Services
Design review - for new homes and renovation projects
The key to keeping construction costs to a minimum while enhancing energy efficiency and durability is to spend time during the pre-build/design phase of the project. Southface examines a number of features during a design review. Considered features include site conditions, window orientation, the type and location of heating and cooling equipment, and duct layout. The design team also makes recommendations for air sealing, insulation levels and types, and moisture issues such as drainage, humidity, and ventilation techniques. Additional design details such as materials selection and equipment installation that can positively affect indoor air quality are discussed. Architectural plans or construction drawings and specifications are required for this process. You should bring paper and pencil and be prepared to take notes during the design review. A written summary can also be provided.
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Load calculation - for new homes & renovations
A load calculation is required to ensure proper sizing of the heating, ventilation and air conditioning (HVAC) equipment. The Air Conditioning Contractors of America (ACCA) (www.acca.org) recommends Manual J as the method to correctly size equipment. This type of calculation is required by Georgia's energy code. Common rules-of-thumb, such as 1 ton of air conditioning per 600 square feet, are not acceptable because there are many factors, other than the size of the home, that affect the size of heating and air conditioning equipment required. A correctly sized cooling unit is critical for providing proper dehumidification, comfort, and efficiency. Manual-J accounts for details such as orientation, window-to-wall area ratio, window type, insulation levels, air infiltration, duct losses and internal heat sources. All are significant factors that affect the load of a home. Architectural plans or construction drawings and specifications are required for this process. Click here to view a sample Manual-J load calculation
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Duct design - for new homes & renovations
A duct design is required to ensure proper sizing of the duct system. The Air Conditioning Contractors of America (ACCA) recommends Manual D as the method for correctly determining the size of the duct system. A duct sizing calculation takes the size of the HVAC equipment, the corresponding air handler, the air requirements for the rooms and the type of ducts being installed (hard pipe or flex duct) into account. The common rules-of-thumb for duct sizing such as an assumed friction rate of .1 per 100 feet of ductwork are not acceptable. The air handler, required air flow and duct length and fittings used all contribute to the friction rate and static pressure of a particular system. Click here to view a sample of a duct design
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Pre-drywall inspection - for new homes & renovations
Some construction details such as installation of wall cavity insulation or energy efficient framing cannot be measured with a diagnostic test but can be confirmed during construction. Southface can provide a visual inspection prior to drywall that identifies potential air sealing and insulation problems, indoor air quality concerns, durability concerns, quality of duct installation, and anything else that could be improved to help the performance of the home. The most useful time for a pre-drywall inspection is after HVAC rough-in but before insulation, although other times can also be useful. Southface staff develops a list of potential problems. This inspection is required for ENERGY STAR Homes® Performance Path certification.
Back to top Blower door and duct blaster testing – for new homes, and renovations
Diagnostic testing can reveal many hidden energy wastes around a home. A blower door test measures the leakiness of the building envelope. Unwanted air infiltration can lead to high energy bills as well as poor indoor air quality, since air that leaks through cracks and holes in the floor and ceiling is unfiltered as well as unconditioned. A duct blaster test measures the leakiness of the ductwork. Ten to thirty percent of a typical home's heating and cooling bill can be attributed to duct leakage. If leaky, supply ducts lose conditioned air and return ducts pull in unhealthy air from attics and crawlspaces. These tests are useful on both new and existing homes. Southface staff communicate test results by phone or in person and if needed will provide a written report to summarize the findings.
Back to top Flow hood and Static Pressure testing - for existing homes, new homes and renovations
Flow hoods measure air flow into or out of registers when the system fan is running. This information can help diagnose air flow problems to particular rooms or for the entire system. Southface can also do static pressure testing. By measuring the static pressure in the return and supply plenums by the air handler, we can determine if there are flow restrictions in your duct system. If fan flow charts are available, we can also tell if the air handler is moving the required amount of air.
Another form of diagnostic testing, a flow hood provides information on the leakage and flow of an HVAC system. With a flow hood Southface can test the amount of air coming out of the supply registers and going into the return registers with the system running. This test tells us the difference in the leaks in supply and the return side and if the air handler is moving the appropriate amount of air for the size of the system. Using the blower door to pressurize the house, the flow hood can also measure the leakage from the duct system entering the house. Southface staff will communicate test results verbally and can provide a written report of the findings.
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Southface Home Assessments - for existing homes
Southface has experience assessing the overall energy efficiency of homes through an on-site inspection. The home assessment includes a visual assessment of air infiltration locations, insulation, windows, ventilation, moisture issues, and HVAC systems. Blower door and duct blaster tests are conducted to assess air infiltration and duct leakage. In addition to energy measures, consideration is given to potential problems with indoor air quality. Southface staff provides a report that summarizes the findings with prioritized recommendations for improvement. Southface trained Home Performance with ENERGY STAR® (www.southfacehomeperformance.com) contractors also perform home performance assessments.
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Home energy rating - for existing homes, new homes, & renovations
A home energy rating assesses the overall energy efficiency of a home using software modeling that meets the RESNET (www.natresnet.org) national standard. It involves entering a home’s component characteristics of the home into a computer modeling program. Home components include insulation, windows, heating and cooling equipment, air infiltration, ductwork, foundations, and other building features needed to calculate the expected energy consumption of the home. The software can predict energy savings with various improvements, which allows improvements to be prioritized based on resulting savings. In addition, a home energy rating is used to qualify a home for energy efficient mortgages, ENERGY STAR Homes® certification and the 2005 Federal Tax Credit for New Homes to builders. A home energy rating involves a visual inspection, diagnostic pressure testing, and computer modeling. Please note that you must also arrange for an insulation inspection and blower door & duct blaster tests in order to get a home energy rating. A home energy rating certificate and a report are issued.
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Additional Resources:
For the Homeowner/Homebuyer:
Southface has been a resource for homeowners and homebuyers for 25 years, providing easy-to-read fact sheets, technical assistance over the phone, and a Home Building School hosted at our Southface Resource Center . For general technical information that may help you improve your house, please review our fact sheets .
For the Professional Contractor:
Southface has working relationships with over 200 construction and renovation firms in Georgia and has several staff members in the field every day troubleshooting real-world situations in high-performance construction. Southface manages several programs that can help high performance contractors and builders distinguish themselves in the marketplace. If you are a contractor who works in energy improvements to existing homes, learn more about Home Performance with Energy Star. To become a part of one of the country's largest green building program, go to www.earthcrafthouse.com.
For more information and to arrange one of the above services or packages:
Southface Energy Institute. 241 Pine St NE. Atlanta, GA 30308 www.southface.org 404/872-3549
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