Abstract: An air handling unit has a fan wheel in offset placement and a plenum configuration preventing line of sight noise transmission into the air system supplied by the air handling unit. The fan wheel is so placed and the plenum configuration optimized so as to obtain the benefit of an eddy current stabilizer flow from the fan wheel, which provides a further improvement in the acoustic performance of the air handling unit.

Abstract: A method of operating a controller of an HVAC system comprising the steps of: constantly establishing the validity of each of a plurality of input devices; and reconfiguring the mode of operation of the HVAC system each time the validity of any of the plurality of input devices changes to ensure that the HVAC system operates in the best available mode of operation.

Abstract: A portable, refrigerant recycle/recovery/charging system comprising: a storage tank; a low pressure refrigeration system; and a housing. The housing includes liquid, vapor, pump and condenser sections. The liquid section has a liquid inlet, a liquid outlet and a liquid conduit connecting the liquid inlet and the liquid outlet where the liquid conduit includes a liquid flow control device and a liquid condition sensing device. The vapor section has a vapor inlet, a vapor outlet, and a vapor conduit connecting the vapor inlet and the vapor outlet where the vapor conduit includes a vapor flow control device and a vapor condition sensing device. The pump section has a pump inlet, a pump outlet, and a pump conduit connecting the pump inlet and the pump outlet where the pump conduit includes a pump. The condensing section has a condensing inlet, a condensing outlet, and a condensing conduit connecting the condensing inlet and the condensing outlet where the condensing conduit includes a condenser.

Abstract: An HVAC controller including a first input; a second input; first means, responsive to a first signal received on the first input, for generating a first mode of operation; second means, responsive to a second signal received on the second input, for generating a second mode of operation; and third means, responsive to a third signal received substantially simultaneously on the first and second inputs, for generating a third mode of operation.

Abstract: An oil purification apparatus for use in conjunction with a refrigeration system. The oil purification apparatus includes an isolation tank for receiving a quantity of contaminated oil from the refrigeration system and holding the oil isolated from the refrigeration system. A separation system including a heater and an agitation mechanism reclaims refrigerant contaminant entrained in the oil. A vapor loop selectively conveys the reclaimed refrigerant from the oil purification apparatus to the refrigeration system.

Abstract: A method of air conditioning an environment with an HVAC system. The method comprises the steps of: determining an environment to be either occupied or vacant; determining a mode of operation for the HVAC system to be heating or cooling; determining a heating setpoint and a cooling setpoint; and determining a setback value equal to a difference between the value of the heating setpoint and the value of the cooling setpoint.

Abstract: An automatic air damper assembly for use with a building conditioned air system. The air damping assembly includes a duct section adapted for insertion into the duct work of the conditioned air system, a adjustable damper installed in the duct section, a sensor for sensing the volume of air flow through the duct and a controller coupled to the sensor. The controller compares the sensed volume of air flow through the duct section to a predetermined design volume of air flow and generates an output signal representative of the comparison of the two air flows. A motor receives the output signal from the controller. The actuator is operably coupled to the damper for actuation thereof responsive to said output signal to position the damper to achieve the design volume of air flow in the duct.

Abstract: A controller for operating a two-speed fan motor at one of two speeds and for selecting the appropriate speed in response to conditions such as a maximum and minimum duct static pressure in a fan unit having moveable inlet guide vanes for controlling air flow rates through the fan unit when employed in a variable air volume system. Position sensing switches are provided on the fan unit for indicating to the controller when the inlet guide vanes are in their preferred switching positions, which may be full open or full closed. The controller then selects one of the two fan speeds as appropriate within an operating deadband limit which serves to prevent undesirable changes of motor speed.

Abstract: A method of configuring a controller of an HVAC system comprising the step of configuring the HVAC system based upon components which are indicated by a wiring harness to be physically connected to the HVAC system.

Abstract: A method of staging and modulating compressors in a multi-circuited refrigeration system including a plurality of condensing heat exchange circuits where each condensing heat exchange circuit includes a plurality of compressors. The method comprises the steps of: accumulating a first operative condition for each compressor; accumulating a second operative condition for each compressor; determining the status of each compressor in each circuit and designating therefrom a first list of circuits having compressors available to be turned on and a second list of circuits having compressors available to be turned off.

Abstract: A building automation system comprising: means for conditioning air; means, associated with the air conditioning means, for distributing the conditioned air to at least one space to be conditioned and means for sensing environmental conditions in the at least one space to be conditioned. The building automation system also includes means for managing the operation of the conditioning means, the distributing means, and the sensing means; and means, using wireless two-way transmissions, for operably linking the managing means, the conditioning means, the distributing means, and the sensing means.

