A fluid flow device that can measure and control a flow of a fluid is described. Various procedures, including measuring, controlling, balancing, or calibration procedures can leverage differential pressure measurement. These differential pressure measurements can be measured across the fluid flow device such that a first pressure measurement is taken upstream of the fluid flow device while a second pressure measurement is taken downstream of the fluid flow device. Moreover, one or more of the various pressure measurements, and in particular the downstream pressure measurement, can be performed at stagnation zone where the flow has stagnated. Such can provide significant amplification and/or turndown capabilities.

A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

An air-conditioning apparatus includes a fan configured to send air to an air-conditioned space, a fan motor configured to drive the fan, a duct having a plurality of air outlets, the air sent by the fan flowing through the duct, a detection unit configured to detect an air flow rate of the fan, a damper provided to each of the plurality of air outlets, and a fan motor control unit configured to control a rotation speed of the fan motor such that the air flow rate assumes a constant value relative to variations in an opening degree of the damper of a plurality of dampers.

An HVAC system is described having components of a variable refrigerant flow (VRF) outdoor compressor unit connected to an indoor fan coil unit. The indoor fan coil unit supplies air to ducts that condition a plurality of zones. Each zone has a volume modulating air damper that can maintain a predetermined volume of air flowing through it. As the dampers for some zones vary between open and close positions, the air pressure in the ducts changes. The volume modulating dampers compensate for these pressure changes, ensuring that only the predetermine volume of air is passing into the zones. By regulating the volume of into each zone, the volume modulating air dampers can restrict the air volume through the fan coil causing the outdoor unit to reduce compressor speed, thereby saving energy.

An electric blower system is described. The blower system includes a blower, an airflow system, a sensor, and an electric motor. The electric motor includes a motor controller. The motor controller is configured to operate the motor at a first torque and a first speed to generate a first airflow, determine a first airflow value wherein the first airflow value, the first torque, and the first speed define a first benchmark data point. The motor controller is also configured to operate the motor at a second torque and a second speed to generate a second airflow and determine a second airflow value wherein the second airflow value, the second torque, and the second speed define a second benchmark data point. The motor controller is further configured to generate an operating profile for the blower system defining torque, speed, and airflow points for different system resistances.

An electric blower system is described. The blower system includes a blower, an airflow system, a sensor, and an electric motor. The electric motor includes a motor controller. The motor controller is configured to operate the motor at a first torque and a first speed to generate a first airflow, determine a first airflow value wherein the first airflow value, the first torque, and the first speed define a first benchmark data point. The motor controller is also configured to operate the motor at a second torque and a second speed to generate a second airflow and determine a second airflow value wherein the second airflow value, the second torque, and the second speed define a second benchmark data point. The motor controller is further configured to generate an operating profile for the blower system defining torque, speed, and airflow points for different system resistances.

An HVAC system is described having components of a variable refrigerant flow (VRF) outdoor compressor unit connected to an indoor fan coil unit. The indoor fan coil unit supplies air to ducts that condition a plurality of zones. Each zone has a volume modulating air damper that can maintain a predetermined volume of air flowing through it. As the dampers for some zones vary between open and close positions, the air pressure in the ducts changes. The volume modulating dampers compensate for these pressure changes, ensuring that only the predetermine volume of air is passing into the zones. By regulating the volume of into each zone, the volume modulating air dampers can restrict the air volume through the fan coil causing the outdoor unit to reduce compressor speed, thereby saving energy.

A ventilation system for ventilating a room, comprising: a lowered ceiling, defining a ceiling space between the lowered ceiling and a ceiling of the room and having an air permeable ceiling surface area; a raised flooring, supported by a support frame and defining a floor space between the raised flooring and a floor of the room, the raised flooring being air permeable over a floor surface area opposite to the air permeable ceiling surface area; an air supply inlet connected to the floor space; and an air outlet, connected to the ceiling space, wherein the air permeability of the raised flooring varies in dependence on distance from the air supply inlet for forming a substantial vertical air flow in which air entering the room through the floor surface area displaces air in the room in the vertical direction and forces air out through the ceiling surface area.