Demand ventilation system

A demand ventilation system, comprising:

• variable exhaust ventilation means, includes exhaust for means, in atmospheric communication between a designated space within a structure of a building and the outside atmosphere for exhausting polluted air within the space to the outside atmosphere;
• variable low velocity ventilation means in atmospheric communication between said designated space and a supply of primary and building return air for supplying the designated space with a given volume of ventilation air at a predetermined temperature to enable the polluted air within the space to rise and be exhausted at a high level into the outside atmosphere;
• pollutant sensing means disposed within the designated space for detecting the presence of pollutants in the air within the designated space to help facilitate air displacement within the space based upon air quality demand requirements;
• control means coupled to said exhaust fan means and said low velocity ventilation means for varying continuously their respective speeds in synchronism relative to one another so that the atmospheric pressure within the space is maintained at a negative pressure relative to the adjacent areas to facilitate exhausting the polluted air with substantially no polluted air being returned to the structure outside of the designated space, and so that a sufficient volume of ventilation air several degrees cooler than the desired room air is discharged into the space at about floor level to cause polluted air in the space to be displaced upwardly so that the polluted air is collected at a high level and is exhausted into the outside atmosphere.

A system for controlling the ventilation within at least one occupant designated space among a plurality of occupant spaces in a building, said at least one designated space being defined by a floor, a ceiling, and a plurality of walls for helping to isolate the exhaust air within the designated space from the supply or return air in the other occupant spaces within the building, comprising:

• exhaust ventilation means partially disposed in the ceiling of the designated space and in atmospheric communication with the atmosphere outside of the building for permitting the exhaust air within the designated space to be exhausted out of the building so that any pollutants in the exhaust air will be substantially prevented from commingling with the indoor air in the other occupant spaces within the building;
• volume sensing means in atmospheric communication with the exhaust air within said exhaust ventilation means for determining the volume of exhaust air being discharged into the atmosphere outside of the building to help facilitate maintaining the atmospheric pressure within the designated space at a pressure level substantially lower than the pressure level of adjacent areas of the building to substantially prevent the exhaust air from infiltrating the air in the other occupant spaces within the building;
• air diffusion means partially disposed at about the floor in the designated space for helping to disburse a clean air mixture supply of low velocity ventilation air at about floor level of the designated space to permit the disbursed air mixture to slowly rise from the floor as it warms to form low velocity plumes around each of the occupants within the designated space to draw clean air past the breathing zone of each occupant therein and thence upwardly carrying any pollutants discharged by the occupants forming the exhaust air so that it may be drawn into said exhaust ventilation means and discharged into the atmosphere outside of the building;
• low velocity ventilating means in atmospheric communication with said air diffusion means for supplying said air mixture supply;
• temperature sensor means disposed within the designated space for helping to determine the temperature of the air within the designated space so that the clean air supplied to said air diffusion means can be maintained at a temperature substantially lower than the temperature of air within the space to enable the disbursed air mixture to slowly rise from the floor as its temperature slowly increases to the sensed temperature of the air within the designated space;
• pollutant sensing means for detecting the presence of pollutants in the air within the designated space to help facilitate air displacement based on actual space demand;
• controller means coupled to said exhaust ventilation means and to said volume sensing means for controlling the air pressure of the exhaust air within the designated space so that it is maintained at a substantially lower pressure than the air in the adjacent areas of the building;
• said controller means further coupled to said low velocity ventilation means, said temperature sensor means and to said pollutant sensing means for supplying a sufficient supply of said clean air mixture to maintain the temperature of the air within the space at a desired temperature in the absence of any detected pollutants in the air within the designated space and for supplying another sufficient supply of said clean air mixture to maintain the temperature of the clean air supplied to said air diffusion means at a temperature substantially below said desired temperature so that the temperature of the air mixture discharged along the floor of the designated space can slowly warm to said desired temperature for helping to form the low velocity plumes around each of the occupants within the designated space only on an actual space demand related to the detection of pollutants within the designated space;
• and
• whereby as occupants within the designated space emit pollutants, the temperature of the air discharged along the floor will be maintained at a temperature substantially below said desired temperature to cause the polluted air within the space to be continuously displaced upwards by the clean air entering the space so that the polluted air is carried above the breathing zone of the occupants and is collected at a high level into said exhaust ventilation means and thence to the atmosphere outside the building without infiltrating or being commingled with the atmosphere in the occupant spaces within the building.

A method permitting the exhaust air within the designated space to be exhausted out of the building so that any pollutants in the exhaust air will be substantially prevented from commingling with the indoor air in the other occupant spaces within the building;

• determining the volume of exhaust air being discharged into the atmosphere outside of the building to help facilitate maintaining the atmospheric pressure within the designated space at a pressure level substantially lower than the pressure level of adjacent areas of the building to substantially prevent the exhaust air from infiltrating the indoor air in the other occupant spaces within the building;
• distributing a clean air mixture supply of primary ventilation air and building return air along the floor of the designated space to permit the distributed air mixture to slowly rise from the floor as it warms to draw clean air past an occupant therein and thence upwardly carrying any pollutants discharged by the occupant away from the breathing zone to form the exhaust air so that it may be discharged into the atmosphere outside of the building;
• helping to determine the temperature of the air within the designated space so that the distributed clean air can be maintained at a temperature substantially lower than the temperature of air within the designated space to enable the disbursed air mixture to slowly rise from the floor as its temperature slowly increases to the sensed temperature of the air within the designated space;
• detecting the presence of pollutants in the air within the designated space to help facilitate air displacement based on actual space demand;
• supplying a sufficient supply of said clean air mixture to maintain the temperature of the air within the space at a desired temperature in the absence of any detected pollutants in the air within the designated space and for supplying another sufficient supply of said clean air mixture to maintain the temperature of the clean air at a temperature substantially below said desired temperature so that the temperature of the air mixture discharged along the floor of the designated space can slowly warm to said desired temperature for helping to form low velocity plumes around each of the occupants within the designated space only on an actual space demand related to the detection of pollutants within the designated space;
• and
• whereby as occupants within the designated space emit pollutants, the temperature of the air discharged along the floor will be maintained at a temperature substantially below said desired temperature to cause the polluted air within the space to be continuously displaced upwards by the clean air entering the space so that the polluted air is carried above the breathing zone of the occupants and is collected at a high level via the exhaust and is then discharged into the atmosphere outside the building without infiltrating or being commingled with the indoor air in the adjacent occupant spaces within the building.