Cold Air Flow Control Apparatus

Many commercial, industrial, and even residential establishments have cold rooms or refrigerated rooms primarily for storage and preservation of food items, as in restaurants, grocery stores, hotels, taverns, hospitals, food processing establishments and the like. The energy requirements of operating such a cold area can be significant. In winter, particularly in northern climates, this results in the anomally that energy is being expended to cool a room in a building that is being heated. In northern climates, during much of the year, the ambient outside temperature of the air is at or below the temperature at which a cold room is normally maintained. Generally the temperature maintained in such cold rooms is above freezing. Storage of food items of the type normally stored in cold rooms directly in an outside environment results in freezing or in alternately freezing and thawing.

The invention relates to an apparatus to circulate and regulate the flow of cold air from an outside, cold environment to and through a cold room located in a building heated to a temperature above the ambient outside temperature, such as a restaurant, grocery store, tavern, hotel, or the like. The apparatus saves some of the energy normally expended by refrigeration equipment in keeping a cold room at a low temperature by drawing cold air from an outside location into the cold room to replace warmed air. The apparatus includes intake duct work open to a location outside of the building and also open to the cold room to draw air from the outside location into the cold room. The apparatus also includes exhaust duct work open to the cold room to exhaust warmed air from the cold room. Blowers are associated with the duct work in order to move the air. Temperature controls are associated with the blowers such that when the outside ambient temperature is below an acceptable upper limit, the apparatus can be operated and when the temperature in the cold room approaches or exceeds a high temperature boundary, the apparatus is automatically operated to introduce cold air into the cold room, while expelling warmed air until the temperature inside the cold room drops to a low temperature boundary at which time the apparatus shuts off. Filters can be associated with the intake duct work in order to filter or clean the air as it enters the cold room.

FIG. 1 is a fragmentary view partly in section showing a cold room and the cold air flow control apparatus of the invention both installed in a building;

FIG. 2 is an enlarged sectional view of a portion of the cold air flow control apparatus of FIG. 1 taken along the line 2--2 thereof.

FIG. 3 is a reduced scale sectional view of the cold air flow control apparatus of FIG. 2 taken along the line 3--3 thereof;

FIG. 4 is an enlarged sectional view of a portion of the cold air flow control apparatus of FIG. 2 taken along the line 4--4 thereof;

FIG. 5 is an enlarged sectional view of a portion of the cold air flow control apparatus of FIG. 2 taken along the line 5--5 thereof; and

FIG. 6 is a diagrammatic depiction showing the control circuit of the cold air flow control apparatus.

Referring to the drawings, there is shown in FIG. 1 a cold air flow apparatus of the invention indicated generally at 10 installed on the outside surface of a top wall 11 of a cold room 12 which is further defined by adjacent complementary walls 13 and 14. Cold room 12 is installed inside of a building 15 partially defined by outside building walls 16 and 17. Cold room 12 has a normally closed and insulated interior volume 18 which can contain racks or shelves 19 for the storage of food items or other perishable items which normally require storage in a cold environment for prolonged preservation. The interior 18 of cold room 12 is normally cooled by standard refrigeration equipment (not shown) and cold air flow apparatus 10 is operative to alleviate some of the energy needs of the standard refrigerator equipment by introducing cold air from outside of the building walls 16, 17 and to the interior 18 of cold room 12 to assist in maintaining a low temperature environment therein, and at the same time providing for exhaust of warmed air from the interior of cold room 12.

As shown in FIGS. 1 and 2, flow control apparatus 10 includes a box-like blower housing 21 fastened by brackets 22 to the outer surface of wall 11 of cold room 12. Housing 21 has laterally spaced side walls 21A and 21B connected to transverse end walls 21C and 21D and top and bottom walls 21E and 21F. The interior of housing 21 is divided by a median portion 23 into an air intake chamber 25 and an air exhaust chamber 26. A first or upstream intake duct 28 extends from the location outside of the building, through an opening in one of the building walls, and to the intake chamber 23 of housing 21. A second or downstream intake duct 29 extends from the opposite end of chamber 25, through an intake opening of wall 11 of cold room 12, and opens into the interior 18 of cold room 12.

The purpose of the upstream and downstream ducts 28, 29 and intake chamber 25 is to provide a conduit for the flow of cold air from a location outside of the building 15 to the interior of cold room 12. An intake blower 31 is mounted on a bulkhead 32 that spans the width of chamber 25 to define a plenum chamber 33. Intake blower 31 is operable by an electric intake blower motor 34 and is positioned to direct air incoming from upstream intake duct 28 through plenum 33 which opens to the downstream intake duct 29.

At the entrance or intake end of chamber 25 where the upstream intake duct 28 opens to the chamber 25 is a power operated louver assembly 36 of a usual and preferred type known in the art. Referring to FIG. 4, louver assembly 36 includes a frame 37 carrying a plurality of transverse, vertically spaced rotatable rods 38. Rods 38 have louver blades 39 mounted for rotation on them for rotation between a vertically orientated, closed orientation and a horizontal, open orientation as shown. In the closed orientation, air is blocked from flowing into the intake chamber 25 through the upstream intake duct 28. This is to close the intake conduit when apparatus 10 is not operating. In the open orientation, air is free to flow from the outside location through the upstream intake duct 28 and into the intake chamber 25. As shown in FIG. 2, a louver assembly motor 41 is provided for opening and closing the louver blades 39. Louver blade assembly motor 41 is electrically associated with intake blower motor 34 such that when intake blower motor 34 is operative, louver blade assembly motor 41 operates to open louver assembly 36. When intake blower motor 34 shuts off, louver assembly motor 41 operates to close louver assembly 36 by rotation of louver blades 39 to the generally vertical orientation.

