commercial air conditioning system

Preventing Legionnaires Disease In Buildings

Legionnaires Disease was first discovered during an outbreak of pneumonia at an American Legion Convention held in Philadelphia in 1976. Conventioneers who attended the event went down with high fever, chills, cough, muscle aches, and fatigue. Eventually, the causative organism as identified as Legionella pneumophila and the disease was called Legionnaires Disease. Poor ventilation systems at the convention center were blamed for the spread of the disease and new regulations were put in to force to ensure that all building HVAC systems were disinfected and safe.


Can This Happen In Modern Day HVAC Systems?

Although most contractors and builders follow the new regulations, problems have cropped up frequently. Outbreaks are frequent during summer months and they are usually caused by higher temperatures and a greater use of water-spray based cooling towers. Ideally, Legionnella bacteria dies at temperatures above 70 degrees C but studies have shown that all HVAC systems show variable internal temperatures that may range from 20-50 degrees C. Apart from these ideal breeding temperatures, some cooling towers also contain waste biofilms that resulted due to stagnant water and poor maintenance. Even a short period of water stagnation could result in rust, scale and corrosion accumulation which will guarantee the growth of Legionnella bacteria.


How Can This Be Prevented?

Proper maintenance is the keystone to eliminating or reducing the risk of Legionnaires’ Disease. Currently, all HVAC systems companies have to follow ASHRAE Standard 188P while designing, installing and maintaining home ventilation systems. Most HVAC system companies follow a three-pronged approach involving regular on-site and office system assessments, monitoring of installed systems, and maintenance of heating and cooling systems. This will include the level of risk of a HVAC system for legionnaires disease, control regimens to ensure safe conditions, documenting of system maintenance checks, hiring adequately trained designers and maintenance engineers, and adhering to federal and national HVAC standards.

However, you have to work with the company as well. You do have to ensure that your home or office HVAC system is checked regularly. Apart from regular maintenance, non-chemical devices like pulsed electric fields, ultrasonic cleaners, hydrodynamic cavitation, and magnet cleaners can be used to ensure a clean and disinfected ventilation system. For more information, do get in touch with us through the comments section. Also, follow our blog.