Download or read book Condensation Potential in High Thermal Performance Walls Cold Winter Climate written by Gerald E. Sherwood and published by . This book was released on 1982 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Condensation Potential in High Thermal Performance Walls written by Gerald E. Sherwood and published by . This book was released on 1985 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Condensation Potential in High Thermal Performance Walls written by Gerald E. Sherwood and published by . This book was released on 1982 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a result of steadily rising energy costs, construction practice for light-frame wood structure has changed over the past few years. The use of 6-inch-thick walls and application of high-'R'-value, low-permeance sheathings to 4-inch walls has caused concern for the changing moisture patterns that may occur in walls. To observe actual moisture patterns and the potential for condensation, a test structure was constructed near Madison, Wis., for exposure of eight types of insulated wall panels at controlled indoor conditions and typical outdoor weather conditions. Panels were instrumented with moisture sensors and tested without (Phase 1) and with (Phase 2) penetrations (electrical outlets) in the indoor surface. Continuous vapor retarders effectively prevented condensation; asphalted paper stapled between studs was inadequate. The installation of an electrical outlet changed the moisture profile and resulted in some condensation in most panels. Moisture levels on the back of siding in most Phase 2 panels have been known to produce buckling in long sections of hardboard siding. Although streaking occurred on the siding of two types of Phase 1 panels and three Phase 2 types, and some condensation occurred in all types of Phase 2 panels, there was no long-term accumulation of free water in the structure. The moisture content of framing remained below 12 percent throughout the 2-year study. There was no apparent increase in condensation potential with the addition of low-permeance foam sheathing in this study with controlled indoor conditions.

Download or read book Condensation Potential in High Thermal Performance Walls written by Gerald E. Sherwood and published by . This book was released on 1985 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: To observe actual moisture patterns and the potential for condensation due to long periods of air conditioning in a hot, humid climate, a test structure was constructed near Gulfport, Mississippi, for exposure of eight types of insulated wall panels at controlled indoor conditions and typical outdoor weather conditions. Panels were instrumented with moisture sensors and tested without (Phase 1) and with (Phase 2) penetrations (electrical outlets) in the indoor surface. There was no sustained condensation in any of the walls during either winter season. One type of high thermal performance wall had sustained condensation during both summers, but the wall dried out as the weather became cooler, and moisture content of framing never exceeded 17 percent. Low-permeance sheathing appeared to provide resistance to the buildup of moisture during summer in walls with high overall 'R' values. Penetrating the walls with electrical outlets resulted in slightly higher moisture levels in all of the walls throughout the year. This paper should be useful to building designers, builders, and building code officials in establishing vapor retarder requirements for walls. Keywords: Condensation, moisture control, vapor retarder, air leakage, wood-frame walls, foam sheathing.

Download or read book Condensation in Exterior Building Wall Systems written by Bruce S. Kaskel and published by . This book was released on 2011 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Sixteen peer-reviewed papers cover the latest research on condensation in exterior building wall systems. This new publication focuses on new ideas and concepts, the consistent application of the principles of physics, and the use of appropriate analytical techniques. Topics cover: Overview: Insulation Draws Water--proposes a framework for reviewing the link between moisture control prescriptive requirements and performance outcomes. ; Testing/Analysis--criteria for moisture control design analysis in buildings; laboratory tests of window-wall interface; moisture measurement, damage, and condensation potential, and more. ; Case Studies--controlling condensation, fenestration condensation resistance, thermal performance of window panes, and others."--Publisher's website.

