What causes high CO2 levels inside a house?

High indoor CO₂ is almost always a ventilation problem. Modern homes are built tight to save energy, but a tight home traps the carbon dioxide people and pets exhale — levels climb in bedrooms overnight and home offices by afternoon, causing stuffiness, fog, and poor sleep.

Fresh Air Without Wasting Energy

The solution is controlled ventilation: energy recovery ventilators (ERVs), balanced fresh air intakes, or ventilation integrated with your HVAC system that exchanges stale indoor air for filtered outdoor air without wasting the energy you paid to condition it. A CO₂ measurement confirms whether ventilation is your issue before you invest.

The All Set HVAC Difference

When it comes to your home’s heating, cooling, and air quality, All Set HVAC is the local choice Northwest Suburbs homeowners trust. We test before we recommend with our $99 Air Score Test, maintain systems with proven Maintenance Club plans, and install new equipment sized right the first time — all backed by the All Set Guarantee. Call (847) 807-6100.