Abstract: A spray cooling system for semiconductor devices. An ink-jet type spray device sprays droplets of a cooling fluid onto the semiconductor devices. The devices vaporize the liquid, which gets passed through a roll bond panel, or other heat exchanger, and is pumped into a spring loaded reservoir that feeds the spray device.

Abstract: An apparatus for maintaining an enclosed space proximate a selected comfort level, and for conserving utilities, the apparatus comprising a housing in communicating relation with the enclosed space and the external environment and having an evaporative cooler for cooling the enclosed space and having a predetermined operating efficiency, and a spaced apart air conditioner for either selectively cooling or heating the enclosed space, having a baffle that restricts airflow to the air conditioner and an operating efficiency different from the evaporative cooler, and a control mechanism for automatically and selectively switching back and forth from operation of the evaporative cooler to the air conditioner in response to ambient conditions of the external environment and the operating efficiencies of the evaporative cooler and the air conditioner.

Abstract: An automatic flush water distribution system for use in an evaporative cooling system includes a water distribution pipe adapted to be connected to a source of pressurized water. The pipe has a plurality of water distribution ports formed therein and a vertical flush pipe is connected at a first end to the water distribution pipe in liquid communication therewith. The flush pipe includes a second lower end and contains at least one valve seat and at least one buoyant float valve located therein between the valve seat and the water distribution pipe.

Abstract: A spray cooling system for semiconductor devices. An ink-jet type spray device sprays droplets of a cooling fluid onto the semiconductor devices. The devices vaporize the liquid, which gets passed through a roil bond panel, or other heat exchanger, and is pumped into a spring loaded reservoir that feeds the spray device.

Abstract: An apparatus for maintaining an enclosed space proximate a selected comfort level, and for conserving utilities, the apparatus comprising a housing in communicating relation with the enclosed space and the external environment and having an evaporative cooler for cooling the enclosed space and having a predetermined operating efficiency, and a spaced apart air conditioner for either selectively cooling or heating the enclosed space, having a baffle that restricts airflow to the air conditioner and an operating efficiency different from the evaporative cooler, and a control mechanism for automatically and selectively switching back and forth from operation of the evaporative cooler to the air conditioner in response to ambient conditions of the external environment and the operating efficiencies of the evaporative cooler and the air conditioner.

Abstract: A mechanical control apparatus is provided for controlling the spray or misting of water into the immediate vicinity of the condenser coils in the compressor unit of an air conditioner, and comprises a hinged, vaned paddle member; and a water valve mechanically connected to and operable by the paddle member. The paddle member is mounted so that blown air flow from an air fan in the compressor unit will impinge on the paddle member, will and cause it to pivot upwardly about a hinge. The paddle member has a mechanical valve operating member, and is connected to a source of pressurized water, so that when the valve is open, water will pass through it to at least one nozzle mounted on the compressor unit to be sprayed or misted into the immediate vicinity of the condenser coils. The mechanical linkage between the paddle member and the valve is such that when the paddle member is pivoted upwardly, the valve will be opened; and when the paddle member is in its horizontal orientation, the valve will be closed.

Abstract: An evaporative condensing apparatus used in an air conditioner to reduce the power consumption of the air conditioner and improves its EER value. The evaporative condensing apparatus is based on the rule that the condensing temperature is directly proportional to the condensing pressure during the exchange of a cooling agent between liquid state and gas state.

Abstract: A combined liquid/vapor distributor and method of assembly are disclosed together with a method for collection and distribution of a liquid and a vapor in an exchange column. The combined liquid/vapor distributor is an apparatus for distributing a liquid and a vapor to or from a packing in an exchange column. The apparatus includes a distributor and a deck above and adjacent the distributor. The distributor has at least one vapor riser, which has generally parallel spaced apart upright walls and an open top and an open bottom opposite the open top. The distributor also has at least one liquid trough adjacent the vapor riser. The liquid trough has an open top and a floor having at least one aperture. The floor is opposite the open top of the liquid trough and is attached to at least one wall of the adjacent vapor riser.

Abstract: A heat exchanging system includes a condenser including a heat exchanging chamber containing a heat exchanging medium therein and having an inlet end for entrance of the heat exchanging medium, and an outlet end for discharge of the heat exchanging medium; a control device; a water mist generating device having a spray pipe for spraying water into the heat exchanging chamber in a mist manner, a supply pipe for supplying water into the spray pipe, and a water valve for controlling the water supply of the supply pipe; a variable speed fan motor operated by the control device; and a sensing device having a first sensor mounted in the heat exchanging chamber, a second sensor mounted to the water mist generating device, and a third sensor mounted to the variable speed fan motor.

