buildingscience.com buildingscience.com buildingscience.com THE PERFECT ENCLOSURE DESIGN IS ONE THAT Has an efficient structural frame

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1 Dtalg Toward Zro-Ergy Buldgs Part 1 Btsy Pttt, FAIA Corporato Buld Bosto Novmbr 19, 2008 Bosto, MA THE PERFECT ENCLOSURE DESIGN IS ONE THAT Has a fft strutural fram Has thoughtful plamt opgs for lght ad vtlato ludg approprat wdow to wall ratos Has xmplary lvls of sulato to otrol hat flow Has a fftv stratgy to otrol ar lakag Has a fftv stratgy to otrol lqud watr ad mostur th vapor form THE PERFECT ENCLOSURE DESIGN PROCESS Dfs aras for lght ad vtlato opgs Dfs layrs (strutur, hat flow, ar flow, mostur flow) Dfs boudars Dtals jots btw dssmlar matrals ENCLOSURE: SIMPLE LAYERS ENCLOSURE: DEFINE BOUNDARIES STRUCTURE RAIN/AIR/VAPOR INSULATION FINISH 1 of 8

2 DETAILS: JOINTS Dtals dmad th sam approah as th losur. Sald drawgs rqurd at ENCLOSURE: SIMPLE LAYERS 2006 Elosurs No. 7 ENCLOSURE: SIMPLE LAYERS ROOF FLOOR 2 of 8

3 THE BEST INSTITUTIONAL WALL ASSEMBLY 3 of 8

4 THE BEST COMMERCIAL WALL ASSEMBLY m o. s g buld m o. s g buld m o. s g d bul 4 of 8

5 THE BEST RESIDENTIAL WALL ASSEMBLY Brk Fa/ avty/mprmabl mmbra as draag pla Imprmabl foam as sulato Hat Flow Easst to udrstad - trasfr of rgy Radato Sold body looss ts hat rgy to othr sold body wth lss hat rgy -MORE TO LESS Ca our a vauum Major fator roof hat loss ad hat ga Covto Hot ar rss ratg ovtv loops -MORE TO LESS Hat rgy lost as loop rahs aras wth lss hat Ours through fluds (lqud or gas) ar movmt Coduto Lquds ad solds, touhg othr wth lss hat rgy -MORE TO LESS R valus oly dal wth oduto, msladg 5 of 8

6 INSULATION CONSIDERATIONS Isulato s omprssd ratg vods wh st staplg s usd Kraft or fol-fag Vod Fa staplg s rommdd whr fad batt sulato s stalld Propr Isulato Prats Noth ut bottom of stud* Altrat Wrg wth Batt Isulato Dtal Wr stalld too hgh or wrappd frot aftr sulato Gap from omprssd ufad batt sulato Ufad batt sulato Bak of batt splt proprly aroud wr Ufad batt sulato Ar Flow Easy to udrstad Bfor you a otrol ar you must los ar Copt of buldg losurs o bg hols Ar barrrs Ar salg Ar Flow Establsh Elosur Tghtss Ar flow dpds o sz of hol Ar flow dpds o prssur dffr Ar flows from hghr prssur to lowr prssur Sam mtr vrywhr What mtr? Not too tght, ot too laky, just rght Btw 1.5 ad 3 ah@ 50 Pa Lakr tha th Caada R-2000 Tghtr tha th typal Amra hom Ahvabl- Ovr 16,000 bult to ths stadard udr ths program Crtra Prat Sour Cotrol Mostur mtr Dsg to xlud watr Dsg to dry should t gt wt Combusto Applas Uoupld from th odtod spa Ddatd ombusto ar Powr-vt xhaust of ombusto produts Spot Vtlato Baths, kths, pots of polluto grato Cotrol Dut Lakag All duts must b tght Dut must b loatd wth th odtod spa so thy do t lak to th outsd Ar Drywall Approah 6 of 8

7 Extror Foam Arsal Mostur Movmt - Ar Lakag vs. Dffuso I most old lmats ovr a tr hatg saso: 1/3 quart of watr a b olltd by dffuso 30 quarts of watr a b olltd by ar lakag 4x8 sht of gypsum board Itror at 70 F ad 40% RH 4x8 sht of gypsum board wth a 1 2 hol Itror at 70 F ad 40% RH 1/3 quart of watr 30 quarts of watr Mostur Flow Mostur Bala Most dffult to udrstad Ca b asy to udrstad Draag of lqud watr Mostur gos from warm to old Mostur gos from mor to lss Vapor barrrs vs. vapor rtardrs Vtg vs. o vtg of roofs, rawl spas ad walls Postv or gatv prssurs Buldg assmbls gt wt from th outsd, gt wt from th sd ad start out wt. W must otrol wttg from th outsd, otrol wttg from th sd, ad lt assmbls dry to th sd, or to th outsd, or to both. Mostur Cotrol Varous stratgs a b mplmtd to mmz th rsk of mostur damag Th stratgs fall to followg thr groups: Cotrol of mostur try Cotrol of mostur aumulato Rmoval of mostur Th Bg Four of Mostur Cotrol Cotrollg ra try Cotrollg groud watr Cotrollg watr vapor va ar trasport Cotrollg watr vapor va vapor dffuso 7 of 8

8 Shd th watr from th fa of th buldg Mostur Movmt through Ar Lakag vs. Dffuso I most old lmats ovr a tr hatg saso, 1/3 quart of watr a b olltd by dffuso, 30 quarts of watr a b olltd by ar lakag 4x8 sht of gypsum board Itror at 70 F ad 40% RH 4x8 sht of gypsum board wth a 1 2 hol Itror at 70 F ad 40% RH 1/3 quart of watr 30 quarts of watr Vapor Dffuso Cotrol Dffuso Mgrato of mostur by mas of vapor prssur dffrtal Ours thr drto basd o lmat odtos ad tror lvls of humdty 8 of 8