Patent Description:
In traditional heating, ventilation and air-conditioning (HVAC) systems, application side air is cooled when it passes over chilled cooling coils. The heat transfer does not take place directly, however, and instead proceeds from air (supplied and return air) to the metal coils and in turn from the metal coils to cold water. This tends to slow the heat transfer processes and results in decreased output and degraded performance.

The invention provides a heating, ventilating and air-conditioning (HVAC) system according to claim <NUM>.

Optionally, the misting system generates about <NUM> X <NUM><NUM> to <NUM> X <NUM><NUM> mist droplets from <NUM> liter of water. In accordance with additional or alternative embodiments, the mist droplets range from about <NUM> to about <NUM> in diameter.

Optionally, a mixed air chamber is upstream from the inlet.

Optionally, the air supply system includes a return air supply conduit operably coupled to the inlet and configured to direct conditioned air to the inlet, a fresh air supply opening disposed adjacent to the inlet and configured to allow fresh air to flow through the inlet and an upstream control element configured to modulate relative amounts of the conditioned and fresh air in the inlet.

Optionally, the misting system includes a mist supply system configured to supply water to the misting system and a drainage system configured to drain water from the enclosure, and the mist supply system includes at least one filter, a high pressure pump downstream from the at least one filter, at least one nozzle and a controllable valve interposed between the high pressure pump and the at least one nozzle.

Optionally, an evaporator is communicative with the mist supply system and the drainage system.

Optionally, a fluid pressure at the at least one nozzle is at least about <NUM> PSI.

According to another aspect of the invention, a method of operating an air handling unit (AHU) system of a heating, ventilation and air-conditioning (HVAC) system according to claim <NUM> is provided.

Optionally, the misting system generates about <NUM> X <NUM><NUM> to <NUM> X <NUM><NUM> mist droplets from <NUM> liter of water And the mist droplets range from about <NUM> to about <NUM> in diameter.

Optionally, a controller is configured to at least adjust sizes of the mist droplets and a volume in which the mist droplets are spread.

Optionally, the air supply system includes a return air supply conduit operably coupled to the inlet and configured to direct conditioned air from the field ductwork to the inlet, a fresh air supply opening disposed adjacent to the inlet and configured to allow fresh air to flow through the inlet and an upstream control element configured to modulate relative amounts of the conditioned and fresh air in the inlet.

Optionally, the misting system includes a mist supply system configured to supply water to the misting system and a drainage system configured to drain the water from the enclosure, and the mist supply system includes at least one filter, a high pressure pump downstream from the at least one filter, at least one nozzle and a controllable valve interposed between the high pressure pump and the nozzle.

Optionally, a fluid pressure at the nozzle is at least about <NUM> PSI.

The invention is defined by the claims and claimed in the claims at the end of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

As will be described below, high pressure cold water mist is used in an air handling unit (AHU) of a heating, ventilation and air-conditioning (HVAC) system to achieve efficient and nearly cooling of air flows. The high pressure cold water mist is mixed with air flows in an air chamber and result in direct heat transfer between the mist and the air flows.

With reference to <FIG>, a portion of a heating, ventilating and air-conditioning (HVAC) system <NUM> is provided and includes an evaporator <NUM>, which is a component of a vapor-cycle machine of the HVAC system <NUM>, field ductwork <NUM> and an AHU <NUM>. The field ductwork <NUM> may be installed through a structure so that conditioned air can be delivered to and drawn from various spaces within the structure.

The AHU <NUM> includes an enclosure <NUM>, which is formed to define an inlet <NUM> and at least one outlet <NUM>. The at least one outlet <NUM> is downstream from the inlet <NUM> and fluidly communicative with the field ductwork <NUM>. The AHU <NUM> further includes a misting system <NUM> and air conditioning elements <NUM>. An air supply system <NUM> is operably coupled to the AHU <NUM>, and is configured to drive return air from the field ductwork <NUM> and fresh air through the enclosure <NUM> from the inlet <NUM> to the at least one outlet <NUM>.