Abstract: A humidifying system containing at least one compressed-air sprayer with a compressed-air input, a water input and an outlet valve for compressed air and water, compressed-air pressure regulators for regulating the pressure of the compressed air that is to be inputted, water pressure regulators for regulating the pressure of the water that is to be inputted, and at least one humidity sensor for measuring the humidity of the air that is humidified or that is to be humidified. The humidifying system also has controls which are actively connected to compressed air pressure regulators and/or water pressure regulators and to the humidity sensor (of which there is at least one).

Abstract: An apparatus for maintaining an enclosed space proximate a selected comfort range, and for conserving utilities, the apparatus comprising a housing in communicating relation with the enclosed space and the external environment and having an evaporative cooler for cooling the enclosed space and having a predetermined operating efficiency, and a spaced apart air conditioner for either selectively cooling or heating the enclosed space and having an operating efficiency different from the evaporative cooler, and a control mechanism for automatically and selectively switching back and forth from operation of the evaporative cooler to the air conditioner.

Abstract: A multi-stage distribution and return control system for use in an evaporative cooling system including a drip conductor, a plurality of cooling cells along which water from the drip conductor passes and a gutter therebelow, including a tank, a conduit for conveying fresh water to the tank and a valve for regulating flow therethrough, a pump within the tank, a conduit for conveying water from the pump to the drip conductor, a conduit for conveying water from the gutter to the tank; high, mid and low-level switches and a float for movement between the switches, and a control system which when cooling is desired opens the valve for conveying fresh water to the tank until the float engages the mid-level switch and for starting the pump until the float engages the low-level switch, stopping the pump until water fills the tank again to the level defined by the mid-level switch and, moreover, when enough water is evaporated from the cooling cells, and the water level falls below the mid-level switch opening the val

Abstract: Method and apparatus for controlling an evaporative gas conditioning system utilizes a controller for controlling the rate at which liquid is introduced into a conditioning chamber, thereby closely controlling the rate at which temperature within the conditioning chamber is adjusted to a desired temperature. Nozzle characteristics of a plurality of different nozzle types are stored in a memory associated with the controller, so that when existing nozzles are replaced with a different nozzle type, an operator can select the new nozzle type, and data stored in memory will be retrieved to permit efficient control of the system without the necessity for manual reconfiguration. Additionally, spray nozzles for spraying water into the conditioning chamber of the system are organized into banks of nozzles, and the banks of nozzles are controlled to maintain optimum water flow through each nozzle, and to evenly distribute the water into the conditioning chamber.

Abstract: The invention relates to an arrangement for cooling supply air in an air-conditioning installation, comprising a heat transfer device for transferring heat between supply air and exhaust air by means of heat transfer surfaces; and a humidifying device for humidifying heat transfer surfaces on the exhaust air side. In order that supply air could be cooled more efficiently, the heat transfer surfaces on the side of supply air and exhaust air are separated into separate heat exchangers; and the heat transfer surfaces are selected in such a way that the surface temperature of the heat transfer surfaces on the exhaust air side is close to the dew-point temperature of exhaust air.

Abstract: Method and apparatus for controlling an evaporative gas conditioning system utilizes a controller for controlling the rate at which liquid is introduced into a conditioning chamber, thereby closely controlling the rate at which temperature within the conditioning chamber is adjusted to a desired temperature. Nozzle characteristics of a plurality of different nozzle types are stored in a memory associated with the controller, so that when existing nozzles are replaced with a different nozzle type, an operator can select the new nozzle type, and data stored in memory will be retrieved to permit efficient control of the system without the necessity for manual reconfiguration. Additionally, spray nozzles for spraying water into the conditioning chamber of the system are organized into banks of nozzles, and the banks of nozzles are controlled to maintain optimum water flow through each nozzle, and to evenly distribute the water into the conditioning chamber.

Abstract: An air conditioning system and method whereby water sprays are arranged and modulated in air washers from recirculated water and a cooled or non-cooled central water source to provide precise psychometric (dry bulb temperature, relative humidity, dew point temperature and specific humidity) conditions in the space being conditioned while conserving energy by reducing the cooling load, reducing the pumping horsepower load, and eliminating reheat under all weather conditions. This system also reduces maintenance and operating costs by allowing chemical treatment, makeup water, water overflow, and water filtration to be provided in a central location even with multiple air washers and water chillers.

