A programmable thermostat supports at least one attribute where each different attribute values may support different sets of thermostatic settings. The programmable thermostat may be programmed based on the different attribute values rather than on temperature set points that are traditionally mapped to programmed times. Each set may include settings for a plurality of controlled equipment including a heating/cooling system, fan, ventilator, humidifier, and/or de-humidifier. Each embodiment may support attribute values associated with an occupancy attribute (which is indicative whether or not people are occupying an environmental entity) and/or a scenario attribute (which flexibly maps different thermostatic settings to different scenario attribute values). Stored configuration data about the thermostatic settings may be organized as a tree structure, where the leaves correspond to the thermostatic settings. A programmable thermostat/ventilator controller may also instruct a ventilator system to run during an adjustable pre-occupancy purge time duration before an environmental entity is occupied.

A programmable thermostat supports at least one attribute where each different attribute values may support different sets of thermostatic settings. The programmable thermostat may be programmed based on the different attribute values rather than on temperature set points that are traditionally mapped to programmed times. Each set may include settings for a plurality of controlled equipment including a heating/cooling system, fan, ventilator, humidifier, and/or de-humidifier. Each embodiment may support attribute values associated with an occupancy attribute (which is indicative whether or not people are occupying an environmental entity) and/or a scenario attribute (which flexibly maps different thermostatic settings to different scenario attribute values). Stored configuration data about the thermostatic settings may be organized as a tree structure, where the leaves correspond to the thermostatic settings. A programmable thermostat/ventilator controller may also instruct a ventilator system to run during an adjustable pre-occupancy purge time duration before an environmental entity is occupied.

A dehumidifier is provided. The dehumidifier may include a case having an air intake opening and an air discharge opening, an evaporator arranged inside the case and having evaporating fins coupled to evaporating tubes, a condenser arranged inside the case spaced apart from the evaporator, a fan that flows air in a direction from the evaporator to the condenser, and a heat pipe assembly positioned in front of and behind the evaporator in the air flow direction spaced apart from the evaporator. The heat pipe assembly may include heat pipes and heat-conducting fins each having a heat pipe coupling hole formed therein to be coupled to the respective heat pipe. Heat pipes may include heat-absorbing pipe portions positioned in front of the evaporator, heat-dissipating pipe portions positioned between the evaporator and the condenser, and connecting pipe portions that connect the heat-absorbing pipe portion to the heat-dissipating pipe portion, respectively.

An energy exchanger is provided. The exchanger includes a housing having a front and a back. A plurality of panels forming desiccant channels extend from the front to the back of the housing. Air channels are formed between adjacent panels. The air channels are configured to direct an air stream in a direction from the front of the housing to the back of the housing. A desiccant inlet is provided in flow communication with the desiccant channels. A desiccant outlet is provided in flow communication with the desiccant channels. The desiccant channels are configured to channel desiccant from the desiccant inlet to the desiccant outlet in at least one of a counter-flow or cross-flow direction with respect to the direction of the air stream.

Conditioning systems and methods for providing cooling to a heat load can include an evaporative cooler arranged in a scavenger plenum with a pre-cooler upstream and a recovery coil downstream of the evaporative cooler. Outdoor or scavenger air can be conditioned in the evaporative cooler such that the conditioned scavenger air can provide cooling to a cooling fluid circulating through the recovery coil. The reduced-temperature cooling fluid can provide liquid cooling or air cooling for an enclosed space (for example, a data center) or for one or more devices that are enclosed or open to the atmosphere. Given the design and arrangement of the pre-cooler, evaporative cooler and recovery coil in the plenum, the system can operate in multiple modes. The pre-cooler can be configured to circulate a cooling fluid to condition the scavenger air. The pre-cooler fluid circuit can be coupled or decoupled from a process cooling fluid circuit.

Systems and methods for providing dehumidification to an enclosed space can include a dehumidification unit in a supply air plenum that receives return air and a regeneration unit in a scavenger air plenum that receives outdoor air. The system can operate in a wet mode and a dry mode, depending on outdoor air conditions and a relative humidity setpoint for the enclosed space. The dehumidification unit and regeneration unit are both operational in the wet mode to dehumidify the return air and regenerate dilute desiccant. In the dry mode, the dehumidification unit and regeneration unit are not needed, and dry outdoor air can be supplied to the enclosed space. A heat recovery system utilizes waste heat from either return air or scavenger air, depending on the operating mode, to heat the outdoor air before it is supplied to the enclosed space or before it is used for regenerating desiccant.

A ventilation system with automatic flow balancing derived from a neural network to consistently achieve a desired flow rate for inlet flow and/or outlet flow in various operating environments to optimize system performance. The system includes a ventilation device that includes an exhaust blower assembly with a blower motor and a control circuit having a mathematical equation that determines an estimated exhaust blower flow based upon select inputs. The ventilation device also includes a supply blower assembly with a blower motor and control circuit having a mathematical equation that determines an estimated supply blower flow based upon select inputs. When the estimated exhaust blower flow is different than an exhaust flow set point, the exhaust control circuit selectively alters power supplied to the exhaust motor. When the estimated supply blower flow is different than a supply flow set point, the supply control circuit selectively alters power supplied to the supply motor.

A heat exchanger system has two heat exchangers, a first heat exchanger and a second heat exchanger, mounted within a single enclosure, a first air inlet for receiving air from a first air system, a first air outlet, one or more second air inlets for receiving air from a second air system, one or more second air outlets, a first air path defined as a sealed air path from the first air inlet through the first heat exchanger, to the first air outlet, and a second air path, a third air path and a fourth air path, wherein the first air path transfers heat/energy through the first heat exchanger in a counterflow relation with the third air path, and the second air path transfer heat/energy through the second heat exchanger in a counterflow relation with the fourth air path.

An HVAC system includes an evaporator coil disposed between a supply air duct and a return air duct. A re-circulation duct fluidly couples the supply air duct and the return air duct. A damper is disposed in the re-circulation duct and is moveable between an open position and a closed position. A controller is operatively coupled to a variable-speed compressor, a variable-speed circulation fan, and the damper. Responsive to a determination that the variable-speed circulation fan is operating at the minimum speed and the suction pressure is above the pre-determined threshold, the controller signals the damper to move to the open position. Responsive to a determination that the variable-speed circulation fan is not operating at the minimum speed or the suction pressure is below the pre-determined threshold, the controller signals the damper to move to the closed position.

An air handler includes a housing with a heat exchanger core. The housing includes a faceplate, a roof panel, a base panel, a first side panel, and a second side panel. A first tunnel and a second tunnel are connected to the housing at the faceplate. A septum protrudes from the faceplate and connects the core at a front edge. The air handler further includes a first recirculation path and a second recirculation path inside the housing. The first and second recirculation paths are defined by the septum, the housing, and the core. The first and second recirculation paths are configured to direct a portion of airflow from the first tunnel to the second tunnel. The air handler further includes a first damper and a second damper disposed on the faceplate and configured to obstruct the first recirculation path and the second recirculation path respectively.