SOFTWARE DESCRIPTION

The Weatherization Assistant is a suite of four audit tools developed by the Oak Ridge National Laboratory to specifically help states and local weatherization agencies implement the US Department of Energy Weatherization Assistance Program, although it can be used by utilities and other home energy professionals:

• National Energy Audit Tool (NEAT) for site-built, single-family homes;
• Manufactured Home Energy Audit (MHEA) for mobile homes;
• Multifamily Tool for Energy Audits (MulTEA) for multifamily buildings;
• Health and Safety Audit for single-family homes (including mobile homes) and individual dwelling units in low-rise multifamily buildings that are being weatherized.

The three energy audit tools identify the cost-effective energy-efficiency retrofit measures for a home or building after taking into account site weather conditions, local retrofit measure costs, area fuel costs, and specific construction details of the home or building. The Health and Safety Audit assists in the identification and selection of health and safety measures when a home or a dwelling unit in a multifamily building is being weatherized or undergoing an energy-efficiency retrofit or remodeling job.

 

The web-based Weatherization Assistant application (WAweb) is the umbrella program to access the latest versions of the Weatherization Assistant’s suite of measure selection and implementation tools listed in the “Overview” tab. Authorized users access WAweb using a web browser and user-specific login credentials. All input and output data are stored in a secure relational database.

WAweb provides State Administrator users with the ability to add weatherization program implementers (“agencies”) and view all audits and work orders within their given state without the risk of inadvertently modifying data. Agency Administrator users can manage all users, audits, work orders, and libraries within their “agency.” For more details about WAweb user privileges, please see the Getting Started Guide.

Overview
The National Energy Audit Tool (NEAT) is specifically designed for site-built single-family houses while the Manufactured Home Energy Audit (MHEA) is designed specifically for mobile homes. The unique construction characteristics of mobile homes require evaluating and installing measures specifically for such homes in order to obtain effective weatherization with high energy and dollar savings. NEAT and MHEA are included in the computer-based Weatherization Assistant application.

NEAT and MHEA evaluate each home individually after taking into account local weather conditions, retrofit measure costs, fuel costs, and specific construction details of the home. After describing envelope components, heating and cooling systems, and base load equipment (e.g., refrigerators, water heaters, lighting), NEAT and MHEA produce a prioritized list of cost-effective weatherization measures customized for the dwelling being evaluated. The output includes estimates of the dollar value for the projected energy savings, installation costs, savings-to-investment ratios (SIRs), a list of the quantities of the major materials necessary to perform the recommended weatherization retrofits, and design heating and cooling loads needed to size any replacement equipment.

NEAT was developed by the Oak Ridge National Laboratory (ORNL). NEAT was formally introduced within the US Department of Energy (DOE) Weatherization Assistance Program in the summer of 1993 and was already being used by local weatherization agencies throughout 20 states by 1994. Based on field tests performed in the late 1980’s and early 1990’s (see Reports Relevant to the Weatherization Assistant), NEAT helped energy auditors improve average space-heating energy savings by 18 to 25% over standard measure selection methods at that time. Today, NEAT is used by approximately 35 states to make retrofit decisions for low-income dwellings served by the Weatherization Assistance Program in these states.

MHEA was originally developed by the National Renewable Energy Laboratory. ORNL, which now maintains and supports the software, converted the software to a Windows-based program and made other modifications to the calculations and retrofits associated with infiltration and baseloads. MHEA was then formally introduced within the US DOE Weatherization Assistance Program in 2003. ORNL made additional modifications to MHEA after a field test and subsequent analyses were performed in 2007 and 2008 (see Reports Relevant to the Weatherization Assistant).

MHEA stands apart from other building energy analysis tools in many ways. Input and calculations incorporated into the software address constructions unique to mobile homes such as bellied floors and bowstring roofs. The retrofit measures evaluated by MHEA are all applicable to mobile homes. Help messages describe common weatherization practices for mobile homes and provide hints on how to install retrofit measures.

Implementation

NEAT and MHEA follow eight steps to select the energy efficiency measures for a particular home that meet a user-defined level of cost effectiveness (i.e., measures that have an SIR greater than a value selected by the user):

1. NEAT and MHEA guide the user through the process of entering data on the home that describe the characteristics of the home, its mechanical systems, and other energy-related information. NEAT and MHEA also allow health and safety deficiencies and repair items to be noted. Both programs use blower door measurements, duct leakage measurements, and steady-state efficiency measurements of space-heating equipment if available. Data may be collected in the field using data input forms and transferred to NEAT or MHEA later in the office, or data may be entered directly into NEAT or MHEA using a portable computer while auditing the home.