Abstract: A system for regulating the amount of fog produced by foggers in a humidification system in which a control signal calling for a certain amount of humidification from foggers is used and wherein the foggers require pressurized air and water to produce fog for an air stream. The pressure differential between the air and water to the foggers is varied according to the amount of required humidification. The pressure differential may be regulated with a pneumatic device or with an electronic control.

Abstract: An atomizing nozzle assembly, comprises a body; a nozzle head secured to the body, the nozzle including a chamber and an orifice for permitting water to flow out; a stem disposed within the chamber, the stem including a tip adapted to slide into or out of the orifice, thereby closing or opening the orifice, respectively; a piston secured to a rear end of the stem, the piston being slidably disposed within a cavity in the body; a spring disposed behind the piston adapted to bias the piston forward such that the tip is disposed within the orifice to close off the orifice when liquid to the nozzle assembly is cut off; a passageway within the body communicating with the chamber and the orifice, the passageway for connecting to a liquid supply to be atomized; and the tip including a resilient tubing adapted to provide a seal against the orifice when the tip is the closed position.

Abstract: A method and apparatus are disclosed for improving the consistency and quality of a frozen carbonated beverage product. The invention utilizes a method of monitoring the level of liquid in the mixing chamber of a frozen carbonated beverage machine to accomplish this result. The method involves measuring the pressure spikes that occur in the mixing chamber. The magnitude of a pressure spike is indicative of the amount of liquid in the mixing chamber. If a pressure spike is too high or too low, that is indicative that there is too much or too little liquid in the mixing chamber. By regulating the amount of liquid in the chamber, the consistency and quality of the beverage product can be maintained. The present invention uses a microprocessor to determine when the spikes are outside of an acceptable predetermined range.

Abstract: An apparatus for cooling a vessel containing molten metal has a quantity of liquid coolant atomized by a gaseous medium and onto a surface to be cooled. The supply of gaseous medium is constant while the supply of liquid coolant to the spray nozzles is controlled by at least one valve the operation of which is brought about by a non-electrical temperature responsive element in thermal contact with the surface to be cooled. The rate at which the liquid coolant is sprayed on to the hot surface is controlled such that the volume of coolant sprayed on to the surface to be cooled does not exceed the volume of liquid that is capable of being vaporized from the surface.

Abstract: An integrated paint spray booth and air conditioning system and process utilize a spray booth housing, scrubber and filtering chambers located below the housing, and an air conditioning apparatus including an adiabatic saturator. The components are arranged to direct the air flow in the system substantially transverse to the length of the system. The air is conditioned to predetermined psychrometric values by sensing only the temperature of the water entering the saturator and the air exiting the conditioning apparatus.

Abstract: A novel delivery system for delivering a fine fog of water through a plurality of nozzles to absorb heat through evaporation. The delivery system comprises the combination of a water supply tank, an air compressor, solenoid valve and an electronic control module for controlling the operation of valve and compressor to allow an operator to adjust the displacement rate of fog as well as providing the operator a choice between continuous, intermittent and pulsing operation.

Abstract: An evaporative cooling system externally mounted around an air cooled condenser to increase the rate of heat transfer. Spray cooling takes place in stages around succeeding portions of the condenser as determined by thermostats which respond to increasing condenser air discharge temperature.

Abstract: The invention is a mist spray system for refrigeration condensers and includes a water spray nozzle centrally affixed to the condenser grill for spraying a circular pattern of water on the condenser when operating. A paddle pivotally suspended over the condenser exhaust is connected to a control arm that functions as a pinch valve controlling the flow of water to the nozzles when the paddle is activated by the flow of exhaust air. Water into the system is pressure controlled, and travels through 1/4 inch plastic tubing to the nozzles which are adjustable.

Abstract: A semi-passive cooling system for an armored vehicle includes an intermittent pressure source, an accumulator for storing pressurized fluid from the intermittent source, and a mechanism to control the pressure in the accumulator. The system also includes a water reservoir and automatic controls for stabilizing pressure in the reservoir at a level lower than the accumulator's pressure. A sheet of water-absorbent, wicking skin on an exterior zone of the vehicle receives pressurized water from the reservoir in response to signals from a heat sensor at the exterior zone. The sensors signals open a valve in a supply line connected between the reservoir and the sheet, the valve remaining open for a predetermined interval.

