Provide, control and reduce

We spend 100% of our time breathing air, so we need to have the best possible indoor air environment at all times. So we need to provide good indoor environment, via controlling air quality and reducing harmful pollutants indoors.

Who needs ventilation? And where?

Simple answer is everybody and everywhere — we all do need ventilation in all the environments.

Who needs ventilation?

Ventilation is important for everyone — from the basic physiological need for air, bringing positive impact on people's health & wellbeing and to creating a healthy environment for all.

Everybody is affected by ventilation, more precisely everyone in a building is affected by the quality of indoor environment in the buildings and therefore directly affected by the ventilation system.

Where the ventilation is needed?

Of course, ventilation is needed everywhere indoors — in people's homes, at various workplaces & educational facilities, at other activity-based spaces such as shopping malls, hotels, restaurants and everywhere else.

And the ventilation is also needed in cars, airplanes and seaships, and many more spaces. As in there there are also ventilation systems that help control air quality and air circulation.

And other spaces dependent on ventilation?

And one of the most dependent on ventilation are the closed structures located in spaces without the natural occurance of air (and also many other substances) — submarines and spaceships.

Why to ventilate — provide, control and reduce

Fresh air comes into buildings, where it then gets recirculated, used and polluted by various sources. And we need to provide a good environment by controlling indoor climate and reducing harmful pollutants — ideally in all environments and for all people.

To provide

  • When we want to create a comfortable, healthy and safe environment for people — in homes, offices, schools, and other environments.
  • When we want to improve productivity of employees in office buildings and performance of students in schools.
  • When we want to reduce sick time, i.e. sick days at offices and absenteeism in schools.

To control

  • When we want to enhance comfort for the buildings' occupants, i.e. control temperature, humidity and other parameters of the indoor environment.
  • When we want to control occupants exposure to air contaminants, i.e. remove or dilute airborne contaminants.
  • When we want to ensure energy-efficient and sustainable operation of a building and also regulated costs, i.e. investment, operating and maintenance costs.

To reduce

Fresh air comes into buildings where it then gets recirculated, used and polluted by various sources. Indoor air can build up high levels of pollutants from people's activity or building materials.

  • People's activity (and also animals) — carbon dioxide (CO2), moisture or odours, etc.
  • Building's materials/technology and equipment — furniture, floorings (VOCs as volatile organic compounds that are carbon-based compounds that easily evaporate).
  • Outside pollutants from traffic and earth — CO or radon from the ground, etc.

Special examples of when we need to ventilate

  • When the outdoor climate is more extreme, for example in cold climates or hot/humid climates.
  • When close proximity creates problems, i.e. to other outdoor conditions surrounding the buildings such as noise from traffic, location near polluting industries or seasonal issues with dust and pollen.
  • When we want to avoid heat build-up in more demanding time periods in a year, such as hot spells during summer. 
  • When the building envelope is too airtight and sealed: this is especially true for new built buildings and/or renovated buildings.
  • When we need to maintain specific conditions due to the purpose of a building, i.e. hospitals and laboratories.

Dealing with ventilation

Who deals with ventilation?

A well-designed system and a continuing preventive maintenance program are key elements in the control of ventilation system problems. However, it allways comes to the people and systems controlling the ventilation.

Being in charge of ventilation could also mean being in control of ventilation. This is very much dependent on the type, size and purpose of the building. One person or a few people can be in control of everything. However for large buildings and extensive systems, typically one or more teams of people are in control. Often the building systems have the automatic control systems in place.

And who is in charge of ventilation?

It is definitely the owner of the building and if specified it could be also the tenant of the building or a building operator/manager (or in his stead, it is the building maitenance management company). This could be one person (as homeowner or caretaker for school building) or building's manager (for offices or large buildings).

And it is the employers that must 'ensure that every enclosed workplace is ventilated by a sufficient quantity of fresh or purified air'. And the employer is in relation with the building owner/manager.

Whilst the employer has overall responsibility for providing adequate ventilation and also securing healthy and safety in the workplace, however everybody has a subtantial part to play in it. All employees (managers, supervisors or general employees) are required to follow up and be part of active team.