2. NEAT and MHEA use engineering calculations and weather data from one of 216 weather cities in the US to compute the annual heat loss and heat gain of the home, and the annual space-heating and space-cooling energy consumption required to keep the home at a specific thermostatic set point. Both programs calculate heat loss and heat gain on a monthly basis using a variable-base degree-day method and ten-year average weather data for the selected city. They also consider the amount of solar energy absorbed by a home and the typical amount of heat generated inside a home by people and their refrigerators, water heater, other appliances, and lights. NEAT and MHEA use ASHRAE Draft Standard 152P algorithms to estimate duct leakage heat gains and losses, if duct leakage is specified. NEAT and MHEA assume a home is maintained at average conditions regardless of specific occupants because efficiency measures typically remain after occupants move, and this follows the intent of the Weatherization Assistance Program that finances energy efficiency measures that generate savings for up to 20 years.

3. NEAT and MHEA compute the energy consumption of selected baseload uses (water heating, refrigerators, and lighting in need of retrofit) if desired. Refrigerator and water heater descriptions use an extensive database of manufacturers and models which eliminate the need to input detailed equipment descriptions by the user.

4. NEAT checks the applicability of 34 building envelope, space-heating and space-cooling system, and baseload energy efficiency measures to the specific home being audited, while MHEA checks the applicability of 31 measures. These measures include air and duct leakage reduction, envelope insulation, window replacements and other treatments, space-heating and space-cooling equipment replacement and tune-up, replacement refrigerators, water heater tank and pipe insulation, replacement lighting, and more. Both programs then calculate an energy savings and discounted SIR for each applicable measure applied individually to the home. User-defined energy efficiency measures can also be entered and evaluated. The SIRs are calculated using fuel costs and installation costs representative of the home and agency as input by the user, as well as measure lifetimes appropriate for each measure.

5. NEAT and MHEA evaluate the interaction between efficiency measures (e.g., since insulation reduces the amount of energy needed for space heating, it also reduces the energy savings from a space-heating system replacement). Beginning with the measure with the highest SIR, NEAT and MHEA apply each energy efficiency measure to the home and then compute a new SIR for the remaining measures, taking into account savings gained by preceding measures.

6. NEAT and MHEA identify a final list of recommended energy efficiency measures by selecting those with an SIR greater than the cut-off value selected by the user once interactions between measures have been accounted for.

7. NEAT and MHEA generate a report of recommended energy efficiency measures that identifies—both individually and cumulatively—the energy savings, installation cost, and SIR of the recommended measures. The report also identifies those health, safety, and repair items selected by the user that need to be performed. In addition, an essential materials list is developed, and design heating and cooling loads needed to size replacement equipment are provided.

8. NEAT and MHEA can adjust their estimated energy savings based on actual utility consumption data and develop a second list of recommend energy efficiency measures if the user desires.

Overview

The Multifamily Tool for Energy Audits (MulTEA) is an energy audit tool designed to provide auditors with an improved energy simulation tool for multifamily buildings and an improved tool for identifying cost-effective energy-efficiency retrofit measures for multifamily buildings. The unique construction, operation, and retrofit measures applicable to multifamily buildings require evaluating measures specifically for such buildings in order to obtain effective weatherization with high energy and dollar savings. MulTEA was developed jointly by the Oak Ridge National Laboratory and the Lawrence Berkeley National Laboratory. It was formally released within the US Department of Energy (DOE) Weatherization Assistance Program in 2017. MulTEA is included in the web-based Weatherization Assistant application.

MulTEA evaluates each building individually after taking into account local weather conditions, retrofit measure costs, and fuel costs, and specific construction and operation details of the building. MulTEA performs an hourly simulation of the building using the DOE-2 energy simulation engine in performing its calculations. After describing envelope components, heating and cooling systems, and base load equipment (e.g., refrigerators, water heaters, lighting), the energy consumption of the existing building can be estimated and calibrated to actual energy consumptions (i.e., utility bills). After an auditor defines and selects the retrofit measures to be analyzed, MulTEA produces a prioritized list of the weatherization measures for the building being evaluated. The output includes estimates of the energy savings, dollar savings, installation cost, and savings-to-investment ratio (SIR) for each recommended measure and the package of recommended measures to be installed. A method for determining the amount of leveraged funds needed to make the DOE Weatherization Assistance Program investment cost effective for each selected measure is also provided.

Implementation

MulTEA is implemented in four basic steps to select the energy efficiency measures for a particular building:

1. MulTEA guides the user through the process of entering data on a building that describe the characteristics of the building, its mechanical systems, and other energy-related information. The user also enters information on all the retrofits to be analyzed. MulTEA uses blower door measurements and steady-state efficiency measurements of space-heating and central water-heating equipment if available.

2. MulTEA performs a calibration run to estimate the existing (i.e., base case) energy consumption of the building and calibrate the building inputs using utility bills. MulTEA uses the DOE-2 hourly simulation program to estimate the annual heating and cooling loads of the building and the annual space-heating and space-cooling energy consumptions required to maintain the building at the specified thermostat settings. These calculations use weather data available from over 1000 cities in the US. They take into account solar energy absorbed by the building and the internal loads of the buildings from people, lighting, and appliances. MulTEA also estimates the energy consumptions associated with lighting, appliances, and domestic water heating by side calculations performed in parallel with the DOE-2 calculations. Currently the calibration is performed by comparing energy consumptions estimated by MulTEA based on standard weather conditions to energy consumptions based on utility bills that occurred for specific weather conditions. In the future, MulTEA will have the capability of performing calibrations using the same weather that the utility bills are based on.

