Ducted Heating and Cooling System

Abstract

A heating and cooling system or installation for heating or cooling air within a building space, including a water chiller for chilling water and a coil to which the chilled water can be delivered. Air can then be driven by a fan through the coil to cool the air and the cooled air can be delivered into the building space for cooling the building space. The system can include a water heating facility to heat water that is delivered to the coil so that air driven through the coil can be heated. The coil is connected to ducting for delivering cooled or heated air to the building space.

Claims

1. A heating and cooling system for heating or cooling air within a building space, the system including: a. a water heating facility to heat water, b. a water chiller to cool or chill water, c. a coil in fluid connection with the water heating facility and the water chiller and through which air can be passed for heating or cooling, d. a fan for driving air through the coil, and e. ducting comprising delivery ducting through which air which has been heated or cooled by the coil can be delivered into the building space and return ducting through which air within the building space can be returned to the coil for heating or cooling, the system being operable such that the water heating facility or the water chiller supplies either heated or cooled or chilled water to the coil and the fan causes air to flow through the return ducting from the building space, then through the coil, and then through the delivery ducting for delivery into the building space.

2. A system according to claim 1, the water heating facility and the water chiller being integrated into a single unit.

3. A system according to claim 1, the water heating facility and the water chiller being separate from each other.

4. A system according to claim 1, the fan and coil being included in a single complete fan/coil unit.

5. A system according to claim 1, the fan being connected to the return ducting or being positioned on the side of the return ducting and the coil being connected to the delivery ducting or being positioned on the side of the delivery ducting, so that the fan is positioned upstream of the coil unit.

6. A system according to claim 1, further including a photovoltaic (PV) solar collection system for providing electrical power to the water heating facility.

7. A system according to claim 1, further including a water storage tank.

8. A system according to claim 7, the water heating facility and the water chiller being in fluid communication with the water storage tank to deliver heated or cooled water to the storage tank for storage.

9. A system according to claim 1, further including a solar hot water system and the solar hot water system being in fluid communication with the water storage tank to deliver heated water to the storage tank for storage.

10. A system according to claim 1, the water chilling system having a power rating of at least less than 60% of the heating device, or of at least less than 50% of the heating device, or of at least less than 45% of the heating device, or of at least less than 40% of the heating device, or about 36% of the heating device.

11. A method of cooling a building space, the method involving installing a heating and cooling system according to claim 1 and thereafter operating the cooling device.

12. A method of cooling a building space according to claim 11, the method including chilling the water of the water chiller to a low temperature at the commencement of a cooling operation, and thereafter operating the water chiller to deliver chilled water to the coil.

13. A method of cooling a building space according to claim 11, including controlling the cooled temperature within the building space by fan speed to adjust the airflow across or circulating through the coil.

14. A heating and cooling system for heating or cooling air within a building space, the system including: a. a heating device which is operational to heat air passing through it, and a cooling device, b. a fan, and c. ducting comprising delivery ducting through which air heated by the heating device or cooled by the cooling device can be delivered into the building space and return ducting through which air within the building space can be returned to the heating and cooling devices, the cooling device comprising a water chilling system having a coil which is operational to cool air passing through it and each of the heating device and the coil having an air inlet and an air outlet, the air inlet of one of the heating device and the coil being connected to the return ducting, and the air outlet of that device being connected to the air inlet of the other of the heating device and the coil, the water chilling system further including a water chiller which is in closed loop connection with the coil to deliver chilled water to the coil and to receive water from the coil, the system being operable such that operation of the fan causes air flow through the return ducting from the building space, then through the heating device and the coil, and the delivery ducting for delivery into the building space, and the system further being operable such that only one of the heating and the cooling devices is operational at any one time.

15. A system according to claim 14, the air inlet of the heating device being connected to the return ducting, so that air that is returned from the building space flows into the heating device first and then into the coil of the cooling device and the air inlet of the coil being connected to the return ducting, so that air that is returned from the building space flows into the coil first and then into the heating device.

16. A system according to claim 14, the heating device being positioned upstream of the cooling device so that the heating device is connected to the return ducting.

