Abstract: A push through conditioned air vestibule unit includes an air vestibule having a top side, a first lateral side, and a second lateral side forming a passage through the unit. Movable barrier members are attached to the unit to reduce external air flow through the passage. Return air ducts are configured to circulate air to an air moving device and a temperature conditioning device. Thermal and humidity sensors measure temperature and humidity of the passage and an external room, and a system controller controls the temperature of air moved into the passage using the temperature conditioning device if the partial pressure of moisture vapor internal to the passage is not greater than or equal to the partial pressure of moisture vapor external to the passage.

Abstract: A push through conditioned air vestibule unit includes an air vestibule having a top side, a first lateral side, and a second lateral side forming a passage through the unit. Movable barrier members are attached to the unit to reduce external air flow through the passage. Return air ducts are configured to circulate air to an air moving device and a temperature conditioning device. Thermal and humidity sensors measure temperature and humidity of the passage and an external room, and a system controller controls the temperature of air moved into the passage using the temperature conditioning device if the partial pressure of moisture vapor internal to the passage is not greater than or equal to the partial pressure of moisture vapor external to the passage.

Abstract: An air curtain arrangement and method of operating the arrangement are provided. The arrangement includes at least one air curtain unit having a supply plenum, a return air duct, and an intermediate air duct therebetween and separates relatively warm and cold areas. The air curtain discharges an air stream across a doorway from an outlet aperture of a discharge plenum toward an air return duct, at a discharge angle. A portion of the air stream is received at an inlet aperture of the return air duct. The portion of the air stream that is received at the air return duct is monitored. The discharge angle is adjusted to maximize the portion of the air that is received. One embodiment controls the discharge angle based on the temperature of the received portion of the air stream. Another embodiment senses the force of the air stream received proximate the inlet aperture.

Abstract: A conditioned vestibule, control system, and method are disclosed for use with a cold storage doorway that separates warm and cold sides. A heater warms an air stream discharged across the doorway by the vestibule. A control unit operates the heater to maintain an air stream temperature. The control unit continuously monitors the air stream temperature and operates the heater to maintain the air stream temperature in a non-saturated state based on a humidity ratio. One embodiment calculates first and second temperatures based, respectively, warm and cold side tangent lines to a psychrometric saturation curve and based on the humidity ratio. The tangent lines are based on humidity and temperature sensed on the warm and cold sides. The air stream is warmed to at least the greater of the first and second temperatures. One embodiment controls air flow to adjust the humidity ratio to more efficiently operate the vestibule.

Abstract: A conditioned vestibule, control system, and method are disclosed for use with a cold storage doorway that separates warm and cold sides. A heater warms an air stream discharged across the doorway by the vestibule. A control unit operates the heater to maintain an air stream temperature. The control unit continuously monitors the air stream temperature and operates the heater to maintain the air stream temperature in a non-saturated state based on a humidity ratio. One embodiment calculates first and second temperatures based, respectively, warm and cold side tangent lines to a psychrometric saturation curve and based on the humidity ratio. The tangent lines are based on humidity and temperature sensed on the warm and cold sides. The air stream is warmed to at least the greater of the first and second temperatures. One embodiment controls air flow to adjust the humidity ratio to more efficiently operate the vestibule.