A liquid level detector for use in a pump control system comprises a chamber 20 for liquid, a liquid inlet 6 to the chamber 20, a liquid outlet 7 from the chamber and connectable to a pump, and a capacitive sensor comprising mutually spaced capacitive sensor elements (21, 22; 22, 23) forming a capacitance which is sensitive to permittivity within a region of the chamber proximate the capacitive sensor. The chamber is defined at least partially by a barrier member 25 and the capacitive sensor elements are provided on the barrier member outside the chamber.

The present invention provides a liquid level sensor and an automatic calibration process which removes the need for prior manual calibration of the liquid level sensor, as this happens dynamically during installation and use of the pump. Further, by frequently monitoring the calibration of the sensor and correcting for long term drift or contamination on the sensing surface, the reliability of the liquid level sensor is considerably better than those of the prior art. By operating a solid state sensor, there are no moving parts in the liquid level sensor described above.

A structure comprises at least one outer wall having an internal wall section and an outer wall section with an air flow passage therebetween. A circulation system circulates air through the flow passage to inhibit moisture accumulation and mold growth. A sensing system determines the presence of moisture in the flow passage and generates a signal in response thereto. A controller receives the signal from the sensing system and controls the circulation system to maintain a predetermined temperature and relative humidity in the flow passage.

A system and method for monitoring a heating, ventilation, or air conditioning (HVAC) system of a building is provided. A monitoring server, located remotely from the building, is configured to receive power consumption data and control signal data from a monitoring device at the building and to receive energy pricing data from a customer device associated with the HVAC system or a database that stores energy pricing data. The monitoring server is configured to determine energy cost data for segments of a selected time period based on the power consumption data, the control signal data, and the energy pricing data. The monitoring server is also configured to communicate the energy cost data to the customer device for display on the customer device.

The electrical connections of a chamber or enclosure for a water tub can be protected through the use of spill element sensors. The spill element sensors can help to disable the delivery of power to the heater of a water tub in the event that the electrical connections become wet.

Certain exemplary embodiments can provide a system, machine, device, and/or manufacture that is configured for operably releasing condensate from a condensate-producing unit without allowing a substantial quantity of gas to enter the condensate-producing unit and/or a substantial quantity of gas to flow through the system, machine, device, and/or manufacture.

A drain pan for a HVAC system includes a middle section defining a cavity extending from a first end of the middle section to a second end of the middle section, a first end section configured to partially extend into the cavity via the first end of the middle section, and a second end section configured to partially extend into the cavity via the second end of the middle section. The second end section includes a drain port. In some embodiments, the drain pan is modular, enabling different middle sections of various lengths to be coupled between the end sections. The cavity of some embodiments is formed by double walls, which insulate the middle section to reduce condensate formation on a bottom surface of the middle section. By forming one or multiple sections from plastic with an anti-microbial additive, the drain pan further reduces corrosion, microbial growth, and/or condensate generation.

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.

An anti-clogging liquid dispersion system and method for an air conditioner or heat pump is disclosed. A tank holds an anti-clogging liquid. A pump or valve connected with the tank periodically supplies the liquid to a condensate drain pan or the outlet of an existing drain line located exteriorly of a structure. One or more sensors are provided to detect moisture, flooding and/or lack of condensate flow and, when so detected, a control circuit causes the liquid to be supplied to the condensate drain pan to prevent flooding of a condensate drain pan or to clear a clogged drain line of an air handler of the air conditioner or heat pump. An additional dose of the liquid can also be supplied at any time when an unacceptable amount of condensate moisture and/or a clogged drain line has been detected.

Certain exemplary embodiments can provide a system, machine, device, and/or manufacture that is configured for operably releasing condensate from a condensate-producing unit without allowing a substantial quantity of gas to enter the condensate-producing unit and/or a substantial quantity of gas to flow through the system, machine, device, and/or manufacture.