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.
On all projects, the need to provide reliability, accuracy, and safety need to be carefully considered as part of the overall design, but when we start looking at critical environments, these requirements become paramount in the design process.
Here, the pressures on the occupants are exceeded only by the weight of the cooling loads. However, underfloor air proves to be a good fit for an unusual setting. Take stock of the requirements, then look for designs that can pay dividends.
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.