The Physics of Thin Mountain Air
At an altitude of 5,000 feet (such as Denver, CO), atmospheric pressure is approximately 17% lower than at sea level. Because air is less dense, an HVAC blower must move higher physical volume (CFM) to deliver equivalent thermal mass flow for heating and cooling.
Decreased air density slightly lowers initial static pressure drop across clean filters, but the higher velocity required to move adequate mass flow accelerates filter dust loading, requiring 20% to 30% more frequent filter changes.
About ClariSelect Editorial & Research Standards:
Sizing measurements, static pressure curves, and filtration ratings referenced across our educational guides are compiled from published ANSI/ASHRAE Standard 52.2 engineering data, AHAM AC-1 verified ratings, and manufacturer technical documentation. ClariSelect provides objective editorial research and analysis with zero sponsored placements.