An engineer's practical tips for good ventilation indoors during COVID-19 pandemic
In July, the World Health Organization (WHO) acknowledged the emerging evidence of airborne transmission of the novel coronavirus.
The Department of Health (DOH) has also recognized that COVID-19 can be airborne in specific settings.
A scientific brief from WHO explained, “Airborne transmission is defined as the spread of an infectious agent caused by the dissemination of droplet nuclei [aerosols[ that remain infectious when suspended in air over long distances and time.
"Airborne transmission of SARS-CoV-2 can occur during medical procedures that generate aerosols [“aerosol generating procedures”].
“WHO, together with the scientific community, has been actively discussing and evaluating whether SARS-CoV-2 may also spread through aerosols in the absence of aerosol generating procedures, particularly in indoor settings with poor ventilation.”
As research continues, it won't hurt to practice additional precaution whether you're at home or you've resumed work at the office.
There are simple ways to manage indoor air pollution at home, and Engr. Roy Hilton Cabrela, a mechanical engineer and construction project manager sheds more light on the importance of good ventilation.
Engr. Cabrela has been in the industry for over a decade and carries an international certification from Project Management Institute.
He refers to the standard guidelines of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) in explaining how “ventilation and filtration can reduce the airborne concentration of SARS-CoV-2 and thus the risk of transmission through the air.”
In his exclusive interview with GMANetwork.com, Engr. Cabrela focuses the discussion on the proper use of air conditioning units as well as exhaust fans to promote a safe and healthy indoor space.
Is it safe to use air conditioning units during the COVID-19 pandemic?
Many of you may have been feeling doubtful if it is safe to turn on your air conditioning system especially when you share a room with other people.
What is generally advised is to have natural ventilation by simply facilitating the supply and removal of air in indoor spaces by opening doors and windows.
However, there are factors such as your immediate environment, building construction, and weather that may discourage this and people would turn to air conditioning for a cooler and more comfortable atmosphere indoors.
Engr. Cabrela advises the use of air conditioning units as long as you allow the circulation of fresh air.
He also stresses that one should keep introducing fresh air inside the room as long as one's air conditioning unit is in use.
He says, “Make sure that it has an outdoor air intake or vent. If none, slightly open the windows or doors for the outside air intake if [there are] no risk in safety and health.”
He also adds, “Pag may airconditioning system ka, maganda may ventilating fan na mag-introduce ng fresh air, tapos may isa ka pang fan na mag-e-exhaust nung air doon sa loob.”
Engr. Cabrela strongly recommends the installation of exhaust fans to improve indoor air quality especially in closed spaces.
He explains, “Kahit 'yung simpleng pagbukas mo ng exhaust fan sa toilet, pwede na 'yun, e.
"Ang problema lang kasi doon, 'yung iba kasing mga bahay, sa mga condo ngayon, 'pag binuksan mo 'yung ilaw, nakasabay na 'yung exhaust fan.
"Kasi, pag wala nga namang gumagamit ng banyo, bakit mo bubuksan ang exhaust fan?
"Ang isa sa mga recommendation doon dapat paghiwalayin 'yung switch ng ilaw pati nung exhaust fan para kung sakaling tumatakbo 'yung airconditioning unit mo, pwede mong buksan 'yung exhaust fan mo sa toilet.
“Kahit hindi sa CR mismo... maganda kasi 'yan ilagay opposite ng pinanggagalingan ng fresh air mo.
"For example nasa left side 'yung bintana mo, ilagay mo 'yang exhaust fan kung sakaling wala ka sa CR mo, sa any part of your house like sa ceiling doon sa opposite side kung saan nakalagay 'yung bintana mo.
“Hihigop kasi 'yun ng hangin. Kung saan mang parts ng bahay mo na merong maliit na maliit na openings o merong cracks, mga ilalim ng pintuan mo, mga bintana mo, kukuha 'yun ng hangin from outside tapos ie-exhaust niya.
"Sa ganoong paraan, nakakapagpasok pa rin siya ng fresh air. Enough 'yun para magpalit ka ng air doon sa loob, para hind maging polluted, para walang contaminants or airborne pathogens.”
Other recommendations
Since not everyone can afford and have access to exhaust fans and air conditioning units, Engr. Cabrela identifies simpler ways to improve ventilation.
He recommends using your fans strategically in the absence of exhaust fans.
He suggests, “Ang pwede nilang gawin diyan, itapat nila sa opening ng pintuan or ng bintana 'yung fan para ipasok niya 'yung sariwang hangin.”
Engr. Cabrela also stresses the critical values of interior design and architecture in maintaining good air quality indoors.
"He also stresses the need to collaborate with these industry players and other engineers to create a safe and healthy environment.
He explains, “Kaya important 'yung layout 'tsaka 'yung design kasi minsan sa mga bahay, 'no, minsan 'yung natural ventilation mo nahaharangan ng furniture, e, na ito 'yung source mo of light and fresh air mo pero may furniture ka dyan, matatabunan siya.
"Hindi na nakakakapasok 'yung hangin. Hangga't maaari nga open 'yung space mo and maayos 'yung ventilation mo inside para safe.
“Kahit na masikip 'yung space mo, kung meron kang cross ventilation or 'yung kabilang side ng bahay mo open, 'yung kabilang side ng bahay mo rin may bintana, 'pag pumasok 'yung hangin doon, may lalabasan siya. 'Yun naman ang importante doon.
"Actually, nasa codes din naman sa local pati sa international na hindi enough na, kunwari, 'yung bahay mo kuwadrado siya 'tapos meron kang isang bintana lang, papasok 'yung hangin pero wala siyan lalabasan. Kaya sabi natin, hangga't maaari meron tayong cross ventilation.
Engr. Cabrela brings to attention that engineers like him will definitely play a vital role in coping with the health crisis and in adjusting to the new normal.
He claims, “In the new normal, engineers play an important role especially in developing designs and guidelines that can be used on building design for future mitigation of the viruses and or bacteria in the air."
He also states, “Meron na tayong na-establish na guidelines, hindi lang siya strictly na-i-implement.
“Kung talagang strict 'yung implementation niyan, during issuance pa lang ng building permit, bago ka pa lang mag-construct kasi ire-review 'yan, e, ire-review mabuti 'yan.”