Method and apparatus for latent heat extraction

A humidity control apparatus for use with a cooling coil means for selectively absorbing thermal energy from a return airstream as a cooled airstream, the apparatus comprising:

• precooling coil means disposed upstream of said cooling coil means for selectively precooling said return airstream;
• reheat coil means disposed downstream of said cooling coil means for selectively reheating the cooled airstream flowing from said cooling coil means;
• sensing means disposed downstream of said reheat coil means for sensing the relative humidity of the reheated airstream flowing from said reheat coil means and generating a humidity signal reflective of said sensed relative humidity;
• conduit means connecting said precooling and reheat coil means for communicating a working fluid flow through a closed loop circuit comprising said precooling coil means and said reheat coil means;
• pump means for controlledely motivating the working fluid flow through said closed loop circuit at a controlled flow rate responsive to said humidity signal;
• and,
• means for selectively introducing thermal energy into said working fluid flow responsive to i) said humidity signal and ii) said pump means motivating the working fluid flow at a predefined maximum controlled flow rate.

A method of heating a supply airstream into a conditioned space from a return airstream and downstream of a cooling coil of a typical air conditioning system operating in a space dehumidification mode for dehumidifying the conditioned space responsive to a humidity sensor in the conditioned space, the method comprising the steps of:

• storing heat energy in a thermal energy storage tank;
• sensing the temperature of the conditioned space;
• selectively circulating a working fluid at a controlled flow rate from a precooling coil in the return airstream of the air conditioning system directly to a reheat coil in said supply airstream when said sensed temperature is below a first predetermined set point;
• and,
• selectively circulating the working fluid from the precooling coil through the thermal energy storage tank and the reheat coil in series combination when said controlled flow rate is at a predetermined maximum rate and said sensed temperature is below the first predetermined set point.

A method of controlling the relative humidity of a supply airstream into a conditioned space from a return airstream and downstream of a cooling coil of a typical air conditioning system operating in a space cooling mode for cooling the conditioned space responsive to a dry bulb temperature sensor in the conditioned space, the method comprising the steps of:

• storing heat energy in a thermal energy storage tank;
• sensing the relative humidity of the supply airstream;
• selectively circulating a working fluid at a controlled flow rate from a precooling coil in the return airstream of the air conditioning system directly to a reheat coil in said supply airstream when said sensed relative humidity is above a first predetermined set point;
• and,
• selectively circulating the working fluid from the precooling coil through the thermal energy storage tank and the reheat coil in series combination when said controlled flow rate is at a predetermined maximum rate and said sensed relative humidity is above the first predetermined set point.

An apparatus for controlling the relative humidity of an airstream supplied into a temperature conditioned space downstream of an air conditioning cooling coil, the apparatus comprising:

• control means for controlling the apparatus according to a predetermined control method;
• precooling means in said airstream for precooling the airstream upstream of said cooling coil;
• reheating means in said airstream for reheating the airstream downstream of said cooling coil;
• connecting means for connecting said precooling means and said reheating means in a series closed loop;
• humidity sensing means in the airstream downstream of the reheating means and connected to said control means for i) sensing the relative humidity of the airstream between said reheating means and said temperature conditioned space and ii) generating a humidity signal representing the sensed humidity;
• working fluid pump means responsive to said control means for selectively pumping a working fluid through said series closed loop when said humidity signal is at a predetermined level, the working fluid pump means having an inherent maximum pumping rate;
• thermal energy storage tank means in fluid communication with said connecting means for storing thermal energy therein;
• and,
• regulating means connected to said connecting means and said thermal energy storage tank means responsive to said control means for selectively regulating a flow of said working fluid through said series closed loop and said thermal energy storage tank means when said working fluid pump means is pumping at said maximum pumping rate and said humidity signal is at said predetermined level.

An apparatus for controlling the temperature of an airstream supplied into a moisture conditioned space downstream of an air conditioning cooling coil, the apparatus comprising:

• control means for controlling the apparatus according to a predetermined control method;
• precooling means in said airstream for precooling the airstream upstream of said cooling coil;
• reheating means in said airstream for reheating the airstream downstream of said cooling coil;
• connecting means for connecting said precooling means and said reheating means in a series closed loop;
• temperature sensing means in the conditioned space downstream of the reheating means and connected to said control means for i) sensing the temperature of the conditioned space downstream of said reheating means and ii) generating a temperature signal representing the sensed temperature;
• working fluid pump means responsive to said control means for selectively pumping a working fluid through said series closed loop when said temperature signal is at a predetermined level, the working fluid pump means having an inherent maximum pumping rate;
• thermal energy storage tank means in fluid communication with said connecting means for storing thermal energy therein;
• and,
• regulating means connected to said connecting means and said thermal energy storage tank means responsive to said control means for selectively regulating a flow of said working fluid through said series closed loop and said thermal energy storage tank means when said working fluid pump means is pumping at said maximum pumping rate and said temperature signal is at said predetermined level.