Indoor Air Quality and Occupant Health: Pollutant Sources, Ventilation Rates and Verification
Four pollutant groups, four different control strategies — and why a building cannot assume it achieved good air just because it was designed with good intentions.
Indoor air quality and occupant health are linked by a simple fact of exposure: people spend the large majority of their time inside buildings, breathing whatever the building delivers, for hours at a stretch, usually with no way to detect gradual degradation until symptoms appear. Indoor air quality is the measure of which pollutants are present in that air and how much outdoor or infiltrated air actually reaches occupied space — and it resolves into four distinct pollutant groups, each with its own source and its own control strategy. No single fix covers all four, which is the central reason air quality design fails when it is treated as a filtration line item.
This article covers the four pollutant groups and their controls, how required ventilation rates are determined under Indonesian regulation, and why verification after construction is not optional for protecting occupant health. For the Jakarta-specific outdoor pollution context and what LEED and WELL require, see our article on indoor air quality in Jakarta buildings.
The Four Indoor Pollutant Groups and Their Controls
| Pollutant group | Typical source | Health effect | Primary control |
|---|---|---|---|
| Volatile organic compounds (VOCs) | Paints, adhesives, furnishings, cleaning products | Respiratory irritation with prolonged exposure | Source control — specify low-VOC materials |
| Particulate matter | Infiltrated outdoor air; micron-scale fragments from materials such as glass fibre | Inhaled deep into the respiratory system | Filtration at an appropriate rating |
| Carbon dioxide | Occupant respiration in under-ventilated space | Reduced alertness and concentration at elevated concentration | Ventilation rate; CO₂ monitoring as the proxy |
| Biological contaminants | Mould, dust mites and allergens in humid or poorly ventilated conditions | Allergen-related illness | Humidity control |
Note that no two rows share a control. Increasing ventilation does nothing about VOCs already off-gassing from a specified adhesive, and filtration does nothing about CO₂ — each group is a distinct occupant health risk that the others leave unaddressed.
Why Indoor Air Quality Is a Building Design Problem
A building has to be comfortable and healthy for its occupants precisely because occupant health depends on it: people carry out nearly all of their daily activity inside one — working, sleeping, studying, socialising. Air quality sits at the centre of that requirement because it governs what people continuously breathe, and because the exposure is cumulative and unnoticed rather than acute and obvious.
That is what separates it from most comfort parameters. An occupant notices a room that is too warm within minutes and can act on it. An occupant does not notice a ventilation rate that has been quietly running below design for two years — a gap with real occupant health consequences that stays invisible until it doesn't.
How Required Ventilation Rates Are Determined in Indonesia
The volume of outdoor air brought into a building has to comply with applicable local regulation, and the required rate depends directly on the occupancy and activity type of the space — a densely occupied classroom or auditorium needs a very different air intake volume from a lightly occupied office, and undersizing either carries real consequences for occupant health. Sizing to floor area alone is the common error.
In Indonesia, ventilation and air-conditioning design is guided by SNI 03-6572-2001, Tata cara perancangan sistem ventilasi dan pengkondisian udara pada bangunan gedung. Worth knowing: that standard covers thermal comfort and air-conditioning conditions as well as ventilation and air velocity, and its limits are set for Indonesian climate conditions rather than adapted from a temperate-climate source. Its own stated scope is a minimum guideline for everyone involved in planning, constructing and managing a building — a floor for occupant health protection, not a target.
Five Design Strategies for Occupant Health and Healthy Indoor Air
Source control comes first, because a pollutant not emitted does not need removing: specify low-VOC materials, furnishings and finishes. Ventilation effectiveness comes second, and it is about distribution rather than volume — fresh air has to reach the occupied zone, not merely the space nominally served by a duct. Filtration handles particulates appropriate to the building's context before they reach occupants. Humidity control keeps conditions outside the range where mould and dust mites establish. And monitoring — tracking CO₂ and other indicator pollutants — is what turns the other four from design intentions into an operating condition.
The ordering matters. A project that starts with filtration and works backwards typically ends up over-specifying equipment to compensate for material choices that could have been made differently at no additional cost — and with no gain for occupant health either.
How to Verify Indoor Air Quality After Construction
A building cannot assume it has achieved good indoor air quality because it was designed with good intentions. Three practical checks cover most of it: measuring indoor CO₂ concentration as a proxy for whether ventilation is adequate in use, testing VOC concentrations after new construction or renovation before occupancy, and confirming that installed ventilation equipment actually delivers the air intake volume it was specified to provide — the last of which fails more often than project teams expect, quietly undermining the occupant health outcome the design was meant to guarantee.
Timing matters as much as method. Verification is most valuable immediately after construction or renovation, when off-gassing from new materials is at its highest, and then periodically through operation, because ventilation performance drifts as filters load and dampers are adjusted.
Why Air Quality Sits at the Centre of Healthy Building Certification
Indoor air quality is one of the clearest and most measurable levers a building has over occupant health outcomes, which is why it is a core pillar of healthy building frameworks alongside thermal comfort, lighting and acoustics. Air infiltration and ventilation have to be engineered deliberately to meet both regulatory requirements and genuine occupant health needs — the work ALTA Integra carries out through its healthy building advisory and certification practice.
FAQ
What is indoor air quality, exactly?
It refers to which pollutants are present in a building's indoor air and how much fresh or infiltrated air actually reaches occupied spaces. Both directly affect occupant health and comfort, and both are design outcomes rather than properties a building acquires automatically.
What are the most common indoor air pollutants?
Four groups: volatile organic compounds from materials and furnishings, fine particulate matter, elevated carbon dioxide from occupant respiration in under-ventilated space, and biological contaminants such as mould and dust mites. Each has a different source and requires a different control strategy.
How is required ventilation rate determined for a building in Indonesia?
It depends on the occupancy level and activity type of each space and must comply with applicable local regulation. In Indonesia, SNI 03-6572-2001 governs ventilation and air-conditioning system design, with limits set for Indonesian climate conditions, and defines a minimum guideline rather than a performance target.
Can good indoor air quality be achieved through ventilation alone?
No. Ventilation addresses carbon dioxide but does nothing about VOCs already off-gassing from specified materials, and filtration does nothing about CO2. A working strategy needs source control, ventilation effectiveness, filtration and humidity management operating together.
How do you verify indoor air quality after construction?
Measure indoor CO2 as a proxy for ventilation adequacy, test VOC concentrations before occupancy following new construction or renovation, and confirm that installed equipment actually delivers its specified air intake volume. Verify immediately after construction, when off-gassing peaks, and periodically thereafter.
Who provides indoor air quality consulting in Indonesia?
ALTA Integra advises building owners in Jakarta and across Indonesia on indoor air quality design and verification, including ventilation and filtration strategy, source control specification, and the air quality criteria within WELL and LEED certification.
These four pollutant groups are specified for and verified on ALTA Integra’s corporate office projects, where occupant health has become a measurable design requirement rather than an afterthought.
Sources
1. SNI 03-6572-2001, Tata cara perancangan sistem ventilasi dan pengkondisian udara pada bangunan gedung, Badan Standardisasi Nasional, 2001.
2. World Health Organization, Air Quality Guidelines: Global Update 2021.
3. International WELL Building Institute, The WELL Certification Guidebook.
