Patent Application
20080139104
The present invention relates generally to heat exchange apparatus having structural installations related to a wall, a floor, or a ceiling structure of a chamber.
The mechanical ventilation of livestock buildings and poultry houses is necessary to minimize stress in animals that can result in sickness and reduced performance. In a typical ventilation system, a fan creates a pressure differential between the inside of a building and the outside that moves fresh air into the building through one or more inlets or forces air out of the building through one or more outlets. Neutral pressure systems, however, use fans to force air into a building and other fans to force air out of a building, thus maintaining an equal pressure between the inside and outside of a building.
It is a fan's size and speed that determine the amount of fresh air that will enter a building. Nonetheless, it is the location, features, and regulation of the inlets that provide even air distribution with few drafts or dead air pockets. During cold weather, air inlets must direct incoming, cold air into a building with a velocity sufficient to permit blending with warm room air before it reaches animals. To somewhat reduce the amount of heat lost from a building, tempered air is often pulled through inlets open to a building's attic. Unfortunately, stale, but warm, air is vented from the building through separate outlets. Thus, much energy is wasted in conventionally ventilating and heating livestock buildings and poultry houses.
In light of the problems associated with the known systems for ventilating livestock buildings and poultry houses, it is a principal object of the invention to provide a heat exchange system that propels fresh air into a livestock building or poultry house and, simultaneously, preheats the fresh air by flowing it past the stale, but warm, air being vented from the livestock building or poultry house. Thus, the amount of energy required to heat the fresh air is minimized.
Position air inlets to promote adequate mixing of cool incoming air with warm air before entering the animal space.
It is another object of the invention to provide a heat exchange system of the type described that can be incorporated into newly constructed livestock buildings and poultry houses and can be retrofit into existing structures.
It is an object of the invention to provide improved features and arrangements thereof in a heat exchange system for the purposes described that is uncomplicated in construction, inexpensive to manufacture, and dependable in use.
Briefly, the heat exchange system in accordance with this invention achieves the intended objects by featuring ductwork having a header and at least one lateral in fluid communication with the header. The lateral includes a trunk passing through an opening in the exterior wall of a building. The trunk extends upwardly into the interior space of the building to an apex whose elevation is higher than the opening. A branching arm extends outwardly from said apex and has an open, terminal end that serves as an air outlet. A tubular sleeve loosely encloses the trunk from the apex downwardly through the opening so as to form an annular space between the trunk and the sleeve through which air is exhausted from the interior space. A fan is connected to the header for blowing fresh air from the exterior of the building into the header and through the lateral into the building.
The foregoing and other objects, features, and advantages of the present invention will become readily apparent upon further review of the following detailed description of the heat exchange system illustrated in the accompanying drawings.
The present invention may be more readily described with reference to the accompanying drawings, in which:
Similar reference characters denote corresponding features consistently throughout the accompanying drawings.
Referring now to the FIGS., a heat exchange system in accordance with the present invention is shown at 10. Heat exchange system 10 includes a fan 12 connected to ductwork 14 for blowing fresh air into a building 16, ventilating same. Ductwork 14 has a principal duct or header 18 that receives air discharged by fan 12 and conveys this air to one or more secondary ducts or laterals 20. Each lateral 20 has a trunk 22 the passes through an opening 24 in the exterior wall 26 of building 16. Each trunk 22 extends upwardly from opening 24 to an apex 28 where it connects to a pair of branching arms 30 whose open, terminal ends 32 served as air outlets. Each trunk 22 is loosely enclosed in a tubular sleeve 34 that extends from its apex 28 downwardly through an associated opening 24. The annular space 36, provided between each trunk 22 and sleeve 34, defines a channel through which air is exhausted from building 16. Air passing through annular space 36 conducts heat to trunk 22, warming trunk 22 and preheating the air within trunk 22 being blown into building 16.
Fan 12 is provided with a housing 38 mounted upon the exterior wall 26 of building 16. Housing 38 has an inlet 40 open to the atmosphere, outside of building 16, and an outlet 42 connected to the inlet of header 18. Positioned within housing 38 is an electric motor 44, the drive shaft of which is operatively connected to a fan blade 46. When motor 44 is energized, fan blade 46 is rotated by the drive shaft at an angular velocity sufficient to drive, say, 800 to 1200 cfm of air, into the inlet 40 and out of outlet 42 into header 18.
Principal duct or header 18 is a tube affixed to wall 26 on the exterior of building 16 so as to permit header 18, and consequently the air passing through header 18, to be passively warmed by the sun. To minimize pressure losses, header 18 extends horizontally away from fan 12. The end of header 18 nearest fan 12 is open so as to serve as the inlet thereto and the end of header 18 remote from fan 12 is capped. Between its opposite ends, header 18 is provided with one or more outlets 48 to which secondary ducts or laterals 20 are connected so as to be in fluid communication with header 18.
