Humidity control system

A method of operating an air conditioning system for a space, the system including an evaporator coil, a compressor, an air circulating blower, and a space heater, the method comprising the steps of:

• operating the blower at a substantially constant speed to provide a substantially constant air turnover rate in the system;
• monitoring the humidity and temperature of the space air and the temperature of the evaporator coil;
• upon the detection of a space air humidity value in excess of a predetermined set point value, energizing the compressor and opening a bypass damper to allow circulating air to bypass the evaporator coil whereby to lower the temperature of the evaporator coil;
• upon the temperature of the evaporator coil dropping to a predetermined value proximate but in excess of freezing, closing the damper to maintain the evaporator coil temperature just above freezing;
• and
• thereafter, if the humidity value has not dropped to the set point value, de-energizing the space heater and re-energizing the compressor to resume dehumidification.

A method of retrofitting an air conditioning system for a space to improve the ability of the system to control moisture and thereby mold in the space, the system including a controller, ducting extending from an entry end opening into the space to an exit end opening into the space, a cooling loop including a compressor and an evaporator coil positioned in the ducting, a heating element positioned in the ducting, and a blower operative to move air through the ducting from the entry end to the exit end with the circulating air passing over the evaporator coil and over the heating device, the method comprising:

• providing a bypass duct extending around the evaporator coil;
• installing a coil temperature probe proximate the liquid inlet of the evaporator coil;
• and
• programming the controller to be operative in response to signals from the coil temperature probe as well as signals indicative of the temperature and humidity of the air in the space to selectively modulate the volume of air moving through the bypass duct and selectively energize and de-energize the compressor and the heating element.

An air conditioning system for a space comprising:

• ducting extending from an entry end opening in the space to an exit end opening in the space;
• a cooling loop including an evaporator coil positioned in the ducting and a compressor;
• a blower operative to move air through the ducting from the entry end to the exit end with the circulating air passing over the evaporator coil and over the heating device;
• bypass ducting extending around the evaporator coil;
• and
• a controller receiving signals indicative of the temperature of the air in the space, the humidity of the air in the space, and the temperature at the evaporator coil and operative in response to the received signals to selectively open and close the bypass ducting and to selectively energize and de-energize the compressor.

An air conditioning system for a space comprising:

• ducting extending from an entry end opening in the space to an exit end discharging into the space;
• a blower operative to move air through the ducting from the entry end to the exit end;
• an evaporator coil positioned in the path of the air moving through the ducting;
• a heating element positioned in the path of the air moving through the ducting;
• bypass ducting extending around the evaporator coil;
• and
• a controller receiving signals indicative of the temperature of the air in the space, the humidity of the air in the space, and the temperature of the evaporator coil and operative in response to the received signals to selectively open and close the bypass ducting and selectively energize the heating element.