Patent Application
20180142912
The present invention generally relates to an environmental room, and more particularly to an environmental room designed to control temperature and/or humidity levels at very close tolerance and uniformity levels.
Environmental rooms, which are essentially enclosures designed to provide carefully controlled conditions therein, are useful in a variety of applications. For example, environmental rooms may find use in biological, medical, and pharmaceutical applications, as well as industrial and consumer product testing and development, electronics, aeronautics and aerospace applications, automotive applications, archival storage, materials testing, entomology, crop and soil science and plant growth, control for human performance test labs, film testing and development, and stability/shelf-life testing.
Typically, an environmental room is designed to provide continually controlled conditions, particularly temperature and/or humidity levels. If desired, other variables such as levels of contamination and pressure may be controlled. In such environmental rooms, it is usually desirable to provide very uniform air temperature at working surfaces as well as throughout the entire room, with a high degree of accuracy (referred to as tolerance). Uniformity generally refers to the temperature distribution, and may refer to the deviation from a specified temperature maintained across the room at working height. With environmental rooms, there are two typical temperature uniformity specifications: ±1.0° C. or ±0.5° C. A desired uniformity of 21° C.±0.5% would mean that the temperature at one end of the working surface can be 20.5° C., but no other point at the working height can exceed 21.5° C., even when all the specified temperature and moisture loads are active in the space at the same time. A typical relative humidity uniformity level may, for example, be on the order of ±5%.
In addition to uniformity, gradient is also important. In an environmental room, the gradient generally refers to the maximum temperature difference between any two points in the room. For example, in the 21° C. room temperature with a uniformity of ±0.5° C., a maximum gradient may be 1.0° C. In order to achieve a particular gradient, it is important to circulate air to evenly distribute and remove heat within the room.
In certain applications, an environmental room is in the form of a test chamber designed to provide variations in one or more conditions therein to determine how the contents of the enclosure react; for example, through exposure to extreme temperatures, thermal cycling, and/or extreme humidity. Such test chambers, thus, must be designed to provide a particular set of conditions within the chamber and must be able to vary one or more of those conditions within the chamber on demand.
Generally, an environmental room is provided as a stand-alone room within an existing building. For example, as depicted in
As shown in the top cutaway view in
The ceiling plenum(s) may further house light fixtures 34 to provide adequate lighting to the room below. In some cases, one or more return air wall plenums 36 are provided for directing air from the floor area of the room and to the ceiling plenum area for proper temperature and humidity control.
Conventionally, when designing an environmental room, one generally begins with a determination of the necessary air flow for the entire room. Based on the air flow need, one then selects the appropriate evaporator and condenser units. As such, the size of the overall system needed to control the temperature and humidity levels is based, ultimately, on the total quantity of air flow. In addition, the system is typically designed based on a schematic in which the latent coil, evaporator, condenser, fans, heater, humidifier, etc. are all positioned on one side of a room's ceiling plenum space (e.g., as depicted in
It would be desirable to provide improvements to such environmental room designs. In particular, it would be desirable to provide improved environmental rooms that are capable of controlling temperature and humidity levels at very close tolerance and uniformity control levels, but with reduced energy consumption during operations and lower overall upfront costs.
Embodiments of the present invention provide an environmental room configured to control temperature and/or humidity levels at very close tolerance and uniformity levels. In particular, according to embodiments of the present invention, air flow of the system is divided, and only a portion of total air flow (also referred to herein as “treated air flow”) for the room is passed through air conditioning components. As referred to herein, “air conditioning components” include the various components/equipment provided to modify one or more properties of the air flow, particularly temperature and/or humidity. One or more fans are provided and arranged so as to mix the portion of air flow that has passed through the air conditioning components with the remainder portion of air flow (wherein the remainder portion of air flow is also referred to herein as “untreated air flow”) that does not pass through the air conditioning components, and provide a homogenous mixture that is then distributed to the environmental room.
By providing an environmental room design in which only a portion of total air flow is passed through the air conditioning components, the required size and capacity of these components can be reduced. This results in lower upfront component costs as well as lower ongoing operating costs by reducing overall energy consumption. Further, such an environmental room design makes it possible to achieve tolerance and uniformity control that is far superior to those provided by currently available environmental room designs. In particular, while current environmental rooms may achieve temperature uniformity of ±1.0° C., or at best ±0.5° C., the present invention environmental rooms are capable of achieving temperature uniformity of ±0.3° C. or better (where “better” refers to lower than ±0.3° C., potentially reaching down to ±0° C.). Further, while current environmental rooms may achieve humidity uniformity on the order of ±5%, the present invention environmental rooms are capable of achieving humidity uniformity of ±3% or better (where “better” refers to lower than ±3%).