Each of the secondary ducts or laterals 20 comprises a tubular trunk 22 having an inlet end connected directly to an outlet 48 in header 18 and an outlet end or apex 28, located within building 16 adjacent its roof or ceiling 50, at an elevation that is higher than its inlet end. (The difference in elevation is normally several feet but is dependent upon the slope of the roof or ceiling 50 beneath which trunk 22 is suspended by brackets 52 and the length of trunk 22—both being matters of design choice. Nonetheless, effective deployment of system 10 may involve elevation differences on the order of several inches.) As shown, each trunk 22 extends at right angles from header 18 to provide each trunk 22 with the shortest length necessary to reach a given height beneath roof or ceiling 50.
Each of the secondary ducts or laterals 20 has a T-shaped configuration when viewed from above and is provided with a pair of branching arms 30 that are oriented 180° to one another and at right angles to trunk 22. Each of arms 30 is oriented horizontally and has an inlet end, connected directly to apex 28 of a trunk 22, and an open, terminal end 32 remote from apex 28. When two or more laterals 20 are employed in a building 16, as illustrated in
For the sake of convenience, terminal ends 32 of arms 30 are shown to be fully open, but they can be fitted with: registers, vents, dampers, louvers, or shutters as required by a user to minimize pressure losses and to control the flow of fresh air into building 16. The goal of arms 30 is to place fresh air within building 16 at points widely located from the apex 28 of each trunk 22 where each sleeve 34 begins. Thus, arm configurations other than the one illustrated in the FIGS. are possible, provided that such offer a good living environment for animals in building 16.
Each tubular sleeve 34 is spaced away from trunk 22 along its entire length so that the dimensions of annular space 36 are maximized to increase the time of contact between vented air and trunk 22 as well as to minimize pressure losses so that fan 12 need not work excessively hard to vent air from building 16. A ring-shaped inlet 54 to space 36 is provided between trunk 22 and sleeve 34 and a similar, ring-shaped outlet 56 from space 36 is provided between trunk 22 and sleeve 34 adjacent opening 24 in wall 26. Sleeve 34 is sealed within opening 24 against wall 26 to prevent the passage of air from building 16 around space 36.
Ductwork 14 (header 18, trunk 22, arms 30, and sleeve 34) is made from a corrosion resistant material such as aluminum sheeting folded and joined to form hollow tubes. PVC pipe, however, is preferred material because of its light weight, low cost, and extreme durability. Trunk 22 and arms 30 having a diameter of about 4-8 inches (10-20 cm) and sleeve 34 has a diameter of about 6-8 inches (15-20 cm). Header 18 is larger in diameter than trunk 22 so as to carry greater volumes of air with small pressure losses.
Air within building 16 is warmed to a temperature that is comfortable for livestock and poultry held with building 16 by means of a forced air heater of conventional construction (not shown). A forced air heater typically derives heat by passing electricity through a resistor or by burning natural gas. If desired, the forced air heater can be connected directly to fan 12 so that warmed air can be driven efficiently into ductwork 14 and, then, into building 16.
After the installation of heat exchange system 10 is accomplished in/on building 16 using techniques known in the art, its use is straightforward. Simply energizing fan 12, by connecting it to a power source, causes fresh air from outside of building 16 to be driven through header 18 and laterals 20 into building 16. Fresh air is ejected from terminal ends 32 of arms 30 positioned closely adjacent roof or ceiling 50 and mixes with warmed air already in building 16. Mixing occurs primarily as the cool, fresh air is blown into warm air that has a tendency to collect adjacent to roof or ceiling 50. Mixing of warm and cold air occurs secondarily as cooler air settles downwardly toward floor 58 of building 16 upon which livestock or poultry is positioned. As mixing takes place, some of the stale, damp, and warm air collected against roof or ceiling 50 passes into the inlet 54 to the annular space 36 and is forced by a pressure differential caused by the operation of fan 12 downwardly toward outlet 56. As the warm, stale air passes downwardly through annular space 36 it warms each trunk 22 which, in turn, warms the fresh air passing upwardly through each trunk 22. The preheated, warmed, fresh air enters building 16 to ventilate livestock or poultry therein with considerable energy savings.
While my heat exchange system 10 has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications can be made to it. For example, the number and location of laterals 20 as well as the number and location of branching arms 30 can be varied as a matter of design choice. Therefore, it is to be understood that the present invention is not limited to heat exchange system 10 described above, but encompasses any and all such systems within the scope of the following claims.
