Fan coil assembly

Abstract

A fan coil assembly (112) for a HVAC (Heating Ventilation and Air Conditioning) system, the assembly having a heat exchange unit (46) for receiving a heat transfer fluid, and a fan unit (54) with one or more centrifugal fans (110) for drawing an airflow (48) through the heat exchange unit.

Description

FAN COIL ASSEMBLYFIELD

[0001] The present invention relates to a fan coil assembly for a HVAC (Heating, Ventilation, Air Conditioning) system. The invention is well suited to fan coil assemblies for HVAC systems on ships and particularly applicable to HVAC systems in naval vessels.BACKGROUND

[0002] Fan coil assemblies are used in HVAC systems to generate an airflow through a coil in which a heat exchange fluid flows. Heat from the airflow transfers through thermally conductive tubes and fins of the coil to reduce the temperature of the discharge airflow. The discharge flow is ducted throughout interior spaces such as offices or residences for the comfort of occupants and / or ventilate and cool equipment.

[0003] Ocean going vessels travel through a range of climates and weather conditions. Robust and reliable HVAC systems are needed to ventilate and condition the air in the various decks where passengers and / or crew live and work. Figure 1 schematically shows a typical air handling unit 10 used on large vessels such cruise ships. A blower fan 22 draws inlet air through filters 12 and the coil 14. A heat transfer fluid 16 (typically chilled water) circulates through the coil 14 to cool the airflow. If necessary, a heater 18 re-heats the air to a desired temperature. Blower fan 22 is belt driven by motor 20 to discharge the conditioned air 24 into the interior space or ducting.

[0004] This type of air handling unit 10 is generally very long and difficult to maneuver through ships passages for installation, repair, upgrade or replacement. Furthermore, the control panel for the unit is remotely positioned on a bulkhead some distance away.

[0005] In naval ships, the available space within the internal decks is more constricted. Navy ships are expensive and all onboard space is extremely valuable. In addition, modem combat systems equipment will generate more heat than previous systems and is often physically larger. The heat must be dissipated by the HVAC system without the system increasing in size to displace new combat capabilities. There is also an overriding imperative to keep vessels compact to minimise ship building costs and enhance the affordability of a fleet.

[0006] Equipment is accessed by very tight passages making repair and maintenance difficult. Deck mounted equipment is also expensive as complex steel foundations and tight cable routing are required, creating difficulties for installation as services are tightly packed. Furthermore, there is a preference for locating cooling equipment local to heat sources to minimize ducting runs. This creates installation difficulties as equipment cannot be located in central fan rooms but rather in nooks throughout the ship, creating tortuous paths to the installation site down narrow passages. These space constraints and other complications are less applicable on cruise ships and ferries which are much larger than navy ships and are not fitted with complex, redundant combat systems generating substantial heat.

[0007] The HVAC systems on US navy ships have changed little in 60 years. Figure 2 shows a typical fan coil assembly 42 in which the air inlet 26, inlet filter 28, motor 38 and belt driven blower fan 36 are vertically stacked on the cooling coils 34 in the cooling section 32. Airflow 30 drawn downwards through the inlet 26 must be redirected to flow though the coils 34 as evenly as possible, and redirected again to be discharged through the outlet 40 by the blower fan 36. These legacy HVAC systems are relatively heavy, energy inefficient and restricted to operating at a single fan speed using a V-belt driven fan. However, the US Navy believe the operational requirements for onboard HVAC will be substantially greater in future. For example, NAVSEA Philadelphia Naval Surface Warfare Center Carderock Division have determined “Projected Next Navy’s thermal loads are 2-5 times those of today’s ships. The current HVAC architecture will have major ship design implications in weight, volume, energy usage, acquisition costs and overall operational maintainability. Advancements in the technology and the architecture of the HVAC system of future surface combatants are needed. ” (see www.navsea.navy.mil / Media / News / Article / 1888251 / navsea-releases-naval-power-and-energy-systems-technology-development-roadmap / )SUMMARY OF INVENTION

[0008] With the above issues in mind, the present invention provides a fan coil assembly for a HVAC (Heating Ventilation and Air Conditioning) system, the assembly comprising: a heat exchange unit for receiving a heat transfer fluid; and a fan unit with one or more centrifugal fans for drawing an airflow through the heat exchange unit. A centrifugal fan draws air (or gas) into the impellor in a direction substantially aligned with the axis of rotation, and expels air in a direction substantially normal to the axis of rotation. In contrast to the blower fans of the priorart, the centrifugal fan allows a reconfiguration of the fan coil assembly components into a more compact form. For example, the drive motor for the fan arranged adjacent the downstream side of the impellor reduces the assembly footprint and allows a smaller discharge air plenum.Similarly, the centrifugal fan allows a larger coil to be used compared to the prior art blower fan systems as the blower fan and the drive motor need to be accommodated such that the motor does not obstruct airflow from the coil to the blower fan.