How to deal with ventilation?

Dealing with ventilation depends on the type of ventilation, i.e. natural, mechanical or a combination of both. Practical ways to improve natural ventilation includes for example increasing natural ventilation by opening doors, windows and vents. With mechanical ventilation, the key is to control, monitor and ensure that mechanical systems recirculating air have been designed with fresh air inlets and that they are kept open to avoid blocking the air, the right amoung of airflow with certain parameters must be secured and also the polluted air must be dilluted and removed. There is always a possiblity of a combination of natural and mechanical ventilation, so-called hybrid ventilation that requires a proper control system.

And what is used to regulate ventilation?

Extensive ventilation norms, standards, guidelines, manufacturer's documentation and various operation manuals are provide vast amount of information needed for ventilation operation.

Typically, there are certain workplace health, safety and welfare regulations that are mandatory and cover a wide range of basic health, safety and welfare issues and apply to most workplaces. These include typically approved code of practice and guidances.

It will help employers understand the regulatory requirements on issues such as ventilation, temperature, lighting, cleanliness, escalators, sanitary conveniences and washing facilities, and many more duties and regulations.

Occupants' interactions with ventilation

An essential need for building occupants is to live and work in a healthy and comfortable indoor environment. Occupant impact on ventilation is about how occupants react to and/or are affected by the indoor environment in buildings, i.e. occupants' perception of ventilation and indoor climate in the buildings where they live/sleep, work and leisurely.

An occupant's interaction with building systems is attributed to the sizeable variation in building energy use and indoor climate environments' continuity, including good air quality to meet health and comfort needs.

There are several effects of occupant interaction on several issues: the influence that occupants have in controlling their environment (especially indoor air quality and thermal comfort), factors beyond the control of occupants, health, well-being and productivity, and energy use and environmental impact.

The degree of ventilation control

A key consideration is the degree of control occupants have over the indoor environment. This depends on the building type and the adequacy of control measures provided.

In residential buildings, the occupant has virtually total access to the various mechanisms available (heating, ventilation controls, window opening, etc.). People can understand and operate the building systems including maintenance.

In non-residential buildings, for example in multi-storey dwellings, offices, shops, schools, public buildings and industrial premises, direct control may not be available to occupants or, if accessible to individual users, they may influence the indoor environment.

Outdoor air quality

The control of the outdoor air quality is an area in which individual occupants have, perhaps, the least control. The steps towards achieving good indoor environment starts with outdoor pollution, source control (via legislation), location of air intakes (design and guidelines) and building location (proximity to pollution sources).

Furthermore, the building characteristics are of importanc such as envelope insulation and airtighness (legislation and guidelines), filtration of particles (i.e. starting with source control + air filters and so on). And delivering clean supply air.

In essence these steps are primarily within the domain of legislation and requirements imposed on the designers and builders to ensure that the occupant is protected.

Indoor air quality

Building's occupants and owners/managers have substantially more control than for outdoor pollutants. Selecting strategy for buildings' operation and maintenance can deliver optimal indoor environment providing ventilation, source control and dilluting/removing pollutans.

Building's occupants could undertake many actions to verify the quality of indoor air and comfort in connection with the occupancy density (for example, temperature, humidity, carbon dioxide, VOCs, etc.).

And thus, building systems including heating / cooling / ventilation / air conditioning play the key role in providing optimum indoor environment.


"One of the challenges with ventilation is that people want a simple rule — but there isn't one. It's a specialist area and we need to recognise it in that way."

— Catherine Noakes, Professor of Environmental Engineering for Buildings, University of Leeds, United Kingdom


Want to read more about the air?

Download our book, AIR. The aim of the book is to provide insights into the factors and circumstances, including the outdoor environment, that significantly influence the creation of a good indoor climate and energy-efficient ventilation solutions.


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Duncan: This castle hath a pleasant seat; the air nimbly and sweetly recommends itself unto our gentle senses.
William Shakespeare, Macbeth