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%. Combining parameters of a higher temperature of 105’F (40’C) degrees and relative humidity between 40-60% in normal indoor conditions can deactivate a lot of viruses.

 

Malaysia's RH (https://weather-and-climate.com/) on average is 70-80% and temperature ranges from 27-33’C that need to be regulated with the combination of Air Conditioning, AC and Ventilation System. AC reduces humidity. A humidifier is not recommended for Malaysia's humid condition. Bringing in untreated outdoor fresh air with naturally high humidity defeats the purpose of AC to regulate indoor temperature and humidity. This will stretch the AC to work harder, and therefore wasted energy. 

 

*Read more on Indoor Air Quality and Mold.