OBJECTIVE To study the source of non-outbreak legionnaires' disease, particularly the role of cooling towers, by comparing the locations of patients' homes in relation to the location of cooling towers. DESIGN Retrospective, descriptive study of a case series of patients with legionnaires' disease ill between 1978 and 1986 and, for comparison, a case series of patients with lung cancer. A pro...

The chilled-water systems, mainly consisting of electric chillers and cooling towers, are crucial for the ventilating and air conditioning systems in commercial buildings. Energy efficient operation of such systems is thus important for the energy saving of commercial buildings. This paper presents an extremum seeking control (ESC) scheme for energy efficient operation of the chilled-water syst...

Viable Legionella spp. in environmental water samples were characterized phylogenetically by a clone library analysis combining the use of ethidium monoazide and quantitative PCR. To examine the diversity of Legionella spp., six cooling tower water samples and three bath water samples were collected and analyzed. A total of 617 clones were analyzed for their 16S rRNA gene sequences and classifi...

Over a Period of three months (summer), 108 samples of water collected from four hospitals in Tehran. They were taken from numerous potable and non-potable water, including main supply cisterns, calorifiers, hot and cold tap water, shower, cooling tower and drain of air condition system. Culturing of concentrated and non-concentrated water samples on Buffered Charcoal Yeast Extract (BCYE) Agar ...

Re-circulating cooling water systems are generally used to remove waste heat from hot process streams in conditions above the ambient temperature in many types of industries such as chemical and petrochemical, electric power generating stations, refrigeration and air conditioning plants, pulp and paper mills, and steel mills. Typical re-circulating cooling water systems are constituted by a mec...

Cooling towers are important equipments for the HVAC systems in commercial buildings, rejecting the process heat generation to the atmosphere. Dynamic modeling of cooling towers is beneficial for control design and fault detection and diagnostics of the chilled-water systems. This paper proposes a simple and yet effective dynamic model for a typical mechanical draft counter-flow wet cooling tow...