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 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 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 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 cooling system for a datacenter is disclosed. An evaporative cooling subsystem provides blown air for cooling the datacenter and a repurposable refrigerant cooling subsystem controls moisture of the blown air in a first configuration and independently cools the datacenter in a second configuration.

An HVAC system for a multi-unit building having a riser stack in flow communication with a single unit HVAC system. The single unit HVAC system has a first heat exchanger thermally connected to the riser stack, a second heat exchanger thermally connected to a fluid distribution system within the unit, and a closed loop fluid flow path extending between the first and second heat exchangers. The first heat exchanger exchanges heat between a riser stack fluid in the riser stack and the closed loop fluid in the closed loop fluid flow path and the second heat exchanger exchanges heat between the closed loop fluid and a distribution fluid of the fluid distribution system.

When a humidity condition, including a humidity detected by a temperature and humidity sensor and a humidification load sensing unit falling below a threshold value, is met, an outside air conditioner supplies the heated and humidified air into the room. When the humidity condition is met during the indoor heating operation, the indoor heating operation is stopped or weakened. When the humidity condition is met, only the outside air conditioner is subjected to a heating and humidifying operation. Since the indoor air is not heated by the inside air conditioner more than necessary, when a heating load is low and a humidification load is present, a “conflicting state” can be prevented in which the inside air conditioner is subjected to a cooling and dehumidifying operation and the outside air conditioner is subjected to the heating and humidifying operation.

A building management system (BMS) includes memory devices having instructions stored thereon that, when executed by processors, cause the processors to perform operations including obtaining a BMS ontology data model defining a plurality of BMS model classes and relationships between the BMS model classes, assigning a BMS model class selected from the plurality of BMS model classes to a plurality of BMS object definitions, generating a semantic site model by classifying a plurality of BMS objects associated with a building site according to the BMS object definitions and the BMS model classes assigned thereto, and transmitting a notification using the semantic site model.

An air conditioning and heat pump tower includes a main casing, a plurality of connecting pipes, a compressor, a front heat exchanger, a rear heat exchanger, a fan unit, and an energy efficient arrangement. The energy efficient arrangement includes a first pre-heating heat exchanger supported in a front compartment of the main casing, and positioned between an outdoor air intake opening and an outdoor heat exchanging portion of the front heat exchanger. The air conditioning and heat pump tower may be operated between an air conditioning mode for absorbing heat from the indoor space, and a heat pump mode for producing heat to the indoor space. A predetermined amount of ambient air may be drawn through the outdoor air intake opening and may be pre-heated by the energy efficient arrangement before delivering to the indoor space.

An environmental control system is provided and includes equipment to generate an environmental control effect, a damper associated with a zone to control a portion of the environmental control effect permitted to affect the zone by assuming one of various damper positions and a capacity controller operably coupled to the equipment and the damper to control operation of the equipment and to adjust the damper to assume the one of the various damper positions based on a demand of the zone and a capacity of the equipment.