Keep Your Lungs Clean And Happy With A DIY Supplied-Air Respirator

July 9, 2024 by Dan Maloney 13 Comments

The smell of resin SLA printing is like the weather — everybody complains about it, but nobody does anything about it. At least until now, as [Aris Alder] tackles the problem with an affordable DIY supplied-air respirator.

Now, we know what you’re thinking, anything as critical as breathing is probably best left to the professionals. While we agree in principle, most solutions from reputable companies would cost multiple thousands of dollars to accomplish, making it hard to justify for a home gamer who just doesn’t want to breathe in nasty volatile organic compounds. [Aris] starts the video below with a careful examination of the different available respirator options, concluding that a supplied air respirator (SAR) is the way to go.

His homebrew version consists of an affordable, commercially available plastic hood with a built-in visor. Rather than an expensive oil-free compressor to supply the needed airflow, he sourced a low-cost inline duct fan and placed it outside the work zone to pull in fresh air. Connecting the two is low-cost polyethylene tubing and a couple of 3D printed adapters. This has the advantage of being very lightweight and less likely to yank the hood off your head, and can be replaced in a few seconds when it inevitably punctures.

Another vital part of the kit is a pulse oximeter, which [Aris] uses to make sure he’s getting enough oxygen. His O₂ saturation actually goes up from his baseline when the hood is on and powered up, which bodes well for the system. Every time we pick up the welding torch or angle grinder we wish for something like this, so it might just be time to build one.

Continue reading “Keep Your Lungs Clean And Happy With A DIY Supplied-Air Respirator” →

DIY HEPA Fan Clears The Stale Office Air

January 20, 2021 by Kristina Panos 26 Comments

Although it would be nice, we can’t all work from home. If you have to spend the day in close quarters with other people, you might want more protection than just a mask and sanitizer. Check out [jshanna]’s DIY HEPA filtering fan — it looks like a breeze to build and uses commonly-available parts plus a few 3D-printed pieces to put it all together.

The basis of this attractive and useful office must-have is a muffin fan from Amazon that has an optional variable speed controller. A long threaded rod runs up the center of the HEPA filter, so it attaches kind of like a lampshade. The fan draws up air from underneath and blows it upward through the filter and out into the room. Whenever the HEPA filter gets dirty, just take it out and wash it.

Are you still buying disposable masks? You might save money in the long run by making your own.

3D Printing Air Filter System Does A Lot

January 14, 2021 by Al Williams 29 Comments

We know we aren’t supposed to eat a lot of sugar, but we still have ice cream. We also know we probably shouldn’t be inhaling solder smoke and 3D printer fumes, but we do that too. Not [Mike Buss]. His 3D printer has a major exhaust system.

We can sympathize with his process. He mentions he started out just wanting a fan running with some filters. Then he decided to add a way to turn the fan on and off when printing. Then he added sensors to detect fumes and fire. Data collection was almost an afterhthought.

Continue reading “3D Printing Air Filter System Does A Lot” →

Hybrid Respirator Uses Repurposed Filters

December 5, 2020 by Lewin Day 15 Comments

With the coronavirus raging worldwide, 2020 has seen major shortages of personal protective equipment impact healthcare workers and individuals alike. This has led many to improvise their own solutions. One of the more complete offerings we’ve seen is this hybrid respirator build from [Ben Howard].

[Ben’s] build goes above and beyond the usual craft project masks. It uses a laser-cut chipboard frame to fit three HEPA filters, originally designed for the Roomba robotic vacuum cleaner. Two are used for exhalation, while one is used for inhalation. A small blower fan is installed with the intake filter, to provide mild positive pressure when breathing in. The assembly is wrapped up in fabric, using layers of spandex, fleece, and ripstop nylon to provide the best possible seal against the wearer’s face.

It’s a build that should appeal to those who want to breathe cleaner air and also protect others from exhaled particles that can spread respiratory viruses. We’ve seen all kind of masks hit the scene this year; the graphene-impregnated variety is one of the more interesting designs. Still, one can hope that future years lead to less reliance on such measures!

DIY Filtered Positive Pressure Suit Shows Fine Workmanship

July 3, 2020 by Donald Papp 19 Comments

[Andrew]’s Air filtering unit & positive pressure supply might look like something off the set of Ghostbusters, but it’s an experiment in making a makeshift (but feasible) positive pressure suit. The idea is to provide an excess of filtered air to what is essentially an inflatable soft helmet. The wearer can breathe filtered air while the positive pressure means nothing else gets in. It’s definitely an involved build that uses some specific hardware he had on hand, but the workmanship is great and shows some thoughtful design elements.

