Abstract: A gas detector and method of operating the gas detector that includes a carbon monoxide sensor and a processor. The carbon monoxide sensor senses an environmental concentration of carbon monoxide and provides the sensed value to the processor. Upon receiving the value of the carbon monoxide level (COppm), the processor determines an alarm threshold level based upon the COppm level. Once the alarm threshold level is determined, the processor calculates the COHb percentage for the current COppm reading based upon a derived, fixed point equation. The processor activates an audible/visual indicator when the sensed COHb percentage exceeds the alarm threshold.

Abstract: A system and method is provided to control the operation of an HVAC system to remove humidity from an indoor air environment without cooling the indoor air environment. The system includes a thermostat that operates the HVAC system to remove humidity when the sensed humidity falls below a humidity set point. After operation of the HVAC system, the thermostat monitors whether the temperature within the indoor air environment falls due to the operation of the HVAC system. If the temperature within the indoor air environment falls consistently, the humidity control algorithm determines that the HVAC system cannot operate without cooling and prevents future operation of the HVAC system to provide only dehumidification. If, however, the humidity control algorithm determines that the HVAC system can operate to dehumidify without cooling, the humidity control algorithm operates the HVAC system accordingly.

Abstract: A field programmable or configurable thermostat for an HVAC system is provided. The configurable thermostat allows field programmability of service contact information, including name and contact telephone number information for the installer or service person. The system reminders and service intervals may be provided based upon calendar time or run time, and may be adjusted to particular periods by the service person in the field. Soft keys whose function is described on various changing menus allow service person to navigate through the various display and information entry screens. Scrolling or selection keys are used in one embodiment to vary the information on appropriate screens. Alternate embodiments utilize touch screens, alphanumeric keypads, etc., for the entry and editing of such information.