A filtering system is provided to filter air incoming through upstream intake duct 28 and includes a first filter or pre-filter 42 disposed across a lateral cross section of chamber 25 immediately adjacent the downstream face of louver assembly 36. Pre-filter 42 can be comprised of a rough, fiber material in order to filter out larger particles, such as rain drops or snow flakes coming through with the incoming air. A second filter or fine filter 43 is disposed in parallel relationship to and immediately downstream of the pre-filter 42 and is comprised of a finer filtering material, such as a Heppa filter, in order to filter out the fine dust, dirt and like particles from the incoming air. Other types of filtering mechanisms or assemblies can be employed.

An exhaust duct system includes an upstream exhaust duct 45 open to the interior 18 of cold room 12 at an exhaust vent location 46 and extending to one end of the exhaust chamber 26 on housing 21. A downstream exhaust vent 47 is open to and extends from the opposite end of the exhaust chamber 26 to a location outside of the building 15 at an exhaust vent location 48.

An exhaust blower 49 has an output nozzle 50 orientated to direct air from the exhaust chamber 26 into a plenum chamber 52 and downstream exhaust 47. The discharge end of blower 49 is mounted on a transverse baffle 48. Exhaust blower 49 is driven by exhaust blower motor 51 such that exhaust blower 49 is operative to cause movement of air from within the interior 18 of cold room 12 through the upstream exhaust duct 45, into the exhaust chamber 26 and out through plenum chamber 52 and downstream exhaust duct 47 to be expelled at the exhaust vent location 48.

FIG. 6 diagrammatically depicts the control system for cold air control apparatus 10. Intake blower motor 34, exhaust blower motor 51 and louver assembly motor 41 are all operatively connected through electrical control means indicated schematically at 54. An outside thermal responsive regulator element 55 is located outside of the building 15 at approximately the location from where cold air is drawn in through upstream intake duct 28. Thermal regulator element 55 is operative to sense the ambient temperature and when the ambient temperature is below an upper limit, it is operative to permit operation of cold air flow apparatus 10 by permitting operation of electrical control means 53. When thermal element 55 senses the ambient temperature is above the upper limit, it is operative to prohibit operation of electrical control means 52 as by interrupting a power circuit or the like. An inside thermal responsive control element 56 is located to sense temperature of the interior 18 of cold room 12. Thermal element 56 senses a lower temperature boundary in cold room 12, and an upper temperature boundary. At the upper temperature boundary, thermal element 56 is operative to cause operation of cold air flow control apparatus 10 if permitted by outside thermal element 55. When the inside thermal element 56 senses that the low temperature boundary has been reached, it is operative to shut off the control apparatus 10.

In use of the cold air flow control apparatus 10, for example, in a lower temperature boundary for the temperature inside cold room 12 can be 30.degree. F. (-1.degree. C.) and the high temperature boundary 40.degree. F. (4.degree. C.), with an outside upper temperature limit of 35.degree. F. (2.degree. C.). When the ambient temperature is 35.degree. F. or less, outside thermal element 55 will permit operation of the electrical control means 53. If the ambient outside temperature exceeds 35.degree. F., then the outside thermal element 55 will not permit operation of the electrical control means 53 regardless of the temperature sensed by the inside thermal control element 56, and cold room 12 will be cooled by the standard refrigeration equipment. When outside thermal control element 55 does permit operation of the electrical control means 53, and when the inside thermal control element 56 senses that the upper temperature boundary (40.degree. F.) has been reached, it is operative to cause operation of the electrical control means 53. When this occurs, the intake blower motor 34 is energized as well as the exhaust blower motor 51 and the louver assembly motor 41. The louver assembly 36 is opened and cold air at a temperature of 35.degree. F. or less is drawn through the upstream intake duct 47, through the intake chamber 25, being filtered by the first and second filters 42,43, then moved through the downstream intake duct 29 into the interior 18 of cold room 12, all under the influence of intake blower 31. At the same time, the warmer air in the interior 18 of cold room 12 is passed through exhaust vent 46 and through upstream exhaust duct 45, then through exhaust chamber 26 of housing 21 and lastly through the downstream exhaust duct 47 and out the exhaust vent 48, all under the influence of exhaust blower 49. At the point where the cold air entering the interior of cold room 12 has displaced a sufficient amount of warmer air such that the temperature inside cold room 12 drops to the lower temperature boundary (30.degree. F.), then inside thermal element 56 operates to shut off the electrical control means 53 which shuts off the intake blower motor 34 and exhaust blower motor 51 as well as causing the louver assembly motor 41 to close the louver assembly 36.

It is apparent that the cold air flow control apparatus 10 can be installed in existing buildings to serve existing cold rooms. Alternatively, the apparatus can be installed in new construction and be constructed integrally with the walls of the cold room and building. It would be apparent to those skilled in the art that other deviations of the apparatus can be had without departing from the scope and spirit of the invention.