Abstract: An underfloor cooling system for cooling a building structure has tubing located in or under a massive floor of the structure for circulating water through the system. The water is directed through a cooling means connected to the tubing to cool the water. The cool water is then returned to the tubing to cool the massive floor and passively cool the structure. The cooling means may be a direct evaporative cooler or an evaporative radiative roof spray system. The cooling means may be located outdoors. The system may additionally include active cooling delivery such as at least one fan coil or at least one hydronic panel, through which cool water from the underfloor tubing is circulated to provide cool air to the structure.

Abstract: The invention relates to an air-conditioning process and device, in particular to humidify and/or temper air which is fed in the form of an air stream to a humidification zone, whereby cooled water is sprayed into the airstream as a function of the conditioning parameters to be met. It is provided that to convey the air, the air stream is blown through the humidification zone, tempered water for adiabatic conditioning and cooled water can be sprayed in, and to influence the conditioning parameters, a control and/or regulation of the arrival of tempered and/or cooled water is carried out.

Abstract: Disclosed is a method for reducing the temperature of the air passing over the condenser surface of an air conditioner unit, thereby reducing the power requirements of the unit. The method is carried out by applying water to the condenser surface to achieve coverage of substantially the entire outside surface and the entire inside surface of the condenser with water while the unit is operating. The amount of water applied should be sufficient to wet substantially the entire inside and outside surface of the condenser. The water can be applied from a tubing having a plurality of passages opening through its sidewall at generally linearly spaced apart positions. An adjustable valve means can be positioned near the inlet end of the tubing to regulate water flow through the tubing. An electrically actuated on-off valve can be operatively connected to the tubing between the adjustable valve and the passages so that water will flow only when the compressor is operating.

Abstract: A fluid cooler having contiguous air cooled and evaporative portions and having a heat exchanger common to both portions. The heat exchanger employs a series of straight tubes which traverse both the air-cooled and the evaporative portions. Separate fans are provided for the air-cooled and for the evaporative portions. The segments of the straight tube laying within the air-cooled portion are finned. The segments of straight tubes laying within the evaporative portion are partially finned and extend further downwards as a sub-cooling section of the evaporative coil portion, thereby providing means for cooling the fluid to a temperature lower than ambient dry-bulb temperature.

Abstract: An apparatus for storing items includes a housing sized to be portable and including a storage compartment for receiving the items, and a mechanism for refrigerating and humidifying the storage compartment joined to the housing. The housing is preferably a cabinet having a having a storage compartment access door and a compartment for retaining at least part of the mechanism for refrigerating and humidifying the storage compartment. A duct is preferably provided for delivering the air streams into the storage compartment. The mechanism for refrigerating and humidifying including a vessel containing water, a wick structure extending above and into the water, a first fan for creating an air stream toward the wick structure, a first electric circuit for delivering electric power to the first fan, a second fan for creating an air stream over the surface of the water, a second electric circuit for delivering electric power to the second fan, and a mechanism for cooling the water.

Abstract: A humidity control system is provided for controlling the humidity of the air confined within a container. The humidity control system includes sensors for determining the temperature of the air both within and outside the container. The sensors are also constructed to determine the humidity of the air inside the container. A controlled droplet applicator that is responsive to a humidity control signal is provided for increasing the humidity of the air within the container. A data processor is responsive to the sensors for providing the humidity control signal to increase and decrease the humidity of the air within the container. The humidity control system also includes a water flow control system for controlling the flow of water within the container. The water flow control system is responsive to the data processor for substantially preventing water from freezing in the controlled droplet applicator.

Abstract: Salinity control of sump water in an evaporative cooler (10) wherein a pump (19) continuously impels a water flow from a sump (11) to an evaporative surface where some of the water is evaporated by air flow from a fan (15, 16). Control is affected by sensing electrical resistance of the sump water with monel probes (36) energised with low voltage alternating current, and initiating an "ON" period of a timer (quad NOR gate) when resistance drops below a preset level. During the "ON" period a solenoid valve (25) is opened in a bleed line and some only of the pumped sump water is passed to drain, without interruption of cooler operation.

