Is Your HVAC System Working For or Against IAQ?

● People spend about 90% of their time indoors, making indoor air quality (IAQ) a major factor in health and comfort.

● East African buildings face unique IAQ challenges, including solid-fuel cooking, seasonal dust, high humidity and urban traffic pollution.

● Effective IAQ depends on three core strategies: source control, ventilation and filtration, supported by regular HVAC maintenance.

● Mechanical ventilation and Energy Recovery Ventilation (ERV) improve indoor air quality by supplying fresh outdoor air while reducing the energy loss associated with ventilation.

● Regular filter maintenance is essential in dusty environments such as many East African cities, where filters can clog faster than standard maintenance schedules anticipate.

Indoor air may be more polluted than you think. Air inside homes and workplaces can sometimes contain higher pollutant concentrations than outdoor air, according to theWorld Health Organization (WHO) . The WHO notes that exposure to pollutants from cooking, heating, poor ventilation and other household sources can significantly affect health, especially in East Africa where solid fuels like charcoal, kerosene and wood are commonly used. Other indoor pollution sources include cleaning products, furniture and building materials, which continuously release contaminants into living and working spaces. Since most people spend about 90% of their time indoors, this exposure builds quickly over time.
Understanding what affects your indoor air is the first step to improving it. This guide explains the most common indoor air pollutants, their health effects, and practical ways to improve indoor air quality in East African homes and workplaces. It references guidance from the World Health Organization (WHO) and ASHRAE as widely recognised benchmarks, though local regulations and standards should always take precedence.

HVAC systems influence IAQ through three functions: ventilation, filtration, and operation and maintenance. Together they reduce pollutant buildup, capture airborne particles, and keep performance consistent over time.

1. Ventilation

2. Filtration

3. Operation and maintenance

Poor indoor air quality (IAQ) affects comfort, productivity and health. Some effects appear within hours of exposure, while others develop after months or years of repeated exposure.
● Short-term effects: Eye, nose and throat irritation, headaches, dizziness, fatigue, and worsened asthma or allergy symptoms.
● Long-term effects: Prolonged exposure to fine particulate matter (PM2.5) increases the risk of cardiovascular and respiratory diseases, while long-term radon exposure increases the risk of lung cancer.
● Higher-risk groups: Children, older adults, pregnant women, and people with existing heart or lung conditions are more vulnerable to the effects of indoor air pollution.
Across much of East Africa, household air pollution from cooking with solid fuels remains a major contributor to these health risks, making effective kitchen ventilation and extraction one of the most impactful ways to improve indoor air quality.

Improving indoor air quality starts with reducing pollution at its source and maintaining good ventilation. These practical steps can help create healthier indoor environments in homes and workplaces.

1. Reduce pollution at the source by moving charcoal or kerosene cooking outdoors or to a well-ventilated area with direct exhaust where possible.

2. Install carbon monoxide alarms in spaces with gas appliances, fuel-burning equipment, or backup generators.

3. Keep indoor spaces smoke-free, as there is no safe level of secondhand smoke exposure.

4. Improve ventilation by opening windows when outdoor air quality allows, using kitchen and bathroom exhaust fans, or installing mechanical ventilation or ERV systems in more airtight buildings.

5. Replace or clean HVAC filters according to the manufacturer's guidance, and inspect them more frequently during dry, dusty seasons.

6. Use portable air cleaners or higher-efficiency HVAC filters to supplement, not replace, source control and ventilation.

7. Choose low-VOC or certified low-emission paints, furnishings and cleaning products to reduce indoor chemical emissions.

8. Monitor indoor air quality by tracking pollutants such as PM2.5 and carbon dioxide (CO₂), while recognising that monitors complement, rather than replace, good ventilation and filtration.

Indoor air quality depends on how effectively buildings control pollution at its source, provide adequate ventilation and remove airborne contaminants through filtration. In East Africa, factors such as solid-fuel cooking, seasonal dust, humidity and urban air pollution make these measures especially important. Ventilation remains the foundation of good indoor air quality, while mechanical ventilation and Energy Recovery Ventilation (ERV) systems help deliver fresh outdoor air with lower energy loss. Combined with effective filtration, indoor air quality monitoring and regular HVAC maintenance, these strategies help create healthier, more comfortable and energy-efficient indoor environments for homes and commercial buildings alike.