Patent Application
20060211361
The invention at hand relates to either heating or cooling the air in a large building, especially with a floor area having multiple persons working therein. The invention is directed primarily to the personal comfort of a person working at a workstation including a desk by directing conditioned air to the immediate vicinity of the person or persons present at those workstations and by giving those persons control over the flow and direction of the conditioned air, and to providing displacement ventilation to the surrounding area.
In the field of heating and cooling, generally known as “air conditioning”, there are known problems causing discomfort to the occupants in the building or a room. Inefficiencies in the system result in excessive operating costs in the operation of the building and problems in the operation and control of the present systems. Also present systems tend to have poor indoor air quality (IAQ).
U.S. Pat. No. 374,424 discloses a system for supplying fresh air to the environment of an auditorium and wherein the air blows directly to the chair which is occupied by a person without any mechanical intervention or modification.
U.S. Pat. No. 1,194,527 shows the ventilation of a class room wherein the outside air under pressure enters the class room through a ventilated floor panel and is further distributed into a desk where the pupil is sitting. The pupil may have some control over the amount of air flowing to or through the desk. In both of the above cited patents, the air is not conditioned or modified as to heat or cold.
U.S. Pat. No. 2,140,829 describes an air conditioning system wherein there is a cooling of high ceiling rooms by providing a stratum of cooled and dehumidified air in the lower levels of the room up to the height of the occupants without considering the relatively large cost and the complications of treating all the air in the room.
U.S. Pat. No. 2,341,125 illustrates a way of ventilating a desk at a workstation by simply mounting a fan within the rear of the desk and by blowing air at the person and by giving the person working at the desk somewhat of a control of the fan by positioning the same or by controlling the speed of the air flow.
U.S. Pat. No. 2,507,643 teaches the ventilation of restaurant equipment by supplying air to and from restaurant table and their equipment. The person or persons seated at the equipment have no control over the flow and/or the direction of the flow of the air.
U.S. Pat. No. 2,572,120 shows a ventilated table having a fan mounted in a horizontal position which is emitting air in horizontal direction and the air flow out of the lateral sides of the table.
U.S. Pat. No. 2,616,617 illustrates a ventilated table similarly constructed as the table shown in the immediately cited patent above.
U.S. Pat. No. 2,734,990 discloses a desk as a workstation having a combination fan and heater mounted therein. The fan blows the conditioned air (heat) directly at the person sitting at the desk. The direction of the air is adjustable by tilting the fan in one direction or the other and the level of the heat is adjustable by way of a rheostat.
U.S. Pat. No. 2,835,186 discloses an air conditioning system wherein there are upstanding air emitting columns receiving air through ducts in the floor of the system. It is considered to be a local or spot air conditioning system.
U.S. Pat. No. 2,877,990 discloses a novel building structure embodying a multi-cellular load supporting floor having an air distributing and an electrical wiring system therein wherein both the heated and cooled air and the electrical wiring are distributed through selected ones of the cells in the floor.
U.S. Pat. No. 3,322,055 teaches the elimination of duct work in a building by adding fan driven diffusers in the ceiling whereby the air in the chamber in the ceiling may be used as an unpressurized distribution chamber.
U.S. Pat. No. 3,516,347 shows the use of a double plenum air conditioning system which creates a space between a structural and the floor of the roof above the building and the double plenum is divided by a horizontal partition into an upper part and a lower plenum and a supply of air is fed to one of the plenums and return air is withdrawn form the other of the plenums. The supply of air can be hot, cold or neutral. Inlets and outlets connect the plenums through the slab to the room below or through the floor to the room above.
U.S. Pat. No. 4,035,018 discloses a system whereby conditioned air is distributed through a floor plenum to a multiple of chairs having exhaust connected to each of the chairs to expel the conditioned air into the general environment of the room. The occupants of the chairs have no control over the speed and the direction of the air flowing to the chairs.
U.S. Pat. No. 4,135,440 illustrates an air conditioning system both ceiling and floor plenums and each of the plenums has individual air outlets diffusing into the room between the plenums. In addition, there are individual elongated air outlets tubes suspended from the ceiling plenum or upstanding from the floor plenum. Each of the outlet tubes can be directed against a person sitting at a workstation. The respective person has control over the direction of the or emanating from the outlets.
U.S. Pat. No. 4,378,727 shows an open space office system including a plurality of freestanding workstations which are constructed of vertical panels and are removably mounted to an upper board member to direct cooling air to a user of the organization permitting its use in a convenient manner in various environments.
Another known prior art air conditioned workstation is known under the word “CLIMADESK”. It is described as a plenum which is installed under the top of the desk. The air plenum has an inlet to receive conditioned air from an air conditioning unit being placed apart but adjacent to the desk. The air conditioning unit receives fresh air from the outside of the building through an air intake vent. The air plenum installed under the top surface of the desk directs conditioned air toward a person sitting at the desk. The conditioned air is exiting toward the person by way of two front louvers and is further directed upwardly from the top surface of the desk in front of the person sitting at the desk. The temperature of the conditioned air can be controlled by way of a thermostat located on a front panel of the desk. This kind of an arrangement greatly reduces the mobility of such a workstation and thereby eliminates an effective arrangement of all of the workstations in an open office concept.