Abstract: A structural cooling system is disclosed, which includes an evaporative cooler suitable for cooling a body of air in an upper, enclosed chamber of a structure, such as an attic, and a series of vents or ducts, particularly around the perimeter of the building, for applying the cooled air selectively to high heat-gain portions of the exterior of the structure. An interior cooling system, which may include an air-conditioning unit, is suitable for cooling the interior of the building, but will require only reduced capacity, because of the cooling effect on the structure's exterior.

Abstract: An air handler for conditioning recirculated or make-up space air and including a conditioning chamber and air flow means for moving air therethrough. An evaporative air cooler of the air handler has an air permeable pad extending across the chamber and a fluid spray system for maintaining a moist condition of the pad. The spray system is constructed and arranged to discharge cooling fluid spray patterns covering the upstream side of the pad in a plurality of predefined zones, and further includes a plurality of moisture sensors positioned at predetermined locations adjacent to the downstream side of the pad. A controller is responsive to sensed moisture conditions for controlling the activation and deactivation of the spraying mechanism to maintain at least a preselected moisture content in the pad.

Abstract: An air conditioner housing employs a fluid manifold operative through a support rod and lift cup to effect fluid flow through an associated fluid valve into the manifold to effect fogging mist of the fluid to be directed upon the condenser coils to enhance cooling efficiency of the air conditioner unit in use.

Abstract: An evaporative cooling system for buildings comprising means to draw air from the building, air ingress means having air permeable pads in an opening in the building, and water supply means to supply water to fogger nozzles which direct a water vapor fog toward the external surface of the pads, thus cooling the air drawn through the pads. The fogger nozzles are connected to interconnected water conduits, one of which is independently operated from the others such that it will only operate in cases of extreme temperature, to insure that the pads will not be oversaturated. Preferably, the water conduits are controlled by a thermostat responsive to the internal building temperature, while the independent conduit is controlled by a second thermostat responsive to the external ambient temperature.

Abstract: A valve operating on hydraulic pressure for the control of water being deposited onto evaporative pads located on a cool tower. The valve utilizes water flow to fill a basin or tank which is slowly being drained. When the tank is empty, a valve is opened that releases water to the evaporative cooling pads and also to the tank; when the tank is filled, the valve closes permitting the tank to slowly drain and repeat the cycle.

Abstract: A valve apparatus in which moisture sensitive material controls the opening size of a water valve. The moisture sensitive material is placed in an evaporative pad of an evaporative cooler. As the material dries, the moisture sensitive material constricts to open a valve draining a timing reservoir so as to hasten the refreshing of moisture to the evaporative pad. In an alternative embodiment, this moisture sensitive material located in the evaporative pad is balanced against an identical moisture sensitive material located in a constantly moisturized pad. This balancing of the materials permits fine control of the moisture content in the evaporative pad.

Abstract: An air conditioning condenser cooling device is characterized by a unique valve assembly which delivers a spray mist to the coils of the condenser only while the condenser is operating. A vibration transducer is provided which senses vibrations of the condenser when the condenser is in operation. The transducer produces a signal which opens a valve to supply fluid such as water from a fluid supply to a spray nozzle adjacent the condenser coils. When the condenser is off and thus not vibrating, the valve closes and the spray is terminated.

Abstract: A portable air conditioning apparatus includes a refrigerating circuit comprising a variable capacity compressor and a condenser cooled by water fed from a water tank and a flow of air generated by a fan device, an inverter for outputing a variable driving frequency to the compressor, and a control section for controlling the frequency of the inverter in response to an air conditioning load in a defined space. The control section has a frequency control function by which the driving frequency of the inverter is forcibly decreased irrespective of the air conditioning load to reduce the consumption of water at the condenser when an amount of water is detected to be below a prescribed value in the water tank.

Abstract: There is disclosed a new and improved cooling system and method for cooling the air in an enclosed space. The cooling system includes a cooling tower having a plurality of fans arranged to cool a first fluid and a chiller including a condenser thermally coupled to the first fluid, a compressor, and an evaporator. The chiller further includes first conduit means for carrying a refrigerant. A chilled fluid loop including second conduit means circulates a second fluid through the evaporator for cooling the second fluid and is arranged to flow air over the second conduit means and into the enclosed space for cooling the air in the enclosed space. Fan control means controls the speed of the cooling tower fans to minimize the total power consumption of the fan motors and the compressor.

