The SP400 and SP500 smart, digital positioners consume approximately 1% of the air of a traditional electro-pneumatic positioner. The SP400 features a simple menu system and auto-stroke calibration at the press of a single button resulting in reduced commissioning time. The SP500 is a full-featured smart digital positioner with optional retransmission of valve position and the ability to use a separate 24 Vdc power supply and communications protocols as well as diagnostics. — Spirax Sarco
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.