TECHNICAL FIELD

[0001] This invention relates to cleaning of HVAC equipment, in general, and specifically to an HVAC coil cleaning unit and associated method for cleaning HVAC coils.

BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application .

[0003] Heating, ventilation and air conditioning ( ^VAC ) systems are well-known in the art and are often found in residential, commercial, and industrial buildings. Such HVAC systems generally include a Fan Coil Unit ( ^CU' ) , which is a generic term applied to a range of products, generally being a simple device consisting of a heating and/or cooling heat exchanger or 'coil', and associated fan or fans for moving air over said coils.

[0004] A typical air conditioning system has two FCUs with sets of coils, namely condenser coils and evaporator coils, usually made of copper tubes with aluminium fins. The evaporator coil, or indoor coil, is often described as the "cold" coil in an air conditioner because it provides indoor cooling. The evaporator coil typically works by absorbing heat from the indoor air that is blown over it by some manner of fan arrangement. Conversely, the condenser coil or outdoor coil is the "warm" coil as it rejects the heat absorbed by the evaporator coil as a suitable fan blows outside air over the surface .

[0005] A Fan Coil Unit design falls principally into two main types, namely ^x blow through' and raw through' . As these names suggest, in the ^x blow through' type the fans are fitted such that they blow air through the heat exchanger, and in the Mraw through' type the fans are fitted after the coil such that they draw air through it.

[0006] In either type of FCU design, inherent to the operation of an FCU, over time the surfaces of these coils can become dirty as the air moving over the coils can contain dust, dirt, pollen, moisture and other contaminants. In FCU coils, the conditions often exist for the growth of microbiological contaminants. Contaminants, such as bacteria, can create toxic allergenic organic fragments, which have been linked with various health complaints in buildings.

[0007] A build-up of such contaminants also decreases the available surface area for heat transfer, reducing heat transfer effectiveness and system efficiency, typically leading to increased energy consumption and generally causes poor system performance.

[0008] For this reason, it is important that FCU coils are regularly inspected and cleaned, even becoming a regulatory requirement in certain circumstances. [0009] Known means for cleaning FCU coils include spray bottles and pump sprayers, but these are not always effective at penetrating coil beds and removing contaminants satisfactorily. Pressure cleaners can also be used, but they often spray at too high pressures, which can damage FCU coils, and typically require mains power and a water supply, hindering portability. In addition, mobile pressure cleaners are often not manufactured to withstand continued and prolonged use in rugged conditions.

[0010] The present invention was conceived with these shortcomings in mind.

SUMMARY OF THE INVENTION

[0011] According to a first aspect of the invention there is provided an HVAC coil cleaning unit comprising:

a wheeled framework having a base portion and a handle portion extending therefrom, at least one axle for supporting a wheel mounted to such framework to form a trolley;

at least one demountable fluid reservoir supported on the base portion, said fluid reservoir for operatively receiving cleaning fluid; and

a housing mounted to the handle portion and having a tamper-resistant fluid-tight sealing access cover, said housing for housing:

i) a pump arrangement comprising a fluid pump with an inlet and a filter arranged in fluid communication with the fluid reservoir, and an outlet arranged in fluid communication with a spray gun having a trigger; and ii) a power supply arrangement comprising a battery and charger for charging the battery from a mains supply and the battery configured to operatively power the fluid pump;

the trolley further including a spray gun holder for storing the spray gun, wherein when triggered, the pump arrangement is configured to deliver fluid via the spray gun below a pressure of 1400kPa.

[0012] Typically, the wheeled framework comprises the base portion with the handle portion extending transversely from and end of said base portion, the axle mounted to a lower part of the handle portion with the reservoir supported on the base portion proximate said handle portion, so that a resultant moment of a weight of the reservoir about said axle is easily offset by a counteracting force operatively applied along a length of the handle portion.

[0013] Typically, the handle portion is height adjustable to operatively vary said counteracting force requirement.

[0014] Typically, the handle portion is telescopically height adjustable, an upper part thereof extending from a lower part and held in place via a detent.

[0015] Typically, the detent comprises a detent mechanism having at least one spring-biased rod configured to lock an upper part of the handle portion in place relative to a lower part thereof.

[0016] Typically, the wheel comprises a tyre dimensioned to facilitate easily offsetting the resultant moment of a weight of the reservoir about said axle by a counteracting force operatively applied along a length of the handle portion. [0017] Typically, the reservoir comprises a resiliently expandable bladder for operatively receiving cleaning fluid, thereby improving portability of the unit when said reservoir is empty.