The unit has three stacked filters that can be easily swapped. The first stage is medical mask material, intended to catch most large particles, which is supported by a honeycomb frame. The next filter is an off-the-shelf HEPA filter sealed with a gasket; these are available in a wide variety of sizes and shapes so [Andrew] selected one that was a good fit. The third and final stage is an activated carbon filter that, like the first stage, is supported by a honeycomb frame. The idea is that air that makes it through all three filters is safe (or at least safer) to breathe. There isn’t any need for the helmet part to be leakproof, because the positive pressure relative to the environment means nothing gets in.

Air is sucked through the filters and moved to the helmet by an HP BLc7000 server fan unit, which he had on hand but are also readily available on eBay. These fan units are capable of shoveling a surprising amount of air, if one doesn’t mind a surprising amount of noise in the process, so while stacked filter stages certainly impede airflow, the fan unit handles it easily. The BLc7000 isn’t a simple DC motor and requires a driver, so for reference [Andrew] has a short YouTube video of how the fan works and acts.

All the 3D models and design files are available online should anyone wish to take a closer look. It’s certainly a neat experiment in making a filtered positive pressure supply and head cover with materials that are fairly common. If [Andrew] ever wants to move to a whole-body suit, maybe repurpose an old Halloween costume into a serviceable positive pressure suit.

Halloween Costume Turned Positive Pressure Suit

May 9, 2020 by Tom Nardi 31 Comments

As a general rule, you probably shouldn’t be getting your Personal Protective Equipment (PPE) from the party store. But these are exceptional times, and rather than potentially depriving medical professionals the equipment they so desperately need on the front lines, the team at [Robots Everywhere] has been looking into improvised PPE. We’re not sure things are at the point where you would need to don this DIY Positive Pressure Suit (PAPR), but it’s certainly an interesting look at what’s possible when you think outside the box.

At the most basic level, a PAPR is a mostly air-tight garment that is continuously pumped full of filtered air. As long as the pressure inside the suit is higher than outside, there’s no way airborne bacteria and viruses can get in without traveling through the filter first.

For this project, the folks at [Robots Everywhere] took an inflatable astronaut costume and replaced the dinky original air pump with a much larger 12 V unit designed for inflating air beds. Upgrading the pump not only increased the internal air pressure of the suit, but also made it easier to add a HEPA filter to the inlet. As long as the suit is inflated and there are no leaks in the hose, the wearer will be surrounded by a bubble of filtered air.

Presumably, you don’t want to be tethered to the wall though, so the write-up briefly touches on how the pump system can be made more mobile with the addition of an RC-style battery pack. With the pump and batteries secured in a pouch attached to the suit, the wearer is free to venture outside the confines of their self-isolation bunker and go about their dystopian daily business.

A getup like this might seem a bit excessive, but with so many folks desperate for information on homemade protective gear, we aren’t passing any judgment. The team says you can modify a cheap painter’s suit in much the same way, but frankly, that doesn’t sound nearly as fun to us.

[Thanks to Aron for the tip.]

Hacked Protective Gear Keeps Doctor Safe In The Hot Zone

February 12, 2020 by Dan Maloney 33 Comments

It’s rarely a wise idea to put a plastic bag over one’s head, but when the choice is between that and possibly being exposed to a dangerous virus, you do what you have to. So you might as well do it right and build a field-expedient positive pressure hood.

We’ve all been keeping tabs on the continuing coronavirus outbreak in China, but nobody is following as closely as our many friends in China. Hackaday contributor [Naomi Wu] is in from Shenzhen, ~~posting regularly from the quarantined zone~~, and she found this little gem of ingenuity from a [Doctor Cui] in one of the hospitals in Wuhan. Quarantines and travel restrictions have put personal protective equipment like masks and gowns in limited supply, with the more advanced gear needed by those deal most closely with coronavirus patients difficult to come by.

There’s no build information, but from the pictures we can guess at what [Dr. Cui] came up with. The boxy bit is an AirPro Car, a HEPA filter meant to clean the cabin air in a motor vehicle. He glued on a USB battery pack to power it, used a scrap of plastic and some silicone adhesive to adapt a heat-moisture exchange filter from a mechanical ventilator to the AirPro’s outlet, and stuck the tube into a plastic bag sealed around his neck. The filter provides dry, positive pressure air to keep the bag from fogging up, and to keep [Dr. Cui] from asphyxiating. Plus he’s protected from droplet contact, which is a big plus over simple paper masks.

With the news always so dark, it’s heartening to see stories of ingenuity like this. We wish [Dr. Cui] and all our friends in China the best during this outbreak.