Why Opening The Window Isn't Enough

This is the air we breathe!

"Just open the window".

It's a common 'solution' in kitchens, bedrooms, offices and classrooms.

But to tell you the truth, it doesn't do the job. Cracking the window in an office where the air feels suspiciously stuffy by 10 am doesn't fix your problem and is definitely not practical.

Cracking open a window is not a ventilation strategy; it's a quick fix (and a guaranteed complaint from whoever's parked nearest to the window).

Opening the windows during winter makes your staff freeze (just ask the guy who brings a blanket to every meeting), while opening them in summer lets in pollen from the outdoors and aggravates your poor office lady's hay fever. Not to mention, you could be inviting all of the outdoor pollution into your space to be breathed in. How kind!

The reality in today's world is that the air outdoors is polluted and it's definitely not what it used to be. Fresh outdoor air is often thought of as the gold standard—natural, refreshing, pure.

But here’s a comparison that flips that perception on its head:

Rainwater is also natural. Yet, none of us would dare drink it straight from the sky. Why? Because we understand it carries pollutants—dust, microbes, industrial residues—from the atmosphere. It’s why we filter and purify water before it ever reaches our glass.

So, here’s the question:If we won’t drink unfiltered water, why are we so willing to breathe unfiltered air?

Outdoor air today is saturated with more than just oxygen and nitrogen. It's filled with CO₂, particulate matter, volatile organic compounds (VOCs), allergens, and microbial contaminants. In urban areas, it also contains emissions from vehicles, industrial activity, and even microplastics. Yet, despite breathing 11,000 litres of air per day, most of us take in every breath without a second thought—no filter, no barrier, no protection.

Opening the windows allows air exchange, but its uncontrolled and one-directional. You're letting your dirty air flow out of the window, and outdoor dirty air flow in. Swapsies!

Studies show that indoor air can be 5x more polluted than outdoor air, this is due to the lack of airflow, which allows CO2 to build up, and dust, dirt and VOCs to hang in the air, just waiting to be breathed in. And no, an open window at the end of the corridor can't fix that. So, what can?

Sigma can.

Our ventilation systems — like our Sigma360 units — don’t rely on wind direction, temperature, or someone remembering to “air the place out.”

They deliver:

• Constant, measured airflow

• Heat recovery to keep energy bills low

• Smart CO₂ monitoring

• Multi-stage filtration for allergens, dust, and airborne pathogens

All of it working silently, efficiently, and automatically — whether it’s July or January.

At Sigma EPD, we see this as a fundamental gap in how we approach health and sustainability. Clean air, like clean water, should be a basic standard—not a luxury. And just as water treatment revolutionized public health in the last century, air purification is the next frontier.

It’s time to stop treating clean air as optional. Because just like contaminated water, polluted air harms our health silently, daily, and cumulatively.

The natural world gives us both air and water—but nature doesn’t pre-clean them for modern pollution. That’s our responsibility.