The invention relates to an air purification apparatus. The apparatus is disposed in a window for separating an indoor space and an outdoor space. The apparatus comprising: an inlet chamber having a first inlet, a second inlet and an outlet, wherein the first inlet is operatively open to the outdoor space and the second inlet is operatively open to the indoor space; an air pumping unit for pumping air from the inlet chamber to the indoor space through the outlet, wherein the air is pumped into the inlet chamber through the first inlet or through the second inlet; and a filtering unit disposed upstream of the air pumping unit, for filtering pollutants in the air.

In a thermostat having a plurality of demand circuits and a thermostat controller, a method of controlling devices connected to the demand circuits. One or more demand circuits in a thermostat are connected to devices in an HVAC system. The thermostat is configured to associate each connected demand circuit with the device to which it is connected and control signals are routed from the thermostat controller to the one or more demand circuits to control devices associated with the demand circuits.

Example implementations relate to a thermal management door assembly. One example apparatus includes a first fan assembly including an intake region and an exhaust region. The apparatus also includes a second fan assembly aligned with the first fan assembly. The apparatus further includes a thermal management door assembly positioned between the first fan assembly and the second fan assembly. The thermal management door assembly includes a frame coupled to the first fan assembly and to the second fan assembly. The thermal management door assembly also includes a sealing door movably coupled to the frame to control an amount of air recirculation from the exhaust region to the intake region.

A ventilation system utilizing fans to bring air into a building and/or exhaust air out of the building powered at least in part by solar panels that can be quickly and easily mounted on the building, such as on roof vents, windows, and the like adjacent to the fans. A sensor may be operatively connected to a controller or logic circuit to measure environmental factors to determine whether to activate the fans. The ventilation system is configured to be a modular device with versatile fasteners for easy installment in windows, attics, or roof tops.

A system and method for a controller of economizers operatively connected to HVAC equipment. The controller is adapted to maintain the temperature within a facility based on inside air setpoints and outside air setpoints. The controller receives inside air temperature readings and compares them to inside air setpoints in order to determine the cooling demand for the facility. The controller also receives outside air temperature readings and compares them to outside air setpoints in order to determine which economizers may be activated. The outside air setpoints may be dynamically adjusted to adapt and meet the cooling demand of the facility. The controller compares the outside air setpoints to predetermined maximum and minimum setpoints in order to determine whether to adjust the outside air setpoints.

Apparatus and methods are disclosed for controlling a cooling ventilation fan after the thermostat call for cooling has ended by providing a variable fan-off delay time based on cooling system parameters including but not limited to the cooling system operating time, duration of the thermostat call for cooling, relative humidity, temperature split, thermostat temperature rate of change, or thermostat temperature reaching a minimum inflection point or crossing a fixed or variable thermostat differential or differential offset. Apparatus and methods are disclosed for controlling a heating ventilation fan after the thermostat call for heating has ended by providing a variable fan-off delay time based on heating system parameters including but not limited to the heating system operating time, duration of the thermostat call for heating, temperature rise, thermostat temperature rate of change, or thermostat temperature reaching a maximum inflection point or crossing a fixed or variable thermostat differential or differential offset.

A thermostat for controlling an HVAC system is described, the thermostat having a user interface that is visually pleasing, approachable, and easy to use while also providing ready access to, and intuitive navigation within, a menuing system capable of receiving a variety of different types of user settings and/or control parameters. For some embodiments, the thermostat comprises a housing, a ring-shaped user-interface component configured to track a rotational input motion of a user, a processing system configured to identify a setpoint temperature value based on the tracked rotational input motion, and an electronic display coupled to the processing system. An interactive thermostat menuing system is accessible to the user by an inward pressing of the ring-shaped user interface component. User navigation within the interactive thermostat menuing system is achievable by virtue of respective rotational input motions and inward pressings of the ring-shaped user interface component.

An electronic sub-assembly for an HVAC Controller includes a touch screen display and a printed circuit board. The touch screen display including a viewing side and a non-viewing side. A conductive trace is disposed on the viewing side of the touch screen display adjacent a perimeter of the touch screen display. The printed circuit board, which includes a grounding feature, is positioned adjacent the non-viewing side of the touch screen display. A connector is in electrical communication with the conductive trace and the grounding feature of the printed circuit board.

An HVAC Controller may include a first sub-assembly and a second sub-assembly capable of releasably engaging the first sub-assembly. The first sub-assembly may include a first housing and a printed circuit board having a controller for providing one or more control signals, where the printed circuit board may be secured relative to the first housing. The second sub-assembly may include a second housing, a power source, one or more output terminals, and a second printed circuit board. The second printed circuit board may be secured relative to the second housing and may have circuitry thereon that is powered by the power source and configured to receive the one or more control signals from the first printed circuit board. The circuitry of the second sub-assembly may set output terminals thereof to a predetermined state when the first sub-assembly is released from the second sub-assembly.

Methods to regulate a discharge fan and a coil of a HVAC system are described. The method may include regulating a discharge air temperature of the cooling/heating coil of the HVAC system while maintain the discharge fan at a low capacity setting. The method may also include maintaining the coil at a low discharge air temperature (or a high discharge air temperature) setting, while varying a fan capacity of the discharge fan. The method may include a discharge capacity boost that includes decreasing (or elevating) the discharge air temperature limit of the coil beyond the low discharge air temperature (or the high discharge air temperature) limit. The methods as described herein may be applicable to a HVAC system that has variable airflow capability.