A pressure control system remotely controls pressure within one or more remote zones, each respectively connected to an enclosure through a conduit, by controlling flow of a fluid into and out of each enclosure. The pressure of the fluid is measured within each enclosure. An estimated pressure within each zone is computed, as a function of the measured pressure in the enclosure and known characteristics of the conduit and the zone. For each zone, an inlet proportional valve and an outlet proportional valve of each enclosure is operated so as to control the input flow rate of the fluid into the respective enclosure and the output flow rate of the fluid out of the enclosure as a function of a pressure set point and the estimated pressure, thereby regulating pressure within the zone in accordance with the pressure set point.