17. A system according to claim 14, the water chilling system having a power rating of at least less than 60% of the heating device, or of at least less than 50% of the heating device, or of at least less than 45% of the heating device, or of at least less than 40% of the heating device, or about 36% of the heating device.

18. A method of cooling a building space, the method involving installing a heating and cooling system according to claim 14 and thereafter operating the cooling device.

19. A method of cooling a building space according to claim 18, the method including chilling the water of the water chiller to a low temperature at the commencement of a cooling operation, and thereafter operating the water chiller to deliver chilled water to the coil.

20. A method of cooling a building space according to claim 18, including controlling the cooled temperature within the building space by fan speed to adjust the airflow across or circulating through the coil.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0062] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which:

[0063] FIG. 1 is a schematic illustration of a heating and cooling system for a building space, according to one embodiment of the invention.

[0064] FIG. 2 illustrates the arrangement of FIG. 1 with a photovoltaic (PV) solar collection system 40 added.

[0065] FIG. 3 illustrates the arrangement of FIG. 2 with a storage tank and a solar hot water system added.

[0066] FIG. 4 is a schematic illustration of a heating and cooling system for a building space, according to another embodiment of the invention.

[0067] FIG. 5 is a data table to compare cooling characteristics of a heating and cooling system according to an embodiment of the invention as illustrated in FIG. 4, with a refrigerated air-conditioning system of the prior art.

DETAILED DESCRIPTION

[0068] FIG. 1 illustrates schematically, a ducted heating and cooling system 10 for heating or cooling a building space according to a first embodiment of the invention. The heating and cooling system 10 is applied to a building 11 which in FIG. 1, is a domestic dwelling (shown schematically only). The heating and cooling system 10 is partly located within the roof space 12 of the building 11 and the building space to be heated is the space 13 below the ceiling 14.

[0069] The heating and cooling system 10 includes the components that are housed within the roof space 12, as well as further components which are located outside of the building 11. The system 10 thus includes a heating/cooling facility 15 and a fan/coil unit 16, comprising a coil 17 and a fan 18. The coil 17 and the fan 18 are connected together and thus form an integrated unit 16, although for clarity, they are shown separately or disconnected in FIG. 1 but within an overall housing 19. The heating/cooling facility 15 can include a water chiller or like water cooler.

[0070] Ducting is provided in connection with the fan/coil unit 16 and the ducting comprises delivery ducting 20 through which air which has been heated or cooled in the fan/coil unit 16 is delivered into the building space 13, and return ducting 21 that facilitates the delivery to the fan/coil unit 16, of air to be heated or cooled. The return ducting 21 receives air from the space 13 through an air filter 22 and connects to an inlet of the fan/coil unit 16. The delivery ducting 20 connects to an outlet of the fan/coil unit 16 and branches into several ducting sections to deliver heated or cooled air through the ceiling 14 and into the space 13.

[0071] The heating or cooling effect that is to be achieved is achieved by way of the delivery of heated or cooled/chilled water from the heating/cooling facility 15 through delivery conduit 25 that fluidly connects the heating/cooling facility 15 to the coil 17 of the fan/coil unit 16. As an example, heated water that is delivered through the conduit 25 circulates through the coil 17 and at the same time, the fan 18 draws air through the filter 22 and the return ducting 21 and displaces that air through and about the coil 17. The air is therefore heated as it passes through or about the coil 17 and it thereafter enters the delivery ducting 20 for discharge through that ducting into the space 13. The water delivered from the heating/cooling facility 15 returns after discharge from the coil 17 via the return conduit 26 back to the heating/cooling facility 15 for reheating or re-cooling. The coil 17 is thus in a closed loop fluid connection with the heating/cooling facility 15 via the delivery and return conduits 25 and 26.

[0072] In the same way, when the space 13 is to be cooled, the heating/cooling facility 15 cools water and delivers that water through the delivery conduit 25 to the coil 17, where it passes through the coil 17 and cools air that is driven through and about the coil 17 via the fan 18. That air is drawn through the return ducting 21 and discharged into the delivery ducting 20 as described above in relation to heated air. A one-way valve 27 is connected into the delivery conduit 25 adjacent the heating/cooling facility 15 and prevents the return of water to the heating/cooling facility 15 which has already been discharged from that facility into the delivery conduit 25 towards the coil 17.

