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Can An HVAC System Control Corrosion In Clean Air Rooms?

Gifty Francis

15 July, 2022


The Heating ventilation and air conditioning system (HVAC) is used to maintain a good air quality index by controlling temperature, humidity, airflow, and air filtration. The main culprits of electronics corrosion are the infiltration of airborne contaminants. It is obvious if a person asks why additional corrosion management measures are needed if an HVAC system is already functioning. In this article let us discuss why additional corrosion monitoring and corrosion control measures are required on top of HVAC. 

What causes corrosion? 

The infiltration of airborne contaminants from outside is the major pollution-causing factor. These contaminants find their way from industries, STPS, heavy traffic, etc. The HEPA filter used in an HVAC system can only filter the particles down to 0.3 microns in size. To know more about the gases causing corrosion in industries please refer to this article - Which are the gases causing corrosion of electronics in data centers?  

Importance of corrosion control unit.

The HEPA filter inside the HVAC does not remove gases. The diesel exhaust, Oil smoke, etc can be well below 0.3 microns and can easily pass through the HVAC filters. Even a minute concentration of these gases can pose a significant threat. The presence of 50 ppb (0.05 ppm) of H2S gas is considered a severe environment for electronics. The list of other gases and the concentrations denoting their severity is mentioned below.


Severity levelG1-Mild
G2-Moderate
G3-Harsh
GX-Severe





Contaminant Gas
Concentration levels in parts per billion (ppb)
Concentration levels in parts per billion (ppb)
Concentration levels in parts per billion (ppb)
Concentration levels in parts per billion (ppb)





H2S  
<3
<10
<50
≥50
SO2, SO3 
<10
<50
<300
≥300
Cl2
<1
<2
<10
≥10
NOx
<50
<125
<1250
≥1250
HF
<1
<2
<10
≥10
NH3 
<500
<10,000
<25,000
≥25,000
O3
<2
<25
<100
≥100

Moreover, the HVAC system itself is not free from corrosion. The condensation of water in the evaporator coils or the chemical gases from cleaning agents could accelerate the coil corrosion and this results in pitting of the coils and leakage of refrigerant which ultimately hinders the efficiency of HVAC systems. The mopping of the floor with bleach or any cleaning substances produces chlorine compounds that can damage the HVAC system as well as the electronics used inside the facility due to corrosion. The corrosion control unit filters the specific gases which cause corrosion. While the humidity and temperature control can be done using an HVAC system, the gas phase filtration can be done by the corrosion control unit to prevent corrosion.

Filtration of corrosive gases requires expert help. Being a specialist vendor in gas phase filtration and monitoring, Aqoza offers optimum performing corrosion control units to various industries. You can always reach our experts for any corrosion monitoring or corrosion control unit requirements. Get in touch with us to know more!!!