| | Mathematical Analysis of Practices to Control Moisture in the |
| | 0,61 | | MB | Roof Cavities of Manufactured Houses |
| | 62 | | stron |
| | 6394 | | ID | National Institute of Standards and Technology |
| | 2004 | | rok |
| | TABLE OF CONTENTS |
| | ABSTRACT 1 |
| | KEYWORDS 1 |
| | INTRODUCTION 2 |
| | THEORY 3 |
| | Assumptions 3 |
| | Basic Transport Equations 4 |
| | Ventilated Cavity Moisture and Heat Balance 4 |
| | Airflow from House into Attic 5 |
| | Roof Cavity Ventilation Rate 6 |
| | Indoor Boundary Conditions 6 |
| | Outdoor Boundary Conditions 7 |
| | Indoor Temperature and Humidity Conditions 7 |
| | Solution Procedure 9 |
| | DESCRIPTION OF CURRENT PRACTICE HOUSE 12 |
| | PARAMETERS USED IN ANALYSIS 14 |
| | Water Vapor Diffusion Properties 14 |
| | Liquid Diffusivity 17 |
| | Airflows 20 |
| | Heat 20 |
| | Other Properties 20 |
| | Indoor and Outdoor Conditions 20 |
| | COLD CLIMATE RESULTS 22 |
| | Performance of Current-Practice House in Madison 22 |
| | Effect of Roof Cavity Ventilation 22 |
| | Effect of a Ceiling Vapor Retarder 25 |
| | Effect of Airflow from House into Roof Cavity 28 |
| | Effect of Indoor Relative Humidity 28 |
| | Effect of Outdoor Climate 32 |
| | Other Factors 32 |
| | Summary of Effect of Parameters 36 |
| | PROVIDING WHOLE HOUSE VENTILATION WITH CEILING VENTS 36 |
| | EFFECTIVENESS OF MOISTURE CONTROL PRACTICES IN COLD CLIMATES 40 |
| | Tight House with High Moisture Generation Rate 40 |
| | Humidified House 42 |
| | AN ALTERNATIVE ATTIC MOISTURE CONTROL PRACTICE IN COLD CLIMATES 42 |
| | EFFECTIVENESS OF CURRENT MOISTURE CONTROL PRACTICES IN HOT AND HUMID |
| | CLIMATES 42 |
| | RECOMMENDATIONS FOR FURTHER STUDY 46 |
| | Model Verification 46 |
| | Roof Moisture Performance in Different U.S. Climates 47 |
| | Uncertainties Regarding Attic Ventilation 47 |
| | Shingle Temperature 48 |
| | SUMMARY AND CONCLUSIONS 48 |
| | ACKNOWLEDGMENTS 50 |
| | NOMENCLATURE 51 |
| | REFERENCES 53 |