How to calculated humidification loads
Posted by Andy Tindale on 07-Apr-11 08:51 AM
It is quite straightforward to set up a simulation to calculate loads due to humidity control using compact HVAC:
  • Switch on Compact HVAC model option
  • Load the "Packaged direct expansion" HVAC template
  • Switch on humidification and dehumidification on the HVAC tab (building level if all zones in building are to have this control)
  • Increase the humidification capacity to a higher value than the default to ensure adequate sizing. 0.1m3/s seems to work well even in small models.
  • Set relative humidity set points on the activity tab (e.g. min=40, max=60)
  • The effect of control on RH can be seen by viewing hourly results.
  • You can obtain latent cooling coil loads by subtracting Total Cooling from Sensible Cooling.
  • The fuel energy consequences can be seen by reviewing the summary reports generated by EnergyPlus in recent versions of DB. Select All summary and All Monthly reports. You can find humidification loads in the humidification row of the End Uses By Subcategory table.
  • Alternatively compare electricity consumption with/without humidity control.