Energy-efficient variable-air-volume (VAV) system with zonal ventilation control

Claim 2

A ventilation and air conditioning system for providing zonal cooling and ventilation, said system comprising: (a) an air-handling unit for distributing air throughout a building or structure, said air-handling unit having (i) a first intake for channeling fresh air to a first heat-exchanging coil capable of producing conditioned fresh air; (ii) a first fan for moving a supply of conditioned fresh air through a fresh air duct; (iii) a second intake for channeling recycled air to a second heat-exchanging coil capable of producing conditioned recycled air; and (iv) a second fan for moving a supply of conditioned recycled air through a recycled air duct; (b) a mixing box connected to a distal end of said fresh air duct and also connected to a distal end of said recycled air duct, said mixing chamber being an enclosure for mixing the conditioned fresh air and the conditioned recycled air for subsequent ventilation into a nearby space; (c) a control system for controlling the supply of conditioned fresh air and the supply of conditioned recycled air whereby a desired mixture of conditioned fresh air and conditioned recycled air is ventilated into said space.

Claim 3

A ventilation and air conditioning system as defined in claim 1 wherein said control system comprises a carbon dioxide sensor for providing a feedback signal to a central processing unit for controlling the supply of conditioned fresh air and a temperature sensor for providing a feedback signal to said central processing unit for controlling the supply of conditioned recycled air.

Claim 4

A ventilation and air conditioning system as defined in claim 2 wherein said mixing box comprises a fresh air chamber connected at a downstream end of said fresh air duct and a recycled air chamber connected at a downstream end of said recycled air duct, each of the chambers having a damper for regulating air flow in to a mixing portion of said mixing box.

Claim 5

A ventilation and air conditioning system as defined in claim 3 wherein the air-handling unit further comprises a fresh air filter downstream of the first intake and a recycled air filter downstream of the second intake.

Claim 6

A ventilation and air conditioning system as defined in claim 4 wherein said carbon dioxide sensor and said temperature sensor are located in a return air duct, the return air duct being connected to the second intake.

Claim 7

A ventilation and air conditioning system as defined in claim 5 wherein said mixing box is a plenum chamber.

Claim 8

A ventilation and air conditioning system as defined in claim 1 wherein said air-handling unit comprises a first variable-air-volume system for moving the fresh air through the fresh air duct and a second variable-air-volume system for moving the recycled air through the recycled air duct.

Claim 9

A ventilation and air conditioning system as defined in claim 1 wherein said air-handling unit comprises a constant-air-volume system for moving the fresh air through the fresh air duct and a variable-air-volume system for moving the recycled air through the recycled air duct.

Claim 10

A ventilation and air conditioning system as defined in claim 1 wherein said air-handling unit comprises a first constant-air-volume system for moving the fresh air through the fresh air duct and a second constant-air-volume system for moving the recycled air through the recycled air duct.

Claim 11

A ventilation and air-conditioning system for providing zonal cooling and ventilation, said system comprising an air-handling unit having (a) a first variable-air-volume system for conditioning and moving a volume of conditioned fresh air through a first duct to a mixing box; (b) a second variable-air-volume system for conditioning and moving a volume of conditioned recycled air through a second duct to said mixing box; (c) said mixing box having a fresh air damper for admitting a supply of conditioned fresh air into a mixing chamber in said mixing box; (d) said mixing box having a recycled air damper for admitting a supply of conditioned recycled air into said mixing chamber of said mixing box whereby a desired mixture of conditioned fresh and recycled air is ventilated into a space of a building; (e) a carbon dioxide sensor for providing a feedback signal to control the first variable-air-volume system and the fresh air damper; (f) a temperature sensor for providing a feedback signal to control the second variable-air-volume system and the recycled air damper.