[0009] In another aspect, the invention provides a method of air conditioning a space, the method comprising, using a fan unit with one or more centrifugal fans to draw an airflow through a heat exchange unit, and supplying a heat exchange fluid to the heat exchange unit for heat transfer from the airflow to the fluid, and discharging the airflow from the fan unit.

[0010] Preferably, the or each centrifugal fan includes an impeller and a motor configured such that the motor is downstream of the impellor.

[0011] Preferably, the impeller rotates on an axis that is inclined up to 50° to the horizontal.

[0012] Preferably, the fan unit is configured to generate a discharge airflow in a direction generally transverse to the airflow through the heat exchange unit.

[0013] Preferably, the or each centrifugal fan rotates in a plane generally transverse to a direction of the airflow through the heat exchanger unit. Preferably, the plane of rotation is inclined at an angle of 0° to 50° to the direction of airflow through the heat exchange unit.

[0014] Preferably, the fan unit has a plurality of the centrifugal fans positioned adjacent each other for drawing the airflow through different portions of the heat exchange unit respectively.

[0015] Preferably, the fan coil assembly further comprises a heater element between the heat exchange unit and the fan unit for heating the airflow drawn into the fan unit.

[0016] In some forms, the fan unit has a plenum wall extending perpendicular to the or each impeller axis, and the or each centrifugal fan is a plenum fan with the or each impeller and respective drive motor positioned on opposite sides of the plenum wall. In other forms, the fan unit has a discharge plenum to direct the discharge airflow, and the or each centrifugal fan andrespective drive motor are housed within the discharge plenum. Preferably, the discharge plenum has access panels for accessing the centrifugal fans and / or respective drive motors.

[0017] Preferably, the fan coil assembly has a control unit for operative control of the or each motor to adjust motor speed to tune motor speeds to airflow requirements for a specific installation location. This allows the assembly to operate the fans at a speed that is sufficient for the required airflow, but less than the manufacturer’s specified maximum speed in order to reduce noise and power consumption. Operating at a lower fan speed reduces noise for the personnel in the area and is more energy efficient.

[0018] Preferably, the control unit has a user interface mounted together with the fan unit to receive control inputs from a user and display system status information.

[0019] Local inbuilt control also controls reheaters, modulating cooling water control valves and communicates with the ship’s integrated platform management system for remote start / stop communicating status and operating parameters and allow for bulk temperature control and reset / adjustment for power shed and share via adjusting bulk or singular temperature set points.

[0020] Preferably, the or each centrifugal fan is mounted within the discharge plenum using shock damping mounts allowing relative movement between the centrifugal fan and the discharge plenum.

[0021] Preferably, internal surfaces of the discharge plenum have an acoustic dampener.

[0022] Preferably, the fan coil assembly has a chassis for mounting the fan unit and the heat exchange unit, the chassis including shock damping mounts for mounting the fan unit and allowing relative movement between the chassis and the fan unit in response to impulse loads to the chassis.

[0023] Preferably, the shock damping mounts have resilient material and are collectively arranged to allow up to 80mm of relative movement in any direction between the fan unit and the chassis. In some forms, the shock damping mounts have resilient material and are collectively arranged to allow up to 50mm of relative movement in any direction between the fan unit and the chassis.

[0024] Preferably, the shock damping mounts have resilient members extending between the fan unit and the chassis, and at least some of the resilient members extend in mutually perpendicular directions.

[0025] Preferably, the resilient members each include a curved or angled portion to decrease resistance to deformation under the impulse load.

[0026] Preferably, the chassis is configured for mounting to the deck of a vessel.

[0027] Preferably, the vessel is a naval vessel or complex civilian vessel for military, coast guard or science activities in complex environments and / or missions.Preferably, the vessel includes an integrated platform management system, and the control unit is configured for at least one of:controlling the heater unit;modulating control valves for the heat transfer fluid; andcommunicating with the integrated platform management system for:remote start / stop of the HVAC system;communicating status and operating parameters; and / orbulk temperature control and reset / adjustment for power shed and share via adjusting bulk or singular temperature set points.

[0028] Preferably, the heat exchange unit includes a tube defining a serpentine flow path through an array of thermally conductive fins for receiving the heat exchange fluid from the HVAC system.

[0029] Preferably, the heat transfer fluid is chilled water.

[0030] Preferably, an air inlet plenum upstream of the heat exchange unit configured for attachment to overhead HVAC ducting, and a discharge plenum directing the discharge airflow from the fan unit into the overhead ducting of the HVAC system.BRIEF DESCRIPTION OF DRAWINGS

[0031] Preferred embodiments of the invention will now be described by way of example only with reference to the accompanying Figures, in which:

[0032] Figure l is a sectioned perspective of a prior art air handling unit of the type often used in large vessels such as cruise ships;

[0033] Figure 2 is a sectioned view of a fan coil assembly used in naval ships;

[0034] Figure 3 is a plan view of a fan coil assembly according to the invention;

[0035] Figure 4 is a front elevation of a first embodiment of the fan coil assembly;

[0036] Figure 5 is the left side view of the first embodiment;

