Abstract: Disclosed is a terminal unit for an air conditioning system. The apparatus has a common chamber for primary and secondary air and a throttling valve at the primary air duct connection controlled by a zone thermostat. The terminal unit fan is independently controlled by an air flow sensor located ahead of the throttling valve in order to prevent fan overload.

Abstract: Disclosed herein is a method and a digital electronic steam humidifier control for use with a humidifier system including an electrode boiler to provide a normally repetitive fill, boil, fill-on-drain cycle. The humidifier control includes circuitry for providing an analog signal proportional to the electrode current, and a comparator network which receives the analog signal and a reference voltage and scaled voltages provided by additional circuitry to establish predetermined levels of electrode current at which the control responds.

Abstract: The invention provides an air flow control mechanism adapted to be slideably insertable into an air duct without substantial structural modification of the air duct and without requiring shut down of the air system.

Abstract: The invention provides an airflow control mechanism for use in an air duct for controlling airflow through the duct. The air flow control mechanism includes a frame positionable in the duct, and a plurality of blades supported by the frame and extending transversely to the direction of the air flow through the air duct. At least one of the blades is supported for pivotal movement about its longitudinal axis and has an elongated edge moveable toward and away from an elongated edge of another of the blades to restrict air flow through the duct. A fiber material strip is applied to at least one of those edges, the fiber material strip including a substrate bonded to that edge and a plurality of closely spaced fibers projecting transversely from the substrate, the fiber covering being functional to prevent the generation of a high frequency standing wave between the adjacent surfaces of the blade.

Abstract: A fluid flow sensor for measuring the conditions of pressure and/or velocity of fluid flow in a passage and which has the capability of averaging measured pressure and/or velocity of flow across the width of the passage.

Abstract: Three embodiments of an air distributor apparatus are shown which utilizes a balanced type air flow control valve of cylindrical configuration co-operatively associated with a cylindrical sleeve having circumferentialy spaced openings closed by the valve. A diaphragm powered valve actuator is disposed within the sleeve which is installed at the air inlet of an air distributor plenum. Several control schemes are disclosed.

Abstract: Three embodiments of an air distributor apparatus are shown which utilizes a balanced type air flow control valve of cylindrical configuration co-operatively associated with a cylindrical sleeve having circumferentially spaced openings closed by the valve. A diaphragm powered valve actuator is disposed within the sleeve which is installed at the air inlet of an air distributor plenum. Several control schemes are disclosed.

Abstract: Three embodiments of an air distributor apparatus are shown which utilizes a balanced type air flow control valve of cylindrical configuration co-operatively associated with a cylindrical sleeve having circumferentially spaced openings closed by the valve. A diaphragm powered valve actuator is disposed within the sleeve which is installed at the air inlet of an air distributor plenum. Several control schemes are disclosed.