e a stiff wind perhaps mph u Ducts total: 8 CFM / 100 SF finished u Total of all ductwork u Ducts outside: 4 CFM / 100 SF finished u Total leakage in ductwork in unconditioned space u Just Right & Airtight, Joe Lstiburek BuildingScience.com
37 OVE Framing Practices
38 Advanced Framing: An Examination of its Practical Use in Residential Construction Based on the case study, some OVE techniques were practical to implement (when visibly marked on the construction plans) and had noticeable material savings, thermal benefits, and positively affected the quality of framing. Other practices were found to be problematic, either from a technical or logistical standpoint, or had minimal energy or lumber saving benefits (considering that exterior foam sheathing was employed on the home). On a first-time home, these added soft costs associated with the implementation of even the most basic OVE practices are likely to offset any savings accrued from reduced lumber use. Furthermore, the energy efficiency gains associated with using continuous exterior insulating sheathing overshadow the efficiency gains from employing OVE framing techniques.
39 Reducing backing requirements
40 Assess energy use in completed homes u u u Energy rater Blower door test and understanding the results Duct leakage test and understanding the results and why it s important
49 Special thanks to Molly Berg, Sustainable Building Program Manager at Habitat for Humanity of Minnesota Contributions: Cost analysis, assistance with Energy Rating, filling out the forms, etc. Molly Berg
50 In accordance with the Department of Labor and Industry s statute , Subd. 11, This educational offering is recognized by the Minnesota Department of Labor and Industry as satisfying 1.5 hours of credit toward Building Officials and Residential Contractors continuing education requirements. For additional continuing education approvals, please see your credit tracking card.
51 Links: OVE: Building Science: Construction Instruction:
52 Time-permitting: Exterior foam board/ new energy code.
54 Incorporating Thick Layers of Exterior Rigid Insulation on Walls Wall assemblies are one portion of the building that provide a separation between the inside environment and the outside environment. This separation is often referred to as a building enclosure or a building envelope. For wall assemblies, control of rainwater, airflow, water vapor flow, and heat flow are key factors to providing a durable enclosure. The control of these elements can be separated into four principle control layers. They are presented in order of importance: u A water control layer u An air control layer u A vapor control layer u A thermal control layer The best place for the control layers is to locate them on the outside of the structure in order to protect the structure.
55 Incorporating Thick Layers of Exterior Rigid Insulation on Walls u u u There are three principle control approaches to dealing with water in the vapor form. The first is to let the water vapor pass through the assembly from the inside out and from the outside in. This type of wall assembly is called a flow-through assembly and can dry to both sides. The second is to locate a distinctive vapor control layer to retard the flow of water vapor into the wall assembly from either the inside or from the outside. This type of assembly is called vapor control layer assembly. The most common location for a vapor control layer is on the inside warm in winter side of the thermal insulation. The third is to control the temperature of the surfaces where condensation is likely to occur by raising the surface temperature with insulation. The most common method of achieving this is to use rigid insulation on the exterior of assemblies. This type of assembly is called control of condensing surface temperature assembly. When rigid insulation is added to the exterior of the structural sheathing, the interior surface temperature of the structural sheathing is increased since the insulation keeps the sheathing warmer. By raising the temperature of the condensing surfac