[0037] Figure 6 is the right side view of the first embodiment;

[0038] Figure 7 is a perspective view of first embodiment;

[0039] Figure 8 is a perspective view of a second embodiment of the fan coil assembly using two plenum fans;

[0040] Figure 9 is a plan view of the second embodiment;

[0041] Figure 10 is a front elevation of the second embodiment of the fan coil assembly;

[0042] Figure 11 is a left side view of the second embodiment of the fan coil assembly;

[0043] Figure 12 is the right-side view of the second embodiment of the fan coil assembly;

[0044] Figure 13 is a perspective view of a third embodiment of the fan coil assembly using three plenum fans;

[0045] Figure 14 is a perspective view of a fourth embodiment of the fan coil assembly using six plenum fans arranged in two adjacent vertical stacks of three;

[0046] Figure 15 is a sectioned front elevation of the second embodiment of the fan coil assembly schematically depicting the airflow to the plenum fans;

[0047] Figurel6 is a schematic front elevation of the second embodiment of the fan coil assembly schematically depicting the increased footprint if a single plenum fan were used;

[0048] Figure 17 is a plan view of the second embodiment schematically depicting the displacement of the fan unit relative to the chassis in response to a shock load;

[0049] Figure 18 is a right-side view of the second embodiment of the fan coil assembly schematically depicting the displacement of the fan coil unit and control unit relative to the chassis in response to a shock load;

[0050] Figure 19 is a sectioned perspective showing the positioning of the drive motors for the plenum fans accessible from outside the discharge plenum of the fan coil assembly;

[0051] Figure 20 is a plan view of a fifth embodiment of the fan coil assembly with a larger discharge plenum housing the impellor and motor of the centrifugal fan;

[0052] Figure 21 is a front elevation of the fifth embodiment showing the inlet airflow to the coil and discharge airflow from the fan unit;

[0053] Figure 22 is a left side view of the fifth embodiment showing the array of conductive fins in the coil;

[0054] Figure 23 is a right side view of the fifth embodiment showing the access panel into the discharge plenum of the fan unit;

[0055] Figure 24 is a perspective view of the fifth embodiment;

[0056] Figure 25 is perspective view of a sixth embodiment of the fan coil assembly with two vertically stacked centrifugal fans in the fan unit and an inlet air plenum on the coil to receive airflow from overhead ducting;

[0057] Figure 26 is a left side elevation of the sixth embodiment;

[0058] Figure 27 is a front elevation of the sixth embodiment;

[0059] Figure 28 is a section view of the sixth embodiment through line A-A of Figure 26;

[0060] Figure 29 is a perspective view of a seventh embodiment of the fan coil assembly with a 2X2 array of centrifugal fans in the fan unit;

[0061] Figure 30 is a left side elevation of the seventh embodiment;

[0062] Figure 31 is a front elevation of the seventh embodiment;

[0063] Figure 32 is a section view of the seventh embodiment through line A-A of Figure 30;

[0064] Figure 33 is a sectioned front elevation of the fifth embodiment of the fan coil assembly schematically depicting the airflow to the centrifugal fans;

[0065] Figure 34 is a schematic front elevation of the fifth embodiment of the fan coil assembly schematically depicting the increased footprint if a single centrifugal fan were used;

[0066] Figure 35 is an exploded perspective a centrifugal fan with shock-resistant mounting the fan in the discharge plenum of an eighth embodiment of the fan coil assembly;

[0067] Figure 36 is a plan view of the centrifugal fan and shock-resistant mounting of Figure 35;

[0068] Figure 37 is a front elevation of the centrifugal fan and shock-resistant mounting of Figure 35;

[0069] Figure 38 is a right side view of the centrifugal fan and shock-resistant mounting of Figure 35;

[0070] Figure 39 is a perspective view of the eighth embodiment of the fan coil assembly;

[0071] Figure 40A is a section view of the eighth embodiment through line B-B of Figure 4 IB;

[0072] Figure 40B is a plan view of the eighth embodiment;

[0073] Figure 41 A is a section view of the eighth embodiment through line A-A of Figure 41B;

[0074] Figure 4 IB is a front elevation of the eighth embodiment;

[0075] Figure 41C is a right side elevation of the eighth embodiment;

[0076] Figure 42 is a perspective view of an alternative form of the eighth embodiment of the fan coil assembly with a control unit, the inlet airflow to the coil and the airflow from the discharge plenum;

[0077] Figure 43 is an exploded perspective of the eighth embodiment showing panels from the discharge plenum removed;

[0078] Figure 44 is a perspective of the eighth embodiment with discharge ducting connected to the discharge plenum where panels have been removed;

[0079] Figures 45A to 45D are a plan view, perspective view front and right side elevations of a ninth embodiment with wider coil in combination with a single centrifugal fan;

[0080] Figures 46A and 46B are plan and perspective views of a tenth embodiment of the fan coil assembly using a 2X2 array of centrifugal fans;

[0081] Figure 46C is a section view of the tenth embodiment through line A-A in Figure 46D;

