Indoor Environment Quality
Indoor Environment Quality (IEQ) encompasses factors, such as air quality, thermal comfort, lighting, acoustics and other elements that can impact the health, comfort and well-being of the occupants.
- Every indoor space is unique.
- Each individual experiences IEQ differently.
- Poor IEQ can impact the health of occupants in a variety of ways through short-term (e.g. discomfort, irritation, asthma attacks, SBS ) and long-term (e.g. respiratory and cardiovascular illnesses, cancer) health problems.
Main Attributes of Indoor Environment Quality
Temperature (T)
- What is it?
The level of thermal energy or heat present in the indoor space. While there is no single comfortable temperature for all the individuals, the
optimal temperature is 22-24oC.
- How it affects your health?
High Temperature: Sleepiness, fatigue, excess sweating and lack of concentration.
Low Temperature: Restlessness and lack of concentration.
Relative Humidity (RH)
- What is it?
The amount of vaporized water in the air which increases the higher the temperature is. Recommended levels are considered 40%-60%.
- Common sources?
Outdoor humidity levels, HVAC systems, occupant-generated moisture (breathing, respiration, metabolic process), watering plants.
- How it affects your health?
Sore throat, blurred vision, eye and skin irritation, allergies and respiratory issues.
Carbon Dioxide (CO2)
- What is it?
A naturally occurring gas that impacts cognitive performance and productivity. Can be linked with the risk of virus transmission and in very high concentrations can become toxic.
- Indoor sources?
People through exhalation and combustion.
- How it affects your health?
Headaches, drowsiness, decreased cognitive performance scores - the effects may worsen with increasing concentration.
Particulate Matter (PM)
- What is it?
A variety of particles that float in the air. Some of them are large enough to be seen, while the most dangerous are the smaller-invisible ones. These can enter your blood circulation.
- Common sources?
Outdoor air pollution, such as vehicle emissions, industrial activities and dust. Cigarettes, mold in the HVAC systems, combustion and building materials.
- How it affects your health?
Eyes, nose and throat irritation, respiratory infections, lung cancer.
Volatile Organic Compounds (VOCs)
- What are they?
Organic chemicals that easily vaporize at room temperature. They are commonly found at much higher levels indoors rather than outdoors.
- Indoor sources?
Oil-based paints, cleaning agents, adhesives, solvents, building materials, furniture and personal care products.
- How they affect your health?
Dizziness, nausea, respiratory issues, allergic reactions and potential health effects on the central nervous system, liver and kidneys.
Radon (Rn)
- What is it?
A naturally occurring gas that is colorless, odorless and tasteless, formed from the decay of uranium in soil, rock and water.
- Indoor sources?
Building materials, water, gaps in doors and walls and microcracks in the building's foundation.
- How it affects your health?
Shortness of breath, cough, pain or tightness in the chest, lung cancer.
Noise
- What is it?
The intensity of loudness of sound.
- Common sources?
Road traffic, occupants, equipment, machines and HVAC systems.
- How it affects your health?
Can trigger stress and anxiety, sleep disturbances and in the long term lead to hypertension.
Light
- What is it?
The amount of visible light that illuminates the space.
- Common sources?
Interior lighting, sunlight.
- How it affects your health?
Can affect circadian rhythms and sleep patterns, mood and mental health, visual comfort and eye health.
Pressure
- What is it?
The force exerted by the air molecules in the atmosphere on a given surface area, also known as the "weight of the air".
- Indoor sources?
HVAC systems, occupants' activities.
- How it affects your health?
Can affect comfort though headaches and feelings of unease.