What’s humidity control got to do with fresh air?

What’s humidity control got to with fresh air?

Organisms’ survival rate varies based on Sterling Relative Humidity (RH).




This chart was taken directly from the ASHRAE handbook suggesting that bacteria, viruses, mold, etc. survival varies across dryer and humid environments. The optimum is between 40-60%. Although this study is not from COVID but on coronaviruses, and with the assumption that all coronaviruses have similar traits. Combining parameters of a higher temperature of 105’F (40’C) degrees and relative humidity between 40-60% in a normal indoor conditions can deactivate a lot of viruses.


Malaysia's RH on average is 80% and temperature ranges from 27-33’C between day and night. These data can easily be obtained from https://weather-and-climate.com/. Indoor air-conditioning will reduce humidity, but adding a humidifier, or bringing in the untreated outdoor fresh air with high natural humidity will increase it. Besides stretching your air-conditioning system to work harder.