Alfa Laval has introduced a patented cooling concept, Low Speed Ventilation, which the company says delivers air at a considerably lower speed: 1.5 to 1.8 meters per second. Reducing air speed and delivering an optimum airflow eliminates the Venturi effect, minimizes pressure differences, and therefore prevents problems such as “hot spots.” As LSV is a normal pressure technology, data center operators only need to control air availability, not air pressure, making it easier to achieve optimum conditions in the server room.
This month, a consultant and NFPA committee chairman looks at the major items involved in a hospital’s life safety design. Like the fire risks themselves, the assorted relevant codes are evolving with regard to specifics like smoke dampers. HVAC wall penetrations, alarm zoning, and response plans are just three other aspects to consider in this demanding design environment.
ASHRAE 170 is just the baseline for the fight against hospital acquired infections (HAIs). The ongoing human and financial tolls taken by these infections point to the need for engineers and facilities to raise their IAQ game wherever possible. Move beyond the minimum and get into the what, where, and how of HEPA filtration, ultraviolet technology, and catalytic air cleaners.
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.
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.