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Air quality

A number of air parameters are important for people's health, efficiency and sleep quality. These are:

-    Carbon dioxide (CO2)

It is a gas, an integral part of the atmospheric air. In nature it has a concentration of about 0.04% of the air or 400 ppm. In enclosed living premices, its concentration increases dramatically. During the sleeping a person emits CO212 l/h, during work in the office - 18 l/h, and during heavy physical work - 63 l/h. Concentration of CO2 up to 700 ppm is normal, up to 1000 ppm is acceptable. At concentration of 1000-2500 ppm there is a worse efficiency and drowsiness. A concentration of 2500 to 5000 can be harmful for the health. At a concentration above 5000 ppm one should not stay in the room more than 8 hours.

- Particle matters up to 2.5µm (PM2.5) and air quality index (AQI)

Particle matters of this size are the most harmful to the human health because they cause damage to lung tissue. The average annual norm for protection of human health according to Bulgarian legislation is 20 µg/m3. U.S. Environmental Protection Agency defines the levels for PM 2.5 and AQI for a period of 24 hours,they are cited below in the following table:

 
Level PM2.5 µg/m3   AQI 
Good  0 до 12.0  0 до 50
Average  12.1 до 35.5  51 до 100
Unhealthy for sensitive groups  35.5 до 55.4  101 до 150
Unhealthy  55.5 до 150.4  151 до 200
Very unhealthy 150.5 до 250.4 201 до 300

- Volatile organic compounds (VOC)

Volatile organic compounds (VOCs) are released as gases from certain solids or liquids. These include a variety of chemicals, some of which can have short-term or long-term adverse health effects. VOCs are distinguished by an impressive number (thousands) of products, such as paints and varnishes, cleaning supplies, pesticides, building materials and furniture, office equipment such as copiers and printers, corrective fluids, copy paper, graphic and craft materials, including adhesives, permanent markers, moth repellents, air fresheners, fuels and automotive products, leisure materials, chemically cleaned clothing, etc.

VOC concentration up to 0.24 µg/m3 is normal, from 0.25 to 0.5 µg/m3 acceptable, from 0.5 to 1.0 µg/m3 high, and above 1 µg/m3 is dangerous to the human health.

- Formaldehyde (HCHO)

Formaldehyde (HCHO) or methanal is a chemical precursor of many industrial products, ranging from varnishes or paints to adhesives, even preservatives. Very small amounts of these and other formaldehyde-containing materials, e.g. wood-based materials, flooring or textiles can pollute indoor air for a long time. Due to its particular toxicity, formaldehyde is classified as a category 1B carcinogen in accordance with the European Chemicals Directive (CLP) and is thought to have carcinogenic potential for humans.

HCHO concentration up to 0.04 µg/m3 is normal, from 0.05 to 0.08 µg/m3 is permissible, from 0.09 to 0.15 µg/m3 is high, and above 0.15 µg/m3 is dangerous to human health.

- Humidity (RH)

The following recommended values ​​for the humidity level in living quarters are given by ASHRAE - American Society of Heating, Cooling and Air Conditioning Engineers (https://www.ashrae.org), also published in the website of Central Heating & Air Conditioning Co. (https://www.centralhtg.com):

- Comfort: 30% - 60%

- Recommended: 45% - 55%

- High: 55% - 80%.

The optimal humidity level in a room / home depends a lot on personal preferences, clothing and level of physical activity.

At implementing of the "AIR QUALITY" solution sensors are used to measure:

  • CO2;
  • PM2.5;
  • VOC;
  • HCHO;
  • RH and others.

Some of the sensors measure individual parameters, while others measure a group or all of the parameters listed above.

The main functions of the "AIR QUALITY" solution are:

  • - monitoring of air quality parameters;
  • - maintening within the limits of basic parameters for air quality.

 

2GreenHomes solutions for

The main functions of the "AIR QUALITY" solution are:

- monitoring of air quality parameters;

- maintening within the limits of basic parameters for air quality.

 

Maintening of basic air quality parameters is provided by controlling the following actuators:

  • recuperator fan with direct electric control;
  • recuperator fan with remote IR control;
  • fan;
  • window opening mechanism;
  • humidifier;
  • air dryer;
  • air purifier.

 

The control can be manual or automatic by a proportional regulator.

RECUPERATOR CONTROL

FAN CONTROL

Humidifier control