The U.S. Department of Energy Solar Decathlon communications team presents a series of technology spotlights in the article below that introduce common technologies used in the Solar Decathlon team houses. This article written by Alexis Powers and Carol Laurie, clarifies Energy-Recovery Ventilation Systems.
Good ventilation is vital for maintaining healthy indoor air quality. Houses built to modern energy efficiency standards, such as U.S. Department of Energy Solar Decathlon competition houses, are tightly constructed to allow very little outside air to leak in. As a result, odors, chemicals, particles, and humidity can become trapped, increasing indoor air pollution.
Energy-recovery ventilation systems provide tightly constructed houses with fresh air while minimizing energy loss. These systems rely on heat exchangers to efficiently transfer heat between indoor and outdoor air supplies. There are two types of energy-recovery ventilation systems: heat-recovery ventilators (HRVs) and energy-recovery (or enthalpy-recovery) ventilators (ERVs). An HRV uses fans to pull fresh air into a house while simultaneously exhausting stale air. In the winter, the heat exchanger transfers heat energy from the warmer outgoing air to the cooler incoming air to reduce the need for heating. In the summer, the system reduces the need to cool incoming fresh air by sending the cooler exhaust air past the warm intake stream. An ERV goes one step further by controlling indoor humidity as well as temperature. An ERV transfers water vapor along with heat energy to keep the interior humidity constant.
These ventilation systems can recover 70%–80% of the energy from a house’s outgoing air supply to help maintain a comfortable indoor environment.
Several Solar Decathlon 2013 teams incorporated energy recovery ventilation technologies into their competition houses. Norwich University provided continuous ventilation of its “Delta T-90” house by using a multiunit HRV system that was 92% efficient, ductless, and whisper-quiet. Team Ontario (Queen’s University, Carleton University, and Algonquin College), which received first place in the Solar Decathlon 2013 Engineering Contest, used an ERV in its “ECHO” house to dramatically reduce the energy needed to condition indoor air.
Visit the Energy Savers website to learn more about energy-efficient ventilation systems.
Fans of the U.S. Department of Energy Solar Decathlon mark your calendars:
Solar Decathlon 2015 will be held October 8-18, 2015, at the Orange County Great Park in Irvine, California. You can check out the team lineup for the competition and the concepts for their net zero houses on the 2015 team pages.
Source: 1Sun4All. Reproduced with permission.