Christopher Martinez, MSME, EI, CIE, MRSA Holmes Engineering Group Chris@HolmesEngineeringGroup.com Office Number: 727-873-3907 Dur Duration tion Requir equired f ed for or Mold Mold Growth Gr wth Arising Arising fr from om Condens Condensation tion De Development elopment on Interior Surf on Interior Surfaces aces th Annua th Annua IAQA IAQA A 19 th A 19 th ual ual l Meetin l Meetin ing ing
Ac Ackno knowledgements wledgements • IAQA • Co-Author: Ralph E. Moon, Ph.D. CIAQP, CHMM • Reviewers: Julie Kahn, MSBE Ross Montgomery, PE Raymond Patenaude, PE – only their names and affiliations can be listed ( John Doe – Acme Company) th Annua IAQA A 19 th ual l Meetin ing • No Images or Logos allowed • No emails or phone numbers allowed
Ov Over erview view 1. Introduction 2. Building Material Properties 3. Condensation 4. Microbial Growth 5. Condensation and Microbial Growth 6. Limitations and Future Work 7. Conclusionsontent th Annua IAQA A 19 th ual l Meetin ing
1. 1. Intr Introduction oduction th Annua IAQA A 19 th ual l Meetin ing
Intr Introduction oduction A th Annua IAQA A 19 th ual l Meetin ing
2. 2. Building Building Ma Material terial Pr Proper operties ties th Annua IAQA A 19 th ual l Meetin ing
Building Ma Building Material terial Pr Proper operties ties Thermal Conductance th Annua IAQA A 19 th ual l Meetin ing
Building Ma Building Material terial Pr Proper operties ties Vapor Permeability th Annua IAQA A 19 th ual l Meetin ing
Building Ma Building Material terial Pr Proper operties ties Moisture Content th Annua IAQA A 19 th ual l Meetin ing
Building Ma Building Material terial Pr Proper operties ties Moisture Content and Thermal Conductance th Annua IAQA A 19 th ual l Meetin ing
3. 3. Condens Condensation tion th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion Water Vapor th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion Water Vapor th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion Vulnerability 1. Dew Point 2. Surface Temperature th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion Relative humidity (RH) is just that, its relative! • Dew Point • Humidity Ratio th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion Visible thin film condensation: Glass, metal, vinyl, etc. th Annua IAQA A 19 th ual l Meetin ing
4. 4. Micr Microbial obial Gr Growth wth th Annua IAQA A 19 th ual l Meetin ing
Micr Microbial obial Gr Growth wth Moisture Nutrients Suitable Spores Climate Mold Growth th Annua IAQA A 19 th ual l Meetin ing
Microbial Micr obial Gr Growth wth Water Activity Moisture Content (A w ) (MC) Moisture available Moisture within 0 to 1 0 to 100% Porous or non-porous Porous only • Non-porous condensation means a w = 1.0 • Some fungi a w <0.65 • Most filamentous fungi a w >0.90 th Annua IAQA A 19 th ual l Meetin ing
5. 5. Condens Condensation tion and and Microbial Micr obial Gr Growth wth th Annua IAQA A 19 th ual l Meetin ing
Condensation Condensa tion and and Micr Microbial obial Gr Growth wth Buildings are dynamic … th Annua IAQA A 19 th ual l Meetin ing
Condensation Condensa tion and and Micr Microbial obial Gr Growth wth … even when unoccupied th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion and and Microbial Micr obial Gr Growth wth Interior Moisture Sources • Occupants (Perspiration and respiration) • Their activities (Cooking and sanitation) • Free water releases (Plumbing leaks) th Annua IAQA A 19 th ual l Meetin ing
Condensation Condensa tion and and Microbial Micr obial Gr Growth wth Locations Vulnerable to Condensation • AC components • Window assemblies • Poorly ventilated areas • Overcrowded areas • Exterior walls, especially those with thermal bridges and thermal breaks th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion and and Micr Microbial obial Gr Growth wth th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion and and Microbial Micr obial Gr Growth wth Thermal Bridging – Passing highly conductive materials through insulation layers … th Annua IAQA A 19 th ual l Meetin ing