Claim 12

A ventilation and air-conditioning system for providing zonal cooling and ventilation, said system comprising an air-handling unit having (a) a first variable-air-volume system for conditioning and moving a volume of conditioned fresh air through a first duct to a mixing box; (b) a second variable-air-volume system for conditioning and moving a volume of conditioned recycled air through a second duct to said mixing box; (c) said mixing box having a fresh air damper for admitting a supply of conditioned fresh air into a mixing chamber in said mixing box; (d) said mixing box having a recycled air damper for admitting a supply of conditioned recycled air into said mixing chamber of said mixing box whereby a desired mixture of conditioned fresh and recycled air is ventilated into a space of a building; (e) a carbon dioxide sensor for providing a feedback signal to control the first variable-air-volume system and the fresh air damper; (f) a temperature sensor for providing a feedback signal to control the second variable-air-volume system and the recycled air damper.

Claim 13

A ventilation and air conditioning system as defined in claim 10 wherein said air-handling unit comprises a first fan for the first duct and a second fan for the second duct and a single heat-exchanging coil for cooling and dehumidifying both the fresh air in the first duct and the recycled air in the second duct.

Claim 14

A ventilation and air conditioning system as defined in claim 11 wherein the first variable-air-volume system comprises a fresh air filter and the second variable-air-volume system comprises a recycled air filter.

Claim 15

A ventilation and air conditioning system as defined in claim 12 wherein said mixing box is a plenum chamber.

Claim 16

A heating, ventilation and air conditioning (HVAC) system for cooling and ventilating a building or other structure, said system comprising: (a) a first air intake for drawing in a volume of fresh air; (b) a first heat exchanging coil for cooling and dehumidifying the volume of fresh air, thereby producing a supply of conditioned fresh air; (c) a first fan for blowing the supply of conditioned fresh air through a first duct to a mixing box, said mixing box having a first damper for regulating air flow into a mixing chamber located with in said mixing box; (d) a second air intake for drawing in a volume of recycled air from inside the building or other structure; (e) a second heat exchanging coil for cooling and dehumidifying the volume of recycled air, thereby producing a supply of conditioned recycled air; (f) a second fan for blowing the supply of conditioned recycled air through a second duct to said mixing box, said mixing box having a second damper for regulating air flow into said mixing chamber where conditioned fresh air is mixed with conditioned recycled air and then ventilated into a room or zone of the building or structure; (g) a carbon dioxide sensor for providing a first feedback signal to a control system for controlling the first fan and the first damper; and (h) a temperature sensor for providing a second feedback signal to said control system for controlling the second fan and the second damper.

Claim 17

A heating, ventilation and air conditioning (HVAC) system for cooling and ventilating a building or other structure, said system comprising: (a) a first air intake for drawing in a volume of fresh air; (b) a first heat exchanging coil for cooling and dehumidifying the volume of fresh air, thereby producing a supply of conditioned fresh air; (c) a first fan for blowing the supply of conditioned fresh air through a first duct to a mixing box, said mixing box having a first damper for regulating air flow into a mixing chamber located with in said mixing box; (d) a second air intake for drawing in a volume of recycled air from inside the building or other structure; (e) a second heat exchanging coil for cooling and dehumidifying the volume of recycled air, thereby producing a supply of conditioned recycled air; (f) a second fan for blowing the supply of conditioned recycled air through a second duct to said mixing box, said mixing box having a second damper for regulating air flow into said mixing chamber where conditioned fresh air is mixed with conditioned recycled air and then ventilated into a room or zone of the building or structure; (g) a carbon dioxide sensor for providing a first feedback signal to a control system for controlling the first fan and the first damper; and (h) a temperature sensor for providing a second feedback signal to said control system for controlling the second fan and the second damper.

Claim 18

A heating, ventilation and air conditioning (HVAC) system as defined in claim 14 further comprising a first filter located downstream of the first air intake and a second filter located downstream of the second air intake.

Claim 19

A heating, ventilation and air conditioning (HVAC) system as defined in claim 15 wherein the first heat exchanging coil and the second heat exchanging coil form a single, integral heat-exchanging coil with a single coolant flowing within said single, integral heat-exchanging coil whereby the volume of fresh air travels in the first duct and the volume of recycled air travels in the second duct without mixing until the mixing box.