Heat Pump Dehumidification System

Abstract

A heat pump dehumidification system comprised of one of an air source heat pump system, a water source heat pump system, and a direct expansion heat pump system, with an extra interior air heat exchange means situated between the system's compressor's hot refrigerant gas discharge side and the exterior heat exchange means, for activation and use in conjunction with the system's primary interior air heat exchange means, located between the exterior heat exchange means and the system's compressor's refrigerant gas suction side, when operation in a dehumidification mode is desired absent sensible cooling, and optimum design sizes for both interior air exchange means while the system is operating in one of a dehumidification mode, a cooling mode, and a heating mode.

Description

APPLICATION FOR UNITED STATES LETTERS PATENT [0001] This application claims priority to co-pending U.S. patent application Ser. No. 10 / 815,530 filed May 5, 2004, entitled “Heat Pump Dehumidification System”, which claims priority to U.S. Patent Application Ser. No. 60 / 547,979 filed Feb. 26, 2004, entitled “Deep Well Direct Expansion System Dehumidifier”, both of which are hereby incorporated by reference in their entireties. [0002] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. [0003] Be it known that I, B. Ryland Wiggs, a citizen of the United States, residing at 425 Sims Lane, Franklin, Tenn. 37069, have invented a new and useful “Heat Pump Dehumidification System.”BA...

AI Technical Summary

Benefits of technology

[0030] More specifically, to accomplish this means of removing humidity once the heat pump system's thermostat setting has been reached, a secondary interior air handler would be placed within the refrigerant transport loop at a location between the system's compressor and one of the sub-surface heat exchange tubing, the refrigerant to circulating water to ground heat exchange loop, and the exterior air heat exchange loop, so as to transfer all or most of the heat removed by the first and primary cooling mode air handler back into the interior air before the heat is rejected into the exterior heat exchange means, which is comprised of one of the earth, water, and exterior air. The warmed air supplied by the secondary and additional air handler would temper the otherwise cooled air traveling through the return air ducts, so as to permit the system to remain in operation without cooling the interior air to so low a point as to call for the thermostat to become uncomfortably cool. Preferably, the cooled air and the warmed air would be mixed together within the supply ductwork, which is well understood by those skilled in the art, prior to the supply air being distributed into the interior air space by the supply air ducts. Further, since all or most (most means all, less the extra heat generated by means of the externally powered system components, such as the compressor, the fans, and the like) of the removed interior air heat is being replaced back into the interior air before it reaches at least one of the ground and the water in a geothermal system application, there is no undue heat load or stress placed upon the sub-surface heat exchange area or upon a geothermal heat pump system by means of an extended system operation in the dehumidification mode.

[0035] The secondary air handler should be sized to remove all the heat extracted from the interior air by the primary air handler operating in the cooling mode so as to maintain a neutral interior air temperature, with the additional heat generated by the operation of the system's compressor and fans still being rejected into the exterior heat exchange means comprised of one of the ground heat sink, the water to ground heat sink, and the exterior air heat sink. The rejection of such a minimal amount of system mechanical operational heat will not impose any undue stress upon a geothermal system's sub-surface heat exchange field, will not impose any stress upon an air source system's exterior air heat exchange means, and will prevent the interior air from becoming too warm too soon.

[0038] There is an additional advantage of utilizing a secondary interior air heat exchange means (second air handler) for optional dehumidification purposes. Namely, the incorporation of the second air handler in the hot gas line enables one to downsize the second air handler so as to gain warmer air in the heating mode, and simultaneously enables one to upsize the first and primary interior air heat exchange means (first air handler) so as to gain cooler air in the cooling mode and so as to remove more humidity in the dehumidification mode. Typically, in a reverse-cycle heat pump application, the standard one air handler is sized somewhere between the smaller heating mode optimum size and the larger cooling mode optimum size, so as to reasonably accommodate both operational modes.

[0040] When operating in the dehumidification mode with a first air handler that is about twice the size of the second air handler, the airflow over both air handlers must still be equalized, less the rate in the second interior air heat exchange means (the second air handler) that is equivalent to the additional heat of compression generated by means of at least one of the system's compressor and externally powered components. The multiple manners of equalizing the airflow over both air handlers is well understood by those skilled in the art, and may, for one example, be easily accomplished by decreasing the fan speed, and resulting cubic feet per minute (“CFM”) airflow, of the first air handler so as to match the desired CFM rate of the second air handler.

[0041] In such an enhanced cooling / dehumidification / heating mode operational system design, which is enabled by means of adding a secondary air handler in the manner as herein described, and where the second air handler is sized at about 50% of the first air handler, a secondary by-pass refrigerant transport line is preferably added around the first air handler for use in the heating mode of operation. The secondary by-pass line is operated by means of solenoid valves, or the like. A first solenoid valve, for example, is located prior to the refrigerant flowing through the self-adjusting thermal expansion device prior to the first air handler, and is in the open position so as to permit system operation in one of the cooling mode and the dehumidification mode. A second solenoid valve, located after the refrigerant has exited the first air handler, is in a closed position so as to prevent system operation in the heating mode. A control connecting wire, for example, connects the control box (the control box is comprised of a thermostat and a humidistat) with the open first solenoid valve; and a control connecting wire, for example, connects the control box with the closed second solenoid valve. As is well understood by those skilled in the art, one reversing valve, or the like, can be substituted for the two solenoid valves with the same effect of by-passing the desired air handler for system operation in one of the cooling mode and heating mode, or of not by-passing either air handler, for operation in the dehumidification mode. Also, the first air handler may be one of completely and mostly by-passed, while the system is operating in the heating mode, by various other alternative means other than by means of solenoid valves and a by-pass refrigerant transport line, as are well understood by those skilled in the art, such as, for example, by disengaging the first air handler's fan and thereby materially reducing the heat transfer over the first air handler's finned tubing.

Problems solved by technology

However, in the cooling mode of operation, a second consequence of the heat pump's operation occurs.

In many areas, excessive moisture can create health concerns, such as fostering molds and dust mites, as well as decreasing comfort levels.

However, historically, as explained, humidity is only removed when the heat pump's cooling system is operating.

Such continuous operation typically results in excessive cooling, to the point of being uncomfortably cold.

While one could continuously operate a small cooling system in an effort to continuously remove humidity, and engage a larger cooling system only when the small unit could not remove the interior heat load, during cooler nighttime periods even the small cooling system could still make the interior space uncomfortably cold.

Further, smaller systems may not have the ability to remove large amounts of humidity present when the primary larger cooling system is shut off.

However, traditional dehumidifiers are not particularly efficient to operate, require additional space, do not have the typically higher design load capacities of heat pump systems, and often require the owner to manually dispose of trays of accumulated water.

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