[0018] Typically, the reservoir is manufactured from a see- through material (either transparent or translucent) to facilitate visual inspection of a level of cleaning fluid therein .

[0019] Typically, the framework defines a receptacle for operatively receiving the reservoir therein, said receptacle configured to facilitate easy replacement of said reservoir.

[0020] Typically, reservoir includes a normally-closed valve which is urged into an open position when the reservoir is mounted or seated in the receptacle and/or on the framework to arrange the reservoir in fluid communication with the pump.

[0021] Typically, the housing is mounted to the handle portion in a manner to counteract the resultant moment of a weight of the reservoir about the axle.

[0022] Typically, the housing includes a control and indicator panel for activating and monitoring the pump and power supply arrangements.

[0023] Typically, the control and indicator panel includes a pressure adjustment configured to adjust a pressure of cleaning fluid delivered via the spray gun. [0024] Typically, the control and indicator panel includes a battery charge indicator for indicating a level of charge of the battery.

[0025] In one example, the tamper-resistant fluid-tight sealing access cover of the housing includes a lockable over- centre toggle latch to secure the access cover to the housing, with a seal arranged around a periphery of the cover to sealingly engage with the housing.

[0026] Typically, the housing defines a viewing-window to allow ease of inspection of the filter arranged in fluid communication with the fluid reservoir.

[0027] Typically, the filter comprises a particle filter configured to remove particles from fluid passing from the reservoir to the pump arrangement.

[0028] Typically, the charger comprises a switched-mode battery charger. The charger may be suppliable by a mains supply via a power socket located on or inside the housing.

[0029] Typically, the power supply arrangement is sealed against the ingress of water.

[0030] Typically, the spray gun holder is diagonally mounted between the handle portion and the base portion so that the spray gun is compactly held therein proximate the trolley . [0031] According to a second aspect of the invention there is provided a method for cleaning HVAC coils, said method comprising the steps of:

providing an HVAC coil cleaning unit comprising a wheeled framework having a base portion and a handle portion extending therefrom, at least one axle for supporting a wheel mounted to such framework to form a trolley; at least one demountable fluid reservoir supported on the base portion, said fluid reservoir for operatively receiving cleaning fluid; and a housing mounted to the handle portion and having a tamper-resistant fluid-tight sealing access cover, said housing for housing:

i) a pump arrangement comprising a fluid pump with an inlet and a filter arranged in fluid communication with the fluid reservoir, and an outlet arranged in fluid communication with a spray gun having a trigger;

ii) a power supply arrangement comprising a battery and charger suppliable by a mains socket on the housing, the charger for charging the battery from a mains supply and the battery configured to operatively power the fluid pump;

the trolley further including a spray gun holder for storing the spray gun, wherein when triggered, the pump arrangement is configured to deliver fluid via the spray gun below a pressure of 1400kPa; and

cleaning HVAC coils with the spray gun.

[0032] According to a third aspect of the invention there is provided a method for cleaning HVAC coils, said method comprising the steps of:

providing an HVAC coil cleaning unit in accordance with the first aspect of the invention; and cleaning HVAC coils with the spray gun.

BRIEF DESCRIPTION OF THE DRAWINGS

The description will be made with reference to the accompanying drawings in which:

Figure 1 is a first side-view diagrammatic representation of one example of an HVAC coil cleaning unit, in accordance with an aspect of the invention;

Figure 2 is a second side-view diagrammatic representation of the HVAC coil cleaning unit of Figure 1 ;

Figure 3 is a rear-view diagrammatic representation of the HVAC coil cleaning unit of Figure 1 ;

Figure 4 is a front-view diagrammatic representation of the HVAC coil cleaning unit of Figure 1 ;

Figure 5 is a rear-view diagrammatic representation of a housing of the HVAC coil cleaning unit of Figure 1 with a cover removed to show housed components;

Figure 6 is a top-view diagrammatic representation of the HVAC coil cleaning unit of Figure 1;

Figure 7 is a perspective-view diagrammatic representation of another embodiment of the HVAC coil cleaning unit ;

Figure 8 is a closer-view perspective diagrammatic representation of a detent mechanism for a telescopically height adjustable handle portion of the HVAC coil cleaning unit of Figure 7 ;

Figure 9 is a perspective-view diagrammatic representation of a wheeled framework of the HVAC coil cleaning unit of Figure 7; and

Figure 10 is a side sectional-view diagrammatic representation of the HVAC coil cleaning unit of Figure 7.

