YouVee
An emergency-response UV irradiation cabinet that anyone can make easily at home.
As thousands of essential workers bravely continue to do their jobs despite limited access to personal protective equipment, the need to sterilize their PPE, especially their masks, increases daily. Contained UV irradiation is an effective way to sterilize non-porous items such as N95 masks, phones, keys, and more. While some front line health care workers have access to professional UV irradiation cabinets, many other essential workers who interact with the public every day do not.
Since many UV irradiation products are sold out, DIY irradiation may be one of the few options left for many people. However, most DIY UV irradiation cabinets require hard-to-find parts, engineering know-how, and/or specialized tools.
YouVee is a DIY irradiation cabinet that can be made at home in under one hour using common tools and simple components—no tech skills required.
ONE HOUR. ONE SHOPPING TRIP.
50 DOLLARS.
PARTS LIST
We designed YouVee so that you can get the parts with a single trip to a home improvement store in your area. Here are the parts you’ll need:
TOOLS YOU’LL NEED
You can build YouVee with some common household tools – no specialized equipment needed. We’d also recommend an optional utility knife for cutting, if you have it on hand and are comfortable using it.
MAKE YOUR OWN
Exposure Times:
Exact dosage required for masks is still under investigation by various organizations and may vary for different mask types. Based on current research (see sources section) and UVC measurements taken inside the box, we approximate exposure times to:
Mask (~1J/cm2) - 1 mask for ~30 minutes per side directly under the bulb on the raised platform.
Non-porous items (~60mJ/cm2) - ~20 minutes anywhere in the box on raised platform(s)
That said, you should visit the sources and read N95DECON’s guidance on mask reuse.
The intensity of the UVC light in the box was measured in μW/cm2. We divided the recommended dosage (units: J/cm2) by this intensity (with a scaling factor to adjust units) to estimate the amount of time required for items placed in the box to receive the UV dosage recommended by the referenced scientific papers (see links below in ‘Sources’).
Research indicates approximately 1 J/cm2 dosage (source) of UVC light is recommended for both sides of a mask to penetrate the inner layers . It is important to note that research shows a mask may start to lose its effectiveness or fit after 10-20 cycles of this level of UVC exposure. For our box, this dosage can be achieved by placing a mask on the raised paint grate directly beneath the bulb for 30 minutes per mask side. You will likely only fit one mask at a time in this space. The side of the box beneath the handle of the work light has significantly lower UVC levels and may require 2+ hours per mask side to receive the recommended dosage
Research indicates, for a surface, a dose of 60 mJ/cm2 is appropriate (source, source). After only 5 minutes, the top surface of items placed directly beneath the bulb will receive this dosage. However, items on the other side of the box and the items’ bottom surface will need more time. To fully treat an item anywhere in the box, leave it in for 20 minutes or more. If you leave them in the box, make sure all the items are on a paint grate so they are off the base of the box and make sure there are gaps between the items to allow the UVC light to reach the base of the box and bounce up to hit the undersides of the items.
Measuring UVC Intensity:
Using a UVC light meter, we measured the intensity of light in various scenarios. We measured the light intensity in various positions and orientations (facing down, facing the wall) to determine the exposure times needed to treat all sides of the objects. Since objects in the box reduce the amount of reflected light, we tested with two used masks in the box. Finally, to capture bulb variations, we tested with 3 different bulbs.
Safety Precautions:
Take necessary precautions to avoid being exposed directly to UV light, which can be damaging.
Wear personal protective equipment for assembly. We recommend safety glasses with an ANSI z87.1 rating which can provide protection from UV exposure, and cut resistant gloves for protection when working with sharp objects.
Only perform cutting on a suitable flat surface.
Some germicidal bulbs produce ozone (including the one we used), so assemble and use your YouVee in a well-ventilated area. Allow the inside of the bin and sanitized content to air out for 30 minutes after extended run cycles.
If you note the smell of any ozone on any masks or PPE, please leave the object outside in a well ventilated area until the traces of ozone dissipate.
Some germicidal bulbs contain mercury, so in the event that your bulb breaks during assembly, wash any exposed skin thoroughly and wear appropriate PPE during clean up.
UVC output may vary from bulb to bulb. The recommended exposure time was based on UVC measurements we made of a specific bulb using a light meter. We do not claim that any specific bulb can produce the same UVC output as the bulb we tested.
Projects that
inspired us:
UVC Sterilizer for COVID-19 Emergency
Sources THAT
we referenced:
Theory Division, Cleveland Clinic Lerner Research Institute
Theory Division, Cleveland Clinic Lerner Research Institute (updated)
Disclaimer: We make no claims that systems using these designs, or the components specified, reduce levels of bacterial, viral, or other types of contamination. Deeplocal is not responsible for injuries or illness resulting from the implementation of these designs or the resulting systems, including but not limited to physical injuries when implementing the designs, or infection from contaminated items treated by such systems or derivative systems. Implement these designs and use the resulting systems at your own risk.
About this project:
YouVee is the second project of our “Cabin Fever” series. During this pandemic, we’re applying our creative engineering expertise to some exploratory work. Some of it is aiming to help solve real challenges that the medical community is facing, and some are maker projects that inject a little bit of fun into all of our lives. Like so many people right now, we hope to use what we have to provide others with help, solutions, or just a bit of joy.