Sizing and control of fresh air dehumidification unit

Claim 2

A fresh air unit comprising: a housing having an airstream flowing therethrough; a pre-cooling portion, located within the housing, for reducing the temperature and moisture level of a gas in the airstream to a predetermined target zone on a psychrometric chart; and a dehumidification portion, located in the housing downstream of the pre-cooling portion, for removing a selected amount of moisture from the gas and for reheating the gas a selected amount of sensible heat gain.

Claim 3

The fresh air conditioning unit of claim 1 wherein the dehumidification portion includes a compressor section, a condenser section, an expansion section, and an evaporator section, all serially linked in a latent air conditioning circuit and wherein the evaporator section and the condenser section of the dehumidification portion are located in the airstream.

Claim 4

The fresh air conditioning unit of claim 2 wherein the evaporator section is upstream of the condensing section and wherein the condensing section is sized to provide a predetermined sensible heat gain from the condensing section.

Claim 5

The fresh air conditioning unit of claim 3 wherein the dehumidification evaporator section is sized to provide a desired amount of moisture removal.

Claim 6

The fresh air conditioning unit of claim 4 further including a controller for the pre-cooling portion operably connected to the pre-cooling portion and controlling its operation to a control point.

Claim 7

A fresh air unit comprising: a housing having an airstream flowing therethrough; a pre-cooling portion, located within the housing, for reducing the temperature and moisture level of a gas in the airstream to a predetermined target zone on a psychrometric chart; and a dehumidification portion, located in the housing downstream of the pre-cooling portion, for removing a selected amount of moisture from the gas and for reheating the gas a selected amount of sensible heat gain; and a controller for the pre-cooling portion operably connected to the pre-cooling portion and controlling its operation to a control point; wherein the dehumidification portion includes a compressor section, a condenser section, an expansion section, and an evaporator section, all serially linked in a latent air conditioning circuit; wherein the evaporator section and the condenser section of the dehumidification portion are located in the airstream; wherein the evaporator section is upstream of the condensing section; wherein the condensing section is sized to provide a predetermined sensible heat gain from the condensing section; wherein the dehumidification evaporator section is sized to provide a desired amount of moisture removal; and wherein the control point of the controller is user selectable.

Claim 8

A fresh air unit comprising: a housing having an airstream flowing therethrough; a pre-cooling portion, located within the housing, for reducing the temperature and moisture level of a gas in the airstream to a predetermined target zone on a psychrometric chart; and a dehumidification portion, located in the housing downstream of the pre-cooling portion, for removing a selected amount of moisture from the gas and for reheating the gas a selected amount of sensible heat gain; and a controller for the pre-cooling portion operably connected to the pre-cooling portion and controlling its operation to a control point; wherein the dehumidification portion includes a compressor section, a condenser section, an expansion section, and an evaporator section, all serially linked in a latent air conditioning circuit; wherein the evaporator section and the condenser section of the dehumidification portion are located in the airstream; wherein the evaporator section is upstream of the condensing section; wherein the condensing section is sized to provide a predetermined sensible heat gain from the condensing section; wherein the dehumidification evaporator section is sized to provide a desired amount of moisture removal; and wherein the control point of the controller is user selectable.

Claim 9

A fresh air unit comprising: a housing having an airstream flowing therethrough; a pre-cooling portion, located within the housing, for reducing the temperature and moisture level of a gas in the airstream to a predetermined target zone on a psychrometric chart; a dehumidification portion, located in the housing downstream of the pre-cooling portion, for removing a selected amount of moisture from the gas and for reheating the gas a selected amount of sensible heat gain; and a controller for the pre-cooling portion operably connected to the pre-cooling portion and controlling its operation to a control point; wherein the dehumidification portion includes a compressor section, a condenser section, an expansion section, and an evaporator section, all serially linked in a latent air conditioning circuit; wherein the evaporator section and the condenser section of the dehumidification portion are located in the airstream; wherein the evaporator section is upstream of the condensing section; wherein the condensing section is sized to provide a predetermined sensible heat gain from the condensing section; wherein the dehumidification evaporator section is sized to provide a desired amount of moisture removal; and wherein the control point is a preselected point on a psychrometric chart.

Claim 10

A fresh air unit comprising: a housing having an airstream flowing therethrough; a pre-cooling portion, located within the housing, for reducing the temperature and moisture level of a gas in the airstream to a predetermined target zone on a psychrometric chart; a dehumidification portion, located in the housing downstream of the pre-cooling portion, for removing a selected amount of moisture from the gas and for reheating the gas a selected amount of sensible heat gain; and a controller for the pre-cooling portion operably connected to the pre-cooling portion and controlling its operation to a control point; wherein the dehumidification portion includes a compressor section, a condenser section, an expansion section, and an evaporator section, all serially linked in a latent air conditioning circuit; wherein the evaporator section and the condenser section of the dehumidification portion are located in the airstream; wherein the evaporator section is upstream of the condensing section; wherein the condensing section is sized to provide a predetermined sensible heat gain from the condensing section; wherein the dehumidification evaporator section is sized to provide a desired amount of moisture removal; and wherein the control point is a preselected point on a psychrometric chart.