According to one aspect, the present invention provides an environmental room comprising an outer housing having a top surface, a bottom surface, and side surfaces; a floor, ceiling, and walls disposed within the outer housing to define an environmental room chamber, the environmental room chamber being provided with a required temperature level and a required humidity level; a ceiling plenum disposed between the ceiling and the top surface of the outer housing; the ceiling plenum divided into at least one conditioning section and at least one distribution section; air conditioning components disposed within the conditioning section, the air conditioning components being configured for modifying temperature and/or humidity of supplied air; and one or more fans disposed in communication with the conditioning section and the distribution section. The environmental room is configured such that air flow from the environmental room chamber is circulated from the environmental room chamber into the conditioning section of the ceiling plenum, and is then divided so that a only a portion of the air flow through the conditioning section is directed through the air conditioning components, and a remainder of the air flow does not pass through the air conditioning components. The portion of air flow directed through the air conditioning components forms treated air, and the remainder of the air flow forms untreated air. The treated air and the untreated air is directed through the one or more fans to form a homogeneous mixture of air having the required temperature level and the required humidity level.
Embodiments according to this aspect can further include one or more of the following features. The air conditioning components can comprise at least one latent heat coil and/or desiccant drier, at least one evaporator, at least one heating assembly, and at least one humidifier. Dividing the ceiling plenum into at least one conditioning section and at least one distribution section, and passing only a portion of the air flow through the air conditioning components, provides a reduction in size, capacity, and/or number of air conditioning components for modifying temperature and/or humidity of air as compared with the size, capacity, and/or number of air conditioning components if the entire air flow was passed through the air conditioning components. The environmental room can further include a control panel for setting the required temperature level and the required humidity level in the environmental room chamber, the control panel being in communication with one or more temperature and humidity sensors disposed in the environmental room chamber and/or in the ceiling plenum. The environmental room can be configured such that about 20% to about 50% of the total air flow can be directed through the air conditioning components. The homogeneous mixture of air is provided with a temperature uniformity of ±0.3° C. or better. The homogeneous mixture of air is provided with a humidity uniformity of ±3% or better.
According to another aspect, the present invention provides a method for fabricating an environmental room having reduced energy requirements comprising: forming an outer housing having a top surface, a bottom surface, and side surfaces; forming a floor, ceiling, and walls within the outer housing to define an environmental room chamber, the environmental room chamber being provided with a required temperature level and a required humidity level; forming a ceiling plenum between the ceiling and the top surface of the outer housing; dividing the ceiling plenum into at least one conditioning section and at least one distribution section; disposing air conditioning components for modifying temperature and/or humidity of air within the conditioning section; disposing one or more fans in communication with the conditioning section and the distribution section; providing air flow passages from the environmental room chamber for circulation from the environmental room chamber into the ceiling plenum where the air flow is provided to the conditioning section and is divided so that a portion of the air flow is directed through the air conditioning components, and a remainder of the air flow is directed through the conditioning section without passing through the air conditioning components. In particular, the portion of air flow directed through the air conditioning components forms treated air, and the remainder of the air flow forms untreated air, where the treated air and the untreated air is directed through the one or more fans to form a homogeneous mixture of air having the required temperature level and the required humidity level.
Embodiments according to this aspect can further include one or more of the following features. The air conditioning components can comprise at least one latent heat coil and/or desiccant drier, at least one evaporator, at least one heating assembly, and at least one humidifier. Dividing the ceiling plenum into at least one conditioning section and at least one distribution section, and passing only a portion of the air flow through the air conditioning components reduces a size, capacity, and/or number of air conditioning components for modifying temperature and/or humidity of air as compared with the size, capacity, and/or number of air conditioning components if the entire air flow was passed through the air conditioning components. The method further comprises disposing a control panel for setting the required temperature level and the required humidity level in the environmental room chamber, the control panel being in communication with one or more temperature and humidity sensors disposed in the environmental room chamber and/or in the ceiling plenum. About 20% to about 50% of the total air flow is directed through the air conditioning components. The homogeneous mixture of air is provided with a temperature uniformity of ±0.3° C. or better. The homogeneous mixture of air is provided with a humidity uniformity of ±3% or better.
According to another aspect, the present invention provides a method for reducing the energy requirement of an environmental room, comprising: forming a ceiling plenum within the environmental room, the ceiling plenum being divided into at least one conditioning section and at least one distribution section; disposing air conditioning components for modifying temperature and/or humidity of air within the conditioning section to produce treated air having a modified temperature and/or humidity; circulating air flow from an environmental room chamber to the ceiling plenum, the environmental room chamber having a predetermined required temperature level and required humidity level; directing only a portion of the air flow less than 100% through the air conditioning components in the conditioning section, and directing a remainder of the air flow to the conditioning section but not through the air conditioning components; modifying the temperature and/or humidity of the portion of air flow directed to the conditioning section to produce treated air; and mixing the treated air with remainder of the air flow to provide a homogeneous mixture of air having the required temperature level and the required humidity level.