DETAILED DESCRIPTION OF EMBODIMENTS

[0033] Further features of the present invention are more fully described in the following description of several non- limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention to the skilled addressee. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. In the figures, incorporated to illustrate features of the example embodiment or embodiments, like reference numerals are used to identify like parts throughout.

[0034] With reference now to the accompanying figures, there is shown examples of an HVAC coil cleaning unit 10. The exemplified unit 10 generally comprises a wheeled framework 12 having a base portion 14 and a handle portion 16 extending therefrom, with at least one axle 18 supporting a wheel 20 mounted to the framework to form a trolley 22, as shown. In the current example, a single axle 18 is used to support two wheels 20 on either side of the framework 12, as shown, however other arrangements are possible and within the scope of the present invention. The wheels 20 may be pneumatic tyres, or resilient foam, substantially solid polymer, and/or the like. In one example, the handle portion 16 is telescopically height adjustable, extending from a lower part of the handle portion and held in place via a suitable detent, pin, or the like.

[0035] The unit 10 also includes at least one demountable fluid reservoir 24 supported on the base portion 14, as shown, the fluid reservoir 24 for operatively receiving cleaning fluid therein. Typically, water is used as cleaning fluid. In one example, the fluid reservoir has a volume of around 20 litres to 30 litres, but other capacities are possible and within the scope of the invention, i.e. larger and smaller capacities. The reservoir 24 is typically easily demountable or similarly removable to facilitate filling said reservoir with water from a tap, or the like. For example, the reservoir 24 may include a normally-closed valve which is urged into an open position when the reservoir 24 is mounted or seated in the receptacle 62 and/or on the framework 12 to arrange the reservoir 24 in fluid communication with the pump 34. In the present example, the reservoir 24 comprises a large polymer bottle or jug in which inlet pipe or conduit 38 is placed.

[0036] In typical circumstances, the unit 10 is transported without cleaning fluid in the reservoir to reduce weight and improve portability. As such, the reservoir 24 is filled with water as cleaning fluid on site where cleaning is required. If the site is particularly isolated or remote, as can be common with rural sites in Australia, clean water for cleaning can be scarce. Accordingly, the unit 10 includes a pump arrangement 32 with replaceable or cleanable filter 36 (described in more detail below) to allow use of unfiltered water as cleaning fluid .

[0037] The unit 10 also includes a housing 26 mounted to the handle portion 16, as shown, and having a tamper-resistant fluid-tight sealing access cover 28. The housing 26 includes a control and indicator panel 56 for activating and monitoring pump and power supply arrangements 32 and 46 (described in more detail below) . The tamper-resistant fluid-tight sealing access cover 28 generally includes a lockable over-centre toggle latch 30 to secure the access cover 28 to the housing 26 to hinder unauthorised access and tampering with the pump and power supply arrangements 32 and 46. In one example, the housing 26 and/or the cover 28 defines a viewing-window 58 to allow ease of inspection of the filter 36 arranged in fluid communication with the fluid reservoir 24.

[0038] It is to be appreciated that the housing 26 with access cover 28 renders the pump and power supply arrangements 32 and 46 largely tamper-proof, particularly where the unit 10 is to be stored or transported accessible to the general public. For example, the unit 10 may be transported on the back or in the tray of a utility vehicle or pickup truck. By having the tamper-proof housing 26, the internals of the unit 10 are protected even in situations where accessible to unauthorised persons, e.g. particularly when transported in a tray of a utility vehicle, or the like.

[0039] The housing 26 houses or encloses a pump arrangement 32 generally comprising a fluid pump 34 with an inlet 38 and a filter 36 arranged in fluid communication with the fluid reservoir 24, as well as an outlet 40 arranged in fluid communication with a spray gun 42 having a trigger 44. The housing 26 also includes a power supply arrangement 46 generally comprising a battery 48 and charger 50 suppliable by a mains socket 52 on, or internal to, the housing 26. The charger 50 is configured for charging the battery 48 from a mains supply and the battery 48 is configured to operatively power the fluid pump 34. The battery is typically a 12V battery chargeable via a 120V and/or 240V mains supple, depending on geographic location, via a power socket 52 (which could also be located inside the housing 26 to minimise chance of electrical shock, or the like) .

[ 0040 ] The trolley 22 also includes a spray gun holder 54 for storing the spray gun 42 when not in use. In use, when the spray gun 42 is triggered by a user actuating the trigger 44, the pump arrangement 32, powered by the power supply arrangement 46, is configured to deliver fluid via the spray gun 42 below a pressure of 1400kPa.

