Environmental factors, IAQ-related codes and standards, even architectural building materials … a lot of factors combine to create a moving target for designers of good humidification systems. That’s not even considering the potential hiccups lurking in the construction process or resulting from an inattentive project team member. From the humidity basics to equipment placement to post-occupancy maintenance that can thwart lawsuits, pursue the path to appropriate humidity and minimal risk.
For many years, duct products have often involved significant on-site measurement and construction, bringing certain advantages and risks. Here, that practice is com-pared to the use of listed ductwork, with an eye on duct integrity, hood connections, clearance to combustibles,
fire ratings, and more.
At Walter Reed National Military Medical Center, the mission was an air handling overhaul without interrupting the usual delivery of care. The project team delivered a safer, upgraded environment via a new desiccant system, air handlers, increased flexibility in the surgical suites, and more.
Air changes in some but not all spaces, duct liner here but not necessarily there, rooftop unit requirements … do the rounds and get a feel for the current condition of ASHRAE Standard 170, Ventilation of Health Care Facilities.
Leaning on experience and data from various K-12 cities and projects, the author pursues some less conventional design approaches. They may revolve around radiant heating and/or cooling, but depending on school size and other factors, the smart use of heat recovery, DOAS, and improved central plants could also put a project on the HVAC honor roll.