Air Quality Management
Air quality management and air quality control are very important parts of a successful healthcare linen facility and should be addressed in all laundry operations to ensure safety of the finished product and safety for all employees. In a well-built healthcare linen facility, the building is divided down the middle completely separating the dirty side from the clean side. Incoming dirty linens are unloaded, sorted and processed on the dirty side. An air quality management system must be installed that will keep all of the air from the dirty linen side from ever entering the clean linen side. This is achieved by creating a negative air pressure on the dirty side that will always be sucking air from any cracks, open doors, pass-thru dryers, etc. into the dirty side. This keeps any contaminated air from ever wafting into the clean side. Positive air pressure is maintained on the clean side which always pushes air out of any cracks, open doors or dryers to prevent any contaminated air from ever accidentally entering the clean side and potentially contaminating clean linens. Air quality management systems like this ensure that all contaminated air is ‘contained’ within the dirty side of the laundry facility.
The clean side must have a positive air pressure relative to the dirty side. The dirty side needs to have exhaust fans running to create a negative pressure in the room. The positive pressure on the clean side ensures that no air will be drawn into the clean area accidentally. This positive pressure is achieved by having a supply of clean, HEPA-filtered air blown into the room with enough volume to prevent any dirty air from coming into the room from an open door, or even a crack or passageway leading to the dirty linen side of the room. The dirty side needs to have a negative pressure in the room to keep any of the dirty air from accidentally being sent into the clean side. This negative pressure is achieved by installing an air handling system that removes more air from the room than is being put into the room. This causes any open doors or cracks or passageways leading to this dirty side to be sucking air into the room from that opening. Even though you need a negative pressure in the dirty side, you will need to make sure that you are putting in enough air into the room to satisfy the dryer’s requirement for fresh air to run the burners and dry the linen.
How the air is put into the room and how it is filtered is extremely important to achieve and maintain the separated environments and keep any airborne pathogens from being redeposited onto clean linens. With all the nasty germs floating around these days, you cannot be too careful when designing an air quality management system for a healthcare linen facility. Certain aspects of the system are mandated by law but you can always make those mandated features more efficient and effective.
Water Energy Green Laundry Systems employ air quality management technologies designed and installed by Dr. Dave Kaiser of Airborne Contamination Control in Los Angeles. Dr. Kaiser has been designing cutting-edge air quality management systems for critical-care environments in burn centers and hospitals and for food processing facilities and other applications for the past 35 years. Dr. Kaiser is one of the founding members of Water Energy and of our laundry design team and will engineer any air quality management system we need when building a new laundry facility.
Water Energy Green Laundry Systems take into account every detail of laundry design, construction and operation and strive to make each as ‘green’ as possible and practical. An important green initiative overlooked by most laundry design engineers is all around us – handling of air flow into and out of the laundry. As described in the Air Quality Management section, air flow is extremely important to the success of a laundry facility. If you don’t need to separate the clean and dirty sides of your laundry, you still need to address air flow. The laundry must have an air intake for the air conditioning system somewhere on the outside of the building. The laundry must also have an exhaust for the dryers somewhere on the outside of the building. You must make sure the ‘stack’ for the dryer exhaust is not vented near the intake for the A/C unit and you must also make sure the ‘stack’ is tall enough to keep the exhausted air from becoming re-entrained into the air foil of the building and therefore potentially drawn back into the A/C system or an open window or door. There are a number of concerns that need to be addressed when planning an energy efficient laundry operation that deal with air quality and lighting.
The most important objective is to remove heat and humidity from the dryers in such a way that the discharged air is not re-entrained back into the building. The building’s airfoil, prevailing wind direction, location of the fresh air intakes and elevation of the fresh air intakes for the rest of the building’s systems is critical. The design of an exhaust system is crucial to years of efficiency and energy savings. The greenest method is to design an exhaust system that takes all of this into account while providing the least possible exhaust discharge resistance.