Ventilation method and means for the same

An air control and conditioning apparatus for establishing and sustaining a predetermined environment in a sealed mobile unit, comprising;

• an inlet receiving blown, filtered external air;
• a port communicating directly with the mobile unit supplying air to maintain a predetermined air pressure within the mobile unit;
• an outlet connected to an air-distribution channel within the mobile unit;
• a cooling/heating unit located between the outlet and the air-distribution channel;
• a motor-driven fan;
• and
• a pressure sensing control device, wherein the fan is connected electrically to the control device and, upon receipt of a signal from the control device, causes blown, filtered external air to flow in through the inlet and mix with air drawn in from the mobile unit through the port and to exit through the outlet to the cooling/heating unit.

A method of establishing and sustaining a predetermined environment in a sealed mobile unit, comprising:

• sensing a pressure in a sealed mobile unit;
• receiving blown, external air filtered to extract contaminating particles and gas;
• allowing the filtered air to flow directly into a sealed mobile unit if the pressure sensed in the mobile unit is below a predetermined pressure, said predetermined pressure being above ambient pressure;
• activating a fan to draw air from the mobile unit and mix the air with inflowing filtered external air if the predetermined pressure sensed is above ambient pressure;
• blowing the mixed air to a conditioning unit for one of selectively heating and cooling the air;
• filtering the conditioned air to extract contaminating particles and gas;
• and,
• distributing the filtered conditioned air to the mobile unit.