Computer-implemented systems and methods for estimating a replacement status of an HVAC air filter. Outdoor weather data (e.g., outdoor temperature information), is obtained. A Total Runtime Value of the HVAC system is determined based upon the obtained outdoor weather data. Finally, a replacement status of the air filter is estimated as a function of a comparison of the Total Runtime Value with a Baseline Value. By correlating air filter replacement status with an estimated runtime of the HVAC system, a credible predictor of air filter usage is provided. By estimating fan runtime based on easily-obtained outdoor weather data, the methods are readily implemented with any existing HVAC system and do not require installation of sensors or other mechanical or electrical components to the HVAC system.

Computer-implemented systems and methods for estimating a replacement status of an HVAC air filter. Outdoor weather data (e.g., outdoor temperature information), is obtained. A Total Runtime Value of the HVAC system is determined based upon the obtained outdoor weather data. Finally, a replacement status of the air filter is estimated as a function of a comparison of the Total Runtime Value with a Baseline Value. By correlating air filter replacement status with an estimated runtime of the HVAC system, a credible predictor of air filter usage is provided. By estimating fan runtime based on easily-obtained outdoor weather data, the methods are readily implemented with any existing HVAC system and do not require installation of sensors or other mechanical or electrical components to the HVAC system.

An HVAC system and method for characterizing a chosen VAV valve involves measuring the valve's volumetric flow rate versus valve position at just one or at some other limited number of data points and comparing that to the average characteristics a rather large group of similar valves. A custom characterization of airflow versus valve position for the chosen VAV valve is then created based on a difference between the characteristics of the chosen valve and that of the group of valves. In some examples, the VAV valve is of a venturi style such that a generic characterization of the group of valves is substantially linear when their flow rates are expressed logarithmically.

Systems and methods for provisioning a component of an HVAC system are presented. A provisioning device, such as a smartphone, is used to scan HVAC component information obtained from a tag on each component and wirelessly transfers the information to a thermostat or HVAC system controller. The thermostat or system controller automatically configures itself to control the equipment based on the details in the tag which are transmitted to the thermostat. The label may include barcode or textual information, which is decoded by software executing in the provisioning device, the thermostat, or a server computer in communication with the provisioning device or the thermostat. In embodiments, the HVAC component information is transmitted to a web services application to facilitate the installation, support, maintenance, and repair of the HVAC system.

An air conditioner includes an indoor unit installed on an indoor side, an outdoor unit installed on an outdoor side, a human detector that detects a person in a room, and a remote controller that performs radio communication with the indoor unit, and the air conditioner conditions the indoor air. The indoor unit includes an indoor unit control section that controls the indoor unit, a diagnostic section that diagnoses whether an operating state of the human detector is normal or abnormal, and a communication section that performs radio communication with the remote controller. The human detector includes a plurality of infrared sensors, a rotary table that supports each of the infrared sensors, and a human detector control section that controls the human detector. The diagnostic section diagnoses whether the operating state of the human detector is normal or abnormal by comparing the detected results between the respective infrared sensors on receiving a trigger signal transmitted from the remote controller.

An air conditioner and a communication method for an air conditioner are provided. The air conditioner may include an outdoor unit; an indoor unit; and a central controller connected to the indoor unit through a communication line. The indoor unit may perform periodic communication for transmitting a plurality of periodic packets to at least one of the outdoor unit or the central controller at predetermined periods, and change and transmit the plurality oaf periodic packets so as to decrease a load on the communication line.

A thermostat resists tampering by including a hidden mechanism for switching from a limit setting mode to an operation mode. In some embodiments, the switching mechanism is in the form of a tamper proof switch or jumper on the thermostat's circuit board. The switching mechanism can be hidden from a potential non-administrative user and can be located on the circuit board of the thermostat, as opposed to on the external housing. While the switching mechanism is in limit setting mode, the limits of the thermostat's temperature range can be adjusted. Once these limits have been set, the adjuster can move the switching mechanism to operation mode, and the thermostat will now be able to maintain temperatures within the new limit settings.

A thermostat may include one or more memory devices comprising a stored setpoint schedule, one or more temperature sensors configured to provide temperature sensor measurements, and a processing system configured to be in operative communication the one or more memory devices to determine a setpoint temperature, and in still further operative communication with a heating, ventilation, and air conditioning (HVAC) system to control the HVAC system based at least in part on the setpoint temperature and the temperature sensor measurements. The processing system may be configured to control the HVAC system by receiving an indication that a total instantaneous energy usage rate for a structure in which the thermostat is installed is projected to exceed a threshold amount; and altering the stored setpoint schedule to reduce an energy usage rate of the HVAC system.

An integrated system and process provides integrated control of the environment within a personal space. A tent or other structure suitable for forming a personal space, is in contact with, and may enclose, a user station. The system includes a control system, main controller, control modules, sensors, environmental units and other controllers that operate in an integrated fashion to provide a controlled environment within the personal space. The tent may enclose all or portions of the control system, main controller, control modules, sensors, environmental units and other controllers. Portions of the control system, main controller, control modules, sensors, environmental units and other controllers may reside outside tent. A process for providing environmental control of the personal space includes learning capabilities.

An apparatus and method for providing selective fan or vent cooling are disclosed. An example embodiment includes: a return plenum box having a return box opening, a fan opening, and a return duct opening; a fan coupled to the fan opening; a controller coupled to the plenum box; and an adjustable damper coupled to a hinge point of the return plenum box, the damper being adjustable between a closed position, which blocks the fan opening and an open position that blocks the return duct opening.