As buildings transition from heating to air conditioning each spring, indoor air quality (IAQ) issues often surface. Complaints related to dust, odours, comfort, and humidity are common during this period and are frequently linked to HVAC changeover conditions rather than new problems.
Taking a preventive approach before switching to cooling can help facility teams reduce complaints, improve occupant comfort, and identify ventilation or airflow issues early.
This checklist outlines key IAQ considerations to review before and during the heat-to–A/C transition.
Why HVAC Changeover Affects Indoor Air Quality
Seasonal changeover can introduce or amplify IAQ issues due to:
- Accumulated dust and debris within HVAC systems
- Changes in airflow patterns and ventilation balance
- Shifts in indoor humidity levels
- Increased allergen circulation
- Systems operating outside optimal design conditions
Addressing these factors proactively helps prevent avoidable IAQ concerns once cooling demand increases.
When to Consider an IAQ Assessment
An IAQ assessment may be beneficial if:
- Complaints increase following HVAC changeover
- Comfort issues persist despite system adjustments
- Ventilation performance is unclear
- Sensitive environments require confirmation of IAQ conditions
THEM supports facility teams with practical IAQ assessments focused on identifying issues early and supporting informed decision-making.