II. BAIHP Technical Assistance (B-C)

• Bellview Air
  Gainesville, Florida

Florida H.E.R.O. discussed a range of issues with Bellview Air, including the impact of input data on Manual J equipment sizing and the air handler location in an effort to improve indoor air quality, comfort, and energy performance. The potential benefits of unvented cathedralized roof systems were also addressed. Construction anticipated in late 2005.

• Bobek Building Systems
  Oviedo, Florida

Figure 7 1800 sq.ft. Steel Frame Residence near Oviedo, Florida.

BAIHP conducted a testing visit to new BAIHP partner. Bobek Building Systems building exclusively with steel frame and partial panelized construction (Figure 7) to measure whole house and duct leakage and to evaluate envelope insulation with IR camera. BAIHP compiled the results of the testing and sent design recommendations to the builder.

Duct testing shows low leakage to out (2.3%) but an excessive level of total leakage. The ducts are located in the attic which is largely sealed (essentially unvented) with an insulated steel panel roof deck. During blower door testing, the attic space was found to depressurize to 13 pascals while the home was at -50 pascals, showing the space is better connected to the conditioned space than to the outside. One known area of attic leakage to outdoors occurs at the front porch overhang.

The high total duct leakage should be addressed to ensure proper distribution and mixing. In many cases this is caused by leakage where the supply register ties into the supply boot. Supply registers with integral foam seals are recommended to provide a tight fit at the boot connection and where the register meets the ceiling surface.

Infrared Imaging

Figure 8 Thermal Image of Exterior, Steel-framed Walls

The IR picture in Figure 8 shows a corner, side and front wall from inside the home. This picture is typical of IR images from inside the house perimeter. Portions of the wall shown violet in color reflect an indoor temperature of approximately 67º. Lighter and brighter colors indicate higher temperatures. Metal studs and points of joining between the ceiling and side walls can be seen in orange and light yellow.

As can be seen from the IR picture, thermal shorts exist between the outdoor and interior space. Though the overall differential between room temperature and stud temperature is relatively small (5ºF), the cumulative effect may represent a significant conduction load on the space conditioning system. Reducing thermal bridging between outside and inside the home will reduce thermal loading taking place inside the home. This, in turn, will reduce air conditioning run times.

BAIHP Recommendations included:

- Sealed supply and return registers to reduce total duct leakage and improve distribution efficiency

- More attention to sealing the attic space from outdoors since this is essentially a buffer to the conditioned interior space. This will also lessen any duct leakage to outdoors.

Additionally, some method of breaking the thermal short between the stud and the back of the drywall should be deployed in future construction efforts. Consideration should be given to applying foam board, ¾” minimum, between the stud and the drywall. At a minimum, application of adhesive backed foam strips applied to the stud prior to drywall installation should be considered.

• Cambridge Homes
  Orlando, Florida
  Category B, 1 Home
  Note 100% Energy Star Builder

Figure 9 The Augusta, Cambridge Homes BA Prototype

This BAIHP partnership resulted in continuation of monitored field research in the Augusta Building America model (Figure 9) and a control home. See BAIHP Research (Section III), Site Built Housing Research, Cambridge Homes.

In November 2004, BAIHP participated in a meeting with this partner to discuss water damage incurred in recently built homes as a result of the 2004 active hurricane season. Approximately 12 people took part in the meeting including BAIHP researchers, and Cambridge Homes design, construction, and architecture personnel.
Results of field investigations were shared, and potential solutions discussed.

• Cardinal Homes, Inc.

During the 4 th budget period in cooperation with the University of Central Florida Industrial Engineering Department (UCFIE), FSEC researchers tested four Cardinal modular homes with the Cardinal sales manager and plant quality engineer. Initial results found that peak loads for heating were almost double that for cooling. All four of the homes had leaky ducts. These leaks accounted for the largest peak load in the homes, averaging 28% of the winter peak and 21% of the summer peak.

