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Frequently Asked Questions and Answers on our Industrial system: the Sprinkool system.

 

Since 1981, we've answered many questions concerning roof cooling.  If you have a question(s) not addressed below, please call (256) 757-5366 or email us through our Contact Us page, we will be happy to answer them. 

 

General Questions About Roof Cooling

 

Question Categories:    
Water Questions     Roof Questions     Mechanical Systems and Designs    
Control Questions     Installation Questions     Maintenance Questions    
Application Questions    

 

A: Water Questions:  Next

Q) What are the physical properties that support roof cooling?

A) Roof cooling is based on the fact that water, as it evaporates, absorbs large quantities of heat.  For example, one gallon of water at 100°F will, when evaporating, absorb approximately 8500 Btu's. In other words, the evaporation of less than 1-1/2 gallons of water over an hour will absorb over 12,750 BTUs.  This is more heat than a one ton mechanical air conditioner.

 

Q) Does the water temperature have an effect on the cooling efficiency of the system?

A) Yes, but it is very slight. For example, if the water is at 120°F, the amount of heat absorbed at the change of phase is approximately 2% less than it would be at 80°F. [For other temperatures, check the steam tables (Thermodynamic Properties of Steam, Keenan and Keyes)]

 

Q) Is the water recirculated?  Is my roof flooded?

A) There should be no water to recirculate.  The controls for the system (Sprinkool's R.O.E. controller) insure that only the amount of water that can be evaporated for the existing conditions on the roof at that particular time, is misted.  Therefore, all of the water misted on the roof is evaporated.  The reason for Sprinkool's emphasis on very low volume sprayheads and a sophisticated (but not complicated) control system is to monitor the water requirements and flow to the extent that even on sloped metal roofs there is no run off.  The roof's temperature is the primary, although not necessarily the only, determining factor in calculating the immediate values of the misting cycles needed by the roof.   Additional information from other analog type sensors can be incorporated (wind speed and direction, light intensity, etc.).  The roof is misted for only a few seconds each cycle, after which the mist evaporates in a few minutes. So the roof is cooled, but dry most of the time.   (Under normal operating conditions, the misting occurs approximately 6 to 10% of the time (3.6 to 6 minutes an hour)).
On average, a Sprinkool system will use less than one pint per square foot per day.

Q) Do I have to use city water?

A) No.  We have systems that operate using river water, pond water, treated waste water and well water.  The customer must provide the water with any filtering or treatment required to insure that the water provided, whether it is process, river, lake, pond, well, municipal water, etcetera, is free from any contaminants that may prove to be harmful to the roof or environment and from any entrained foreign material that may clog the system.
When using city water, typically the sewage charge can be waived, since the water used for the system is evaporated. Normally, the sewage charge constitutes about 1/2 the total water bill.  
 

Q) Does the system require a pump?

A) For optimal performance on large systems, 75 - 90 psi is required.  The increased pressure allows the system more control and flexibility.    Sprinkool can specify and/or provide the booster pump, pump controls, and piping design and/or assembly.    

Q) My water is of very poor quality, will it clog the sprayheads?

A) We have over 2-1/2 million Sprinkool sprayheads in operation, with systems operating in 19 states and several foreign countries.  In addition, we have a lifetime guarantee on each sprayhead against clogging.  The are several reasons for this:
1. Each sprayhead is filtered.
2. The sprayhead itself is constructed from ABS and Celecon.  The advantage of these plastics is that they are very slick (high lubricity) and simply do not collect precipitates as do metal sprayheads or nozzles.
3. A filter can be placed in the system at the source if needed.
In the long run, however, the sprayhead lifetime warranty protects the customer from clogging problems and the fact that we can offer this guarantee, is indicative of our experience that clogging is not a problem.  
 

B: Roof Questions:  Back to Categories    Previous    Next

Q) What will the installation of a system do to my roof warranty?  How will it affect the life of my roof?

A) The system has been installed on many types of roofs; single ply roofing (EPDM, PVC, etc.), built up, metal, asbestos and modified bitumen roofs.  Many systems have been installed strictly to extend the life of the roof.    

Q) How is the system anchored to the roof?

A) The hydraulic and the electric system (conduit) are mounted on Sprinkool's supports which are in turn attached with an adhesive that is compatible to the roofing membrane.  The roofing membrane material is not penetrated.    

Q) I am going to have to replace this roof in a few years.   Can I remove and replace the system?

A) We have had several customers replace their roofs after the installation and because of the design of the system, it has presented no problems.   A system of 100,000 sq. ft. can be easily disassembled into segments and removed from the roof by two men with pipe cutters within 1 - 2 days.  Reassembling would require approximately 2 - 4 days.    