[0082] Figure 46D front elevation of the tenth embodiment; and

[0083] Figure 46E right side elevation of the tenth embodiment.DESCRIPTION OF EMBODIMENTS

[0084] Referring to Figures 3 to 7, a single fan example of the fan coil assembly 44 is shown. The assembly has a chassis 56 for mounting directly to the deck of a vessel such as a navy ship (not shown). The chassis 56 supports a heat exchange unit 46, a heater unit 52 and a fan unit 54. The heat exchange unit 46 is typically in the form of conductive coils 90 circulating a heat exchange fluid, usually chilled water, flowing from fluid inlet 50 to the fluid outlet 49. From the outlet 49, the water recirculates back to the water chiller (not shown). The conductive coils 90 have a serpentine configuration through an array of thermally conductive fins 92 (see Figure 5) for heat transfer from the airflow to the chilled water.

[0085] A heater unit 52 is mounted adjacent the coil 46 for reheating the airflow to a desired temperature if necessary. The heater unit 52 uses one or more resistive heater elements 86 extending across the input airflow 48 downstream of the coil 46.

[0086] The fan unit 54 is mounted on resilient shock mounts 64 and 66. The connecting duct 84 between the heater unit 52 and the fan unit 54 is also resilient to allow relative movement between the fan unit 54 and chassis 56 to absorb shock loading to the ship during warfare. This is described in more detail below.

[0087] The fan unit 54 includes at least one centrifugal fan 74. In this embodiment, the centrifugal fan is a plenum fan to position the drive motor 58 outside the plenum wall 80 for ease of maintenance and repair. If this configuration does not allow for a discharge plenum with sufficient volume for the required airflow, other forms of the fan coil assembly (described below) house the centrifugal fan(s) and respective motors within the discharge plenum and provide access panels for servicing and maintenance.

[0088] The drive motor 58 drives the impeller 60 about an impeller axis 72 that is substantially parallel to the airflow 68 drawn through the coil 46. Skilled workers will readily appreciate the airflow 68 drawn through the coil 46 by the impeller 60 tapers slightly towards the fan 74. In light of this, the local flow direction at the edges of the tapering airflow section will not be exactly parallel to the impeller axis 72 but a general or substantial alignment between the impeller axis 72 and the inlet airflow 48 is adequate for effective operation of the fan coil unit 44.

[0089] The impeller 60 redirects the inlet airflow 68 radially outwards to generate a discharge airflow 70 in a direction generally transverse to the inlet airflow 68. Typically, the discharge airflow 70 feeds into overhead ducting for distribution throughout the ship.

[0090] Using a centrifugal fan unit 54 adjacent the coil 46 allows the coil to be larger compared to the prior art fan coil assembly depicted in Figure 2. As shown in Figure 2, the prior art coil has a restricted height as the blower fan 36 and drive motor 38 must be accommodated between the top of the coils 34 and the overhead HVAC ducts. The fan coil assembly 44 of the present invention, allows the coil 46 to extend from the chassis 56 on the deck to the overhead ducting (not shown) for a substantially increased cooling capacity, or the same capacity can be provided with a much smaller footprint or overall unit size.

[0091] Referring to Figures 8 to 12, a second example of the fan coil assembly 45 is shown to illustrate the modular nature of the present invention. In this embodiment, the fan unit 54 includes two adjacent plenum fans 74 and 75. While the fans are shown vertically stacked on one another, other configurations may be better suited to evenly draw air through a coil 46 of different dimensions. Using two fans allows the coil 46 to be larger and the overall capacity of the fan coil assembly 45 is significantly higher. The assembly can be increased in height by increasing the height of the coil (i.e. heat exchange unit 46) and adding extra fans in a vertical stack. Likewise, the width of the assembly may be increased with a wider coil unit 46 paired a wider fan unit 54 with additional fans arranged in a grid pattern.

[0092] Figure 13 shows a third embodiment of the fan coil assembly 94 with a fan unit 54 having three plenum fans 98, 100, 102 mounted to the chassis 56 in a vertical stack. In Figure 14, a fourth embodiment 96 has a wider fan unit 54 with six plenum fans (98 to 103) in two adjacent stacks of three. The modular nature of the assembly design varies the number of fans to suit coils (i.e. the heat exchange unit 46) of different sizes and configurations.

[0093] As best shown in the section views of Figures 15 and 16, the two fans 74 and 75 draw a larger inlet airflow 48 through the larger coil 46 in a manner that is relatively uniform over the entire cross section of the coil 46. Immediately downstream of the coil 46, the inlet airflow 48 divides into an upper airflow 48 A and lower airflow 48B. The upper airflow 48 A is drawn through the upper portion of the coil 46 by the upper fan 75, and the lower airflow 48B is drawn though the lower portion of the coil 46 by the lower fan 74.

[0094] As with the single fan version of the assembly 44, the upper and lower airflows 48A and 48B taper in a frustoconical flow path into the impellers 60 of the upper and lower fans 75 and 74 respectively. Both fans 74 and 75 collectively generate the discharge airflow 70 vertically upwards through the discharge plenum 78.

