Brain Fog and Fatigue at Home? Your CO₂ Levels May Be Too High

You slept 8 hours, had your coffee, and still can't focus by 10am. You assume it's stress, screen time, or just a long week. But if it happens consistently at home and clears up when you leave, your indoor CO₂ level deserves a serious look.

What CO₂ does to your brain

Fresh outdoor air contains about 420 ppm of CO₂. Inside a sealed home, levels can easily climb past 1,000 ppm — especially in bedrooms overnight, in rooms with poor ventilation, or in energy-efficient homes that trap air. At 1,000 ppm, cognitive performance measurably declines. At 1,500 ppm, most people experience drowsiness, headaches, and difficulty concentrating. Above 2,000 ppm, the effects are similar to mild altitude sickness.

Why Florida homes are particularly affected

South Florida homes run air conditioning nearly year-round with windows closed, which dramatically reduces fresh air exchange. The same insulation that keeps your energy bill manageable also keeps CO₂ trapped inside. Bedrooms are especially problematic — a closed room with one or two sleeping adults can reach elevated CO₂ levels within hours.

CO₂ alone isn't the only cause

High CO₂ often correlates with elevated VOCs and humidity — because all three are products of the same problem: poor ventilation. When fresh air exchange is limited, every gas that gets released inside stays inside. That's why a complete IAQ inspection measures all parameters together, not just CO₂ in isolation.

How to know if CO₂ is your problem

The only way to know your actual levels is to measure them continuously — not a one-time snapshot. FloridaProShield installs Airthings Space Pro sensors for 48 hours, capturing levels throughout the day and night, in the rooms where you actually spend time. The resulting report shows exactly when and where concentrations peak, so you know whether to focus on bedroom ventilation, living areas, or the whole home.