C: Mechanical Systems and Design:  Back to Categories    Previous    Next

Q) Does the system require a pump?

A) For optimal performance on large systems, 75 - 90 static psi is required.  Sprinkool can specify and/or provide the booster pump, pump controls, and piping design and/or assembly.  The increased pressure allows the system more control and flexibility.    

Q) I have mechanical equipment on the roof.  Will this be sprayed?

A) Our designer and technicians check with the maintenance staff or owners of the facility to insure that any equipment on the roof that is to be avoided can be taken into consideration in the design.  Directional spray nozzles (360o, 270o 180o and 90o) can also be employed to avoid spraying equipment.    

Q) My maintenance staff is on the roof often.  Will they get wet?

A) The spray emitted does not normally get above the knee, and it is, of course, very light.  In addition, a particular field can easily be deactivated by means of a control handle atop the solenoid valve.  Finally, it has been our experience that the maintenance staff finds the cooled roof a much easier environment in which to work and normally they will avoid disabling the system unless it is absolutely essential.    

Q) How is the system constructed?

A) The system is a network of UVRPVC tubing and sprayheads placed atop the roof on 10' to 20' centers. The network is subdivided into "fields", which are activated by the Sprinkool R.O.E. controller, normally one field at a time.
1. Each field is controlled by 24 VAC pressure differential solenoid valves.
2. The main or supply line constitutes a manifold supplying water to the fields.
3. The roof sensor(s) is (are) placed under a thin coating of mastic on the roof surface.
4. The control enclosure can be placed virtually anywhere the client wishes.  
 

Q) Why do you recommend that the wire for the system be placed in conduit since it is 24 volt and is not required by code?

A) We highly recommend that all wiring be placed within conduit in order to protect it from people's feet, the elements, and for aesthetic reasons.    

Q) Do you supply the conduit and fittings?

A) No.  Conduit requirements vary from one customer to another (PVC, Thin-walled Steel, Rigid Steel or Aluminum), and normally can be purchased locally for less than the shipping cost.   Suggested size and quantity are specified on the Bill of Material and the electrical design drawings. Sprinkool can provide the Junction Boxes (Exterior PVC) for wire connections and to ease the pulling of the wires.    

D: Controls Questions:  Back to Categories    Previous    Next

Q) Is the Sprinkool R.O.E.™ (Rate Of Evaporation) controller just a timer?

A) No, the amount of solar radiation impinging on the roof varies, hour by hour, throughout the day and varies day by day.  Likewise, the amount of water required varies throughout the day with the morning and evening requiring less than what is needed during midday.  A set time "on" and a set time "off" obviously does not allow for this, resulting in a system that will be set correctly for only two times throughout the entire day (Even a stopped clock is correct two times a day!).  In addition, the weather conditions are constantly changing and so does the amount of water required to maintain the roof surface temperature at its lowest point.  Therefore, the problem with controlling a system in this non-responsive fashion is that the amount of water issued to the roof is either too much or too little for the majority of the time.   When too much water is issued, you have runoff and water is wasted.  When too little water is issued, the roof’s temperature rises and the heat entering the building through the roof increases. By contrast, the Sprinkool R.O.E.™ control system monitors (every 1/10 sec.) the temperature of the roof and/or other weather conditions. The R.O.E.™ controller constantly monitors and adjusts the on-time of the misting spray and the frequency of the spraying cycles, in order to minimize both the roof temperature and the water usage. It is the weather/temperature conditions at the roof’s surface at any time, minute by minute, hour by hour, day or night, that determines if, when, and how the Sprinkool system will operate.    

Q) What if my control system goes down?

A) The control system is built of standard, interchangeable, commercially available, PLC components that are modular in design and require nothing more than a screwdriver to replace.  Modules can be replaced, depending upon available stock, within 48 hours.  The CIM (Customer Interface Module) is provided with every R.O.E™ controller.  This module allows a person to adjust particular options within the PLC without concerns of harming the "basic" program (a Factory Reset button is also present).  The CIM also allows the customer to monitor the system's inputs and outputs, as well as informing the customer with alarms.  This module is normally physically attached to the controller(s), although a portable CIM device is available.  Every customer’s individual program is provided on a CD alone with drawings, Bill of Materials, and other information pertaining to that particular project.This information is also stored at Sprinkool.  If the program needs adjusting, the program can be emailed to the customer and downloaded into the CPU with the supplied communication cable.  If the CPU needs replacing along with the program, the program can be downloaded into another CPU and next-day aired to the customer.    

Q) What if I wish to monitor or control the PLC?