The misting system <NUM> is configured to spray a high pressure, cold water mist that includes mist droplets <NUM> which are generated from water received from the evaporator <NUM> into a portion <NUM> of the enclosure <NUM> that is proximate to the inlet <NUM> and upstream from the at least one outlet <NUM> whereupon heat transfer occurs directly between mist droplets <NUM> and air prior to the air reaching the at least one outlet <NUM>. The misting system <NUM> is further configured to return water drained from the enclosure <NUM> to the evaporator <NUM> (it is to be understood that drainage can be accomplished by the misting system <NUM> or by another suitable drainage system and that the description herein is merely exemplary). The air conditioning elements <NUM> are operably disposed in the enclosure <NUM>, or more particularly, in the at least one outlet <NUM>, to condition the air upstream from the field ductwork <NUM>.

The misting system <NUM> may include a mist supply system <NUM> configured to supply water to the misting system <NUM>. Where the misting system <NUM> is responsible for drainage, the misting system <NUM> may also include a drainage system <NUM> that is configured to drain water from the enclosure <NUM>. The mist supply system <NUM> may include: one or more filters <NUM> (e.g. ultraviolet (UV) and water filters) to prevent bacterial formation and growth therein, a high pressure pump <NUM> disposed downstream from the one or more filters <NUM>, at least one nozzle <NUM>, and at least one controllable valve <NUM> (with secondary nozzle <NUM> to be discussed below) that is fluidly interposed between the high pressure pump <NUM> and the at least one nozzle <NUM>.

In accordance with embodiments, the misting system <NUM> is configured to generate about <NUM> X <NUM><NUM> to <NUM> X <NUM><NUM> mist droplets <NUM> from <NUM> liter of water. The mist droplets <NUM> can range from about <NUM> to about <NUM> in diameter or less in some cases. In addition, a fluid pressure at the at least one nozzle <NUM> can be at least about <NUM> PSI.

With reference to <FIG>, the AHU <NUM> (or the HVAC <NUM> as a whole) may further include a controller <NUM>. The controller <NUM> includes a processing unit <NUM>, a memory unit <NUM> and a networking unit <NUM> by which the processing unit <NUM> is communicative with at least the misting system <NUM> (see <FIG>) and, in some cases, with the air supply system <NUM> and the air conditioning elements <NUM> (see <FIG>). The memory unit <NUM> has executable instructions stored thereon which are readable and executable by the processing unit <NUM>. When the executable instructions are read and executed by the processing unit <NUM>, the executable instructions cause the processing unit <NUM> to at least control or adjust the sizes of the mist droplets <NUM> by either increasing fluid pressures within the misting system <NUM> or by increasing an amount of fluid within the misting system <NUM> and/or to control a volume of the enclosure <NUM> in which the mist droplets <NUM> are spread. Such control may be based on or in accordance with a quantity of air received in the inlet <NUM> (or the mixed air chamber <NUM> discussed below).

With reference back to <FIG>, the inlet <NUM> may include or be provided as mixed air chamber <NUM> that is defined upstream from the portion <NUM> of the enclosure <NUM> into which the high pressure, cold water mist is sprayed by the misting system <NUM>. The at least one outlet <NUM> includes a first outlet section <NUM> defined downstream from the portion <NUM> of the enclosure <NUM>. A second outlet section <NUM>, also downstream from the portion <NUM> of the enclosure <NUM>, is disposed in parallel with the first outlet <NUM>. A baffle <NUM> is interposed between the first and second outlets <NUM> and <NUM>. A downstream control element <NUM> may include or be provided as a damper or a valve and may be disposable in the second outlet section <NUM>. The downstream control element <NUM> is configured to modulate relative sizes of flows or air permitted to flow through the first and second outlet sections <NUM> and <NUM>.

The air conditioning elements <NUM> disposed in or upstream of the first outlet section <NUM> include: a cooling coil <NUM>, a blower <NUM>, a heating coil <NUM> that is interposed between the cooling coil <NUM> and the blower <NUM>, and one or more filters <NUM> adjacent to the heating coil <NUM> and the blower <NUM>. The filters <NUM> may include or be provided as carbon/microbial air filters. The air conditioning elements <NUM> disposed in or upstream of the second outlet section <NUM> include:
a secondary nozzle <NUM>, a blower <NUM>, a heating coil <NUM> interposed between the secondary nozzle <NUM> and the blower <NUM>, and one or more filters <NUM>. The filters <NUM> may be provided at or adjacent to the heating coil <NUM> and the blower <NUM> and may include or be provided as carbon/microbial air filters.

