What type of room pressurization equipment is best? Fans with heating, ventilation, and air conditioning (HVAC) filters have traditionally been used but are they the right choice today? Which room air pressurization systems are ideal for steel mill applications like MCC electrical rooms?
While most steel mills use HVAC systems in an attempt to keep areas clean, this is inefficient and ineffective because these types of filters are not able to catch all of the dust particles. When these filters have dust on them it increases the static pressure resistance on the HVAC system and can reduce the amount of positive pressure in the room.
HVAC systems with standard filters are typically rated MERV 5. However, this type of system is not ideal for use in a steel mill. The airborne dust load in a typical steel mill is very high. Standard HVAC filters are not designed to deal with this type of dust load. They will quickly become overwhelmed with dust and will start to block airflow through the system as well as allowing smaller dust particles through the filters.
Also, it is common for the HVAC filters to require changing once a week or even once a day. Besides the expense of constant filter changes, steel mills also must deal with the time and labor required to change these filters. Further, the cost of disposal must be handled since the filters may contain hazardous materials.