A) Many customers are uneasy with the idea that they cannot control or monitor the system or the controller may be in a location that is not easily accessible to an analog phone line.  For those who wish to be able to adjust the amount or the frequency of the misting, Sprinkool offers two types of interfaces to the PLC. 
1. The CIM (Customer Interface Module), which is standard equipment with all R.O.E™ controller, allows a person to adjust  particular options within the PLC without concerns of harming the "basic" program (a Factory Reset button is also present).  The CIM also allows the customer to monitor the system's inputs and outputs, as well as informing the customer with alarms.  This module is normally physically attached to the controller(s), although a portable CIM device is available.
2. The HMI (Human Machine Interface) is an event-driven monitoring system software that is loaded onto a customer computer/s and gives the customer many various visual displays of the system.  For example (but not limited to):
a. Display Panel/s: Real-time displays of the system and fields operating (graphic and analog/digital),
b. Control Panel/s: Allows the customer to change certain aspects of the program without concern of damage to the program, such as misting times, frequencies, activation / deactivation of the system and or sections of the system,
c. Information Panel/s: Displays the information from all inputs and outputs of the system and,
d. Logging Panels: Shows multiple real-time trend graphs over various hours / days.  Also data-log files may be generated automatically showing input information.  
 

Q) Which should I consider for my system?

A) This depends upon a number of items.  The CIM is standard and most customers prefer this type of monitoring and control for systems under 250,000 square feet that have minimum number of input signals (sensors).    The HMI option is more expensive due to the cost of the software and added programming for both the PLC controller and the HMI software (customized graphic screens for the customer’s computer).  It is more ideally set for very large systems or systems with multiple or remote controllers and requires that the customer have means to communicate with the controller, such as a modem, and a computer with the requirements needed to load the HMI software.  Some customers use both types in tandem.  For more information about which option is best for your facility, please call us at 256-757-5366.    

E: Installation Questions:  Back to Categories    Previous    Next

Q) Who installs the system?

A) Sprinkool provides a detailed Installation Manual which makes the installation of a system simple and may be installed by either the customer or a local contractor.    Options to help facilitate the installation are available, such as assembly of common components prior to shipment or, on-site technicians to instruct the customer’s selected installers in the layout and general construction of the system.   The manual walks the installer step-by-step through the installation procedures.    

Q) What is the average time it takes to installs the system?

A) When Sprinkool installed systems, we installed an average 5000 square feet of system per man per day for the entire system (hydraulics and electrical) without preassembly of any major components.  Sprinkool estimates that an installer who has never seen a system can easily install 2500 square feet per man per day.  This time can be reduced considerably if the installer reads the Installation Manual and Sprinkool and preassembles the major components prior to going on the roof to install the system.    

Q) Can I buy the parts for a system and install it myself?

A) Yes, we sell "component kits" only.   Component kits include essentially everything required to install a system.  Those items not provided are indicated on the Proposal and a recommended quantity is indicated on the Bill of Material.  Our kits include a complete design (hydraulics and electrical) of the system for the customer's facility, a Bill of Material and an instruction manual.    

Q) Will I need to cut the pipe?

A) Sprinkool's tubing is typically supplied in 15-foot lengths, and systems are designed in what we term as a "15 by 15 design".  This means that the Fields-lines as well as the Sprayheads are 15-feet apart.  Although some tubing will need to be cut, the system is designed to maximize material and minimize cutting.    

Q) What sizes are used?

A) Sprinkool has standardized on 2-inch and 1-inch nominal size tubing (ATSM).  The length of our UVRPVC tubing is typically 15-feet.    

Q) Would it be advantageous for me to buy a component kit and install it myself?

A) If the customer has the maintenance staff and time enough to install the system properly (or a responsible local contractor), purchasing a component kit will save the customer money.  Sprinkool can provide on-site technicians to instruct the customer’s selected installers in the layout and general construction of the system.   They can make available many time-saving installation procedures gained from our many years of experience installing these systems. Customers contemplating component kits for large systems (250,000 square feet or greater) will find this option very cost-effective.    

F: Maintenance Questions:  Back to Categories    Previous    Next

Q) How much maintenance does the system require?

A) Very little, but the system must be addressed twice during the year:
1. Fall/Winter period to drain and/or blow down the system, purging the system of water and,
2. Spring period to restart the system.

The hydraulics of the system is constructed of UVRPVC tubing (specifically manufactured for exterior use) along with high quality solenoid valves and, of course, sprayheads and the control system. The only moving parts of the system, are the 24 VAC solenoid valves and in some systems the "rotor spray" nozzles. The Sprinkool R.O.E.™ controller is industrial grade and will retain the program memory with no power.  Because of the intelligent program, the controller itself needs little to no adjustment by plant personnel.  
 

Q) The system may freeze in the winter, how can damage be prevented?

A) In order to avoid freezing and subsequent damage, the system is "blown-down" for the winter.  Sprinkool provides manual drain valves and a pneumatic fitting to which a compressed air line can be attached. Systems are designed to facilitate normal gravity drainage so often blowing-down is minimal or not required.  In the spring, the system has to be restarted and, of course, checked for proper operation.  Opening the water valves and applying the power to the controller is all that is needed.    

Q) What about a "freeze protection" program?

A) All Sprinkool R.O.E.™ controller programs include a subroutine that provides emergency freeze protection from sudden, unanticipated drops in roof temperatures.  The controller activates the system, intermittently, to prevent damage during these conditions. Complete automatic winterization of the system is also available.   This option monitors the roof temperature and after specific conditions are met, the R.O.E.™ controller runs subroutines to evacuate the system of water.    

Q) How long can I expect a system to operate?

A) From a cost consideration, the most critical component in the system is the exposure of the tubing to the sun’s ultra-violet radiation.  The extruded UVRPVC tubing, made specifically for exterior use, contains a large amount of titanium dioxide throughout the tubing, much higher than is normally found in standard PVC tubing.    

G: Application Questions:  Back to Categories    Previous 

Q) Is our building a good candidate for a Sprinkool system?

A) A Sprinkool system can be used cost effectively in a number of different situations (see the next question: When should a Sprinkool roof cooling system be considered?).  Afterward, we suggest that you go to our Contact page about your particular application.    

Q) When should a Sprinkool roof cooling system be considered?

1. In Non Air-Conditioned Buildings:
In the typical building (warehouse and light manufacturing) most of the heat entering comes through the roof. Consequently, when the roof is cooled with the Sprinkool system and the heat entering is eliminated, the effective temperature of the interior of an non air-conditioned building can be reduced 8º - 12ºF (MRT) or more.
2. In Buildings With High Internal Heat Loads:
There are many instances in which the combinations of a large congregation of workers, lights, and high heat-producing production equipment yield unacceptable high temperatures within the work area. Cooling the roof creates a large cooling panel and accelerates the transfer of heat from the interior. Temperature decreases up to 25ºF have been recorded in non air-conditioned facilities.
3. In Marginally Air-Conditioned Buildings:
In buildings where additional air-conditioning capacity is required to meet internal design temperatures, the Sprinkool system frequently eliminates, or greatly reduces, the cost of new or additional mechanical A/C equipment. The Sprinkool system can often remove enough heat to provide sufficient additional cooling to bring the effective internal temperature down to the original acceptable level.
4. In Air-Conditioned Buildings:
Removing the solar heat load from the roof and providing a large cooling panel in the building translates into a smaller heat load problem for existing air-conditioners. As the work required by the A/C diminishes, the electrical power demand also diminishes and correspondingly the operating / maintenance costs are less. (Many utilities companies recommend using roof cooling to reduce demand peaks during the summer time.) The cost savings vary with the usage cost (kWh), the demand cost (kW), the EER (Energy Efficiency Rating) of the air-conditioning unit or system, and the cost of water to operate the roof cooling system. Typically, the Sprinkool system will provide a payback after 3 - 5 seasons of operation.
5. In New Construction:
Heat that is eliminated before entering a building does not have to be removed by mechanical air-conditioning equipment.
Consequently, in new construction, the cooling load tonnage due to the roof can be virtually eliminated from the overall cooling load calculations. Using the Sprinkool roof cooling system in conjunction with smaller tonnage mechanical air-conditioning equipment means that air-conditioning will cost fewer dollars per ton both to buy and to operate. Also the summertime insulation value (approx. R = 100) of the Sprinkool roof cooling system reduces the amount of conventional building insulation required in the roof for cooling. This reduces the builder's cost as well as saving the energy required in manufacturing the insulation (and any of the associated detrimental effects to the environment incurred during the insulation's manufacturing process).
6. Prior to purchasing additional ventilation equipment:
While proper ventilation of a building is important, its sole purpose is to exchange and move air. A fan alone does not and cannot cool air. However, a Sprinkool roof cooling system can lower the effective temperature within non air-conditioned buildings as much as 8º - 12ºF (MRT) during the hottest part of the day.
 
 

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Contact

For information on any of our cooling products:
Go to our Contact Us page or:
Phone:
(256) 757-5366
Address: P.O. Box 326 Killen, AL 35645
E-mail: info@sprinkool.com