Abstract: The ventilator system and method use a isolating heat exchanger to selectively transfer heat between exhaust air leaving an enclosed space and outside air entering the enclosed space. The system operates in three basic modes, under the control of a microprocessor-based controller which is responsive to the temperatures inside and outside of the enclosed space. In the heating mode, heat is transferred from the exhaust air to the outside air when the enclosed space requires heating. In the cooling mode, heat is transferred from the outside air to the exhaust air when the outside air temperature is higher than that in the enclosed space. In the supplemental cooling mode, heat transfer between the exhaust and outside air is reduced or eliminated when the outside air temperature is below the desired temperature in the enclosed space and cooling is required. In the heating mode, the heat exchanger is selectively heated when necessary to defrost it.

Abstract: Described is an apparatus for air conditioning a passenger compartment of an automotive vehicle which achieves a quick warming-up of the passenger compartment. In the air conditioning apparatus, in addition to a coolant of a vehicular engine which is utilized as a heat source of a heater core, a highly compressed refrigerant discharged from a compressor can be utilized as a heat source of a sub condenser which is disposed in an air passage of the air conditioning apparatus, during the inside air warming up in the passenger compartment. During the warming up operation, the refrigerant discharged from the compressor is circulated through a bypass line bypassing a condenser disposed at a front part of an engine compartment and through the sub condenser and an evaporator.

Abstract: The present invention is directed toward a VAV (variable air volume) air conditioning system which is capable of varying the supply air volume to a space based upon discharge temperature while simultaneously maintaining constant ventilation. The thermal dynamic balancing system of the present invention includes a bypass air box and an outside air ventilation box, each having adjustable dampers, which are controlled, in concert with one another, to provide a system which constantly dehumidifies the air in the conditioned space while simultaneously maintaining the discharge air temperature and degree of ventilation at constant values.

Abstract: The present invention is a system for controlling the quality of air in a building. The system includes a sensor disposed for sensing the air quality in a building. Upon a sensing of an air quality problem, the system issues a command to draw in additional outside air into the building to alleviate the problem. The issuing of such command can be made conditional on a measurement of outside air temperature. The flow of additional outside air may be limited or avoided altogether where drawing in additional outside air would adversely affect the inside air temperature. Additional air can be drawn into a building, for example, by opening an economizer, activating a fan system, or by increasing a pressure setpoint in a supply air duct.

Abstract: A control system for controlling an air handling unit. The control system links the position of an exhaust air damper and a recirculation air damper so as the exhaust air damper is opened, the recirculation air damper is closed the same amount, and vice versa. An outside air damper remains completely open at all times. The relative positions of the exhaust air damper and the recirculation air damper control the amount of outside air that is emitted into the air handling unit through the outside air damper. For each of the control states of heating with minimum outside air, cooling with outside air, mechanical cooling with maximum outside air, and mechanical cooling with minimum outside air, the outside air damper remains completely open, and the position of the exhaust air damper and the recirculation air damper are controlled based on a particular state. Sequencing strategies are employed for transitions between the control states that utilize these positions of the dampers.

Abstract: A ventilation display system determines when a ventilation system has remained in recirculation mode for a predefined time, and in response generates a stale air alert message inside the cab of a truck. The system can generate messages alerting the driver that the HVAC system has switched into recirculation mode, and alerting the driver that the recirculation mode has remained active for the predefined time. When equipped with a CO.sub.2 sensor, the system can generate air quality messages based on either the status of the recirculation mode or the level of CO.sub.2 in the cab of the truck or both.

Abstract: In vehicles having drive systems with a highly variable degree of heat generation but in which the total quantity of heat generated is small, the heat given off is inadequate to warm the vehicle properly. The cooling system must nevertheless be designed for the worst-possible operating point, i.e. the greatest amount of heat generated, even if it is generated only briefly. It is the purpose of the present development to make the best possibly exergetic use of the available energy sources while ensuring that the drive components are cooled. The air extracted from the passenger compartment (1) comprises a proportion of exhaust air and one of recirculated air, where the recirculated air is heated in the heat exchanger (9) for the cooling circuit (16) of the drive system and taken to the passenger compartment. The system is particularly suitable for electric vehicles, vehicles with hydrogen and hybrid drives and vehicles developing little heat.

Abstract: A motor vehicle air conditioning system includes an adjustable position air inlet valve for controlling the relative proportions of recirculated air and fresh air from outside entering the system. A first sensor and a second sensor give respective measurement signals representing the inside temperature of the cabin and the outside temperature. The occupant of the vehicle can set a required value of inside temperature on a data unit, which memorizing this setting. The installation includes a processor for computing the difference between the actual inside temperature and its required value, and for memorizing at least one first temperature threshold value. The processor makes a first comparison between this first threshold value and the computed absolute value of the temperature difference, and then performs a second comparison between the inside and outside temperatures.

Abstract: According to the present invention, when the inside air circulation mode is determined, the blower for blowing air to the heat exchanger is operated with the regular blower voltage. When the outside air introduction mode is determined, the blower is operated with the lower blower voltage lower than the regular blower voltage. As a result, consumed electric power of a compressor in the outside air introduction mode can be controlled and the deterioration of the efficiency of the refrigerating cycle in the inside air circulation mode can be prevented.

Abstract: A method and apparatus for ventilating an enclosed air space, such as the crawl space under a building, and which includes a controller which is switchable between a cooling mode which activates a ventilating fan upon the temperature in the space reaching a predetermined upper limit and the differential of the temperatures inside and outside of the space reaching a predetermined value, and a heating mode which activates the ventilating fan upon the temperature in the space reaching a predetermined lower limit and the differential of the temperatures inside and outside of the space reaching a predetermined value. The ventilating fan may also be activated by the presence of predetermined concentrations of dangerous or destructive gases, such as radon and water vapor.