b'T&R Update Hygrothermal Analysis: The Devil Is in the Details Matt Dupuis, PhD PE Researchers continue to pushboundariesourCan we male a climateanswer theofknowl file for Milwaukee? The edge base. One ofadvancing areas is inisbutrequires a goodofand skills. A thesehygrothermalyes,itdealknowledge analysis of the buildingwhich meanstheclimaterequires weatheris relatively envelope,calculatingfiledata, whicheasy andof,withinobtain flow of heatmoisture into, outanda portion oftofrom numerous sources. However, it also requires the buildingwhich can be a wall or roof.incomingThis quantitative information envelope,radiation data.is The development ofanalysis beganleastavailable for selectbutothers, we must hygrothermalatlocations,foruse as far backthe 1980s. During thatresearchers weresyntheticwhich use a different mathematical model astime,sources, seeking to eA\'J)lain moisture accumulation in built-up roofs.tothe radiation. A modelmodel is predictbased upon another Several computerwere written toandthe devil\'s playground. programsanalyze moisture accumulation. Somethese predictofprograms metThese initial challenges face a WUFI user anytime he or limitedwhile others could notvalidated.shedown toanBut these are not success,besitsperformanalysis.the In the1990s, researchers in Europe refined a math onlyOnce theyselected materials and climate lateissues.haveto ematical hygrothermal model, which is atcore of theanalyze, there are mathematical and heatlections thetransfer securrentstandardhygrothermal analysis, Warmeto be made before runningsimulation. The ramifications industryforthe undinstationar (WUFr).andofof these choices arethe realm of Feuchteimplicationsmanyin hygrothermaldegrees Today we have a seasonedprogram thatgraduatein physics and engineering. has been onmarketwith WUFI versionAt the turn ofcentury there was a smallof thefor over 15 years,the,grouppeople 5.3.1 being the most recent release. With this program, wewho knew ofusedAt this time, andhygrothermal programs. can construct a cross-section ofroofandaOak Ridge National Labs (ORNL) partneredGerman asystemperformwith the hygrothermal analysis onthe results ofcan be usedgroup Fraunhofer Institute for Building Physics (IBP), which it,which for research, marketing, design, orforensics.produces the vVUFI program, to offer a free version ofWUFI, even The inputs required for analysis are climateandcalledorORNL/IBP.\'\' This free version data"WUFI Light""WUFI -by thematerials, climateoptions. material properties; the mathematics is broughtWUFIhas reduced sets ofsets, and other program.program operatorrequired to select theThe full-feature set, WUFI Pro, costs more than $2,500. Theis inputs, andis where the devil is hiding.Since then, groups have settousers, primarily dethisouttrain On the materialcomparedwhatavailable onsigners andfor the WUFI program. 1hese training side,withisconsultants, the marketdesign anda roof, there are veryprogramsa few days andreallyintroduction-not toinstallfewlastarean materials built intoprogramFinding hygrothermalthorough training. Here lies another devil, because these thefor use. materialin the literature is a veritable treasure hunt.newlydesigners andleave these courses datatrainedconsultants Measuringvalues in thecosts time andIffeeling they"certified" to runcouldn\'t be furtheselabmoney.youareanalyses. This hadopportunitydiscuss these material measurementstherthe truth, since thesepeople only received an thetofromsame with thewho actuallythem, you mightintroduction.advanceddo notsubject individualsmadebeEvencoursesproduce surprised to learn the rudimentary ways in which WUFI\'smatter experts. material database arrived atofhygrothermalReviewingproblems: somethevaluesthe built into it.Hygrothermal material dataandto are limiteddifficult data,byliterature for any Regarding the climatethe WUFI program has ancomeinproprietary material. Generic available database ofthan 100 cities in North moreAmerica. So, ifwant toan analysis inWI, it youperformMadison,is The Technical and&R) Committeeprovide builtyou needselectsaywantedResearch (Twill in andonlyit. However,you an update onongoingadhesives (WEA) tofor Milwaukee, \\NL Milwaukee isbuilt into theitswater-based designnot climate database. 1heto selectthe weatheratMRCAAnnualFridaystudythe65thConference on, user hasfromfiles December 12, atam. Learn about for Chicago, Madison, orto represent10-11:15fundamental Green Bay, WI,Milwauweight-lossofWBA material andrate ofrehykee\'s weatherthe analysis. Which is the bestthisbehaviorits forchoice? Is dration undertemperatureshumidity a defensible choice?variousandlevels. 14www mrca.org~Roofer Midwest'