[0095] Figure 16 illustrates how the larger coil 46 can be used together with a single fan schematically depicted by the rectangle 76. The single fan 76 could be configured to operate at a higher capacity to draw the inlet airflow through the larger coil 46. However, due to the tapering of the airflow 48 towards the impeller of the single fan 76, the spacing between the fan 76 and the coil 46 needs to increase to ensure airflow through all the coil. This, in turn increases the overall footprint of the fan coil assembly 45. Furthermore, using a single high-capacity fan 76 operating at a higher speed generates significantly more noise than two similar fans 74 and 75 operating below the manufacturer’s specified maximum capacity. In addition, using multiple fans creates a more uniform inlet airflow 48 through the larger coil 46. The Applicant’s have found operating the fans 74 and 75 at between 20% - 100% of their specified maximum capacity can provide a low noise, uniform flow through the coil 46, tailored to the specific airflow requirements of the installed location. This reduces the fan coil assembly footprint, and creates versatility.

[0096] Figures 17 and 18 schematically depict the operation of the shock mounts 64 and 66 connecting the fan unit 54 to the chassis 56. A naval ship is at risk of explosive shock loads during military conflict and as the HVAC systems cool combat systems which generate heat, they must continue to operate un-impeded through combat events. To guard against damage to the fan coil assembly 45, the fan unit 54 and its associated control unit 62, mount to the chassis 56 using U-shaped lower shock mounts 64 and curved upper shock mounts 66. The shock mounts 64 and 66 are formed of resilient material such as rubber and the duct 84 from the heater unit 52 to the fan unit 54 is also resiliently flexible.

[0097] The lower shock mounts 64 extend in a direction that is generally perpendicular to the upper shock mounts 66 such that the fan unit 54 can displace in any direction relative to the chassis 56. Furthermore, the resilient members of the shock mounts 64 and 66 each have a generally curved configuration to more easily buckle and collapse, or conversely straighten and extend to accommodate the displacement caused by a shock load to the chassis 56. Skilledworkers will understand other configurations for the shock mounts 64 and 66 would be suitable such as angled members extending between the fan unit 54 and the chassis 56.

[0098] The embodiment shown in Figures 16 and 17 comfortably allow a relative displacement of around 50mm in all directions as schematically indicated by the displaced fan unit outline 79. However, the shock mounts 64 and 66 should be configured to allow up to 80mm displacement between the fan unit 54 and the chassis 56 to better protect the fan unit 54.

[0099] Mounting the control unit 52 directly to the fan unit 54 reduces the need for cabling and conduits between the fan coil assembly 45 and a remotely positioned control panel. The current practice of remotely mounted control panels consumes additional valuable space / weight within the ship. Furthermore, the circuitry and components within the control unit 62 have the same protection from impact loads via the shock mounts 64 and 66 supporting the fan unit 54. The control unit also interfaces with the ships integrated platform management system which allows for remote performance indication, start / stop control, load shed and share commands to be initiated shipwide.

[0100] The control unit 62 includes a user interface 82 for receiving control inputs from a user as well as providing a display system to indicate system status information and defect indicators.

[0101] As best shown in Figure 19, the use of plenum beltless direct drive fans 74 and 75 conveniently provide the fan motors 58 outside of the plenum wall 80 of the discharge plenum 78. Any operational issues indicated on the user interface 82 (see Figure 4) are more readily addressed with direct access to the externally accessible fan motors 58 for repair, troubleshooting and maintenance.

[0102] As previously discussed, the discharge plenum 78 can connect directly to overhead HVAC ducting and similarly an inlet plenum 88 may be positioned upstream of the heat exchange unit 46 for connection to the overhead HVAC ducting.

[0103] Typically, the heat exchange unit 46 will include one or more thermally conductive coils 90 defining a serpentine flow path through an array of conductive fins 92 to enhance heat transfer from the inlet airflow 48 to the heat transfer fluid (chilled water).

[0104] Figures 20 to 24 show a fifth embodiment 104 of the fan coil assembly. The fifth embodiment 104 is similar to the first embodiment 44 shown in Figures 3 to 7, but has an enlarged fan box or discharge plenum 78. The fifth embodiment 104 has many features in common with the first embodiment 44, and corresponding features are indicated in the figures using the same reference numerals.

[0105] In applications requiring a larger discharge airflow 70, the centrifugal fan 74 operates at a higher speed and a larger discharge plenum 78 is used instead of the smaller fan box in the first embodiment 44. The smaller fan box can be an airflow constriction at higher flow rates. The larger discharge plenum 78 of the fifth embodiment 104 encloses both the impellor 60 and the motor 58 of the centrifugal fan 74. In light of this, an access panel 106 is provides in the plenum wall 80 for maintenance of the centrifugal fan 74.