Embodiments according to this aspect can further include one or more of the following features. About 20% to about 50% of the total air flow is directed to the air conditioning components. The homogeneous mixture of air is provided with a temperature uniformity of ±0.3° C. or better. The homogeneous mixture of air is provided with a humidity uniformity of ±3% or better.
Other systems, methods and features of the present invention will be or become apparent to one having ordinary skill in the art upon examining the following drawings and detailed description. It is intended that all such additional systems, methods, and features be included in this description, be within the scope of the present invention and protected by the accompanying claims.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principals of the invention.
The present invention generally provides improved environmental rooms that are capable of achieving previously unattainable levels of uniformity and tolerance levels, particularly with respect to temperature and humidity control. In particular, the present invention provides an environmental room in which a plenum space is divided into a conditioning section and one or more distribution sections. According to embodiments of the invention, only a portion of the air flow in the system passes through air conditioning components in the conditioning section. By reducing the total air flow passing through the air conditioning components, these various air conditioning components can be reduced in size, thus reducing construction costs. In addition, energy consumption is reduced due to the decrease in treated air flow.
The general structure of the present environmental room can be in accordance with the general structure of conventional environmental rooms. In particular, the environmental room is typically constructed as a stand-alone room for placement in an existing building. As such, it is designed to have its own floor, ceiling and walls. The size of the room may vary widely depending on ultimate use, and the room can be formed as a single compartment or may be divided into multiple compartments, if desired. Access may be provided through one or more doors of varying sizes to allow for entry of people, as well as the various equipment that may enter and/or exit the room.
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
The outer housing 102 can be fabricated of any conventional materials used on forming environmental rooms, for example, insulated walls fabricated of a cladding material (e.g., various metals such as galvanized steel and aluminum, plastic, etc.) in combination with an insulating material (e.g., foamed-in-place isocyanurate insulation). Disposed within the outer housing 102 are the necessary integral parts for operating the environmental room and equipment therein such as, for example, refrigeration piping, electrical wiring, control wiring, and various connectors. Electrical feeds for the equipment and control panel are further suitable disposed therein to thus provide a complete self-contained unit and system, with all essential plenums, controls, balanced air circulation and all other equipment necessary to reach the specified environmental conditions.
The floor 104 is in accordance with any conventional environmental room floor designs. In some embodiments, the floor 104 is preferably constructed to be about 3″-4″ thick, and is fabricated of any conventional materials. In an exemplary embodiment, the floor is insulated and is formed of a combination of top and bottom layers of cladding (e.g., galvanized steel, aluminum, plastic, etc.) sandwiching a layer of insulation. The walls and ceiling are preferably constructed using about 3″-4″ thick rectangular wall panels. The panels may be constructed in accordance with any conventional panel designs. If desired, one or more hermetically sealed observation windows may be provided in one or more walls.
In the illustrated embodiment, the environmental room 100 includes three separate chambers 101, 103, 105 separated by dividers 107, with each chamber 101, 103, 105, having its own entry door(s) 109. It is noted that while the present invention depicts three separate chambers, the present invention is not limited as such, and could be provided with a single chamber, or any other desired number of chambers.
A control panel 111 is provided for each chamber 101, 103, 105 at any convenient location along the outer housing 102, such as near one or more entry/exit doors 109. The control panel 111 is configured and designed to allow a user to set, modify, monitor, etc. the various conditions (e.g., temperature, humidity, etc.) within the chambers 101, 103, 105. By having a plurality of chambers 101, 103, 105, each with its own control panel 111, one can beneficially set each of the chambers' 101, 103, 105 conditions independently, so as to provide the same or different conditions in any of the chambers 101, 103, 105 as needed.
According to embodiments of the present invention, the control panel 111 includes a temperature control unit that may generally be in accordance with any conventional temperature control unit and, for example, may be microprocessor based. The temperature control unit is configured to continuously monitor room conditions (through communication with one or more sensors disposed within the room and/or ceiling plenum) versus the set temperature specifications, and can provide an output which will modify the treatment equipment (particularly the conditioning system) capacity in response to any deviation from the set temperature specification. The sensor(s) may be provided for rapid response to temperature fluctuation. The control panel 111 further includes a relative humidity control unit, which may generally be in accordance with any conventional humidity control unit and, for example, may be microprocessor based. The relative humidity control unit is configured to continuously monitor room humidity conditions (through communication with one or more sensors disposed within the room and/or ceiling plenum) versus the set humidity specification, and can provide an output which will modify the treatment equipment (particularly the conditioning system) capacity in response to any deviation from the set humidity specification. The sensors may be provided for rapid response to humidity fluctuation. An alarm and safety control system may further be provided, which monitors for high and low temperature and/or humidity set points, thus triggering the alarm sound and, if appropriate, shutting down heat producing devices (for a high temperature alarm set point), or shutting down cold producing devices (for a low temperature alarm set point) if the conditions within the environmental room deviate above or below the high and low set points.