Modeling Condensa Modeling Condensation tion • A glimpse at condensation modeling with Nusselt number based estimations • 3 ft. by 3 ft. non-porous material symbolizing a window • Various dew point and surface temperatures th Annua IAQA A 19 th ual l Meetin ing
Modeling Condensa Modeling Condensation tion Maximum Total Dew Point Surface Temp. condensation condensation (°F) (°F) film depth rate (mils) (oz./min.) 62.5 40.0 7.54 34.8 62.5 60.0 4.27 7.04 65.0 60.0 5.03 12.0 67.5 60.0 5.57 16.3 82.5 60.0 7.17 40.2 85.0 60.0 7.10 47.1 87.5 60.0 7.22 51.5 82.5 80.0 4.04 7.74 th Annua IAQA A 19 th ual l Meetin ing
Modeling Condensa Modeling Condensation tion • 8,000 ft 3 space with 62.5 ° F dew point and air temperature has 14 oz. of water • So when windows do feature 1/16 in. of condensation … • Condensation results from a sequence … Moisture Persistent Moisture Source Diffusion Conditions th Annua IAQA A 19 th ual l Meetin ing
Modeling Micr Modeling Microbial obial Gr Growth wth Model/study assumptions: • No previous microbial growth • Limited environmental variables • Scenario and variability limitations th Annua IAQA A 19 th ual l Meetin ing
Modeling Micr Modeling Microbial obial Gr Growth wth Despite these limitations ... • 70% RH = Summer season • 85% RH = Within a week For condensation, benefit can come from understanding the fungal genus Cladosporium th Annua IAQA A 19 th ual l Meetin ing
Modeling Micr Modeling Microbial obial Gr Growth wth Cladosporium • 0.80 A w 0.90 • Frequents areas of condensation – Goldstein 2011 – Internal case study review • 20 samples surfaced, present in 18 • Aspergillus second most frequent, present in 3 th Annua IAQA A 19 th ual l Meetin ing
Modeling Micr Modeling Microbial obial Gr Growth wth Cladosporium • Clinical detection: – 7 day average – 14 day maximum • Growth identified on wetted building materials on day 14 • Growth diameters: – 0.008 to 48 mm in 14 days – 32 to 64 mm in one month th Annua IAQA A 19 th ual l Meetin ing
Condensa Condensation tion and and Microbial Micr obial Gr Growth wth Relating the microbial studies to residential condensation • A failure must occur • Latent time period • Microbial studies are often ideal or worst- case scenarios • Therefore, the mold growth timelines are often extended th Annua IAQA A 19 th ual l Meetin ing
Condensation Condensa tion and and Microbial Micr obial Gr Growth wth Cladosporium growth arising from condensation development on interior building surfaces requires a two-week minimum duration of elevated moisture exposure. This duration includes the time required for moisture accumulation and mold growth. th Annua IAQA A 19 th ual l Meetin ing
6. 6. Limita Limitations tions and and Futur Future W e Wor ork th Annua IAQA A 19 th ual l Meetin ing
Limita Limitations tions and and Futur Future W e Wor ork Limitations • Hot and humid U.S. climate • Residential activity and occupancy • Cooled and dehumidified by an air- conditioning system th Annua IAQA A 19 th ual l Meetin ing
Limita Limitations tions and and Future W Futur e Wor ork Future Work • Experimentally verified condensation references • Hygrothermal analysis – Building components – Transient behavior • Encourage Standard and Guideline adherence th Annua IAQA A 19 th ual l Meetin ing
7. 7. Conc Conclusions lusions • Conclusions can be listed here. th Annua IAQA A 19 th ual l Meetin ing
Conc Conclusions lusions • Mold can be costly • Buildings are dynamic • Sequence of events • Cladosporium • Two-week duration • Hot and humid U.S. climate th Annua IAQA A 19 th ual l Meetin ing
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