[0073] It is envisaged that the heating/cooling facility 15 will be able to supply water which is sufficiently heated or cooled to the coil 17 of the fan/coil unit 16 for the building space 13 to likewise be sufficiently heated or cooled subject to the size of the space 13 and the capacity of the heating/cooling facility 15. However, it is an option to provide additional capacity for heating or cooling and for example, FIG. 1 shows an additional appliance 30 that connects into the delivery and return conduits 25, 26 and this appliance 30 can be operated if the heating or cooling requirements for the space 13 exceed the capacity of the heating/cooling facility 15.

[0074] The appliance 30 can be a heating appliance in the form of an instant gas hot water heater that can be operated in circumstances where the facility 15 cannot supply sufficiently heated water to the coil 17 to heat the space 13 sufficiently. The arrangement can be such that the appliance 30 can draw water from the return conduit 26, heat that water and return it to the delivery conduit 25 in addition to heated water that is already being supplied to the delivery conduit 25 via the heating/cooling facility 15. Of course the appliance 30 could be a cooling appliance and operate in the same manner with the exception that it provides cooled or chilled water, rather than heated water.

[0075] In alternative arrangements, the heating/cooling facility 15 can provide only one of the heating or cooling functions, so that it becomes a heating or cooling facility but not both. Whichever of the heating or cooling functions that the facility 15 does not provide, can then be provided by the appliance 30. in this arrangement, a source valve 31 is provided in the delivery conduit 25 to connect to the delivery conduit 32 that extends from the appliance 30 and the operational controls of the system 10 can control the valve 31, so that it opens to either of the facility 15 or the appliance 30 depending on the heating or cooling requirements that have been selected by the operator. It is not necessary to include a similar valve in connection with the return conduit 33 of the appliance 30 where it connects to the return conduit 26, as water returning through the conduit 26 will be diverted to whichever of the facility 15 or the appliance 30 is operating, because only that facility or appliance will be pumping water back through the return conduit 25 (via the return conduit 32 in respect of the appliance 30). That is, with the source valve 31 closed to the facility 15 and open to the appliance 30, water returning through the return conduit 26 will divert through the return conduit 33 and enter the appliance 30 rather than returning to the facility 15, because the facility 15 will have no capacity to receive return water. Likewise, the reverse occurs when the valve 31 is open to the facility 15 and closed to the appliance 30.

[0076] The heating and cooling system 10 is ideally controlled by a controller 35 that is mounted on a wall 36 of the building 11. The controller 35 can be of a standard form which includes the ability to select heating or cooling, the temperature to which the space 13 is to be heated or cooled and timing options for heating and cooling to take place. The controller 35 can communicate with the system 10 in order to cause the facility 15, and optionally the appliance 30, to operate in the manner required to deliver heated or cooled water to the fan/coil unit 16 and also for the fan 18 to be operated at a suitable speed.

[0077] FIG. 2 illustrates the arrangement of FIG. 1 but advantageously has been created for use with a photovoltaic (PV) solar collection system 40. The same reference numerals are used in FIG. 2 for components and parts that are common to FIGS. 1 and 2.

[0078] Added to the system 10 is a PV solar panel array 41 (only one panel or module of which is shown) which is electrically connected to an inverter 42 and to a main electrical circuit box 43. A current sensor 44 is positioned between the inverter 42 and the circuit box 43.

[0079] The obvious benefit of the arrangement of FIG. 2 is via the use of solar generated electricity to fully or partially power the heating/cooling facility 15 and/or the appliance 30. Further advantageously, the use of a current sensor 44 enables the system 40 to determine whether the current being produced by the PV array 41 is sufficient to power or at least contribute to powering whichever of the facility 15 or the appliance 30 is operating to heat or cool water.

[0080] In circumstances where there is sufficient power for the PV array 41 to fully power the facility 15 or the appliance 30, then the facility 15 or the appliance 30 could be automatically operated at that time (which would always be during the day) to either heat or cool the interior space 13 as required without the need to draw electricity from the mains supply and with the aim to minimise the need to later heat or cool the interior space 13 when solar collection is not available. This means that, particularly if the space 13 is well insulated, the heating or cooling affect achieved during the day might remove the need, or at least alleviate the need for further heating or cooling at night time. This of course would require the facility 15 or the appliance 30 to provide electric heating or cooling.