The environmental room 100 is designed with a particular inner ceiling 106 height (e.g., 7-8 ft. above the finished floor 104) above which a ceiling plenum 112 (typically about 1-2 ft. in height above the inner ceiling 106) is disposed. The ceiling plenum 112 provides air circulation and distribution for the environmental room, and houses much of the equipment required for maintaining the desired temperature and humidity performance levels within the chamber below. The ceiling plenum 112 may further be arranged to house light fixtures 113 to provide lighting to the room below, as well as any other fixtures and components conventionally provided within a ceiling plenum of an environmental room (e.g., particulate filters, contaminant filters, air blowers, etc.). In some cases, one or more return air wall plenums 114 are also included for directing air from the floor 104 area of the room to the ceiling plenum 112 for proper temperature and humidity control.
According to the present invention, as shown in
As noted, the equipment necessary to “treat” air flow to provide the desired temperature and humidity specifications (i.e., air conditioning components) is disposed within the conditioning section 116. Because only a portion of the total air flow for a given chamber is passed through the air conditioning components, the equipment size can be reduced (e.g., by providing equipment with reduced capacity and/or by providing fewer numbers of a given type of equipment—e.g., two heater assemblies as opposed to four) as compared with the equipment that would be necessary in a conventional environmental room. As depicted in
As such, the conditions within the chamber 101, 103, 105 can be controlled by adding and/or removing moisture and/or heating and/or cooling the portion of air flow that is circulated from the chamber 101, 103, 105 and through the air conditioning components within the conditioning section 116. The air passing through the air conditioning components can, for example, be heated by the heater assembly 126 if needed, through the control of the control unit 111 based on sensed conditions within the chamber. In addition, the air can be cooled by, for example, passing through the evaporator 124. If humidity control is needed, then a moisture input can be provided to increase humidity of air directed through the conditioning section 116, or a drying input can be provided to decrease humidity of air directed through the conditioning section 116. For example, a moisture input can include transporting a water supply into the conditioning section 116, and a drying input can include utilizing latent refrigeration coils, desiccant dehumidifiers, or transporting dry air or the like into the conditioning section 116.
Thus, an air flow is provided into the ceiling plenum 112 as shown by the downward directed and upward directed dashed arrows (this is schematically depicted in the right chamber 105 only). A portion of this air (which is not 100% of the air flow) passes through the air conditioning components within the conditioning section 116 (this air flow is depicted in
As depicted in
Because the homogeneous mixture is formed of (1) a percentage of treated air having a first set of conditions (in other words, a particular temperature and humidity as obtained through the air conditioning components/equipment) and (2) a percentage of untreated air having a second set of conditions (in other words, a temperature and humidity of circulated air that has not been treated/adjusted), the percentage of treated air vs. untreated air as well as the first set of conditions and second set of conditions are all taken into account so as to form the homogeneous mixture with the necessary room specifications. According to embodiments of the present invention, the percentage of air that is passed through the air conditioning components is about 20-50% of the total air flow. Thus, the remainder of the air (untreated air) makes up the remainder 80-50% of the total air flow. According to an exemplary embodiment of the invention, this ratio of treated air to untreated air remains constant or relatively constant, while the air conditioning components vary their output in order to provide the desired homogeneous mixture having the desired composition and specifications required in the environmental chamber below. In other words, for example, if the temperature of the homogeneous mixture needs to be reduced more, then the air conditioning components function so as to reduce the treated air temperature further. This applies equally to increases in temperature as well as increases and decreases in humidity.
By splitting up the plenum space so that only a portion of the total air flow passes through the air conditioning components for treatment, smaller and/or fewer units of equipment (e.g., evaporator and condenser units) can be used than would otherwise be required in a conventional environmental room in which the entire air flow passes through the air conditioning components/equipment. This beneficially provides lower construction costs and a reduction in energy consumption. In addition, the design of the system provides for improved uniformity of the desired environmental parameters, particularly temperature and humidity uniformity.
It is noted that while the present detailed description refers generally to environmental rooms, the present design could beneficially be applied to any specific variety of controlled rooms such as, for example, stability rooms, warm rooms, cold rooms and test chambers.
