Systems and methods are provided and include a variable frequency drive configured to drive a fan motor of an HVAC system to ventilate an indoor space, the HVAC system having a cooling assembly that includes at least one of an economizer and a compressor. A controller is configured to communicate with the variable frequency drive, receive at least one signal from an occupancy sensing device, determine whether the indoor space is less than fully occupied based on the at least one signal, and control the variable frequency drive to reduce a speed of the fan motor in response to determining that the indoor space is less than fully occupied.

Described herein is an air handling unit that includes canopies for compressor fans and exhaust fans located on a top thereof, which canopies provide for noise abatement and a canopy to assist in keeping precipitation out. The canopies further include louvers that can be controlled to provide for even further noise abatement and precipitation control.

An energy-reducing method and apparatus for retrofitting a single zone, constant volume HVAC system, with or without an economizer, that provides heating, cooling, and ventilation to occupants within a building space. The present invention includes the introduction of a programmable logic controller and variable frequency drive (VFD) that takes control of the existing fan, heating, cooling, and optional economizer operation. The reduction of the fan speed in the ventilation mode when the 100% operation is not needed saves significant energy of the existing constant volume HVAC system where the fan motor is designed to run 100% of the time.

A pressure probe includes a tube having an output end, an internal passage, an axial run, and pressure orifices axially aligned along a downstream side of the axial run. The pressure orifices are in communication with the output end through the internal passage and an upstream side of the axial run that is opposite from the downstream side of the axial run and does not include a pressure orifice. The downstream side is perpendicular to airflow.

A fresh air cooling and ventilating system can include a whole house fan for introducing fresh air into a building structure. The fresh air cooling and ventilating system can include a whole house fan and/or a controller. The controller can be operably in communication with an air conditioning system and coordinate the usage of the fresh air cooling and ventilating system and the air conditioning system to reduce overall energy consumption. The system can be automated to run with no or minimal user input.

A multifunction adaptive whole house fan system can include a whole house fan to pull large volume of air through a building structure. The whole house fan can pull air from a motorized window or damper into the building structure and expel air through an attic. The system can monitor the environment to operate the whole house fan when desired conditions are present in coordination with other systems of the building structure to reduce overall energy consumption.

A ventilation system for a building in some cases includes a main HVAC blower for moving temperature-conditioned air through the building plus a smaller ventilation blower for providing fresh air. A controller regulates the ventilation blower's speed to provide a target ventilation flow rate regardless of changes in the pressure differential between the indoor and outdoor air. To ensure that the target rate is appropriate for a particular building, the target flow rate is determined based on a ventilation setting that reflects a specified number of bedrooms and a specified amount of floor space of the building.

A multifunction adaptive whole house fan system can include a whole house fan to pull large volume of air through a building structure. The whole house fan can pull air from a motorized window or damper into the building structure and expel air through an attic. The system can monitor the environment to operate the whole house fan when desired conditions are present in coordination with other systems of the building structure to reduce overall energy consumption.

A fresh-air cooling system and methods of cooling a building structure with the same are provided. The system has an exterior interface assembly, a damper, a register, a duct, and a motorized fan. The exterior interface assembly is connected to the register by the duct and provides a flow path for air outside the building to enter the duct. The motorized fan is disposed in an attic of the building structure and pulls air into the attic from a living space to create a negative static pressure in the living space. The damper is positioned along the flow path from the exterior interface assembly to the living space and opens to allow air outside the building structure to enter the living space in response to motorized fan creating in the living space a negative static pressure that exceeds the cracking pressure of the damper. The cracking pressure of the damper can be adjusted to control the flow rate of outside air through the damper.

A device and a method to provide direct room air cooling. The device is a duct-less economizer that runs independent of existing HVAC systems. The device has its own thermostat setting and is capable of providing significant insulation values when closed. In addition, the method by which the device determines the availability of cool air is improved. This is achieved by using internet weather data, to read outdoor heat indexes, instead of primarily relying on local sensors.