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hrai3 jun112021

Technologies attracting more attention in the trade press and in the marketplace include the combination of dedicated outdoor air systems (DOAS) combined with chilled beams, because they can offer cleaner indoor air without a significant energy penalty.

Before the COVID-19 disruption, chilled beams were achieving impressive steady growth in the US market, increasing from $239 million in 2015 to an estimated $406m in 2020, (although the latter number now likely won’t be realized this year due to the economic downturn). Part of the upward trajectory was driven by recent legislation that allows the use of chilled beams in healthcare facilities.

Installations include Manitoba schools Northlands, Steinbach HS, Amber Trails, and Woodlands, plus other kinds of buildings such as Astra-Zeneca offices in Boston, Portland Center Stage Theatre in Portland, Oregon, university buildings at Penn State in Philadelphia, and Clemson in South Carolina.

Chilled beams use a building's chilled and hot water supply instead of refrigerant, and are quiet and efficient. Their airflow rates are typically only 25% to 35% compared with all-air systems, however active chilled beams coupled with DOAS offer improved contaminant removal, without significantly raising energy and maintenance costs. When combined with DOAS, they can exhaust rather than recirculate aerosol and respiratory contaminants.

Chilled beams are installed for either active or passive operation. An active beam incorporates fresh air into the room, while a passive beam only utilizes air in the room.

Early reviews of the technology raised concerns about condensation, which should not be an issue as long as the space humidity is controlled and chilled water temperatures are maintained at or above the space dew point. Manufacturers are working on full integration of these systems into building controls.

If customers are concerned with pathogens and the IAQ implications of new work arrangements, and more time than usual spent in homes or other buildings, chilled beams with DOAS systems might be worth consideration.