Microbial Efficiency of Air Conditioners and other Ventilation Devices for Enhancing Future Air Quality

Abstract

Microbial efficiency of air-conditioners (A/Cs) and other ventilation devices like electric fans (EFs) and open doors/windows (DWs), as means of enhancing future air quality was studied in Anambra state. Four hundred (400ml) of water samples dripping from A/Cs discharge nozzles were collected from 45banks, 61 hospitals and 44 hotels (total of 150 samples) selected from the 21 local government areas( LGAs) in the state, using proportionate random sampling technique. A/Cs vents, EFs blades and DWs surfaces in the selected institutions were also swabbed and examined. Some of the findings are as follows; One hundred and twenty-six (126) bacterial isolates were recovered from the 150 water samples collected from A/Cs in the various establishments. Bacterial isolates from banks were 36(28.6%), hospitals 54(36.0%) and 33(22.0%) from hotels. There were 4 predominant and frequently isolated bacterial species, which when pooled in the institutions recorded; Micrococcus luteus 50(39.7%), Arthrobacter globiformis 36(28.6%), Staphylococcus epidemidis 30(23.8%) and Staphylococcus aureus 10(7.9%). Statistical analysis of the results showed that calc. F value of 0.10 was < 3.11 critical value p 0.05 df 2/60. The null hypothesis of no significant statistical differenc in bacterial isolates from A/Cs water samples was accepted. Eighty-eight bacterial isolates from 135 swab samples from A/Cs vents, EFs blades and DWs surfaces in banks using the various devices showed that they had 36(26.7%), 28(20.7%) and 24(17.8%) bacterial isolates respectively. Statistical analysis of the results indicated that calc. F value 11.57 was > 3.11 critical value p 0.05 df 2/60. The alternative hypothesis of, there was significant statistical difference in bacterial isolates from surfaces of A/Cs, EFs and DWs in banks was accepted. Ability of the isolates to access and inhabit ventilation devices, call for alternative materials for their construction by engineers, to make them un-habitable by microbes. This will guarantee their safe use as means of achieving future air quality globally.

DOI: 10.5901/ajis.2013.v2n5p163