Double DX Hydronic System

Abstract

A double DX hydronic heating / cooling system includes a primary DX system for maintaining a primary interior fluid loop at a desired temperature range. Secondary DX sub-systems are operatively coupled to the primary interior fluid loop and are operable in either a heating mode or a cooling mode to provide independent control of interior air temperature in different spaces. Each sub-system includes a dedicated water pump to minimize power requirements for the system.

Description

FIELD OF THE DISCLOSURE[0001]The present disclosure relates to geothermal direct exchange (“DX”) heating / cooling systems, which are also commonly referred to as “direct exchange” or “direct expansion” heating / cooling systems.BACKGROUND OF THE DISCLOSURE[0002]Geothermal ground source / water source heat exchange systems typically include closed loops of tubing that are buried in the ground, or submerged in a body of water. Fluid is circulated through the loops of tubing so that the fluid either absorbs heat from or rejects heat into the naturally occurring geothermal mass and / or water surrounding the tubing. The ends of the tubing loop extend to the surface and are fluidly coupled to an interior air heat exchanger. The naturally warmed or cooled fluid is circulated through the interior air heat exchanger to warm or cool an interior space.[0003]Common and older design geothermal water-source heating / cooling systems typically have a pump for circulating a fluid comprised of water, or wat...

AI Technical Summary

Benefits of technology

[0023]Accordingly, the DX system may provide room-by-room control of air temperature, in which one of the secondary compressor boxes may operate in the heating mode (i.e., furnishing heated air to one room) while the other secondary compressor box simultaneously operates in the cooling mode (i.e., furnishing cooled air to another room). Expanding on the basic two DX sub-system, a secondary DX sub-system may be installed in each room of a building to allow independent temperature control of each room. For example, a first secondary DX sub-system may reject heat into the interior fluid loop from a computer room, kitchen, or the like, while a second secondary DX sub-system pulls heat out of the interior fluid loop to operate in the heating mode to warm a different room. Still further, there may be periods where the primary geothermal DX system is not required to operate at all, thereby providing extremely high overall operational efficiencies.

[0024]Finally, a respective liquid circulator pump may be positioned within each respective secondary fluid line servicing each respective secondary DX sub-system interior heat exchanger. The pump may operate only when the secondary respective DX compressor box was on, thereby further maximizing overall system operational efficiencies. By providing smaller pumps dedicated to each secondary DX sub-system, the use of a single, larger, more power consuming, water pump is avoided, and the pumps may operate only when fluid circulation is required in the associated sub-system. Consequently, power consumption required to operate the system is minimized.

Problems solved by technology

(sometimes even below 52 degrees if the return air in the interior air handler is below 70 degrees F., which is not normally the case), the interior heat exchanger tubing is more susceptible to developing frost, which decreases system operational efficiencies.

Conversely, supply fluid temperatures above 80 degrees F. increase the head refrigerant pressures, which increases the power draw of the compressor and decreases system operational efficiencies.

Based on testing, however, it has been found that supply fluid temperatures above 68 degrees F. produces excessive refrigerant head pressure, which increases the power draw of the compressor, thereby decreasing system operational efficiencies.

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