Abstract: In a co-rotational scroll apparatus having two interleaving scroll wraps secured to end plates rotating about parallel, non-concentric axes to produce a relative orbital motion, a means for enhancing lubricant flow through the scroll wraps. One or more passages are provided in one or both of the scroll end plates, each passage disposed to discharge lubricant between the scroll end plates, discharging adjacent the outer end of the scroll wraps immediately before the point where the scroll wraps form the first compression chamber to provide lubricant to the entire scroll wrap length. Lubricant is provided to the passages by a combination of pickup tubes affixed to the scroll end plates and inlet openings in the scroll end plates. The inlet openings accept lubricant discharged from the bearings in the apparatus. The pickup tubes rotate with the scroll end plates and remove lubricant from a sump adjacent the scroll end plates.

Abstract: An unloading arrangement for a rotary screw compressor includes discrete and different unloading apparatus associated with the male and female rotors respectively. The unloading apparatus associated with the male rotor is an axial piston continuous unloader movably disposed in a bore which is remote from but in flow communication, through a series of ports, with the compressor's working chamber. The unloading apparatus associated with the female rotor is a step unloader which, when opened, unloads the compressor in a single, relatively large capacity step. The compressor is therefore capable of being unloaded both over a continuous operating range and in a discontinuous, stepwise fashion. By duplexing compressors of this type, continuous capacity modulation of a multiple compressor system is made available over a large operating range without the employment of compressors unloaded by slide valve mechanisms.

Abstract: A centrifugal fan has blades the effective width of which are variable during fan operation through the actuation of modulation apparatus which rotates with the fan wheel and is driven thereby. The modulation apparatus isolates the blocked off and unused portions of the fan blades which prevents the interaction of the blocked off portion of the blades with air flowing through the fan housing in a manner which results in a highly efficient and extremely quiet fan.

Abstract: A screw compressor employs a piston unloader which is disposed in a bore remote from the compressor's working chamber. Flow communication between the bore and working chamber is through a series of non-overlapping unloader ports. The unloader piston has a notched end face which effectively causes the unloader ports to overlap in operation. Precise and continuous capacity control of the compressor over a predetermined portion of its operating range is thereby achieved while internal high to low side gas leakage within the compressor and the clearance volume of the unloader ports is minimized. Compressor efficiency is thereby increased.

Abstract: An integral member is disposed internal of a refrigeration screw compressor which, upon compressor shutdown, shuts off the flow of oil injected into the compressor's working chamber as well as the oil directed to the compressor rotor bearings and which, at compressor startup, opens oil flow to those locations by the use of ambient internal compressor conditions that inherently exist at those respective times. The operation of the apparatus is therefore "fail safe" and the need for external oil flow cutoff valving and the need to monitor and/or prove oil flow within the compressor is eliminated.

Abstract: In a co-rotational scroll apparatus having two interleaving scroll wraps secured to end plates rotating about parallel, non-concentric axes, a precharging device affixed to one end plate and substantially enclosing the scroll wraps and the second end plate. Preferably, the precharging device includes a cup-shaped drive housing secured to one end plate and enclosing the scroll wraps, and a flexible torque-transmitting member connecting between the enclosure member and the second end plate. Apertures are provided in the enclosure member to permit fluid flow into the space enclosed by the enclosure device, with vanes disposed adjacent the apertures to force fluid into the enclosed space during rotation of the scroll wraps. Fluid thus forced into the enclosed space is precharged prior to entering the scroll wraps, being at higher pressure than fluid exterior the enclosed space, improving the operating efficiency of the scroll apparatus.

Abstract: A low side scroll compressor is protected from both the potentially damaging effects of improper electrical hookup and the development of high discharge temperatures by the disposition of a valve member in a passage which communicates between the suction pressure portion and a discharge pressure portion of the compressor. The valve operates to permit the flow of gas from the suction to the discharge pressure portion of the compressor through a protective passage when the compressor is caused to run backwards due to miswiring so as to avert damage to the scroll members. The valve permits the flow of gas from the discharge to the suction pressure portion of the compressor through the protective passage when the temperature of the discharge gas produced by the compressor is caused to exceed a predetermined temperature. The resulting flow causes the compressor motor to de-energize.

Abstract: A method of determining and controlling a load by a controller. The method comprises the steps of transmitting a signal for a first predetermined time period on an electrical line having a load in parallel with a capacitor; monitoring the electrical line for electrical activity within a second predetermined time period following the first time period; and controlling the load in response to the presence or absence of the electrical activity.