Claim 11

The fresh air conditioning unit of claim 7 further including a controller for the dehumidification portion.

Claim 12

The fresh air conditioning unit of claim 8 wherein the controllers modulate the operation of the pre-cooling and dehumidification portions to user selectable setpoints.

Claim 13

A fresh air unit comprising: a housing having an airstream flowing therethrough; a pre-cooling portion, located within the housing, for reducing the temperature and moisture level of a gas in the airstream to a predetermined target zone on a psychrometric chart; and a dehumidification portion, located in the housing downstream of the pre-cooling portion, for removing a selected amount of moisture from the gas and for reheating the gas a selected amount of sensible heat gain; and a controller for the pre-cooling portion operably connected to the pre-cooling portion and controlling its operation to a control point; wherein the dehumidification portion includes a compressor section, a condenser section, an expansion section, and an evaporator section, all serially linked in a latent air conditioning circuit; wherein the evaporator section and the condenser section of the dehumidification portion are located in the airstream; wherein the evaporator section is upstream of the condensing section; wherein the condensing section is sized to provide a predetermined sensible heat gain from the condensing section; wherein the dehumidification evaporator section is sized to provide a desired amount of moisture removal; and wherein the pre-cooling portion is an air conditioning system comprising a compressor section, a condenser section, an expansion section and an evaporator section, all serially linked to form an air conditioning circuit and wherein the evaporator section of the pre-cooling portion is located in the airstream.

Claim 14

A fresh air unit comprising: a housing having an airstream flowing therethrough; a pre-cooling portion, located within the housing, for reducing the temperature and moisture level of a gas in the airstream to a predetermined target zone on a psychrometric chart; and a dehumidification portion, located in the housing downstream of the pre-cooling portion, for removing a selected amount of moisture from the gas and for reheating the gas a selected amount of sensible heat gain; and a controller for the pre-cooling portion operably connected to the pre-cooling portion and controlling its operation to a control point; wherein the dehumidification portion includes a compressor section, a condenser section, an expansion section, and an evaporator section, all serially linked in a latent air conditioning circuit; wherein the evaporator section and the condenser section of the dehumidification portion are located in the airstream; wherein the evaporator section is upstream of the condensing section; wherein the condensing section is sized to provide a predetermined sensible heat gain from the condensing section; wherein the dehumidification evaporator section is sized to provide a desired amount of moisture removal; and wherein the pre-cooling portion is an air conditioning system comprising a compressor section, a condenser section, an expansion section and an evaporator section, all serially linked to form an air conditioning circuit and wherein the evaporator section of the pre-cooling portion is located in the airstream.

Claim 15

The fresh air conditioning unit of claim 10 wherein the condenser section and the compressor section are not located in the airstream.

Claim 16

The fresh air conditioning unit of claim 10 wherein the compressor section includes a variable speed compressor.

Claim 17

The fresh air conditioning unit of claim 10 wherein the compressor section comprises a set of manifolded compressors and the compressors are staged.

Claim 18

The fresh air conditioning unit of claim 10 further including a blower in the housing providing a motive force to the airstream.

Claim 19

The fresh air conditioning unit of claim 2 wherein the evaporator section is upstream of the condensing section and wherein the evaporator section is sized to remove a predetermined amount of moisture.

Claim 20

The fresh air conditioning unit of claim 15 wherein the condensing section is sized to provide a desired sensible heat gain.

Claim 23

The method of claim 17 wherein operating the precooling portion step includes the further steps of establishing two or more adjacent cooling stages, cycling between these stages and controlling a discharge air temperature to a setpoint.

Claim 24

The method of claim 18 wherein average supply air dewpoint is controlled by establishing an average supply air drybulb temperature.

Claim 27

The method of claim 20 including the further steps of cycling the unit at the control points and thereby independently controlling average drybulb temperature and average dewpoint temperature.

Claim 30

The method of claim 22 including the further step of providing a constant airflow sequentially through the precooling portion and the dehumidification portion.

Claim 31

The method of claim 22 including the further steps of independently cycling the precooling portion to maintain an average dry bulb temperature and independently cycling the dehumidifier portion to maintain an average dewpoint temperature within the control envelope.

Claim 32

The method of claim 24 including the further step of placing a dry bulb sensor between an evaporator and a condenser of the dehumidifier portion.

Claim 33

The method of claim 24 wherein the precooling portion includes at least two compressors and wherein operating the precooling portion step includes the further step of staging the at least two compressors.