The Science Behind MyAirHat™

Understanding the science behind MyAirHat™ can help explain why it works so effectively. While human respiration is complex, the core concepts are surprisingly easy to grasp — and they lead naturally into the principles behind MyAirHat's design.

Why Particle Size Matters

To understand how MyAirHat functions, it helps to visualize the relative sizes of particles in the air:

• Imagine an oxygen, nitrogen, or carbon dioxide molecule as the size of a marble.
• On that scale, a virus would be the size of a three-story apartment building.
• A human hair — or a cotton thread, which is similar in diameter — would be a couple of kilometers wide (over a mile).

From a molecule's perspective, cotton fabric looks like a wide-open structure with enormous gaps. That's why sound waves travel easily through fabric and also why small gas molecules can move freely through the cotton wall of the MyAirHat.

Particle Sizes

Note: This table shows particle sizes and their relative scale. A meter is 39.4 inches. A micron is a millionth of a meter (abbreviated μm). A marble (1 cm / 0.4 inches) is used as the reference size of an air molecule. This table shows how much larger other particles would be at this scale.

Particles	Average Size	Midrange Size (microns)	Compared to Marble (meters)	Compared to Marble (feet)
Air molecule (Nitrogen, Oxygen, Carbon Dioxide)	0.0005μm	0.0005	0.01	0.033
Coronavirus	0.1-0.3μm	0.3	6	20
Light dust particle	1μm	1	20	66
Bacterium	1-3μm	2	40	131
Dust particle: PM2.5	≤2.5μm	2	40	131
Respiratory droplets containing coronavirus	7.5μm	7.5	150	492
Red blood cell	7-8μm	7.5	150	492
Dust particle: PM10	≤10μm	10	200	656
Pollen grain	15μm	15	300	984
White blood cell	25μm	25	500	1,640
Visibility threshold (Limit of what the naked eye can see)	10-40μm	30	600	1,968
Grain of salt	60μm	60	1,200	3,936
Fine beach sand	90μm	90	1,800	5,904
Human hair	50-180μm	115	2,300	7,544

How Molecular Diffusion Works

Diffusion is the key scientific principle behind MyAirHat. Britannica defines diffusion as:

"A process resulting from random motion of molecules by which there is a net flow of matter from a region of high concentration to a region of low concentration."

You've experienced diffusion any time you've smelled perfume spreading through a room — the scent molecules move naturally through the air without needing to be blown or pumped.

Diffusion in the Lungs — and in MyAirHat

Human lungs rely on diffusion too. Each adult lung contains about 300 million alveoli, tiny sacs that expose inhaled air to your bloodstream. The total surface area is roughly the size of a tennis court, separated only by a thin membrane where oxygen enters the blood and carbon dioxide exits.

The MyAirHat doesn't need anywhere near that surface area, because gas diffusion is about 100,000 times faster in air than in liquid. The cotton wall of the hat provides enough surface area to allow for the passive exchange of oxygen and carbon dioxide.

Here's what happens during use:

• After a few minutes of breathing inside the MyAirHat, carbon dioxide levels inside the hat become several times higher than outside — but still below recommended safe limits, as discussed in the Safety section.
• At the same time, oxygen levels inside the hat are quite a bit lower than the levels outside.

Despite these differences, the small, fast-moving gas molecules — in constant Brownian motion — continue to diffuse naturally across the cotton fabric wall. Oxygen enters, carbon dioxide exits. No fans, filters, or moving parts required.

Why It Doesn't Need a Tight Seal

Unlike masks or respirators, MyAirHat doesn't require a tight seal around the face or neck. That's because there's no significant pressure forcing air in or out — just gentle expansion and contraction.

• When you exhale, the bag slightly expands or billows out.
• When you inhale, it gently draws inward.
• This keeps the internal pressure nearly equal to the outside air, so air doesn't rush in or out through small gaps.

This is the opposite of a traditional mask, where any gap drastically reduces filtration efficiency, because the pressure forces unfiltered air through leaks. That's why respirators must be sealed to the skin with petroleum jelly to achieve ideal efficiencies — to ensure the air is actually passing through the filter media, not around it.

What Doesn't Move

Because nitrogen levels are essentially the same on both sides of the fabric, there is no net flow of nitrogen in or out. The same is true for dust, pollen, and viruses — once the hat is on, they mostly stay put. That's why it's important to put on your MyAirHat in clean, well-ventilated air, such as outdoors or by an open window.

Diffusion vs. Filtration

Traditional masks use filtration and pressure — your lungs pull air in through a material barrier, then push it back out. MyAirHat takes a different approach. It uses passive molecular diffusion, driven by natural concentration differences and the incredible speed of gas molecules.

It's not a filter. It's a physics engine — powered by air molecules doing what they always do.