Download or read book Research Paper FPL written by and published by . This book was released on 1983 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Moisture control in buildings written by Heinz R. Trechsel and published by ASTM International. This book was released on 1994 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Hygrothermal Performance of Exterior Insulated Wall Systems written by Trevor Trainor and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As energy certification programs and mandatory governmental building codes demand better building energy performance, the development of durable, highly insulated wall systems has become a top priority. Wood framed walls are the most common form of residential wall in North America and the materials used are vulnerable to moisture damage. This damage typically occurs first at the wall sheathing in the form of mould, fungal growth and rot. Increased thermal resistance can lead to two potential issues related to moisture durability: 1) increased potential for air leakage condensation at the sheathing and 2) decreased ability of the wall to dry after a wetting event. A natural exposure experimental study was performed at the University of Waterloo's BEGHUT test facility to evaluate the hygrothermal performance of exterior insulated wall systems utilizing 3 different insulation types. These walls had approximately 2/3 of their total thermal resistance interior to the sheathing and 1/3 exterior to the sheathing. These walls were compared to a standard construction wall and a highly insulated double stud wall system. The test walls were evaluated during as-built conditions and during imposed wetting conditions. Moisture was introduced into the walls in two phases. The air injection wetting phase was designed to evaluate air leakage condensation potential during winter conditions, and the wetting mat wetting phase simulated an exterior rain leak and was used to evaluate the drying potential of the test walls. Hourly temperature, relative humidity and moisture content measurements were taken at multiple locations within each test wall. This data was analyzed to determine the air leakage condensation potential and the drying capability of each test wall. Results showed that the effective thermal resistance of the polyisocyanurate (PIC) insulation was significantly less than its nominal R-value rating under cold and moderate temperature conditions, and slightly higher under hot conditions. The effective thermal resistance of the extruded polystyrene (XPS) insulation was slightly less than its rated value under cold and moderate temperature conditions and significantly less under hot conditions. The rockwool (RW) insulation performed slightly above its rated thermal resistance under cold and moderate conditions and slightly less under hot conditions. Results also showed that only the double stud wall was vulnerable to winter-time interstitial condensation during the as-built (air-sealed) condition. This was a result of the hygroscopic nature of the cellulose insulation and a large temperature gradient across the insulation cavity. During the air leakage wetting phase, all of the exterior insulated walls showed a significantly decreased risk of air leakage condensation compared to the Datum and Double stud walls. During and following the wetting mat wetting phase, the PIC and XPS walls showed significantly reduced drying capability, while the RW wall showed a small reduction in drying capacity compared to the Datum and Double stud walls. It was concluded that adding insulation exterior to the wall sheathing can be an effective method to minimize air leakage condensation. The minimum ratio of exterior to interior insulation, however, must be suitable for the local climate and interior humidity conditions. Exterior insulation materials with low vapour permeability can significantly reduce the drying capacity of a wall system, but may be appropriate where exterior solar vapour drive is a concern or sufficient drying to the interior is available. Exterior insulation materials with high vapour permeability facilitate drying to the exterior and dry nearly as well as wall systems with no exterior insulation.

Download or read book Monthly Catalog of United States Government Publications written by United States. Superintendent of Documents and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1985-11 with total page 1358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1986 with total page 1108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research for Tomorrow s Forests written by and published by . This book was released on 1984 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Moisture Cycling on Mechanical Response of Metal plate Connector Joints with and Without an Adhesive Interface written by Leslie H. Groom and published by . This book was released on 1995 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Paper SO written by and published by . This book was released on 1977 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Long term Load Performance of Hardboard I beams written by J. Dobbin McNatt and published by . This book was released on 1983 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Moisture and Addition of Rigid Insulation to Exterior Walls on Building Envelope Performance written by Henry Safavian and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the northern prairie climate of Manitoba, the thermal resistance provided by the building envelope is an on-going concern. To improve thermal performance, some existing buildings need to be renovated. One common approach to achieve a higher thermal resistance for building enclosures is the addition of rigid insulation, such as extruded polystyrene foam (XPS), on the exterior side of a building without any changes to the inside of the structure. One challenge of this strategy is the possibility of having a damaged or absent vapour barrier, and the effect this may have on the building envelope performance. The field-based study presented in this thesis was conducted on two identical wood frame test buildings with different insulation materials inside the wall cavities. One had fiberglass batt and other with dense pack cellulose. The test program was completed at the Alternative Village at the University of Manitoba. Combinations of external rigid insulation and vapour barrier systems were compared to a typical wall assembly over a heating season. Three different indoor RH levels were used to compare hygrothermal behaviour and the potential for condensation and mold growth within the wall cavity. It was found that the addition of XPS in fiberglass and cellulose wall assemblies rose the outer wall cavity temperature. Also, the outer RH within the wall cavity increased in the cellulose building, while the addition of XPS did not affect outer RH in the fiberglass wall assembly considerably. It was found, however, that for the fiberglass building with a non-consistent vapour barrier, the average outer RH increased dramatically to 80% and 90% in mid and high levels of indoor RH, respectively. Similarly, in cellulose wall assemblies with non-consistent vapour barrier, the average outer RH in high-level indoor RH rose considerably to 49% and 63% considering without and with XPS, respectively. Therefore, the potential for condensation and mold growth on outside sheathing increased in both buildings. In terms of heat flux density, both the addition of rigid insulation and having consistent vapour barrier improved the thermal resistance of fiberglass wall assemblies. That is, the heat flux density through the wall assembly with non-consistent vapour barrier was 2.6 to 2.8 times greater than the value through the wall assembly with XPS and continuous vapour barrier. Furthermore, even though vapour barrier system did not affect the heat flux noticeably in cellulose enclosure, the heat flux density decreased considerably due to the addition of rigid insulation.

Download or read book Reliability Analysis of Fire exposed Light frame Wood Floor Assemblies written by Frank E. Woeste and published by . This book was released on 1980 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt: