UBT Product Brochure - Evapco

EARTHQUAKES & HURRICANESEach year natural disasters such asearthquakes and hurricanes claimhundreds of lives and cause billionsof dollars in damage. With thecontinued commercial development ofearthquake prone regions and coastalareas, millions of people are withinarms reach of a major, life-threateningcatastrophe.The International Conference ofBuilding Officials developed theUniform Building Code* to providestructural engineering design guidelinesin an effort to protect human life.This code and numerous local codesapply to all building structures andshould be applied to mechanicalequipment; such as cooling towers,closed circuit coolers and evaporativecondensers.EVAPCO, Inc. is leading the industryby providing a product line designedto withstand the worst forces MotherNature has to offer... The UB Series ®of Evaporative Cooling Products.Hurricane Andrew - 1992San Francisco Earthquake - 1989Following the 1994 earthquake in SouthernCalifornia, EVAPCO worked closely withStone & Webster Engineering Corporation, aworldwide leader in the Structural EngineeringCommunity, in developing a research program toanalyze and increase the structural integrity ofevaporative cooling products. The intent was toprovide equipment capable of withstanding thegreatest forces of nature.The result of this research is the UB Series ® ofCooling Towers, Closed Circuit Coolers andEvaporative Condensers. These units aredesigned and constructed to withstand seismic“accelerations” of up to 1.0g horizontal andwindloads of 125 psf. The UB Series ® productsare the result of a comprehensive analysis inwhich each structural joint was analyzed toensure it exceeded the acceleration standardsas defined by the Uniform Building Code.These units provide insurance against structuralfailure of mechanical equipment beyond thetraditional concerns of “reinforced anchorage”or “external bracing” to prevent overturning.Stone & Webster, using computer modeling andactual proof tests has independently certifiedthe seismic and windload rating of each model.*The EVAPCO UB Series products are not sponsored by the International Conference of Building Officials, compilers of the Uniform Building Code.2

DESIGN FEATURESThe UB Series ® of products represent a dramatic advancement in structural technology of evaporative coolingproducts. Structural enhancements include:• Heavier gauge steel for critical structural panels• Increased size and number of fasteners• Reinforced mounting flanges• Internal cross-bracingUB Series ® Products also provide the same product features and customer-oriented benefits found in all ofEVAPCO’s induced draft cooling products. UB models offer:• Guaranteed thermal performance established by thousands of hours of research and testing in EVAPCO’senvironmental test chambers.• Low operating cost and long equipment life from the unique induced draft, axial fan design withpremium materials of construction.• Lower preventative maintenance costs from the ease of access to the mechanical equipmentand cold water basin.UBT COOLING TOWERS ®100 Models -116 to 2,755 tonscooling capacityUBW CLOSED CIRCUIT COOLERS ®30 Models - 150 to 7,400 gpm UBC EVAPORATIVE CONDENSERS ®63 Models - 180 to 3,225 tonsof refrigeration3

SEISMIC FORCEThe Uniform Building Code categorizes geographicregions into one of four “Seismic Zones” based onthe probability and potential severity of a seismicevent. The zones are numbered 1 to 4 with Zone4 having the highest risk and strongest seismicforce potential.However, specifying mechanical equipment tomeet Seismic Zone 4 requirements is not enough.The forces that can be applied under Zone 4 varysubstantially. Many factors go into determining theactual force applied on cooling equipment. VolumeTwo of the 1994 Uniform Building Codeprovides the following formula to calculate theseismic force:This formula canexpress the force as apercentage of theequipment weight org’s. To calculate theLateral Force, Fp,the value of eachfactor must bedetermined. Thefactors are found inthe Uniform BuildingCode and vary basedon equipmentlocation and thetype of installation.Within Zone 4 it ispossible to calculatea horizontal accelerationranging from0.3g to 0.9g dependingon the method ofFp=ZIpCpWpFp = Lateral ForceZ = Zone FactorIp = Importance FactorCp = Horizontal Force FactorWp = Weight of EquipmentWithin Zone 4it is possibleto calculatea horizontalaccelerationranging from0.3g to 0.9gdepending on themethod ofinstallation and ...the mechanicalequipment’simportance.installation and the interpretation of the mechanicalequipment’s importance.Multi-directional seismic forces acting through center of gravityWith the development of the UB Series ® Products,EVAPCO has taken this subjective approach out ofdetermining the seismic requirement for mechanicalequipment. Based on actual forces experiencedduring recent earthquakes, EVAPCO designed theUB Series ® to withstand the following maximumaccelerations when applied concurrently to eachcomponent relative to the center of gravity:1.0g Horizontal0.3g Horizontal, Orthogonal0.5g VerticalThese seismic accelerations exceed themaximum requirement of Zone 4 and areindependently certified by Stone & WebsterEngineering Corporation. The accelerations includehorizontal concurrent with horizontal, orthogonaland vertical. The Uniform Building Code is limitedto horizontal force calculations. We have found thatmost seismic events include accelerationsin more than one direction and often includesubstantial vertical movement.In order to calculate the Lateral Force, Fp, the valueof the Zone Factor, Z, must be obtained. This variablerelates the risk and severity of force potential to eachgeographic region. A map of the United States in theUniform Building Code identifies each Seismic Zoneand applies a factor for each region.Seismic Zone 1 2A 2B 3 4Zone Factor 0.075 0.15 0.2 0.3 0.44

EXAMPLE:Hospital - Miami Beach, FL.A cooling tower is to be installed on the roofof an 8 story hospital on the coastin Miami Beach, FL. The design wind speedof 110 mph equates to a StagnationPressure, qs, of 31 psf. Since the coolingtower is on the roof at the 80’ level and isexposed to ocean, the Exposure Factor, Ce,is 1.81. Being a vertical surface theShape Factor, Cq, for a cooling tower is 1.3.Since the unit is installed on ahospital, the Importance Factor is 1.15.P = qs Ce Cq Iw = 31.0 x 1.81 x 1.3 x 1.15 =83.9 psfThe 83.9 psf design wind pressure is wellbeyond the traditional industry standard of30 psf. A UBT Cooling Tower ® is required.EXAMPLE:Communication Center - Atlanta, GAA cooling tower is to be installed on theroof of a communication center outsideAtlanta. Given the location away from town,the Exposure Factor, Ce, is 1.79. The designwind speed is 80 mph which equates to aStagnation Pressure, of 16.4 psf. Given theapplication, use a 1.15 Importance Factor.The Shape Factor, Cq, is 1.3.P = qs Ce Cq Iw = 16.4 x 1.79 x 1.3 x 1.15 =43.9 psfThe design wind pressure is 43.9 psfrequires the use of a UB SeriesCooling Tower ® .Many assume the areas most prone to the forces associated with seismic events and hurricanes are onlythe coastal areas of the United States. However, as shown in these examples, applications requiring UBSeries ® Products are not limited to coastal regions. Installations such as hospitals, emergency facilities,telephone switching stations, research labs and industrial processes require that their cooling equipmentremain operational following seismic or severe weather events.Since potential seismic and wind forces can be interpreted differently, each installation should be analyzedto determine the actual forces which may impact the mechanical equipment. Such analysis is imperative toidentify the potential dangers each installation may face and take appropriate action to protect human lifeand minimize property damage. Contact your local EVAPCO Sales Representative or the EVAPCO MarketingDepartment in Taneytown, MD at 410-756-2600 for assistance prior to specifying equipment on yournext project.EVAPCO has been successful in providing UB Series ® cooling products nationwide.EVAPCO’s UB Series ® of cooling products.Built to withstand the forces of Mother Nature...Built to Last.7