Aug 17

The Quality Of The Indoor Air We Breathe. Impact On Our Health And Productivity. (IAQ)

  • August 17, 2023

Several international studies show that the time a modern individual spends indoors ranges from 70% to 90% of their life. Whether at home, at the workplace, in the store where we shop, in a restaurant or coffee, at a cinema or school, the Indoor Air Quality (IAQ) directly influences our health and productivity. This topic was rightfully emphasized during the SarS-Cov-2 (Covid-19) pandemic. Even after the pandemic’s conclusion, all scientists are united around the thesis that the virus most commonly spreads through respiratory means, as its aerosols can travel up to 8 meters and remain active for up to 12 hours.

European leaders, doctors, scientists, ventilation and air conditioning associations, and experts are aware that exposure to poor air quality causes much more harm than we presume.

It is known that poor Indoor Air Quality (IAQ) and lack of fresh air in enclosed spaces are associated with various diseases, such as asthma, lung cancer, chronic respiratory diseases, and allergies.

Since there is no unified statistic in Europe, we used data from Public Health England. According to an analysis in the United Kingdom, the annual number of deaths due to air pollution there ranges between 24,000 and 36,000 people, with healthcare costs associated with their treatment reaching up to £20 billion.

When at rest, a person inhales and exhales about 13 kg of air per day. If you spend between 70% and 90% of your time indoors in polluted and poorly ventilated environments, it can have a significant impact on your health, as well as affect workplace productivity, sick leave, and more.

Open your eyes to a better indoor microclimate (IAQ).

Poor air quality can have an impact not only on health but also on brain functions. Research has shown that the poor air quality in the office can significantly affect employees’ cognitive functions, including reaction time and focusing ability, which in turn affects productivity. A Danish study suggests that mathematical tasks could be solved up to 14% faster and more efficiently in a better microclimate.

The topic of air quality is particularly relevant in the context of ongoing debates about bringing employees back to the office and the emergence of new hybrid and remote work models. A recent study found that one-third of employees have not returned to the workplace since the beginning of the pandemic, and some managers are facing resistance from employees who are working from home.


Should investment be made in ventilation systems in offices and production industries?

The year-long study by Harvard School of Public Health, involving participants from six different countries working in offices as well as various industrial plants and factories, reveals the following results: Elevated concentrations of fine particulate matter – PM2.5 – and poor ventilation are associated with significant declines in cognitive function, with participants showing slower reactions and reduced accuracy.

Most concerning is that according to the study, “indoor air quality affects health and productivity much more than we previously thought” – according to the lead author of the research, Jose Guillermo Cedeno-Laurent, a researcher in the Department of Environmental Health.

We must act now!

Considering all that has been described above, with knowledge about indoor air quality and its impact on health accessible to everyone, and with building owners, businesses, investors, and managers being well-informed about its effects on productivity and well-being, serious and vital improvements in the quality of the air (IAQ) we breathe in various indoor spaces must be undertaken.

In the United Kingdom, the Building Engineering Services Association (BESA) issued a guide regarding indoor air quality for the health and well-being of occupants, stating that there is an “urgent need to set targets for reducing IAQ pollutants and to establish industry best practice to safeguard building occupants’ health and well-being.” This guide was followed by other publications by European associations, each with the goal of promoting investments in better microclimates and healthy parameters of indoor air quality (IAQ), thus contributing to improved physical and health conditions for occupants. The conclusion reached by various institutions through years of observation and research is that air quality and proper ventilation not only make a building efficient but also create a healthy living environment.

What can be done in Bulgaria?

Of course, in Bulgaria, there are sufficient laws, regulations, and rules for both the design and implementation of new buildings. We have set goals before the European Union to achieve renovation and improvements in the existing building stock. Unfortunately, there is a lack of accountability in the execution of building projects, and often, with the aim of financial optimization of capital investment, investors overlook investments in appropriate ventilation systems.

If government authorities enforce compliance with EU regulations and standards regarding the installation of ventilation systems, there will be five crucial outcomes for Bulgaria:

  1. People will live and work in a healthier environment. They will suffer less from illnesses, allergies, asthma, and respiratory diseases.
  2. There will be reduced expenditures for treating illnesses. People will be more active and contribute to the country’s development, leading to a higher GDP.
  3. By installing energy-efficient ventilation systems with energy recovery, heating and air conditioning costs for factories, enterprises, offices, administrative buildings, schools, and hospitals will decrease. Consequently, the nation’s economy will become more competitive.
  4. Lowering heating expenses will also lead to a decrease in greenhouse gas emissions. The air in cities will be cleaner, resulting in fewer EU sanctions and fines.
  5. By accounting for lower carbon emissions, Bulgaria will have a surplus capacity of greenhouse gas emissions that it can trade on the market, thus earning additional revenue for the budget.

We present to your attention various devices aimed at assessing and enhancing indoor microclimate parameters:

  1. Soler & Palau AirSens – A CO2 monitor, which provides an effective way to measure air quality in any environment and simultaneously signals when actions need to be taken to improve ventilation through LED indicators.


  1. Heat Recovery Ventilation – TANGRA produces a wide range of indoor air ventilation and filtering devices. Through its line of energy-efficient units and climate chambers, the company meets the highest air purity standards. TANGRA’s recuperative ventilation systems are used in schools, kindergartens, single-family homes, administrative and office buildings, manufacturing plants, factories, swimming pools, hospitals, sanatoriums, auto service complexes, and commercial centres.
    • Decentralized energy recovery devices TANGRA EVB School: deliver fresh, filtered air at the desired temperature to a single room, eliminating the need for additional ventilation elements (air ducts, ventilation grilles, etc.). They can be equipped with an air quality measurement sensor. The fresh air is automatically adjusted based on the occupants’ needs, while simultaneously monitoring parameters for maximum energy efficiency.


    • High efficient energy recovery ventilation TANGRA EVB HiE: 14 models with varying airflow from 150 to 6400 m3/h, AC/EC fans, aluminium heat exchanger, Eurovent certified, various thermal boxes for heating and cooling, low noise, and low electrical consumption.
    • Thermodynamic recovery units TANGRA EVB DX: High-efficiency energy recovery systems utilizing energy recovery with an air-to-air plate exchanger and an integrated thermopump. The efficiency of this type of system exceeds 92%.

    3. Air purifier TANGRA AirSterilizer 07 – a device for cold air sterilization. The unit features a built-in HEPA filter that captures up to 99.995% of microscopic particles, including aerosols carrying viruses. The device is ideal for spaces without mechanical ventilation, waiting rooms, changing rooms, and dining areas.


The team at “TANGRA – AV” Ltd. offers free consultation regarding the assessment and establishment of proper ventilation systems, aiming to achieve a healthy working environment and microclimate that will make your team healthier and more productive! By reaching out to us, we can assist you in maintaining a clean and healthy workspace.

0887 73 73 75 / office@tangra.bg




National Service Telephone:
0887 73 73 75