Methods and systems for estimating energy loss or controlling ventilation in a building based on measurements of air pressure differences between inside and outside of the building envelope. The measured differences may be used to calculate air leakage and corresponding energy loss, or to control a ventilation system in order to minimize air pressure difference and thereby the energy loss. Energy loss may be calculated by obtaining an estimate of a correspondence between air flow through a building envelope and a difference in air pressure on respective sides of the envelope, obtaining a measurement of a current difference in air pressure on respective sides of the envelope, calculating a current flow of air per unit time through the envelope based on said correspondence and said current difference in air pressure, and providing a representation of the calculated current flow of air per unit time through the envelope.

A heating, ventilating, and air conditioning (HVAC) system is provided. The HVAC system includes a non-transitory computer readable medium that includes instructions that are configured to cause a processor to generate a custom application for an HVAC unit in response to an inquiry regarding the HVAC unit. The custom application comprises a custom sequence of equipment operation of the HVAC unit, and the custom application is configured to regulate operation of components of the HVAC unit. Moreover, the custom application comprises operating parameters and control parameters associated with the HVAC unit.

A flow control device for controlling flow in a heating, ventilation, or air conditioning (HVAC) system is shown. The flow control device includes a valve body including an inlet path, an outlet path, a valve member, and a valve stem coupled to the valve member. The flow control device includes a first sensor configured to obtain pressure measurements within the valve body, a second sensor configured to obtain displacement measurements of the valve stem, and a controller including a processing circuit configured to determine a flowrate based at least on the pressure measurements from the first sensor and the displacement measurements from the second sensor.

A filter apparatus includes a filter, a pipe, a blower that sucks, through the pipe, air filtered by the filter, a wind speed sensor that measures a mass flow rate of gas flowing through the pipe, a temperature sensor that measures a temperature, a pressure sensor that measures an air pressure, and a processor that controls suction of the blower, based on the measured air pressure, the measured temperature, and the measured mass flow rate.

A method comprising detecting an indoor carbon dioxide level; detecting an outdoor fine dust level; driving an air supply fan and an exhaust fan such that an air supply amount of the air supply fan is greater than an exhaust amount of the exhaust fan based on detected indoor carbon dioxide level and outdoor fine dust level; and performing a first indoor pressure control of detecting an indoor pressure and controlling the air supply fan and the exhaust fan. In the indoor pressure control, based on the detected indoor pressure being less than a first set value, a number of revolutions per minute of the exhaust fan is controlled to be decreased, and based on the detected indoor pressure is greater than or equal to a second set value greater than the first set value, the number of revolutions per minute of the exhaust fan is controlled to be increased.

A distributed zone control system having one or more vents with sensors and effectors is provided. The effectors operate in response to the sensors. In various embodiments, the effectors of one vent may operate in response to the sensors of another vent. In various instances, the distributed zone control system connects to an HVAC system and controls operation of the HVAC system. In this manner, temperatures may be detected by a vent and conditioned air from the HVAC system directed to appropriate zones to maintain desired conditions.

A method of controlling a Heating, Ventilating and Air Conditioning (HVAC) system including a fluid transportation network that includes one or more network sections, each network section being connected to a fluid transportation circuit through respective supply lines and return lines, each network section including plural parallel zones, includes arranging a pressure regulating device in the supply lines and/or respective return lines of the network sections, arranging flow regulating devices in the zones of the network sections, measuring a remote differential pressure of the fluid in a first zone of the plurality of zones of each of the network sections, and controlling, by a controller, the pressure regulating devices of each network section to maintain the measured remote differential pressure within a specified differential pressure range.