[0106] Figures 25 to 28 show a sixth embodiment 108 of the fan coil assembly. The sixth embodiment 108 is similar to the second embodiment 45 shown in Figures 8 to 12, but has an enlarged discharge plenum 78 for the same reasons discussed above in relation to the fifth embodiment. The sixth embodiment 104 has many features in common with the second embodiment 45, and corresponding features are indicated in the figures using the same reference numerals.

[0107] As with the second embodiment 45, the sixth embodiment 108 has a fan unit 54 with two vertically stacked centrifugal fans - lower centrifugal fan 74 and upper centrifugal fan 75. However, the lower and upper centrifugal fans 74 and 75 are wholly within the discharge plenum 78. Access to the motors of the fans 74 and 75 is though access panels 106 in the plenum wall 80. The larger discharge plenum 78 does not create a flow construction on the discharge airflow 70 to the overhead ducting (not shown). The heat exchange unit 46 has an inlet plenum 88 to direct the inlet airflow 48 from the overhead ducting into the coil.

[0108] Figures 29 to 32 show a seventh embodiment 112 of the fan coil assembly. The seventh embodiment 112 is wider than the sixth embodiment 108 shown in Figures 25 to 28, to increase the airflow capacity. The wider assembly uses a 2X2 array 110 of centrifugal fans in the fan unit 54 to draw inlet airflow 48 through a wider coil 46 and heater unit 52. Once again, features in this embodiment corresponding with equivalent features in other embodiments are indicated using the same reference numerals.

[0109] The fan unit 54 has a wider and deeper discharge plenum 78 that encloses all four centrifugal fans 74 and their respective drive motors 58. The plenum wall 80 has access panels 106 arranged in registration with the motors of the 2X2 array 110. The increased discharge airflow 70 is directed upwardly from the discharge plenum 78, and typically supplied to overhead ducting (not shown). In this embodiment, the coil 46 does not include an inlet plenum 88 to receive inlet airflow 48 from overhead ducting however, workers in this field will understand an inlet plenum 88 dimensioned to suit the wider coil 46 can be added if required.

[0110] As best shown in the section views of Figures 15 and 16, the two fans 74 and 75 draw a larger inlet airflow 48 through the larger coil 46 in a manner that is relatively uniform over the entire cross section of the coil 46. Immediately downstream of the coil 46, the inlet airflow 48 divides into an upper airflow 48 A and lower airflow 48B. The upper airflow 48 A is drawn through the upper portion of the coil 46 by the upper fan 75, and the lower airflow 48B is drawn though the lower portion of the coil 46 by the lower fan 74.

[0111] Figures 33 and 34 are section views similar to Figures 15 and 16 schematically depicting the airflow through the coil 46 and heater unit 52 to the centrifugal fans 74 and 75. As with the single fan versions of the assembly (e.g. 44 and 108), the upper and lower airflows 48 A and 48B taper in a frustoconical flow path into the impellers 60 of the upper and lower fans 75 and 74 respectively. Both fans 74 and 75 collectively generate the discharge airflow 70 vertically upwards through the discharge plenum 78. As discussed above, the discharge plenum 78 in the fifth embodiment 108 is larger than that of the Figures 15 and 16, to increase the discharge airflow rate 70. The larger discharge plenum 78 marginally increases the footprint of the fan coil assembly 108 compared to the assembly shown in Figure 15, but still substantially reduced compared to the prior art air handling systems with blower fans.

[0112] Figure 34 illustrates how the larger coil 46 can be used together with a single fan schematically depicted by the rectangle 76. The single fan 76 could be configured to operate at a higher capacity to draw the inlet airflow through the larger coil 46. However, due to the tapering of the airflow 48 towards the impeller of the single fan 76, the spacing between the centrifugal fan 76 and the coil 46 needs to increase to ensure airflow through all the coil. This, in turn increases the overall footprint of the fan coil assembly 45. Furthermore, using a single high-capacity centrifugal fan 76 operating at a higher speed generates significantly more noise than two centrifugal fans 74 and 75 operating below the manufacturer’s specified maximum capacity.

[0113] As previous discussed in relation to Figures 15 and 16, multiple fans improve the uniformity of the inlet airflow 48 through the larger coil 46. The Applicant’s have found operating the fans 74 and 75 at between 20% - 100% of their specified maximum capacity can provide a low noise, uniform flow through the coil 46, tailored to the specific airflow requirements of the installed location. This reduces the fan coil assembly footprint and creates versatility.

[0114] Figures 35 to 44 show the components of an eighth embodiment 130 of the fan coil assembly. The eighth embodiment 130 has addressed the issue of an extended footprint in single fan 76 embodiments because of the longer distance from a larger coil 46 (see Figure 34 discussed above). Furthermore, the eighth embodiment 130 is quieter relative to embodiments that shock mount the fan unit 54 to the chassis 56 and the heater unit 52.

[0115] Referring back to Figure 21, the fan unit 54 is mounted to the chassis 56 and the heater unit 52 with resilient shock mounts 64 and 60 respectively. Explosive impacts to the ship are dampened by the shock mounts 60 and 64 which allows some movement of the fan unit 54 relative to the chassis and heater unit. This requires resilient duct 84 between the heater unit 52 and the fan unit 54. A second resilient duct or collar (not shown) is also required to connect the discharge plenum 78 to a discharge air duct. During operation, a significant level of noise transmits through these resilient connections.

