We are delighted to share with you this article in Buildings Magazine on continuous air replacement.

The conditioning of continuous air replacement (makeup air) is typically the top operating expense in facilities such as science centers, laboratories, and hospital environments where no air recirculation is permitted. Ambient air is continuously pulled from outside, filtered to remove impurities, conditioned, fed through the facility, and then exhausted out. In this way, such things as toxic chemicals, combustible substances, flammable solvents, harmful organisms, noxious vapors, and other contaminants are expelled from the occupied environment.

Heat recovery systems can substantially reduce the energy required for conditioning outside air by transferring energy from the exhaust air to the makeup air in the winter. However, most heat recovery that can be used for contaminated airstreams does a poor job of recovering energy during warm weather (pre-cooling outside air). However, by utilizing indirect evaporative cooling with a glycol energy recovery system, the cooling energy required to condition outside air in the summer can be greatly reduced. For this approach, fog is injected into the exhaust stream to evaporatively reduce the exhaust temperature, improving precooling performance and reducing peak cooling loads.  Such was the case at Amherst College Science Center in Amherst, MA.

Amherst College embarked upon an ambitious plan to dramatically reduce its carbon footprint by 2030. Major progress has already been made courtesy of the new science center, which incorporates a great many sustainability features. These serve to both lower energy usage and improve overall efficiency. van Zelm designed the mechanical, electrical, and plumbing/fire protection systems for this project.  A design goal was to reduce energy usage by 73% compared to the typical science building via features such as HVAC high-efficiency systems, variable flow lab hood control, high-performance building envelope, lab ventilation rate reset based on monitoring environmental conditions, rainwater harvesting, rooftop solar and contracting additional solar energy from the Farmington Solar project in Maine.

Many thanks to Eric Fontaine, PE, LEED BD+C, vice president, and Jean Zangor, PE, technical associate of van Zelm for contributing to this article.

Click on “Read More” below to read the article.