How Is HVAC Designed for a High-Altitude Mountain School?

The dedicated outdoor-air approach gives the engineer independent control of air quality and temperature. Each classroom gets its code-required outdoor air — filtered to a high level, which matters in mountain towns during wildfire smoke season when the engineer may need to upgrade filtration temporarily — delivered at a neutral temperature by the central unit. CO2 sensors in each classroom let the system trim ventilation to actual occupancy: a half-empty classroom on a testing day does not need the full thirty-student air rate, and the energy savings across a whole school are significant. The engineer commissions the CO2 control sequence because a sensor that never gets calibrated quietly reverts the building to full ventilation all day. Exhaust placement is designed with the prevailing wind and the snow in mind. Restroom, locker-room, and kitchen exhausts terminate where the wind cannot push them back into the outdoor-air intakes, and the engineer keeps the separation distances the code requires even when parapets and rooftop units crowd the roof. During wildfire smoke events — increasingly a design consideration from California's Sierra districts to Colorado's Front Range foothills — the engineer provides a smoke mode: intakes stay open for the code-required ventilation but filtration steps up and the building goes slightly positive to keep smoke from infiltrating through the envelope.

Use this checklist before the design development set is issued: • Combustion heating derated for the site elevation and checked against the jurisdiction's true design temperature • Dedicated outdoor-air system with energy recovery serving every classroom independently of local heating/cooling • CO2 demand-controlled ventilation in classrooms, with a commissioning plan for sensor calibration • Rooftop intakes, exhausts, and combustion air raised above ASCE 7 drift heights and oriented away from storm winds • Ductwork sized for low velocity with sound lining at classroom diffusers; noise ratings checked at every grille • Heated, pressurized vestibules at student entries sized for the morning door-cycle rush • Filtration strategy covering wildfire smoke season, with an operating smoke mode defined • Emergency-shelter spaces (gym, cafeteria) evaluated for backup heat independent of the grid • Jurisdiction confirmed: school district standards, town or county building permit, and any state school-facility review