[0116] The eighth embodiment 130 of the fan coil assembly rigidly attaches the fan unit 54 to the chassis 56 and the heater unit 52, and resiliently mounts the centrifugal fan 76 inside the discharge plenum 78. To reduce the footprint, the centrifugal fan 76 is mounted such that the axis of rotation of the impellor is inclined to the horizontal. In turn, the frustoconical airflow drawn into the fan 76 (see for example airflows 48 A and 48B in Figure 15) also inclines to encompass more of the downstream side of the coil 46, while having a relatively short lateral spacing from the coil 46. Inclining the axis 72 of the fan 76 up to 50 degrees to the horizontal is a workable range while an inclination of 25 to 45 degrees is particularly suitable.

[0117] Figures 35 to 38 show the internal fan mount assembly 114. A pair of side beams 116 are internally mounted within the discharge plenum 78. A fan skeleton structure 118 is attached around centrifugal fan 76. Resilient shock mounts 120 connect each of the side beams116 to the skeleton structure 118. The fan skeleton structure 118 is configured to hold the fan at the required inclination when attached to the shock mounts 120.

[0118] An upper baffle plate 122 and lower baffle plate 124 are provided to define a boundary between the suction-side airflow upstream of the centrifugal fan 76 and the dischargeside airflow downstream of the fan. The lower baffle plate 124 includes weep holes 126 along the lowest edge to allow condensate to drain to the sloped bottom 156 of the discharge plenum 78 for collection.

[0119] As best shown in Figures 37 and 38, a flow straightener grille 128 may be used to better align the suction-side airflow 132 with the impellor axis of the centrifugal fan 76.Conveniently, the front-most component of the skeleton structure 118 and the grille 128 are mutually configured for detachable engagement.

[0120] Figures 39 to 41C show the inclined centrifugal fan 76 mounted in the eighth embodiment 130 of the fan coil assembly. The heater unit 52 and the fan unit 54 are integrated into the same casing 152 that provides the discharge plenum 78. The ‘external’ shock mounts 60 and 64 and the resilient duct 84 used in the fifth embodiment are not required. The chilled water supply line 136 and the chilled water return line 138 connect to the inlet and outlet respectively on top of the coil 46. The supply line 136 and return line 138 are machine bent piping to allow the chilled water connection to be positioned in the void under the sloped floor 156 of the discharge plenum 78.

[0121] The outer casing 152 holds the heater unit 52 and the fan unit 54. Top opening 154 connects the discharge airflow 70 to the overhead ducting (not shown). Removable rear access panel 140 and side panels 144 allow maintenance and attachment of additional ducting (see Figure 44). As best shown in Figure 41 A, interior surfaces on the discharge side of the discharge plenum 78 are lined with acoustic damping 134 to further reduce noise. Figure 41 A also clearly shows the relatively close lateral spacing between the coil 46 / heater unit 52, and the centrifugal fan 76.

[0122] Figure 42 shows the eighth embodiment of the fan coil assembly 130 with an optional control unit 62 attached. In contrast, operative control of the fan coil assembly shown in Figure 39 is remote from the assembly itself.

[0123] Figure 43 shows the eighth embodiment of the fan coil assembly 130 with an optional inlet plenum 88 attached. The rear panel 140 and side panels 142 are shown removed from the outer casing 152 to expose the centrifugal fan 76 and internal fan mount assembly 114.

[0124] Figure 44 shows side ducts 144, rear duct 146 and top duct 148 connected to the discharge plenum 78 once all access panelling has been removed. The discharge airflow 70 can be ducted in any direction, or a combination of directions.

[0125] Figures 45A to 45D show a ninth embodiment 150 of the fan coil assembly. The ninth embodiment 150 is constructed in the same manner as the eighth embodiment 130, has a single centrifugal fan 76, but has a wider coil 46. The wider coil 46 provides additional capacity with the speed and positioning of the centrifugal fan 76 being adjusted accordingly. The capacity of the fan coil assembly may also be increased by increasing the height of the coil 46, or increasing both the height and the width.

[0126] Figures 46A to 46E show a tenth embodiment 160 of the fan coil assembly. The capacity is significantly increased by a substantially wider and taller coil 46 and a 2X2 centrifugal fan array 110. The 2X2 array 110 has a top left fan 158, top right fan 162, bottom right fan 164, and bottom left fan (not shown). The top row of fans (158 and 162) are internally shock mounted within the discharge plenum 78, with no inclination to the horizontal, while the bottom row of fans (164) are internally, shock mounted in the discharge plenum 78, at an inclination to the horizontal. The tenth embodiment 160 shown does not have an integrated control unit 62, however the top and bottom fans may be selectively operated at the same speed or at different speeds for a desired discharge airflow 70.

