from the atmosphere and the rest from the soil. But of course, a great deal of tree waste winds up in landfills. Cellulose isn’t exactly that hard to break down though (termites do a fantastic job as do bacterial, etc).

  5. Uranium has less mass and CONSIDERABLY less impact than burning coal. But uranium waste tends to stick around… for tens of thousands of years. It also isn’t incredibly easy to just throw it in a big pile and forget about it. Between coal and uranium? Uranium hands down. Between wind/solar/tidal/dam/geothermal/etc – any of those vs uranium.

  6. actually spork, ive found meds and shrinks dont work all the time. as a matter of fact the meds made me worse. i have ocd like he does… not fun, although i dont have the germophobia. im a counter.. now.. i need some gadgets for that.. lol

  7. @CutThroughStuffGuy

    Nuclear power waste only sticks around for thousands of years because it’s illegal to shorten that time span (thank you international treaties….). We can easily get it down to a couple hundred, which really ain’t that bad…

  8. Proper hack, I like :)

    I wonder if a PIR would do the job instead of IR LEDs + phototransistor + 555 timer, or wether the heat from the hairdryer would make it continually trigger the PIR once you take your hands away.

  9. I also have OCD, the counting and the germophobia as well as a compulsive need to fix things. this would be useful to me, I do use towels but if the towel is damp then its really gross, this would definitely be preferable.

  10. As a next step I’d suggest something similar to the dyson air blade design of hand dryers.

    Rather than blow hot air at your hands to evaporate the water on them, the air blade design forces the water off your hand with focused streams of air.

    From my observations, I spend a lot less time using an airblade-type dryer than a hot air dryer. And you don’t need to heat the air, so you can just replace the hairdryer with a blower (like an inflator for an air bed), so maybe you can reduce the power usage. Plus, it would simplify the circuit: no need to detect distance; just an interrupted beam is needed.

  11. I love shaking hand with guys like that. After we shake, I usually slip in some reference to having had at myself earlier in the day.

    You know – I bet you could get a commercial unit second hand for not much money. And the real hack would be making the damn thing actually stay on long enough to actually dry your hand! Now that would be a hack! It’s so annoying when it turns off mid-drying action…

  12. My wife suffered with severe OCD, and I along with her through the worst of it – treatment and drugs help a lot. Nice project, but made me feel sick to my stomach. No laughing matter!

  13. I’m suprised a germaphobe would use a hot air hand dryer. With rumors of hot air dryers causing more spread of germs. Paper towels are probably a OCD’s best friend.

    And air dryers take so long. He would never have time to do anything but wash and dry his hands ;) 20 times an hour!

    I was at great america recently and they had the new air hand dryers that blow high PSI air at your hands. I do say they seemed to dry faster the hot air dryers.

  14. fail. hot air blowers are not at all cleaner. that is a total myth. its not the heat that dries your hands either with the hand blow driers, its just the air flow over your hands blowing away the water. people try so hard to make them hotter and hotter when its just wasting energy. im afraid my little OCD suffering friend, you just made your hands significantly dirtier by using this.

  15. I was looking to replicate a dysonair blade as a DIY project. You you thought of a clever way of building a dryier.

    But why not have an infared camera to track the moisture of the hands and when they are dry, then to shut the dryier off, instead of having a timer? Sounds geeky but is a nice idea

  16. 20 times an hour? i think you need a professional tool to dry your hands. shell out for one of those new dyson hand dryers. they work really well and quickly.

    and you should probably shell out for a professional psychiatrist too, since ocd that extreme obviously lowers your “quality of life” considerably.

  17. OCD is a complex and difficult condition to handle. I suggest all those telling the builder to get medicated and see a shrink quit pretending to be medical experts. SSRI’s are not a miracle drug and have some really nasty side effects. Therapy is not always successful. If you really want to help, go back to school and get enough education to help do research to find the root cause, o/w stick to commenting on the build!

  18. Hopefully he won’t think about all the chemicals outgassing from his storage box caused by the hot blower that are being forcefully blown onto his once clean hands.

    Oops… bad

  19. @Kron
    the Dyson airblade is horrible, you have to put your hands in at an angle which leaves your sleeves touching against the device, not something recommended in some places you go to. Also how useful is this for people with arthritis or others affected with restricted movement in their joints?

  20. The build looks good, but I seriously don’t this is a great idea for a germophobe. I have long referred to the model of hot air dryers located in public restrooms as the “Fecal Flinger 2000” because of studies showing concentrations of fecal coliform bacteria growing in the air ducts, and being spread about the room, as well as being spread to the hands, lips, and lungs of the users.

  21. Hey, its haqnmaq. Thought I would add some feedback to some of your comments. Yes, the hairdryer isnt probabbly the best way of conserving energy over paper towels, but it sure helps my “pocket book” out! Paper towels cost can really add up. I didnt think I needed to add a really long back-story to my ocd, but it didnt happen over the week, I have been seeing “doctors” , medication, etc, etc. Also, I said it could be up too 20 times an hour, sometimes its alot less, just depends on what I am doing within that hour. Also about the hairdryer not beeing very germ “friendly”, I am sure u are probabbly right, but It is more of a “mental” thing; as long as they feel clean, I dont worry about it…..I dont examine my hands under a microscope after each wash ;) I will also admitt that it isnt the best hand dryer, but it was fun to design, and make, so I think it was worth it. The circuit can also be used for alot of different things.

  22. I have a mild form of this OCD too. Glad you found something that helps.. We all know its irrational but can’t stop.

    Those dyson air blowers literally get up my nose. Can’t get your hands in without touching the (“germ ridden”) sides, then it blows all the water all over your face..

    C- mr Dyson, just slightly worse than your fragile, poncy hoovers.

  23. @oko

    I saw a variation on the Dyson Air Blade type hand dryer that was manufactured by Mitsubishi. I was very simple and box-shaped, unlike the curvy design by Dyson. You don’t have to angle your hands or anything, you just stick your hands straight in.


    Great project you have here. I’ve always worried about the cleanliness of when I dry my hands but I never had a good way of executing it, you did a great job.

  24. @oko, I work for the US branch of the Jet Towel and I would like to make a correction. The Dyson is actually a variation of the Mitsubishi Jet Towel, not the other way around. Mitsubishi first started making that type of hand dryer in 1993, Dyson in 2006.

    Ryan, this is an impressive device. Good job.

  25. Hello!

    I work in the mold remediation industry. I only have empirical evidence to contribute, but I have done a bit of homework.

    Disposable paper towels make an excellent means of cleaning your hands due to the absorbency, surface area, mechanical action and that they arrive sealed.

    Having had to perform tests for ATP to determine the efficacy of cleaning an area, I’d have to say that fans are one of the dirtiest things. A single fan running in a clean area can contain particulate which will slowly fall off and be spread about the room unless you disassemble the entire fan and clean it on a regular basis (a time consuming task).

    I’ve seen one of those Misubishi hand dryers mentioned by Michael at the Vineyard Zippy’s here on O’ahu. It is a formidable device, and seems to not contribute that rather foul smell that accompanies traditional push-button, receive-bacon hand driers. While it is a very unscientific way of going about things, I’d imagine that the lack of a smell is due to the fact that the pressurized air forces the water off the hands into a small drain receptacle in the bottom.

    While your hands will make contact with the sides of the unit, the one I saw had a casing impregnated with Microban. That will likely help prevent pathogenic growth.

  26. This is a cool build. At least it will be YOUR germs in the house, so your immune system should be up to the task.

    You could always compost your paper towels to fertilize a garden. At least you will get some awesome veggies to eat.

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