You may not notice it or smell it, but the air within your home or workplace may be impacting your health, concentration, and even your utility bills. Indoor air quality (IAQ) with poor standards has been associated with fatigue, headaches, respiratory problems, and decreased productivity.
One of the largest silent dangers? Radon. Odorless and colorless, this gas is the second most prevalent cause of lung cancer in America and can go undetected in homes, particularly basements and ground floors. And that’s not the only risk—dust, mold, VOCs, and poor filtration all contribute to unhealthy spaces.
The good news? It doesn’t have to be complicated to monitor and boost your air quality. In this guide, we’re going to take you step-by-step through what “optimal” actually is when it comes to air quality—tackling radon levels, ideal IAQ standards, and how you can breathe easier, think clearer, and save on energy.
Understanding Indoor Air Quality Standards
Before we address concrete metrics, let’s define indoor air quality standards quickly. These are recommendations—established by organizations such as ASHRAE, WHO, and the EPA—that suggest safe levels for different pollutants and conditions within buildings. They provide us with tangible targets, so “good” air can be measured.
Key Air Quality Metrics & Their Optimal Levels
Here’s the heart of the matter: the numbers you want to hit. We’ll cover six critical metrics, explain why they matter, and share the optimal air quality levels for each.
Carbon Dioxide: The Silent Productivity Killer
Let’s start with the invisible enemy – CO2. You can’t smell it, taste it, or even see it, but when indoor air quality carbon dioxide levels drop below standards, your brain begins shutting down.
Maintain your CO2 levels below 800 ppm for peak mental performance. If you reach 1000 ppm, the ability to make decisions decreases by at least 50%. Consider this – half of your mental functionality is impaired by something you can’t even sense without monitoring.
Radon Risk Chart & Radon Levels in the House
Now let’s speak about something that keeps me awake at night: radon. When people ask us “what is a normal radon level,” we must tell them the uncomfortable truth: there is no truly “safe” level.
In terms of the World Health Organization, radon levels in the home should remain at or below 100 Bq/m3 (or 2.7 pCi/L). But here is what most folks do not know – radon is responsible for between 3% to 14% of all lung cancer, so it is the second most important cause of lung cancer in the United States after smoking.
We’ve created this handy radon level chart that we work with our customers:
Radon Risk Chart:
| Radon Concentration | Approx. pCi/L | Risk Category | Action Recommended |
| Below 100 Bq/m³ | Below 2.7 | Low (Acceptable) | No immediate action |
| 100–200 Bq/m³ | 2.7–5.4 | Moderate | Consider mitigation |
| 200–400 Bq/m³ | 5.4–10.8 | Elevated | Plan for mitigation soon |
| Above 400 Bq/m³ | Above 10.8 | High | Immediate mitigation required |
The difficult thing about radon is that radon levels in the home can change significantly between neighboring buildings and even inside the same building from one day to another. That’s why we always suggest a minimum of three months of testing to find an accurate yearly average.
Temperature & Energy Savings: Finding That Sweet Spot
You’re familiar with that constant office thermostat battle, right? Well, it turns out there’s some science to the ideal temperature. Studies indicate that indoor employees commit fewer errors when the thermometer is at 71.6°F (21°C).
We have worked with schools in which merely tweaking classroom temperatures from 77°F to 68°F during late summer made students perform drastically better. It’s all about making a space where brains will be able to work best.
Humidity
Keeping humidity levels at 40-60% isn’t simply a matter of comfort – it’s a matter of stopping two big problems: infection transmission and mold growth.
Dropped below 30-40% humidity, infections are more easily transmitted. Higher than 70%, you’re creating a paradise for mold and fungi.
Particulate Matter (PM₂.₅): The Invisible Threat
Here’s something that might surprise you: the World Health Organization revised its guidelines in 2021 to suggest PM2.5 concentrations below 5 µg/m3 annually. These tiny particles are particularly risky for individuals with respiratory issues like asthma.
During Oregon’s wildfire season, we observe PM levels increase hugely. That’s when our emergency response comes into play – buildings require same-day filter replacement to safeguard their occupants. Our western United States’ largest stocking facility enables us to react within hours, not days.
Volatile Organic Compounds (VOCs)
VOCs must remain 0-250 ppb to ensure building satisfaction. VOCs are airborne chemicals that irritate the eyes, nose, and throat – causing what’s referred to as “sick building syndrome.”
Putting It All Together: A Quick Cheat Sheet
| Metric | Optimal Level |
| CO₂ | < 800 ppm |
| PM₂.₅ | Annual ≤ 5 µg/m³; 24 h ≤ 15 µg/m³ |
| Temperature | 71.6 °F (21 °C) |
| Humidity | 40–60 % RH |
| VOCs | < 250 ppb per chemical |
| Radon | < 100 Bq/m³ (2.7 pCi/L) |
Print this, tape it to your wall, or bookmark it on your phone—these are your go‑to indoor air quality standards.
Taking Action: Improve Your Indoor Air Quality Today
- Monitor Continuously: Invest in a good IAQ monitor that tracks CO₂, PM₂.₅, VOCs, humidity, and ideally radon.
- Ventilate Smartly: Utilize energy‑recovery ventilators (ERVs) or heat‑recovery ventilators (HRVs) to introduce fresh air without losing heating/cooling.
- Control Sources: Choose low‑VOC paints and furnishings, manage humidity with humidifiers/dehumidifiers, and test for radon every few years.
- Filter & Purify: Use MERV‑rated filters (MERV 13+ in high‑risk settings) and consider standalone HEPA purifiers for critical areas.
- Adjust Thermostat: Keep around 71.6 °F, and widen the deadband by a degree or two when unoccupied.
Final Thoughts
Excellent indoor air quality is the foundation of health, productivity, and energy efficiency. By aiming for these ideal air quality levels, you provide the finest possible environment for everyone under your roof to live, work, and prosper in.
Don’t wait until symptoms occur or productivity falls. If you’re in doubt about the air quality in your facility, call us at (503) 968-3261 for a thorough site survey. Because when it comes to the air you breathe, “good enough” just isn’t good enough.