Building a Crude UV-C Mask/PPE/IPad/Phone Disinfection Chamber (1 hour, $30, minimal tools) Part 1
UPDATE: Some additional resources:
UPDATE: This build below was last resort. Here is what I am actually using day-to-day:
Links to Part 2 and 3
I intentionally made this as much of a hack as possible.
In theory, almost anyone should be able to do this if they have the components, but if you don’t understand AC electricity, you should read up on it. Watch some YouTube videos and probably ask a friend to check your work.
If you can get your hands on low-voltage DC UV-C LEDs that might be a better bet, but make sure you are getting enough power. I didn’t dig deep into UVC LEDs but this company provides a useful power analysis:
https://www.klaran.com/intensity-comparison-uvc-leds-vs-lamps
The build description below is just an example of what can be done quickly with almost no tools. I don’t guarantee it is safe or that it will work for you.
I should mention that my friend, Dr. Pavel K, suggested pursuing UV disinfection and also came up with the suspension bridge wire rack during our video chat discussions.
Some Background
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Nebraska Hospital UV Guideline
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Commercial product that this is meant to emulate:
Something like this (note it’s currently unavailable… the price is~$200):
More details can be seen at the link below. It seems that the power ratings are around 10W which means it’s likely safe to aim for that number in our system (but it’s worth cross-referencing mask specific literature for dosage- exposure time and wattage/power)
UV-C explainer
UV-C is used for sterilization because it is absorbed well by biological molecules and damages DNA.
Are masks effective after UV sterilization… it appears they are:
General UV-C Safety Guideline:
Components
Note that I ordered this in late February so your mileage may vary depending on what is sold out etc.
2x 5-Watt UV-C sterilization compact fluorescent bulb
https://www.amazon.com/gp/product/B01BTBJCLG/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1
These bulbs contain mercury vapor. Don’t break them and if you do, don’t breathe the vapor.
2x Socket (this turned out to not be the exactly correct model but it was easy to make it fit as I show below)
https://www.amazon.com/gp/product/B000U39SZ0/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
1x Ballast rated 13-Watts (THIS IS REQUIRED)
The ballast is a necessary component for making fluorescent bulbs work. Please watch this video (Electroboom does great layman explanations) before working with fluorescent bulbs. If you don’t understand it, do some reading.
Aluminum foil
Aluminum performs better than other metals in the UV band:
It would be less wasteful to use some aluminized plastic sheet (you only need ~1 micron of aluminum thickness)
Something like:
But all I had on hand was Aluminum foil.
The Build
- Attaching Aluminum foil to a cardboard box using double-sided tape:
2. Attaching the sockets
3. Mating the bulb and socket
4. Cutting the door
5. Hot gluing the things into place (hot glue can be replaced with one of many bonding options)
6. Wiring
7. More wiring
8. Protect the 120V AC electronics
9. Test
10. Install a rack
Note: cloth-hanger pins would be even better probably for some things like masks.
Missing feature: Door activated interlock switch
A timer switch to shut off the UV after 20 or 30 minutes would be nice too.
Update… I built these features in Part 2:
Happy Disinfecting :)
