Avondale, Arizona in Maricopa County just west of Phoenix, is one of the major growth areas of the Valley of the Sun. This weatherization project targeted 46 multi-family, low-income housing units in Norton Circle, a housing authority complex in the City of Avondale, to reduce energy costs and provide comfort and safety for residents. The project entailed an innovative collaboration among 7 organizations, spearheaded by the County’s housing authority. Usually, homes in Maricopa County are weatherized as single-family dwellings, one at a time. This project weatherized 46 units at one time, thereby creating unique program efficiency. Labor costs, material costs and administrative costs were reduced by over 50% as a result.
The project promoted intergovernmental cooperation and coordination in addressing shared problems through the collaborative efforts of federal, state, and city governments, and private sector agencies. The project displayed a creative approach to enhance services to low-income families, going above and beyond base line regulations and contract expectations. The project produced measurable results in terms of cost savings, improved intergovernmental cooperation, and community benefits.
The Norton Circle HUD apartment complex was constructed in 1973 and consists of 25 single story buildings made of block construction, with single-pane aluminum frame windows and uneven R-11 cellulose in the attics. Norton Circle includes 18 one-bedroom apartments of 625 square feet each, 11 two-bedroom units of 900 square feet, 13 three-bedroom apartments of 1,050 square feet, and 4 four-bedroom apartments of 1,350 square feet.
Prior to weatherization, each unit had an evaporative cooler located on the roof and a forced air furnace located in an interior closet. The evaporative coolers and the furnaces shared a duct system. There was significant duct leakage as observed during the site inspection and based on blower door analysis. Old inefficient refrigerators contributed to the energy demands on each apartment. Duct diagnostic testing prior to weatherization provides an example of the severity of the duct leakage.
Due to the ineffectiveness of evaporative cooling in the Phoenix climate and the need to replace broken or inefficient HVAC equipment, the complex was going to upgrade to gas package roof mounted heating and cooling units. However, there were no plans to replace the leaky duct system. In addition, there were no provisions to upgrade insulation in the attic from its original R-11. This would have resulted in higher energy bills for the low-income residents. Lastly, some of the water heaters located in interior closets raised combustion air zone health and safety concerns. Due to the toxicity of the combustion appliance emissions, some of these units needed to be replaced with sealed combustion units.
In the early stages of the work, one partner, the Foundation for Senior Living, completed a REM Design analysis under the assumption that the complex installed 13 SEER/80% efficient gas package systems on the existing leaky ductwork with the existing R-11 insulation. This analysis showed a very modest cost to benefit ratio. The duct diagnostic testing indicated that new ducts could reduce leakage by up to 400 cubic feet per minute. A new sealed duct system for these 46 units cost $86,400. According to the Arizona Department of Commerce, Energy Climate zone 2 provides for $540 savings per 100CFM duct leakage reduction. With this in mind, the overall savings from duct leakage reduction would be $99,360. So, the simple investment return on duct replacement was 1.15.
The total project involved appliance replacement as well as weatherization. The project installed 29 15” ENERGY STAR refrigerators and 17 18” ENERGY STAR refrigerators. The work also removed roof mounted evaporative coolers and gas furnaces located in interior closets and replaced with energy efficient roof mounted 13 SEER air conditioning-gas heat package units including all new sealed duct system. The work included the electrical and plumbing repairs necessary to accommodate the new installations. The existing old duct system was used to provide for air exchange to relieve room pressures. The work also included the increase of attic insulation from R-11 to R-30 using blown cellulose. In addition, all incandescent light bulbs in the units were replaced by compact fluorescent light bulbs. Landscaping at the site was also upgraded to reduce water usage and facilitate maintenance.
Norton Circle residents were paying between $300 and $400 a month in utility bills. Weatherization should cut these energy bills in half and may reduce them to one third of the prior amounts. Total project cost was $337,420 with $95,732.80 coming from the Weatherization program and utility funds, an additional $21,000 from Arizona Public Service to cover refrigerators and the remaining balance $220,687.20 came from the property owner, Maricopa County Housing Authority. About 700 homes are weatherized annually across the state.
Posted on: September 8th, 2011