[ 0041 ] In this manner, the unit 10 provides a compact and portable 12V HVAC cleaner that provides a low-pressure residual spray to remove contaminants from an FCU of a wall-mounted split system or a ceiling cassette air conditioner.

[ 0042 ] As described, the trolley 22 has a base portion 14 or similar compartment for receiving a removable 25 litre fluid reservoir 24 or water container, a built-in 12V battery charger 50 and a control panel display 56.

[ 0043 ] In one example, the fluid pump 34 is a 107psi (pound- force per square inch) or 738kPa (Kilopascal) water pump with an inline water filter 36. The unit 10 also includes a built- in 3-pin 240 Volt power socket 52 (external to the housing or internal), delivery spray gun holder 54, and two pneumatic wheels 20 and includes a lm hose from the pump 34 to the water container 24 and an 8m hose on the delivery side from the pump 34 to the spray gun 42.

[0044] In one example, the unit 10 consists of a light ^¬ weight, upright aluminium trolley 22 with two wheels 20, as shown. Also included is a waterproof and vandal-proof housing 26 with a control panel or station 56 with a latched fold-down access cover 26 housing a 12V, 17A fully-sealed battery, a 200psi pressure-controllable water pump 34 and an inline water filter 36, and a 12V battery charger. The exterior control panel 46 typically consists of and ^λ Οη/οΐΐ' switch, an automatic reset circuit breaker, and an amber power light.

[0045] Figures 7 to 10 show a further embodiment of the HVAC coil cleaning unit 10 in accordance with the present invention. In this embodiment, the power socket 52 is removed for safety purposes from an outside of the housing 26. In this embodiment, the charger 50 is connectable via a mains supply via a suitable electrical connection inside the sealed housing 26, as will be appreciated by the skilled addressee.

[0046] In addition, in this embodiment, the framework 12 defines a receptacle 62 for operatively receiving the reservoir 24 therein, said receptacle 62 configured to facilitate easy replacement of the reservoir, i.e. a reservoir bottle of uniform size can be used as the reservoir, or the like.

[0047] Similarly, as shown in more detail in Figure 8, in this embodiment, the detent for the handle portion 16 comprises a detent mechanism 60 having at least one spring-biased rod configured to lock an upper part of the handle portion 16 in place relative to a lower part thereof. In this example, the detent mechanism 60 comprises two spring-biased rods that can be urged towards each other to retract from the handle portions, thereby allowing said portions to telescopically slide with respect to each other.

[0048] The skilled addressee will appreciate that the present invention includes an associated method for cleaning HVAC coils, said method generally comprising the steps of providing an HVAC coil cleaning unit 10, as described above, and subsequently cleaning HVAC coils with the spray gun 42.

[0049] Applicant believes is advantageous that the present invention provides for an HVAC coil cleaning unit 10 that is robust and easily transportable, portable, as well as able to use unfiltered water for HVAC cleaning purposes. Applicant believes it further advantageous that the unit 10 is configured to be substantially tamper-proof, particularly when transported on a tray of a utility vehicle. In addition, the unit 10 is configured to be compact with the telescopic handle and the described housing and framework configurations.

[0050] Optional embodiments of the present invention may also be said to broadly consist in the parts, elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts, elements or features, and wherein specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. In the example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail, as such will be readily understood by the skilled addressee .

[0051] The use of the terms "a", "an", "said", "the", and/or similar referents in the context of describing various embodiments (especially in the context of the claimed subject matter) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including, " and "containing" are to be construed as open- ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. No language in the specification should be construed as indicating any non-claimed subject matter as essential to the practice of the claimed subject matter .

[0052] It is to be appreciated that reference to "one example" or "an example" of the invention, or similar exemplary language (e.g., "such as") herein, is not made in an exclusive sense. Various substantially and specifically practical and useful exemplary embodiments of the claimed subject matter are described herein, textually and/or graphically, for carrying out the claimed subject matter.

[0053] Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example. These examples are intended to assist the skilled person in performing the invention and are not intended to limit the overall scope of the invention in any way unless the context clearly indicates otherwise. Variations (e.g. modifications and/or enhancements) of one or more embodiments described herein might become apparent to those of ordinary skill in the art upon reading this application. The inventor (s) expects skilled artisans to employ such variations as appropriate, and the inventor (s) intends for the claimed subject matter to be practiced other than as specifically described herein.

[0054] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.