Abstract: A non-circulating water system for use in evaporative coolers which incorporates a timing means in conjunction with a valve means, to control the flow of water to the pads. It applies measured amounts of water to the pad and allows measured amounts of time between applications so that most of the water is used in the evaporation process and minimal amounts of water are discharged though a drain. Domestic water line pressure is used to transfer water to the pads, eliminating the need for reservoir water, float valve, pump and overflow pipe. The cycle of the timing means may be varied dependent on moisture or temperature conditions sensed in the pad.

Abstract: Improved means for automatically controlling an evaporative cooler having a pump and blower, said control system comprising a solid state electronic temperature sensing circuit capable of sensing temperature differences of considerably less than 0.1 degree Fahrenheit, a timer for activating the cooler pump a predetermined period prior to and following activation of the blower, logic means for controlling activation and cycling of said blower, and humidity sensing means for developing an electrical signal indicative of excessive atmospheric humidity for turning off said cooler and controlling an associated air conditioner.

Abstract: A control apparatus for automobile air-conditioners includes a vehicle compartment humidity calculating unit for calculating a relative humidity in the vehicle compartment based on the relative humidity on the inside surface of the windshield of a motor vehicle, the temperature of the inside surface of the windshield and the vehicle compartment temperature. The results of calculation are used for the control of operation of the air-conditioner.

Abstract: An energy conservation system for cooling and conditioning air, particularly air at elevated temperatures which is discharged from the rotors of open-end spinning machines. The air is directed along a predetermined flow path in which a first stage cooling zone is established, which utilizes one or more cooling coils through which flow a heat exchange fluid that is cooled by an externally located cooling tower. The system includes a second stage cooling zone comprising an air washer in which water is sprayed into the air stream, such water being chilled in part by a mechanical refrigeration unit. The air washer preferably includes two spray pipes, one being located upstream of the other, with the downstream spray pipe receiving some liquid chilled by the refrigeration unit, and with the upstream spray pipe receiving its spray liquid from the discharge collected from the downstream spray pipe.

Abstract: The present invention discloses an apparatus for monitoring the level of a liquid such as water in a reservoir of a water cooling tower or the like wherein it is required to maintain a predetermined desired liquid level and for generating a first control signal for controlling the addition of make-up liquid to the reservoir and a second control signal for terminating the addition of liquid to the reservoir. The apparatus includes a float chamber having it bottom coupled to the reservoir for equalizing the water levels therebetween. A float is positioned within the float chamber for rising and falling with the level of monitored liquid therein. A float rod extends vertically upward from a central portion the float for movement therewith. A lever housing is fixedly secured in an intermediate position within the float chamber, and the lever housing pivotally mounts a lever member therein. The lever member has a long lever arm and a short lever arm.

Abstract: An appliance for purifying, humidifying or dehumidifying, cooling or heating gases, especially room air, and in it purification is carried out by means of a plate stack rotating in a liquid. To regulate or vary the air humidity, the incoming air is conveyed through an evaporator and the purified outgoing air is conveyed through a condenser of a refrigerant circuit. The effectiveness of the condenser is influenced by an additional condenser.

Abstract: A conventional evaporator of a cooling tower system is modified so that anti-corrosion additives are introduced into the cooling tower system in response to the flow of make-up water into the cooling tower to replenish the supply of recirculating water.

Abstract: The invention concerns an air conditioning installation with centrifugal sprayers (1). Said installation is essentially comprised of centrifugal sprayers (1) each provided with a deflector (2) and connected to a loop circuit (3) incorporating a buffer reservoir (4) which is supplied with liquid, a centrifugal purifier (5), a filter (6), a pump (7), individual flow regulating devices (8) and a collective flow regulating electro-valve (9), controlled by a regulation device (10) which is servo-controlled by a temperature sensor (11) and by a hygrometry sensor (12). The driving motors (13) for the sprayers (1) are power supplied through an adjustable frequency inverter (14).

Abstract: An evaporative roof cooling system for placement upon a roof surface exposed to relatively high levels of solar radiation. The system includes water distribution piping and a plurality of mist/spray nozzles positioned on the roof surface for supplying a uniform spray of water thereover to lay down a substantially uniform thin film of water on the roof surface. A solenoid-controlled valve controls the supply of water to the system over periods during which the temperature of the roof surface is measured to be within a predetermined temperature range. A thermistor, encapsulated in an expoxy block, is affixed to the roof surface and monitors and measures the actual roof temperature.