In accordance with embodiments, air flows exiting the second outlet <NUM> can be employed in various applications including, but not limited to, pharmaceutical, medical, recreational, etc. applications.

The air supply system <NUM> may include a return air supply conduit <NUM>, a fresh air supply opening <NUM> and an upstream control element <NUM>. The return air supply conduit <NUM> may be configured to allow conditioned air from the field ductwork <NUM> to enter the mixed air chamber <NUM> and/or the inlet <NUM>. The fresh air supply opening <NUM> may be configured to allow fresh air to enter the mixed air chamber <NUM> and/or the inlet <NUM>. The upstream control element <NUM> may include or be provided as a damper or a valve that is disposable along the fresh air supply opening <NUM> and which is configured to modulate relative amounts of the fresh air in the mixed air chamber <NUM> and the inlet <NUM>.

With reference to <FIG>, a method of operating the AHU <NUM> described herein is provided. The method includes driving an air flow through the enclosure <NUM> upstream from the field ductwork <NUM> (block <NUM>), spraying a high pressure, cold water mist into the enclosure <NUM> whereupon heat transfer occurs directly between mist droplets <NUM> and air (block <NUM>) and controlling a size and a quantity of the mist droplets <NUM> and a volume of the enclosure <NUM> in which the mist droplets <NUM> are spread in accordance with a quantity of the air driven through the enclosure <NUM> (block <NUM>).

When homogenous or mixed air flows proceed through the mist droplets <NUM> of the high pressure, cold water mist provided by the misting system <NUM>, the air eventually transforms into fully saturated air within the inlet <NUM>. The mist droplets <NUM> will thus absorb heat from the passing air in a direct heat transfer process while the fully saturated air passes into and through at least one of the first and second outlets <NUM> and <NUM>. Within the first outlet, for example, the fully saturated air passes over or through the cooling coil <NUM> to accomplish a secondary cooling and also to removes excess moisture content. The cold air is passed over or through the heating coil <NUM> to achieve a required supply air temperature for the HVAC system <NUM> and to provide for humidity control as well. Condensed water can be extracted by the drainage system <NUM> and may be passed through one or more semi-permeable membranes before being fed back to the evaporator <NUM>.

Benefits of the features described herein are improved heat transfer and efficiency as compared to traditional AHU systems owing to the addition of high pressure cold water mist to air flows so that heat transfer between the air flows and the mist occurs directly.

Claim 1:
A heating, ventilating and air-conditioning (HVAC) system, comprising:
an evaporator (<NUM>);
field ductwork (<NUM>); and
an air handling unit (AHU) system (<NUM>), comprising:
an enclosure (<NUM>) formed to define an inlet (<NUM>) and at least one outlet (<NUM>) downstream from the inlet;
an air supply system (<NUM>) to drive an air flow through the enclosure from the inlet to the at least one outlet; and
a misting system (<NUM>) operably coupled to the rest of the AHU system, the misting system configured to
spray high pressure, cold water mist, comprising mist droplets, into a portion of the enclosure upstream from the at least one outlet whereupon heat transfer occurs directly between the mist droplets and air prior to the air reaching the at least one outlet;
characterized in that the at least one outlet comprises:
a first outlet section (<NUM>);
a second outlet section (<NUM>);
a baffle (<NUM>) interposed between the first and second outlet sections; and
a downstream control element (<NUM>) configured to modulate relative sizes of flows along the first and second outlet sections;
wherein the first outlet section (<NUM>) comprises a cooling coil (<NUM>), a blower (<NUM>), a heating coil (<NUM>) interposed between the cooling coil and the blower and at least one filter (<NUM>);
wherein the second outlet section (<NUM>) comprises a secondary nozzle (<NUM>), a blower (<NUM>), a heating coil (<NUM>) interposed between the secondary nozzle and the blower and at least one filter (<NUM>);
wherein the at least one outlet (<NUM>) is communicative with the field ductwork (<NUM>); the air supply system (<NUM>) is to drive return air from the field ductwork and fresh air through the enclosure (<NUM>) from the inlet (<NUM>) to the at least one outlet (<NUM>); and the misting system (<NUM>) is configured to use water received from the evaporator, with the misting system also configured to return water drained from the enclosure to the evaporator; and
wherein the system comprises air conditioning elements operably disposed in the at least one outlet to condition the air upstream from the field ductwork.