Air quality in administrative buildings has a big influence on the users’ performance and primarily on their health. In cases where ventilation in offices does not work properly and there is no possibility of natural venting, headaches, tiredness and fatigue, dry mucosa and with that associated unpleasant feelings from the work environment can occur more often. With air quality, it is more important to focus on the correct setting and operating of air-conditioning equipment than with any other elements – especially on the speed and type of distribution and on the temperature of air brought to the work and meet zone.
What other aspects is one to focus on with regards to the air?
Firstly, on its distribution.What is important is to use induction distribution elements in a maximal possible way as they are, due to the principle of their function, to secure a minimized difference of the supplied air’s temperature as well as the temperature of air in the work and meet zone and to secure quality ventilation without the need for a high speed of air flow within the work and meet zone. Then it is also important to focus on the quality of fresh air, which is mainly provided by the position of the suction vent from the air-conditioning equipment. The optimal position is the northern and not sunlit part of the building or plot. When drawing in the air on the roof of the building, one needs to be careful about the surface in front of the suction vents of the air-conditioning equipment (that means light surfaces, possibly a green roof), and also about the quality and regular maintenance of filters inside the equipment and about the cleanness of wiring and distribution elements.
Last but not least, it is necessary to also focus on the quality regulation of air distribution throughout the building and rooms in a way whereby the differently utilised premises do not influence one another (layout modifications, occupying of only part of the building and others).
Requirements in the quality of supplied air Basic qualitative parameters are temperature, humidity and a content of harmful substances (solid particles, oxides, volatile substances).
The human organism has a natural ability to adapt to outdoor conditions which is why air temperature should be regulated in accordance with the seasons of the year. Apart from a feeling of comfort and wellbeing we are also able to secure a more energy optimal operation.
A pleasant temperature in winter time is about 22 °C and in extreme summer months we find a temperature of 26 °C very pleasant. The possibility of individual temperature settings is an advantage with regards to temperature comfort.
Humidity is directly connected with air temperature. Air is naturally more humid in summer months, which means that supplied air doesn’t need to be additionally humidified. In winter, humidity can drop to under 30%, which is the minimal norm value. Humidity should optimally be around 35% in winter months in our conditions so it is, with forced venting, necessary to humidify the supplied air.
The amount of air secures a reduced content of harmful substances and conduction of odours. Thereby applies the rule ‘the more, the better’. Large amounts of supplied air are connected with increased energy demand (more energy for heating/cooling, bigger ventilators).
Based on legislative requirements, the minimal amount of air per person is 25 cc m/hour. Optimal amounts of fresh air that takes into consideration energy consumption is 36 cc m/hour per person. From an environment quality point of view, optimal air exchange per person is 50–60 cc m/hour.
“It is necessary to mention the possibility of utilising natural venting, especially in conditions that make it possible – approximately 16 to 26 °C that is for the major part of the year.
Natural venting works as cooling and also replaces the supply of fresh and mechanically modified air. Utilisation of natural venting leads to reduced energy consumption with regards to air-conditioning equipment (ventilators, heating/ cooling supplied air) and disposing of problems associated with the operation (filter replacement, cleanliness of wiring and distribution elements),” Kateřina Kuklová from PBA International Prague adds. Natural venting can dispose of problems with polluting the freshness of the air by modifying it in air-conditioning units and distributing it through a network of piping. The metal environment causes so called deionisation that is the deterioration of fresh air. Highly ionised air feels too fresh. Like the feeling of freshness we get after a storm.
Negatively charged ions of ionised air can get from one’s lungs into the bloodstream and thus influence various body functions: Increased immunity, speeded up cell regeneration, the working against free radicals, adjusting the level of serotonin (hormone of well-being and happiness). Potassium electrolyte modifies the excitability of neuron – thus contributing to one’s well-being, deepening and/or intensifying of one’s concentration and improving one’s memory. www.czgbc.org