3. MulTEA performs a measures run to evaluate the energy savings and cost effectiveness of individual energy efficiency retrofit measures applied to the building individually. In this run, each measure selected by the user is analyzed as if it is the only measure applied to the building, so there are no interactive effects between measures. This run provides the auditor with information to help in the selection of the measures to be included in the final package. MulTEA provides the capability of analyzing 36 different building envelope, space-heating and space-cooling, and baseload retrofit measures. Once MulTEA has estimated the energy savings associated with each of the selected retrofit measures, the user can enter the installation costs of the measures manually or using data bases that they have created to automate the process. MulTEA then calculates a discounted SIR for each measure using the estimated energy savings, installation costs, user-specified fuel costs, and measure lifetimes appropriate for each measure.

4. Finally, MulTEA performs a package run to evaluate the energy savings and cost effectiveness of a package of energy efficiency retrofit measures selected by the user for the building. In this run, the interactive effects between measures are accounted for. Beginning with the measure with the highest SIR, MulTEA applies each selected measure to the building and then recalculates a new SIR for the measure until all of the selected measures have been applied to the building. Repair and health and safety measures can be added to the package of energy efficiency retrofit measures selected for the building. Cost sharing/leveraging can also be specified and their impact on SIRs as viewed for the perspective of the weatherization program can be determined.

Overview

The Health and Safety Audit is designed to be used on existing homes, especially those undergoing weatherization. When combined with weatherization programs, the audit provides a comprehensive health and safety evaluation that ensures the health and safety of occupants and weatherization crews during and after weatherization, and facilitates integrated interventions of energy efficiency with health and safety. The design of the Health and Safety Audit is based upon the US Environmental Protection Agency’s Healthy Indoor Environment Protocols for Home Energy Upgrades (dated October 2011) and incorporates the guidance contained in the US Department of Energy (DOE) Weatherization Program Notice 11-6, Weatherization Health and Safety Guidance (dated January 12, 2011) (to be updated based on DOE Weatherization Program Notice 17-7, Weatherization Health and Safety Guidance, dated August 9, 2017). The Health and Safety Audit is included in the web-based Weatherization Assistant application.

The tool utilizes comprehensive checklists together with measured diagnostic data to identify potential health and safety issues in a home and provide recommendations for the prevention and mitigation of identified problems. The tool assesses not only existing health and safety issues, but also the impact of existing conditions on weatherization work and planned weatherization work on the health and safety of occupants and weatherization crews. The audit recommends actions to remediate existing health and safety problems, perform weatherization work in a healthy and safe manner, and prevent potential problems in the future.

The tool was developed by the Oak Ridge National Laboratory for the US Department of Housing and Urban Development’s Office of Healthy Homes and Lead Hazard Control and its Healthy Homes Program, and the DOE Weatherization Assistance Program. It was released within the US Deparment of Energy Weatherization Assistance Program in 2017.

Implementation

The Health and Safety Audit is implemented in four basic steps to identify health and safety measures applicable to a particular dwelling unit:

1. A set of three general survey forms are completed which include audit information and preliminary screening questions on health and safety issues. These include specific occupant health symptoms that may indicate the presence of existing health and safety issues in the dwelling. They also include general observations regarding the dwelling that also may indicate the presence of existing or potential problems. Observations related to mold and moisture, lead, radon, formaldehyde and VOCs, combustion appliances, pest infestation, and planned weatherization work can be identified.

2. Guidance is viewed on which of the nine detailed survey forms need to be completed to investigate specific health and safety issues based on the preliminary screening questions. The guidance identifies those forms that are recommended, optional, or not applicable, and provides an explanation as to why the guidance is presented.

3. Detailed survey forms are completed that were recommended or were optional to further investigate those health and safety issues. There are separate forms for mold and moisture, lead, radon, asbestos, formaldehyde and VOCs, combustion appliances, pest infestation, safety, and ventilation (based on ASHRAE Standard 62.2). Most of the input is provided via checklists that identify the existence of an issue and/or the source of the issue. However, diagnostic measurements can also be entered related to lead, radon, formaldehyde, combustion appliances, and ventilation.

4. The audit is then run to generate its recommendations on remedial actions needed to address existing health and safety issues and preventive measures for potential issues. Columns are provided on the recommendation form so that an auditor can identify those measures for which weatherization work should be delayed until corrective actions are taken. Additional columns are provided so that an auditor can identify the party responsible for implementing the recommended measure or if will be deferred. Notes that discuss the implementation of the recommended measures within the DOE Weatherization Assistance Program are provided below the recommendations. Also provided are factors to consider in determining if recommendations need to be performed before weatherization work should proceed.