DeHumidification Model

Start with a single room as shown in the diagram with volume V_Rm.

• Moisture from the outside at a humidity of 'rh' and temperature of 'T1' is cooled by AC coils to T2 deg F and then pushed into ductwork at a rate of k1.
  
• The Pre-cooling is 20 degrees below T1 or to 55 deg F. When the Outside air is cooler than 55 deg, then the pre-cool is turned off and air exits the pre-cool at temperature T1.
  
• The HVAC box includes a humidification by steam injection, HI. It is labeled HV and its volume is V_Hv.
  
• The air in the duct is well mixed by virtue of circulation at k2 cfm, through duct work, D, with volume V_D including a dehumidifier, DH.
  
• The dehumidifier is capable of removing DH grains/lb of air pushed through it. DH is typically 24 grains/lb but may be reduced with age or contamination.
  
• The temperature in the room, T3 is held at ~70 deg F. Air is exhausted from the room at the rate k3 which is approximately the same rate that it is introduced.
  
• Additionally, there is an assumed moisture loading, RL as a result of people and processing inside the room. The Room Load, RL, varies liberally from none to < 20 grains/lb.
  
• CONTROL There is a damper on k1 and k3, variable from full open to full close and humidification (steam injection) can be turned off and on.

Use the sliders beside the picture to adjust inputs.

Outside Humidity

%Opening of Intake & Exhaust damper

Outside Temperture if farenheit degrees

Dehumidifier Capacity in grains/lb dry air

Room Load in grains/lb dry air

Humidifier Capacity in lb/hr

k2 is in m³/s

DH1 is in grains/m³

<= Amount of water removed by DH

<= room Load