ILO Home
Go to the home page
Site map | Contact us Franšais | Espa˝ol

CISDOC database

Document ID (ISN)65462
CIS number 95-1885
ISSN - Serial title 1047-322X - Applied Occupational and Environmental Hygiene
Year 1993
Convention or series no.
Author(s) Burkhart J.E., Stanevich R., Kovak B.
Title Microorganism contamination of HVAC humidification systems - Case study
Bibliographic information Dec. 1993, Vol.8, No.12, p.1010-1014. Illus. 8 ref.
Abstract Water samples were collected from humidification system water reservoir pans in a large office building. Air washers and steam injection humidification systems are used in the building. Streptococcus and Pseudomonas were found to be the most predominant microorganisms. Only small quantities of bacteria were found in the steam systems, while water collected from the air wash systems was highly contaminated. Data were also available to test the effectiveness of the cleaning system. A sample collected one day before cleaning had 58,100 colony forming units per millilitre (CFU/mL). Samples collected one and two days after cleaning had 250,200 and 258,160 CFU/mL, respectively. This demonstrates not only that the cleaning process is ineffective biologically but also that it may increase the risk of bioaerosol contamination. Sample concentrations, in colony forming units per millilitre, were found to be quite different depending upon the side of the baffle plates from which the sample was collected.
Descriptors (primary) heating systems; microorganisms; buildings; determination of concentration; air conditioning; air humidification; ventilation systems
Descriptors (secondary) contamination monitoring; case study; thermophilic fungi; steam cleaning; fungi; taking of samples; bacteria
Document type D - Periodical articles
Country / State or ProvinceUSA
Subject(s) Heating, ventilation and climate
Broad subject area(s) Biological hazards
Browse category(ies) Heating and air conditioning
Ventilation