[0127] The present invention has been described here by way of example only and skilled workers will readily recognise many variations and modifications which do not depart from the spirit and scope of the broad inventive concept.

[0128] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms a part of the common general knowledge in the field.

[0129] Unless the context clearly requires otherwise, throughout the description and claims, the words “comprise”, “comprising” and the like are to be construed in an inclusivesense as an opposed to an exclusive or exhaustive sense; that is to say in the sense of “including, but not limited to”.

[0130] The terms such as “generally”, “about” and “substantially” should be construed by the skilled addressee having regard to normal tolerances in this field of technology.

[0131] The terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and are not intended to exclude other embodiments from the scope of the invention.

[0132] Throughout the specification and appended claims, the singular forms “a”, “an” and “the” include the potential for options with plural forms unless the context clearly dictates otherwise.

[0133] A feature in the claims stated in general terms will represent a principle of general application, where it is reason to expect (i.e. reasonable to predict) that the claimed invention will work with anything that falls within the general term. Such a feature defined in general terms may be a major part of the claim, or it may be a simple descriptive word. In any other case, a feature in the claims expressed in general terms will be sufficiently enabled if the disclosure enables at least one form of, or one application of, a general principle in respect of the feature, and a person skilled in the art would reasonably expect the invention to work with anything that falls within the general term.

[0134] Broadly drafted claims may be considered enabled if, prima facie:(a) the disclosure teaches a principle that the person skilled in the art would need to follow in order to achieve each and every embodiment falling within the claim; and (b) the specification discloses at least one application of the principle and provides sufficient information for the person skilled in the art to perform alternative applications of the principle in that way, while not explicitly disclosed, but nevertheless be obvious to the person skilled in the art.

Claims

CLAIMS1. A fan coil assembly for a HVAC (Heating Ventilation and Air Conditioning) system, the assembly comprising:a heat exchange unit for receiving a heat transfer fluid; anda fan unit with one or more centrifugal fans for drawing an airflow through the heat exchange unit.

2. The fan coil assembly according to claim 1, wherein the or each centrifugal fan includes an impeller and a motor configured such that the motor is downstream of the impellor.

3. The fan coil assembly according to claim 2, wherein the impeller rotates on an axis that is inclined up to 50° to the horizontal.

4. The fan coil assembly according to claim 1, wherein the or each centrifugal fan rotates in a plane generally transverse to a direction of the airflow through the heat exchanger unit.

5. The fan coil assembly according to claim 1, further comprising a heater unit between the heat exchange unit and the fan unit for heating the airflow drawn into the fan unit.

6. A fan coil assembly according to claim 3, wherein the fan unit has a discharge plenum configured to direct a discharge airflow transverse to the airflow drawn through the heat exchange unit.

7. A fan coil assembly according to claim 2, further comprising a control unit for operative control of the or each motor.

8. A fan coil assembly according to claim 7, wherein the control unit has a user interface mounted together with the fan unit.

9. A fan coil assembly according to any one of claims 1 to 8, further comprising a chassis for mounting the fan unit and the heat exchange unit, the chassis including shock damping mounts for mounting the fan unit and allowing relative movement between the chassis and the fan unit in response to impulse loads to the chassis.

10. A fan coil assembly according to claim 6, wherein the or each centrifugal fan is mounted within the discharge plenum using shock damping mounts allowing relative movement between the centrifugal fan and the discharge plenum.

11. A fan coil assembly according to claim 6, wherein internal surfaces of the discharge plenum have an acoustic dampener.

12. The fan coil assembly according to claim 9, wherein the shock damping mounts have resilient material and are collectively arranged to allow up to 80mm of relative movement in any direction between the fan unit and the chassis.

13. The fan coil assembly according to claim 12, wherein the shock damping mounts have resilient members extending between the fan unit and the chassis, and at least some of the resilient members extend in mutually perpendicular directions.

14. The fan coil assembly according to any one of claims 1 to 13, wherein the chassis is configured for mounting to the deck of a vessel.

15. The fan coil assembly according to any one of claims 1 to 14, wherein the heat exchange unit includes a tube defining a serpentine flow path through an array of thermally conductive fins for receiving the heat exchange fluid from the HVAC system.

16. The fan coil assembly according to claim 15, wherein the heat transfer fluid is chilled water.

17. The fan coil assembly according to any one of claims 1 to 16, further comprising an air inlet plenum upstream of the heat exchange unit configured for attachment to overhead HVAC ducting, and a discharge plenum directing the discharge airflow from the fan unit into the overhead ducting of the HVAC system.

18. A method of air conditioning a space, the method comprising, using a fan unit with one or more centrifugal fans to draw an airflow through a heat exchange unit, and supplying a heat exchange fluid to the heat exchange unit for heat transfer from the airflow to the fluid, and discharging the airflow from the fan unit.

19. The method of claim 18 wherein the or each centrifugal fan includes an impeller and a motor configured such that the motor is downstream of the impellor.

20. The method of claim 19 wherein the impeller rotates on an axis that is inclined up to 50° to the horizontal.

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