Nordyne, Inc.

Nortek Global Hvac, LLC

Allan J Reifel

Jie Chen

David L Koesterer

Siegfried J Weigl

Aaron D Herzon

Yi Heng Chen

Russell W Hoeffken

William F Raleigh

James E Roth

Dave L Koesterer

David W Garvin

Robert A Borgeson

Heat pumps for climates where demand for cooling and heating are unequal and methods of adapting and distributing heat pumps for such climates. Heat pumps include a compressor, compressor motor, variable-speed drive, and controller. In a number of embodiments, non-volatile memory stores sets of constant speeds for cooling and heating, and a person can select, via an input device, different sets of speeds for cooling and heating to provide the different cooling and heating capacities. The controller then operates the unit at the selected speeds, selecting from within the set based on demand for cooling or heating. In some embodiments, different sets of speeds may have the same minimum speed but different maximum speeds. Identical heat pumps can be configured to have different capacity ratings and different advertized efficiencies for different climates.

Heat pumps with unequal cooling and heating capacities for climates where demand for cooling and heating are unequal, and method of adapting and distributing such heat pumps

Heat pumps for climates where demand for cooling and heating are unequal and methods of adapting and distributing heat pumps for such climates. Heat pumps include a compressor, compressor motor, variable speed drive, and controller. In a number of embodiments, non-volatile memory stores sets of constant speeds for cooling and heating, and a person can select, via an input device, different sets of speeds for cooling and heating to provide the different cooling and heating capacities. The controller then operates the unit at the selected speeds, selecting from within the set based on demand for cooling or heating. In some embodiments, different sets of speeds may have the same minimum speed but different maximum speeds. Identical heat pumps can be configured to have different capacity ratings and different advertised efficiencies for different climates.

Airflow rates within a ventilation system are controlled using motor speed or torque and motor electric current or pressure. Fan speed or torque may be varied to compensate for differing restriction in ductwork, and may provide a constant airflow rate over a range of varying airflow restriction. Air handlers or air conditioning units may be mass produced in common configurations, and installed in different buildings or structures with different ductwork configurations. Methods operate a fan motor at a present speed or torque, sample speed or torque, sample current of the fan motor or pressure within the ventilation system, calculate a present airflow rate within the ventilation system, calculate a new input setting using the present airflow rate and a target airflow rate, change the speed or torque to the new input setting, and repeat these steps to converge on the target airflow rate, often avoiding overshoot.

Ventilation airflow rate control

Air conditioning units packaged with condensing gas heat exchangers include a drain line connected to a collector attached to the heat exchanger. In different embodiments, the drain line, or a conduit for the drain line, may extend to the return duct opening for routing of the drain line through the return duct for disposal of the condensate, for instance, within the building, or the drain line may extend through a hole in the floor of the unit. The conduit may protect the drain line from direct heat from the heat exchanger, from freezing where the drain line passes through an outdoor section, or both. In some embodiments, air may be circulated through the conduit to prevent freezing. The conduit may guide the drain line through the unit, roof curb assembly, or roof, or the drain line may be routed through the unit by the manufacturer to the return duct opening.

Condensing gas package unit with a tubular conduit for passing a condensate drain line

Premix furnace for heating an occupied space while producing lower NOx emissions and methods of mixing air and fuel delivered to a premix burner and of improving combustion stability. A mixing device may be located within an inlet tube, may have a flat surface that is perpendicular to the direction of fuel flow, or may have two surfaces held at substantially opposite angles to induce swirl. A mixing device may be attached to the fuel injector, may be made from a piece of sheet metal, and may have bends and a hole for attachment to the fuel injector. A fluidic diode in the inlet tube may improve combustion stability and may include a hollow frustum or a frustoconical portion, a cylinder concentric with the inlet tube, or a combination thereof. Some embodiments include refractory insulation lining the combustion chamber or may adjust for elevation or fuel characteristics.

Premix furnace and methods of mixing air and fuel and improving combustion stability

Methods of controlling air conditioning and HVAC units using a thermostat for a discrete-speed unit that include changing speed based on how long the unit operates at a particular speed. Speed may be increased if a unit operates for longer than a predetermined time at a particular speed, and speed may be reduced if the unit operated for less than a specific amount of time during the prior run. In different embodiments, single-stage thermostats may control units that operate at three speeds, and two-stage thermostats may control units that operate at three to five or more speeds. In addition, in some embodiments, outdoor coil temperature may be measured and considered in determining speed. Further, in some embodiments, maintaining continuous or repeated operation at a boost speed may be avoided. Energy savings and noise reduction may result.

HVAC control using discrete-speed thermostats and run times

A control procedure operates an expansion valve of an air conditioning system. The control procedure utilizes a first control procedure to bring a calculated superheat value within a range of a target superheat value, and a second control procedure to cause the calculated superheat value to match the target superheat value. Both the first and second control procedures preferably use Proportional, Integral, Derivative control algorithms.

System and method for controlling an air conditioner or heat pump

Relatively constant temperatures are maintained in a space by varying the capacity of heating or cooling equipment. A proportional band is used to adjust capacity to compensate for changes in heating or cooling load, and the proportional band is adjusted to bring the actual temperature within the space closer to the set point temperature. Such an adjustment may be made by determining the difference between the present temperature and the set point temperature, and adjusting a floating temperature set point by a percentage (e.g., ten percent) of the difference. Such a process may be repeated, for example, at regular intervals, such as once per minute. As a result, the temperature within the space approaches (e.g., asymptotically) the set point temperature whether the heating or cooling load is high or low. Methods, systems, and apparatuses are contemplated, including HVAC units and controls, including for residential applications, including using variable-speed drives.

Temperature control in variable-capacity HVAC system

Bi-directional fin stock, for use in heat exchangers of the fin and tube type, having louvers formed from the planar surface of the fin stock to project progressively farther into the airstream. This enables the fin stock to exchange heat with a broader airstream by translating the airflow substantially, permitting wider fin spacing.

Louvered heat exchanger fin stock

A heater and limit switch assembly, particularly useful for installation in the conditioned air duct of a rooftop air conditioner. The loop of a rigid-loop heater, mounted on a vertical plate by two parallel legs, is modified to provide an inward offset portion leading to the second leg. Radiation, from the offset portion and its bend into the second leg, is received at close range by a simple disk-type limit switch, positioned on the plate outward of the second leg and facing the offset, inducing prompt response to any increase over design temperature.

Electric resistance heater and limit switch assembly

A fin-and-tube heat exchanger designed for one-way airflow, in which louvers, formed from the fin stock, progressively increase in length from the fin leading edge to its trailing edge. Their end walls channel air into stagnant air spaces behind the tubes. The tube collars may be offset somewhat toward the fin trailing edge, further reducing the stagnant air zones. In those bent heat exchangers in which air flows in from outside the curve, offsetting the collars also lessens the angular convergence of fin trailing edges inside the curve and presents less resistance to airflow.

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Florissant, MO, United States of America

Allan J Reifel