Practical measures for the operation of building installations regarding to Covid 19
In this document we will briefly summarize some tips on the operation and operation of buildings in buildings, in order to avoid the spread of Covid-19 bacteria, as a result of factors related to HVAC or sanitary facilities.
All guidance and advice is geared towards measures that are easy to organize and implement in most existing buildings.
The recommended practical measures for the operation of building installations with respect to Covid-19 are:
1. Ensure natural ventilation of the spaces / rooms with outdoor air.
2. Set the mechanical ventilation system to rated flow at least two hours before the start of the building use program and switch to a lower flow rate two hours after the end of the program.
3. During the night and on weekends, the mechanical ventilation system does not stop, but will operate continuously at low flow rates.
4. Ensure regular natural ventilation through windows (even in the case of buildings with mechanical ventilation).
5. Maintain toilet ventilation 24/7.
6. Avoid opening windows in toilets to ensure the correct direction of mechanical ventilation in the depression.
7. Instruct building users to flush toilet bowls with the lid closed.
8. Switch recirculated air handling units to 100% outside air.
9. Inspect the heat recovery equipment to make sure air leaks are under control.
10. Switch off the fan coils or program them so that the fans run continuously.
11. Do not change the setpoints for heating, cooling and humidification.
12. Do not plan to clean pipes during this period.
13. Replace the inlet and outlet air filters of the air handling units, as usual, in accordance with the maintenance schedule.
14. Replacement and periodic maintenance of filters shall be carried out under normal protective measures, including respiratory protection.
As shown in Figure 1, there are 4 main modes or routes of infection transmission:
1. Close contact of 1-2 m through droplets and nucleosols (when sneezing, coughing or talking).
2. By air through nucleosols (droplet nuclei), which can remain in the air for hours and can be transported over long distances (released by breathing, speech, sneezing or coughing).
3. By surface contact (hand-hand, hand-surface, etc.).
4. On the fecal-oral route.
Figure 1 - Exposure mechanism of droplets
