valutazioni - 3, GPA: 3.3
(
)
)
|
Facilità d'uso
1706 Canterbury Rd Greenville, NC 27858 Ph. 252.355.6789 Oysterdoctor@aol.com Efficiency Of Bacterial Disinfection By A Duct Mounted UV-AireO Air Purifier For: Table of Contents Table of Contents Background ..........................................................................................................................3 Organism.........................................................................................................................3 Testing Structure.............................................................................................................3 Testing Airflow Rate........................................................................................................3 Organism Applicator........................................................................................................4 UV Device .......................................................................................................................4 Air Sampling Method.......................................................................................................4 Test Apparatus .....................................................................................................................4 Testing Procedure ................................................................................................................5 Tables............................................................................................................................... 6-7 Table 1: Control Data......................................................................................................6 Table 2: UV-18 Test Data Results ..................................................................................6 Table 3: UV-18X Test Data Results................................................................................7 Conclusion............................................................................................................................8 Page 2 Background Background This product study evaluates the effectiveness of the UV-Aire air purifier in reducing the levels of bacteria with a single pass through a simulated air duct system. This device is designed to irradiate the air as it circulates through the home, so the single pass evaluation is the worst-case scenario use of this device. The air in the home will pass through the heating and air conditioning system many times a day, as the air is circulated throughout the home. Knowing the effectiveness of the UV-Aire in a single pass application, enables us to project how effectively the device will treat the air with multiple passes a day. UV light technology has been successfully used for the disinfection of drinking water for years. Applications for air disinfection with the use of UV light technology include: commercial air treatment in hospitals, clean rooms, meat packing plants, bakeries, dairies, breweries, bottling plants and large commercial HVAC systems. ORGANISM: Serratia marcescens (ATCC 14756) was chosen as the test bacterium. The distinctive red colonies made it easy to evaluate from any background organisms. A raw test suspension of the organism of approximately 95,000 CFU/ml was used. As dispersed into the test system, this suspension yielded bacterial counts of 269 CFU/ft3 @ 500 ft/min airflow and 107.5 CFU/ft3 @ 1000 ft/min airflow. (CFU = Colony Forming Units) TESTING STRUCTURE: An 18” x 18” galvanized air duct, 38 feet long was constructed as the test chamber (see Figure 1). A fan was mounted at the exit end of the chamber and the treated air exhausted to the outdoors. To reduce contamination of the intake air, all air intakes on the exhaust side of the building were sealed. The exhaust fan was equipped with a flow adjustment to allow for adjustable air speeds measured in feet per minute (FPM) through the duct. TESTING AIRFLOW RATE: The airflow rate through the ductwork was adjusted to two nominal velocities of 500 ft/min and 1000 ft/min. The airflow velocities were measured at the center of the duct at the intake end of the test duct. Page 3 ORGANISM APPLICATOR: An atomizing humidifier spray nozzle mounted at the center of the test duct intake was used to distribute the organism into the air stream. The application flow rate was 0.45 gallons per hour. UV DEVICE: A Field Controls UV-Aire air purifier model UV-18 was mounted onto the center of the side of the test duct 6 feet from the exit end of the chamber. The lamp is a UVC germicidal lamp (non ozone producing) 18 inches long with a UV output rating of 73 mW/cm2 at 1 meter from the lamp. AIR SAMPLING METHOD: An Andersen N6 single stage “bioaerosal” sampler was used to take the air samples and distribute the sampled air onto agar medium. The test medium was Tryptic Soy Agar from PathCon, Inc. The air sampling pump airflow rate was 1 CFM. The Anderson sampler method requires corrections to the actual colony counts on the plates. This provides a more accurate measure of th...