Energy Savings From System Efficiency Improvements in Iowa's HVAC SAVE Program

The objective of this project is to explore the energy savings potential of maximizing furnace and distribution system performance by adjusting operating, installation, and distribution conditions. The objective of the Iowa HVAC System Adjusted and Verified Efficiency (SAVE) program is to train contractors to measure installed system efficiency as a diagnostic tool to ensure that the homeownerachieves the energy reduction target for the home rather than simply performing a tune-up on the furnace or having a replacement furnace added to a leaky system. The PARR research team first examined baseline energy usage from a sample of 48 existing homes, before any repairs or adjustments were made, to calculate an average energy savings potential and to determine which system deficiencieswere prevalent. The results of the baseline study of 48 homes found that on average about 10% of the space heating energy available from the furnace was not reaching the conditioned space. In the second part of the project, the team examined a sample of ten homes that had completed the initial evaluation for more in-depth study. For these ten homes, the diagnostic data shows that it is possibleto deliver up to 23% more energy from the furnace to the conditioned space by doing system tune ups with or without upgrading the furnace. Replacing the furnace provides additional energy reduction. The results support the author's belief that residential heating and cooling equipment should be tested and improved as a system rather than a collection of individual components.