In the middle of the second wave of covid-19, with the new confinements and the cabbages that started in September, there is much talk about how the spaces should be ventilated in order to make it more difficult for the virus. And be careful, because in many spaces it is not enough to open the windows.
You may have considered how you should ventilate your house if you are going to have a meeting of those allowed (remember, six people maximum). Or how the office should be ventilated, your ‘coworking’ space that you go to several times a week, etc. You may think that perhaps, just opening the windows at your child’s school is enough… And maybe it isn’t.
Pablo García, founder of Atrezo Arquitectos, gives us the following keys to know how the different spaces should be ventilated.
“Except for homes, the rest of buildings for different uses such as schools, offices, hospitals, restaurants, etc., must have a ventilation system to provide sufficient air flow to avoid the formation of high concentrations of pollutants. Although it is true that this obligation came into force in 2007 and its fulfillment before that date is not mandatory, it should serve for future renovations or to adapt our buildings ”, says García. Especially in times of a health pandemic.
“Depending on the use of the buildings, we have 4 categories of indoor air quality. It is in the quality that we should be breathing in these places ”:
IDA 1 (optimum quality air): for hospitals, clinics, laboratories and nurseries.
IDA 2 (good quality air): offices, residences (common premises of hotels and the like, residences for the elderly and students), reading rooms, museums, court rooms, teaching and similar classrooms and swimming pools.
IDA 3 (medium quality air): commercial buildings, cinemas, theaters, function rooms, hotel rooms and the like, restaurants, cafes, bars, party rooms, gyms, sports venues (except swimming pools) and computer rooms .
IDA 4 (low quality air): rest.
“This means that, to achieve these qualities, we will have to be bringing in air from outside and also, it will have to go through filters that guarantee that it is clean of viruses and bacteria,” he explains.
The air flows per person are as follows:
IDA 1 – 72m3 / h
IDA 2 – 45m3 / h
IDA 3 – 28m3 / h
IDA 4 – 18m3 / h
“That is, you have to multiply these values by the number of people in the space and we will get how much air should be replaced every hour. To get an idea, and if we take a school as an example, a class with 20 students should renew 900m3 every hour and the only thing that guarantees compliance with that value is that it is forced, that is, natural ventilation by opening the windows would not be valid ”, Garcia details.
And why don’t most schools have these systems? “Because they were built before and the norm only requires new construction”, clarifies the architect.
When in doubt as to whether these ventilation systems could be implemented in these facilities, García explains that “it depends on each building, but if possible, it would be a highly recommended work.”
At this point, if we only have our windows to ventilate, we summarize some tips. The first is to try to make it cross, because the air has to move.
If the air conditioning machine has the ventilation option, but you do not have the HEPA filters, the advice is not to use that function.
Finally, measure the CO2 concentration (since the pandemic CO2 meters have become very fashionable) and if it exceeds the maximum allowed, ventilate as many times as needed. And this is the concentration of CO2 depending on the required quality (ppm is parts per million volume above the concentration in the outside air):
ADI 1 – 350 ppm
ADI 2 – 500 ppm
ADI 3 – 800 ppm
ADI 4 – 1200 ppm
Source : Idealista