• Champion Homes
  Washington (state)

Champion Homes built the first stress skin insulated panel (SIP) manufactured home now sited in western Washington. The house air tightness was measured at ACH50=3.55, well below the average numbers for all homes previously tested in the WSU random home study (see Northwest Energy Efficient Manufactured Homes). Energy savings are estimated at 50% greater than a home constructed to the HUD Code. These results were presented at the 2003 ASHRAE Summer Meeting, authored by Pacific Northwest National Laboratory (PNNL), with contributions from BAIHP staff.

• City of Gainesville, Cedar Grove II
  Gainesville, Florida
  Category B, 139 Homes
  Award: HUD award for Innovation in Housing in 2004

Figure 10 City of Gainesville house in Cedar Grove II

Florida H.E.R.O. began working with the City of Gainesville before the ground-breaking in the Cedar Grove II subdivision of HUD housing. Project manager Judy Raymond envisioned a new urban style development (HUD’s first) with single family homes featuring high quality construction and individualized character with front porches and front façade details (Figure 10). She worked with Florida H.E.R.O. to develop engineered plans for mechanical and air distribution systems and a whole house package that was recognized with a HUD award in 2004. Table 9 summarizes the specifications.

• City of Orlando, The Orlando House
  Orlando, Florida
  Category A, 1 House

Figure 11 The Orlando House

The City of Orlando, through the office of Housing and Community Development in the Planning and Development Department, constructed an environmentally friendly demonstration home called The Orlando House: Florida’s Future, on an infill site within the city (Figure 11). The City requested FSEC assistance to assure the home met Building America goals and the Florida Green Home Designation Standards. Ground broke on the demonstration home in December 2001 and the home was open to the public for community education purposes for approximately one year. Specifications are listed in Table 10.

The City acquired more than $100,000 in donated materials and services for the project, and completed much of the construction using their own staff. Along with public education, a primary purpose for this project was to give the city staff first hand experience in the use of green building materials and techniques - especially those relating to energy efficiency, indoor air quality, durability, disaster mitigation, and termite resistance. That experience would allow the products and techniques to be effectively used in future low-income housing constructed by the city.

One particular focus of this project was disaster resistance. For protection from wind storms, a durable steel structure was used along with a safe room located in the detached garage. For termite resistance, all structural and exterior finish materials were selected on the basis of providing the least amount of available food source. Materials such as borate treated lumber and sheathing, steel structural components, and plastic/composite finishes were used extensively in conjunction with a Termi-mesh barrier system.

FSEC certified the house for the Florida Green Home Designation Standard in February 2003. FSEC staff also presented information regarding Florida Green Home Designation as part of a builder training event held at the Orlando House. Two CEUs were available to attendees, and approx. 30 people attended from the central Florida area. Training also included talks on Zero Energy Homes, Florida Sun Built Program, and a “builder panel” that included 3 BAIHP partner builders.

The demonstration home was sold in May 2003, and money acquired from the sale will go directly towards the construction of low income housing that utilizes several green building techniques.

• City of Lubbock Community Development
  Lubbock, Texas

Figure 12 Low income housing built by the City of Lubbock using insulated concrete forms.

Through the Portland Cement Association (PCA), contact was established with the City of Lubbock who is building low income houses with insulated concrete form (ICF) systems (Figure 12). FSEC researchers visited Lubbock twice to conduct diagnostic tests and provide training and technical assistance. FSEC also conducted initial HERS ratings on four Lubbock Habitat for Humanity (see Habitat for Humanity, Texas) homes plans and introduced the Habitat affiliate to the City of Lubbock’s other low-income housing activities.

• Clayton Homes
  Waycross, Georgia

FSEC personnel conducted a plant visit of the Clayton Homes factory in Waycross, Georgia in June 2002. A singlewide home was tested and observations recorded of home and duct construction techniques. Findings and remedies for leaky ducts found during the visit were reported to factory representatives in a follow-up trip report (see Appendix A).