German published specification (Offenlegungsschrift) No. 24 07 448 discloses a workstation in the form of a desk receiving conditioned air by way of a flexible hose through the floor having air ducts therein. The occupant at the desk has no control over the flow of the air with regard to direction and/or speed.
German published specification (Offenlegungsschrift) No. 27 19 570 discloses a similar system as was disclosed in the German publication above. In this arrangement, conditioned air is supplied by way of ducts located below the floor of the open office area. From there the conditioned air is funneled to upstanding tubes located at each of the workstations. The conditioned air is blown into the room at a location above the desk surface at each of the workstations. The occupant at the desk has some control over the direction and the speed of the air flowing through the outlets of the upstanding tubes.
German published application (Offenlegungsschrift) No. 29 38 702 is similar to both German publications discussed above and does not add any more knowledge to the already known prior art.
Japanese Patent No. 61-11535 discloses an air conditioning system having a floor plenum installed over a floor slab of a building. The conditioned air is driven by a fan into a hollow partition situated over an opening in the floor. Conditioned air may exit into the room at a higher elevation than the height of the desk. At the bottom of the floor whereupon the desk is placed, there is a further air outlet which is directing conditioned air to the feet of a person sitting at the desk. It appears that the person has very little control over the volume, speed and direction of the conditioned air entering the vicinity of the desk.
An object of the invention is to present a system for distributing conditioned air throughout an open office layout in a most efficient way. In a building whether large or small, for example, the control of temperature, air flow, humidity and the like, or even individual rooms and workstations leaves many persons in the building or within a room or in the vicinity of a workstation uncomfortable or dissatisfied with the condition of their particular environment. Different people have different levels of metabolism and therefore different comfort needs.
Also, different locations in a building or on a floor, or even a single room or closer yet in the vicinity of a workstation, are not satisfactorily heated or cooled, that is, air conditioned, and give rise to complaints about discomfort and illness, resulting in absenteeism, sickness and, of course, loss of productivity.
Further, conventional air conditioning systems generally require expensive duct work and installations, usually in floors or ceilings or both, which cause unnecessary heating or cooling of unused space, particularly the spaces that between the room dividers or partitions there is no means for providing the workstation occupant with an acceptable flow of conditioned air. Therefore, the workers often become uncomfortable, or even ill, which in turn decreases productivity and/or causes absenteeism.
Consequently, in the field of heating and cooling there exists a need for providing a flow of conditioned air directly to or near a person sitting at a workstation, without blowing at the person and without creating a draft, as well as to occupants of the surrounding area. More particularly, there exists a need for a workstation to be so equipped wherein the occupant can individually control and obtain the amount of conditioned air supplied within the workstation while maintaining a desirable flow of conditioned air to surrounding areas. The amount of conditioned air within the workstation is controlled by the person to maximize the comfort level, well being health and level of productivity of each worker, while maintaining a desirable flow of conditioned air to surrounding areas.
Conventional room dividers for workstations may supply conditioned air to workstations, which conditioned air flows through an air flow grille at about the height where the worker is seated but the worker has very little control over the flow of the air or its direction. Such room dividers consist of a hollow space being created by panels that are spaced from each other by a predetermined distance to define an air flow there between. The hollow room divider is placed on an opening in the floor which floor is spaced above the slab of the building which constitutes the building floor to thereby form a large or major air plenum. This air plenum, therefore, is formed by the slab of the building floor and the raised floor being spaced above the slab of the building. The air plenum is charged with conditioned air (hot or cold) at or near room pressure to be explained below. Applicants' prior art U.S. Pat. Nos. 4,646,966; 4,860,642; 5,135,436; 5,238,452 and 6,318,113 are directed to conditioned air being supplied through a floor plenum and from there distributed to individual workstations through various forms of air delivery. This system differs from others by pressurizing the air which causes excessive leakage and loss of energy. All of the noted patents operate in various satisfactory manners, but there is still room for improvement. In all the known prior art patents as well as applicants' own patents there is a tendency of the air that is introduced into the workstation and into various open spaces to create air streams or air whirls that have a detrimental effect on the overall climate within the room where persons are working. This circulating air does not contribute to the cleanliness of the ambient air. On the contrary, the circulating air will pick up various contaminants present in the ambient atmosphere until exhausted.
The inventive workstation is constructed to take advantage of the known principle of “displacement ventilation”. In all known systems mentioned above the air conditioning is called the mixing type where cold and hot or warm are mixed by blowing the conditioned air into a workstation or an open office area. A typical displacement ventilation system for cooling supplies conditioned air from a low side wall diffuser of very low velocity to limit entrainment of impurities. In the inventive concept, the conditioned air is supplied from a plenum below the floor which will be explained below. The supply temperature is slightly lower than the desired room air temperature, and the supply air velocity is very low. From the floor plenum below the conditioned air is directly introduced to the occupied zone, where the occupants stay. Exhausts are located at or close to the ceiling through which the warm room air is exhausted from the room. Because it is cooler than the room air, the supply air spreads near the floor and then is heated by the heat sources in the occupied zone. These heat sources (e.g., persons and computers) create upward convective flows in the form of thermal plumes. The plumes remove heat and contaminants that are less dense than air from the surrounding occupied zones.
By using the principle of “displacement ventilation”, the amount of supply air is less than the mixing-type system. This necessitates a careful design of the system configuration and operation to adequately handle the space cooling loads. The inventive workstation will take the above into account and will be described below.
