A method of defrosting an energy recovery ventilator unit. The method comprises defrosting an energy recovery ventilator unit. The method comprises activating a defrost process of an enthalpy-exchange zone of the energy recovery ventilator unit when an air-flow blockage in the enthalpy-exchange zone coincides with a frost threshold in the ambient environment surrounding the energy recovery ventilator unit. The method also comprises terminating the defrost process when a heat transfer efficiency across the enthalpy-exchange zone returns to within 10 percent of a pre-frosting heat transfer efficiency wherein, the heat transfer efficiency is proportional to a temperature difference between an intake air zone of the energy recovery ventilator and a supply air zone of the energy recovery ventilator divided by a temperature difference between an return air zone of the energy recovery ventilator and the intake air zone.

An HVAC system includes an evaporator. The evaporator includes a sensor configured to measure a property value (i.e., a saturated suction temperature or a saturated suction pressure) associated with saturated refrigerant flowing through the evaporator. The system includes a variable-speed compressor configured to receive the refrigerant and compress the received refrigerant. The system includes a controller communicatively coupled to the sensor and the variable-speed compressor. The controller monitors the property value measured by the sensor and detects a system fault, based on the monitored property value. In response to detecting the system fault, the controller operates the compressor in a freeze-prevention mode, which is configured to maintain the property value above a setpoint value by adjusting a speed of the variable-speed compressor. This prevents or delays freezing of the evaporator during operation of the system during the detected system fault.

An air conditioner shut-off system includes an overflow conduit that is coupled, at one end, to the drainage system of an air handler unit of the air conditioner system. The opposite end of the overflow conduit is positioned over an overflow container, which is suspended by a harness at the lower end of the harness. The upper end of the harness being operably coupled to the shut off switch throw of a shut off switch, which is provided on or proximate to the air handler unit. If the drainage system becomes obstructed, water will flow into the overflow container through the conduit, and eventually the mass of the water accumulated in the overflow container will produce enough force acting on the shut off switch throw through the harness to flip the shut off switch throw to the OFF position, resulting in the air conditioner system being shut off.

An HVAC actuator (1) comprises a motor (12), a motor controller (13) coupled to the motor (12), and a heating apparatus (14) thermally coupled to the HVAC actuator (1). The HVAC actuator (1) further comprises a condensation controller (15) coupled to the heating apparatus (14). The condensation controller (15) is configured to monitor at least one condensation parameter, and to control the heating apparatus (14) using the at least one condensation parameter.

In one embodiment, an overflow sensor assembly of an HVAC unit includes a sensor mounting bracket that is configured to be coupled to a mounting surface of the HVAC unit such that sensor probes of the overflow sensor assembly are suspended within and extend into a condensate drain pan of the HVAC unit. The sensor probes are defined by a sensor element that is coupled to the sensor mounting bracket and a spring that is coupled to the sensor element. The sensor probes are configured to activate an overflow detection circuit when the sensor probes come in contact with condensate fluid collected in the condensate drain pan prior to the condensate fluid overflowing from the condensate drain pan.

Enhancements to an air handler of an air conditioning system. The enhancements can include a scent dispersion system, a heat exchanger rinse system, and/or an air handler condensation drain pipe flush system. The scent dispersion system employs a pressure differential established within the air handler to draw a scent mist from a scent reservoir. The scent is disbursed throughout the structure by the air conditioning ventilation system. The heat exchanger rinse system dispenses a rinse fluid onto the heat exchanger. A cleaning composition can be injected into the rinse fluid to aid in the cleaning process. The flush system automatically configures a check valve upstream of the flush injection point. A flush fluid flows through the drain pipe applying a pressure to dislodge a blockage therein. A chemical composition can be added into the flush fluid to assist in the dislodging process.

A condensate trap for providing improved gas seal to a heating, ventilation, air conditioning, and refrigeration (HVAC/R) system. The trap can include an interior reservoir containing a volume of fluid to create a gas seal between an inlet pathway and an output. The interior reservoir can be accessed through an access port, by removing a removable cover, for maintenance and inspection. The trap can include vents or vent precursors for aiding in drainage of excess fluid, as well as early detection of problem conditions. The trap can be made from modified parts put together in a specific manner, or through purpose-built parts. The trap can include liquid level sensors and inspection windows to aid in early detection of problem conditions.

Methods and apparatus to monitor environmental conditions and reduce condensation are disclosed. An example apparatus includes a first sensor system to measure a first temperature in a first area and a second sensor system to measure a second temperature in a second area adjacent to the first area. The first area being separated from the second area by a door. A controller has at least one memory, instructions, and processor circuitry to execute the instructions to at least: compare the first temperature and the second temperature; determine if a temperature difference between the first temperature and the second temperature exceeds a temperature threshold; and in response to determining that the temperature difference does not exceed the temperature threshold, deactivate a fan located in the first area.

The air conditioner according to the present disclosure may comprise a heat exchanger exchanging heat between air and refrigerant, a fan discharging air toward the heat exchanger, a first drain pan disposed in a direction crossed to a direction of air flowing from the fan to the heat exchanger, wherein the first drain pan has an inlet opening through which air discharged from the fan flows toward the heat exchanger, a second drain pan disposed in a direction parallel to a direction of air flowing from the fan to the heat exchanger and a water level sensor rotatably disposed with reference to a rotating center spaced apart from the first drain pan and the second drain pan, wherein the water level sensor detects a water level of water gathered in one of the first drain pan and the second drain pan.

A dehumidification system includes a compressor, a primary evaporator, a primary condenser, a secondary evaporator, a secondary condenser, and a water pump. The secondary evaporator receives an inlet airflow and outputs a first airflow to the primary evaporator. The primary evaporator receives the first airflow and outputs a second airflow to the secondary condenser. The secondary condenser receives the second airflow and outputs a dehumidified airflow. The compressor receives a flow of refrigerant from the primary evaporator and provides the flow of refrigerant to the primary condenser. The primary condenser receives the flow of refrigerant and outputs the flow of refrigerant at a lower temperature through heat transfer with a flow of fluid. The flow of fluid is directed, by the water pump, to a heat exchanger or an external source, where heat is rejected from the flow of fluid.