Visual inspection, diagnostic testing, and numerical analysis are three types of energy auditing procedures we discuss in this section. These procedures should aid you in evaluating all the possible ECMs that are cost-effective according to DOE-approved software: Weatherization Assistant or approved equivalent. See “SIR Calculations with Weatherization Assistant” on page 72.
To understand the features of Weatherization Assistant, consult the DOE Weatherization Assistant training site.
The energy audit must also propose solutions to health and safety problems related to the energy conservation measures.
Visual inspection orients the energy auditor to the physical realities of the home and home site. Among the areas of inspection are these.
• Health and safety issues
• Building air leakage
• Building insulation and thermal resistance
• Heating and cooling systems
• Ventilation fans and operable windows
• Baseload energy uses
• The home’s physical dimensions: area and volume
Measurement instruments provide important information about a building’s unknowns, such as air leakage and combustion efficiency. Use these diagnostic tests as appropriate during the energy audit.
• Blower door testing: A variety of procedures using a blower door to evaluate the airtightness of a home and parts of its air barrier.
• Duct leakage testing: A variety of tests using a blower door and pressure pan to locate duct leaks.
• Combustion safety and efficiency testing: Combustion analyzers sample combustion by-products to evaluate safety and efficiency.
• Infrared scanning: Viewing building components through an infrared scanner shows differences in the temperature of building components inside building cavities.
• Appliance consumption testing: Refrigerators are monitored with logging watt-hour meters to measure electricity consumption.
Energy auditors currently use Weatherization Assistant (WA)or other DOE-approved software, to determine which ECMs have the highest Savings-to-Investment Ratio (SIR). The ECMs with the highest SIRs are at the top of the WA priority list for a particular home.
SIR = Initial investment ÷ Lifetime savings
The DOE also approves priority lists based on the results of Weatherization Assistant or other DOE-approved software on typical homes within the State. The priority list is then used instead of the software, which saves time for evaluating common home types. Energy auditors still use software to evaluate ECMs for uncommon home types.
DOE WAP and the State WAP program require that ECMs have an SIR greater than 1. ECMs with higher SIRs should be installed before or instead of ECMs with lower SIRs.
Whether a weatherization provider uses software or a priority list, the auditor must collect information to inform decisions about which ECMs to choose.
ü Measure the home’s exterior horizontal dimensions, wall height, floor area, volume, and area of windows and doors.
ü Measure the current insulation levels.
ü Do a blower door test to evaluate air leakage.
ü Do a combustion efficiency test to evaluate the central heating system.
ü Evaluate energy bills and adjust the job’s budget within limits to reflect the potential energy savings.