title: Efficacy of the Precise Climate Controller on the reduction of indoor microorganisms.
abstract: BACKGROUND
  Nowadays, there are many methods to reduce microorganisms in the air, such as dehumidifier, air purifier or humidity and temperature controller. The Precise Climate Controller is an instrument for controlling humidity and temperature, a concept that is demonstrated.
  
  
  OBJECTIVE
  To determine the efficacy of this device, in order to reduce the quantity of the fungi and bacteria in the closed system.
  
  
  METHODS
  This study is a perspective experimental study and is conducted as follows - the air sample in the closed system, a 42-cubic-meter room, is collected before the installation of the Precise Climate Controller. Next, the room is fumed with Aspergillus flavus and closed for 2 days. Then the instrument is in use in order to keep the relative humidity (RH) and the temperature constant at 55% RH and 25 degrees Celsius (℃). The air samples are collected every 3 days for 5 times during the period of 15 days to identify the type and calculate the quantity of the microorganisms.
  
  
  RESULTS
  Before the Precise Climate Controller has been installed. Three species of bacteria are found in the air samples, but none of the fungus exists in the testing room. Once the room has been fumed with a large amount of A. flavus and the instrument is in use for 3 days, nine colonies of A. flavus are identified, but later on when the instrument is in use for 6, 9, 12, and 15 days, the air samples contain neither fungus nor bacteria.
  
  
  CONCLUSIONS
  After keeping the RH and temperature of the closed system constant at 55% RH and 25℃ by using the Precise Climate Controller, it is found that the efficaciousness in controlling the quantity and species of fungi and bacteria is clinically significant.
authors.affiliation: Department of Otolaryngology, Phramongkutklao Hospital, Bangkok 10400, Thailand.
authors.forename: Greetha
authors.initials: G
authors.lastname: Moungthong
authors.affiliation: Department of Otolaryngology, Phramongkutklao Hospital, Bangkok 10400, Thailand.
authors.forename: Pana
authors.initials: P
authors.lastname: Klamkam
authors.affiliation: Department of Otolaryngology, Phramongkutklao Hospital, Bangkok 10400, Thailand.
authors.forename: Prasit
authors.initials: P
authors.lastname: Mahakit
authors.affiliation: Department of Otolaryngology, Phramongkutklao Hospital, Bangkok 10400, Thailand.
authors.forename: Thanit
authors.initials: T
authors.lastname: Chalermwatanachai
authors.affiliation: Department of Microbiology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand.
authors.forename: Sudaluck
authors.initials: S
authors.lastname: Thunyaharn
authors.affiliation: Biochemical Engineering and Pilot Plant Research and Development Unit (BEC), King Mongkut's University of Technology Thonburi, Bangkok 10400, Thailand.
authors.forename: Veerapol
authors.initials: V
authors.lastname: Monyakul
keywords: Climate control; Fungal count; Humidity