Di Lalabas ang Aircon: Ventilation as one of the Preventive Measures Against Covid-19


The Germans are embracing proper air ventilation as one of the key components in fighting the spread of coronavirus and COVID-19. They learned from various scientific researches that the virus spreads more efficiently indoors than outdoors. Its government is now recommending having the windows open twice a day, install air purifiers, or CO2 detectors. (Connolly, 2020)

This brought us to look and think twice about proper ventilation in our homes and offices here in the Philippines. The Germans, which is now on the verge of its second wave with Covid-19, are now looking for other ways to improve combating the disease—and it entails some of the most affordable and historical solutions—proper ventilation.

Aircon Dependence and Indoor Air

Isara ang mga bintana at pintuan at baka lumabas ang aircon!” (“Close the windows and doors and the air-conditioning might go out!”) This is a common Filipino expression that commands anyone who is going in or out of an air conditioned room. The cool air produced by the airconditioner might go out and, for the budget-conscious Filipino, increase the consumption of energy which is equivalent to “Mahabagin! Ang taas ng bayarin sa kuryete!” (“Oh my! The electric bill is expensive!”). I should have listened on my science teacher back on High School regarding the Laws of Thermodynamics, particularly the second one.

Most contemporary buildings in our country have airconditioning due to the heat and humidity in the tropics that is uncomfortable. Air filtration and ventilation solutions can help minimize stale air indoors.

However, it has created a culture of air-conditioning dependence and cross-ventilation has become a thing of the past. Malls are air conditioned. Classrooms and offices became air conditioned. Houses, especially those of the rich, may even have centralized air-conditioning. I mean, I could not blame it. We are living in tropical climate where heat and humidity makes us uncomfortable.

Isara ang mga bintana at pintuan at baka lumabas ang aircon!

It was only recent when Covid-19’s aerosol transmission was supported by increasing number of scientists that made us look and think twice about our dependence on air-conditioning. Indoor air is now looked at as a medium for spreading the virus due to poor ventilation. According to an article at Science, “aerosols containing infectious virus (2) can also travel more than 2 m and accumulate in poorly ventilated indoor air, leading to super-spreading events.” (Prather, et al., 2020)

The researchers have recommended that aside from physical distancing, proper wearing of face masks, and hygiene efforts, they recommend that public officials to move some of these indoor activities outside and improving indoor air through ventilation and filtration systems. (Prather, et al., 2020)

Ventilation: One of Our Ancestors’ Solution

Yet we Filipinos nowadays may have forgotten how our ancestors have designed our homes a long time ago, when air conditioning was not a trend. Living in the tropics, proper air ventilation was our way of air conditioning. Our homes, from the simple bahay kubo to bahay na bato, or even the torogan in Ranao, they all sport big windows, high ceilings to make sure that the ventilation is right. 

The Iwahig Penal Farm's Recreational Hall, built during the 1920s incorporated full openings.

The Arzobispado (Archbishop's Palace) of Nueva Segovia in Vigan and its large sliding capiz windows. It is said to be one of the largest buildings during the colonial-era Vigan.

Even during the American colonial era, Gabaldon schoolhouses sport these ventilation devices to as simple as ventanillas (little windows) to the transom windows on top of doors and windows. Hospitals and sanitaria at that time have high ceilings along with these full openings.

I come even to realize that even AS, or Palma Hall in UP Diliman, has these aspects of proper ventilation in the non-air-conditioned classrooms.

Old Iloilo City Hall - It may have an airconditioner nowadays but if the temperature is right, the staff opens up the window. However, some people may have noticed that it is indeed warmer nowadays.

These houses and buildings have what we call “passive energy characteristics.” According to the Heritage Homeowner’s Preservation Manual of Vigan City, a typical bahay na bato “Vigan house” has these features (City Government of Vigan, 2010, p. 27):

  • Ceiling heights allow hot air to rise above which raises the comfort level indoors.
  • The combination of big windows and ventanillas increases the flow of air indoors, especially during dry or hot season.
  • Shadings like roof overhangs and canopies (media agua) help regulate indoor temperatures, especially on rooms that have direct sunlight.

These heritage homes have been built with environmental context and resources in mind—maximizing air circulation in such climate like ours. Architects and experts have a complete grasp of the significance of ventilation to improve air circulation indoors, minimizing stale air that inhibits the spread of airborne diseases like Covid-19. Some Philippine government officials have already acknowledged that most super-spreading events happened indoors.

The post-war architecture: Those expanded transom windows at AS (Palma Hall) at UP Diliman were made to encourage cross-ventilation within these rooms. The corridor hall is closed, the doors can be closed for better appreciation of the classes, but they can open up those transom windows to keep the air from being stale.

It is probably unfortunate that big windows have suffered a downtrend. It is for reasons like mosquitoes and flies coming in, lalabas daw ang aircon, dust coming in, it is not trendy, and prone to akyat bahay (cat burglars). Our mass housing architecture has preferred the Western smaller windows, to which restricts air ventilation in our homes. I have told my parents to open their rooms for proper ventilation, but they are hesitant to do so because of the reasons mentioned. My room, only having one window, has to open up the door and open up the terrace portal for air to come in and out.

With Covid-19 in mind, we may have to revisit our ventilation as part of designing better homes and buildings. Our ancestors have given us one affordable solution and I hope architects and building administrators can make a healthier place for everyone to live and work within the near future. Together with better technology like air filters and improved hygiene practices, fresh air is what we need for us to be healthier—and it’s not just your usual probinsya air, but our air in our very homes itself.

NOTE: Like all Covid-19 related literature, please take note that it is dynamic in nature and may be subject to changes, especially that the scientific community continues to research about it.


City Government of Vigan. (2010). Heritage Homeowner's Preservation Manual: World Heritage City of Vigan Philippines. Bangkok: UNESCO Asia and Pacific Regional Bureau for Education.

Connolly, K. (2020, September 30). Germans embrace fresh air to ward off coronavirus. Retrieved October 24, 2020, from The Guardian: https://www.theguardian.com/world/2020/sep/30/germans-embrace-fresh-air-to-ward-off-coronavirus

Prather, K. A., Marr, L. C., Schooley, R. T., McDiarmid, M. A., Wilson, M. E., & Milton, D. K. (2020, October 16). Airborne transmission of SARS-CoV-2. Retrieved from Science: https://science.sciencemag.org/content/370/6514/303.2/tab-pdf