Indoor air quality control for constant volume heating, ventilating and air conditioning units
First Claim
1. A system for circulating ventilating air in a space, the space including a supply air duct and a return air duct, the system comprising:
- a supply air chamber configured for communication with the supply air duct;
a return air chamber configured for communication with the return air duct;
an outside air chamber configured to receive outside air from an outside air intake, the outside air chamber including an outside air damper having a plurality of settings for varying outside air flow volume in the outside air chamber, the outside air damper establishing a predetermined relationship between each outside air damper setting and the outside air flow volume, the outside air damper establishing each setting in response to a damper control signal;
a mixed air plenum in communication with the return air chamber and the outside air chamber;
a fan positioned between the mixed air plenum and the supply air chamber, the fan supplying a constant volume of air to the supply air chamber in response to a fan control signal; and
a controller coupled to the outside air damper and the fan for providing the damper control signal and the fan control signal, the controller providing the damper control signal to establish a minimum outside air flow volume to the mixed air plenum, the controller including;
an initialization input configured to receive an initialization signal, the initialization signal having one value of a plurality of values corresponding to an associated plurality of predetermined duct resistances, the one value corresponding to the minimum outside air flow volume; and
a memory for storing data defining the predetermined relationship between each outside air damper setting and the outside air flow volume, the data being organized in sets, each respective set corresponding to a respective duct resistance, the controller selecting a set of data in response to the initialization signal, the controller being responsive to the selected set of data for providing the damper control signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A system for circulating ventilating air in a space includes a supply air chamber configured for communication with a supply duct, a return air chamber configured for communication with a return air duct, and an outside air chamber configured to receive outside air from an outside air intake. The outside air chamber includes an outside air damper having a plurality of settings for varying outside air flow volume in the outside air chamber. The outside air damper establishes a predetermined relationship between each outside air damper setting and the outside air flow volume. The outside air damper establishes each setting in response to a damper control signal. The system further includes a mixed air plenum in communication with the return air chamber and the outside air chamber and a fan positioned between the mixed air plenum and the supply air chamber, the fan supplying a constant volume of air to the supply air chamber in response to a fan control signal. The system further includes a controller coupled to the outside air damper and the fan for providing the damper control signal and the fan control signal to establish a minimum outside air flow volume to the mixed air plenum.
124 Citations
28 Claims
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1. A system for circulating ventilating air in a space, the space including a supply air duct and a return air duct, the system comprising:
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a supply air chamber configured for communication with the supply air duct; a return air chamber configured for communication with the return air duct; an outside air chamber configured to receive outside air from an outside air intake, the outside air chamber including an outside air damper having a plurality of settings for varying outside air flow volume in the outside air chamber, the outside air damper establishing a predetermined relationship between each outside air damper setting and the outside air flow volume, the outside air damper establishing each setting in response to a damper control signal; a mixed air plenum in communication with the return air chamber and the outside air chamber; a fan positioned between the mixed air plenum and the supply air chamber, the fan supplying a constant volume of air to the supply air chamber in response to a fan control signal; and a controller coupled to the outside air damper and the fan for providing the damper control signal and the fan control signal, the controller providing the damper control signal to establish a minimum outside air flow volume to the mixed air plenum, the controller including; an initialization input configured to receive an initialization signal, the initialization signal having one value of a plurality of values corresponding to an associated plurality of predetermined duct resistances, the one value corresponding to the minimum outside air flow volume; and a memory for storing data defining the predetermined relationship between each outside air damper setting and the outside air flow volume, the data being organized in sets, each respective set corresponding to a respective duct resistance, the controller selecting a set of data in response to the initialization signal, the controller being responsive to the selected set of data for providing the damper control signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for controlling the amount of outside air introduced into a system for circulating ventilating air in a space, the system including a fan for circulating the ventilating air and an outside air damper for controlling supply of outside air to the system, the outside air damper having a plurality of settings, the outside air damper establishing a predetermined relationship between each outside air damper setting and outside air flow volume, the method comprising the steps of:
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determining a minimum outside air flow volume for the space; selecting an outside air damper setting according to the predetermined relationship to provide the minimum outside air flow volume; adjusting the outside air damper to the selected setting; and wherein the system further includes a supply duct for communicating supply air from the fan to the space, the method further comprising the steps of determining a supply duct resistance associated with the supply duct and adjusting the outside air damper position in response to the supply duct resistance to maintain the minimum outside air flow. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A method for controlling the amount of outside air introduced into a system for circulating ventilating air in a space, the system including a fan for circulating the ventilating air and an outside air damper for controlling supply of outside air to the system, the outside air damper having a plurality of settings, the outside air damper establishing a predetermined relationship between each outside air damper setting and outside air flow volume, the method comprising the steps of:
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determining a minimum outside air flow volume for the space; selecting an outside air damper setting according to the predetermined relationship to provide the minimum outside air flow volume; and adjusting the outside air damper to the selected setting wherein the method further includes a return duct for communicating return air from the space to the fan, the method further comprising the steps of determining a return duct resistance associated with the return duct and adjusting the outside air damper position in response to the return duct resistance to maintain the minimum outside air flow. - View Dependent Claims (20)
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21. A method for controlling the amount of outside air introduced into a system for circulating ventilating air in a space, the system including a fan for circulating the ventilating air and an outside air damper for controlling supply of outside air to the system, the outside air damper having a plurality of settings, the outside air damper establishing a predetermined relationship between each outside air damper setting and outside air flow volume, the method comprising the steps of:
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determining a minimum outside air flow volume for the space; selecting an outside air damper setting according to the predetermined relationship to provide the minimum outside air flow volume; adjusting the outside air damper to the selected setting; and further comprising the steps of detecting a wind velocity characteristic of the outside air and selecting an outside air damper setting according to the detected wind velocity characteristic. - View Dependent Claims (22)
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23. A system which circulates ventilating air in a space, the space including a supply air duct and a return air duct, the system comprising:
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a supply air chamber configured for communication with the supply air duct, a return air chamber configured for communication with the return air duct, and an outside air chamber configured to receive outside air from an outside air intake; an outside air damper having a plurality of settings for varying outside air flow volume in the outside air chamber, the outside air damper establishing a predetermined relationship between each outside air damper setting and the outside air flow volume, the outside air damper establishing each setting in response to a damper control signal; a mixed air plenum in communication with the return air chamber and the outside air chamber, air within the mixed air plenum having a mixed air plenum pressure; a pressure detector coupled to the mixed air plenum, the pressure differential detector producing a pressure signal corresponding to the mixed air plenum pressure; a fan positioned between the mixed air plenum and the supply air chamber for supplying a constant volume of air to the supply air chamber; and a controller having a memory for storing data defining the predetermined relationship between each outside air damper setting and the outside air flow volume, a pressure input coupled to the pressure detector for receiving the pressure signal, an initialization input configured to receive an initialization signal corresponding to a minimum outside air flow volume to the mixed air plenum, and a processor coupled to the memory, the processor receiving the stored data from the memory and calculating an outside air damper position in response to the pressure signal and the initialization signal, the processor providing the damper control signal in response to the calculated outside air damper position to establish an outside air damper setting corresponding to the minimum outside air flow volume. - View Dependent Claims (24, 25, 26, 27, 28)
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Specification