[Bldg-sim] In search of Dehumidifiers

[Eduardo Barrigana]

Dear Mohammed Aliyu

The very important information is at what temperature you are operating the environment to dehumidify.

Example 1.    In a very wet climate, (Angola), a large textile mill (cotton spinning frames), could not operate due to high humidity of the environment causing breakages and other problems.  They sorted the problem for a while reducing the capacity of the evaporative air conditioning and leting the temperature raise to almost 40ºC.    At this temperature without removing any water from the ambiente, the resulting RH reached 45/55%.   The conditions were terrible for the personell and the whole operation had to be moved to the plateau with cooller and dryer environment.

Example 2.    To maintain 0,0% RH,  ( to be precise a dewpoint of -50ºC),  in a closed small environment, with a temperature of 23ºC.  The system that we specified had two big housings with silica gell.   Working in tandem, while one of the systems was dehumidifying the others was being regenerated with electric heaters.  Cooling was assured with  some DX equipment, nothing complicated. Works but expensive.

You need to calculate you sensible and latent loads.   Dividing the sensible load by the total load you get the sensible heat factor for the process.    Place your entering point in the chart and strike a line from this point in the direction of the saturation curve with the slope of the SHL.  If this line does not cross the saturation line then your process is impossible with the refrigeration alone.  You need Reheat. 

If you give me some more detail I can send you the guidelines for your project plotted on a chart.

Best regards
Eduardo Barrigana


  ----- Original Message ----- 
  From: mohammed aliyu 
  To: bldg-sim at lists.onebuilding.org 
  Sent: Tuesday, May 12, 2009 9:41 AM
  Subject: [Bldg-sim] In search of Dehumidifiers


        Hello All,


        Im about to carry out an experiment by dehumidifying an indoor environment, so Im seeking for advice on the type of dehumidifier to use which can lower the humidity by as much as 40-60%. RH reach 100% in Malaysia frequentyl. Has any one got an idea or experience on the practical performance of such units?


        Regards
       

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