[0081] The system 40 could be an already installed system that could be connected up to the system 10 with relative ease.

[0082] FIG. 3 is a further modification of the arrangements of FIGS. 1 and 2 and so for FIG. 3, the same reference numerals are used for components and parts that are common to the earlier figures.

[0083] In addition to the heating and cooling system 10 and the PV system 40 of FIGS. 1 and 2, the arrangement of FIG. 3 further includes a water storage tank 50 and a solar hot water system 51.

[0084] By the arrangement of FIG. 3, heated or cooled water can be stored in the tank 50, so that the heated or cooled water can be produced during the day using solar energy collected by the PV array 41 and used later during the night.

[0085] Likewise, water can be heated through the system 51 and delivered to the tank 50, again for use, predominately in cooler weather, to provide a source of heated water, so that the heating requirements of the facility 15 are reduced. A pump 52 is provided to pump water from the tank 50 through conduit 53 for heating within the system 51 and then return to the tank 50 via the conduit 54. One-way valves 55 and 56 control the direction of flow of water from each of the facility 15 and the system 51 into the tank 50.

[0086] It can be seen in the FIG. 3 arrangement that the delivery and return conduits 25, 26 are in fluid communication with the tank 50. Thus, the tank 50 becomes the primary source of heated or cooled water which is produced by the facility 15 and/or the system 51.

[0087] The arrangements of FIGS. 1 to 3 advantageously, as discussed earlier herein, can reduce the energy consumption required to heat or cool a building space. The arrangements have been developed for use without including refrigerated air conditioning appliances. The systems disclosed herein are expected to be easily retrofitted to existing heating and cooling systems, and can also be installed as a completely new system. The adaptability of the system for use with solar collection, either through solar PV arrays or hot water solar collectors, gives the system flexibility and attractiveness to consumers who wish to minimise mains electricity consumption for both cost and environmental reasons.

[0088] FIG. 4 illustrates schematically, a ducted heating and cooling system for heating or cooling a building space according to a second embodiment of the invention.

[0089] The heating and cooling system 110 is applied to a building 111 within which is a building space 112 which is to be heated or cooled by the system 110.

[0090] The heating and cooling system 100 includes a gas heating device 115 and a cooling device that comprises a cooling coil 116 and a water chiller 117. The water chiller can for example be a 7 kW unit coupled with a 20 kW heating device 115. Other combinations as discussed earlier herein can alternatively be adopted.

[0091] Ducting 120 is provided in communication with the building space 112 and with each of the heating device 115 and the coil 116. The ducting 120 comprises a return ducting section 121 that includes an inlet 122 that opens into the building space 112 and which connects to an inlet of the heating device 115. Airflow into the heating device 115 takes place through the return ducting section 121. The ducting 120 further comprises a connecting ducting section 123 that connects between an outlet of the heating device 115 and an inlet of the coil 116. Finally, the ducting 120 comprises a delivery ducting section 124 that connects to an outlet of the coil 116 and which includes outlet branches 125 and 126 that communicate with the building space 112.

[0092] It is of course to be appreciated that the ducting 120 illustrated in FIG. 4 is of a schematic nature only and in practice, the ducting 120 could include more than one return ducting section 121, and additional delivery ducting sections 124 and branches 125 and 126.

[0093] The water chiller 117 is in closed loop connection with the coil 116 via delivery conduit 128 and return conduit 129. The passage of water in therefore quarantined to remain between the coil 116 and the water chiller 117.

[0094] While not illustrated in FIG. 4, the heating device 115 is a gas heating device and includes an integrated fan. Accordingly, a separate fan is not illustrated in FIG. 4, but additional fans could be provided as required in any of the ducting sections 121, 123 or 124.

[0095] The operation of the heating and cooling system 110 will now be described. If the building space 112 is to be heated, then the heating device 115 is operated. Because the system is set up so that only one of the heating and cooling devices can be operated at one time, with the heating device 115 operational, the cooling device is inoperative or disabled. With the heating device 115 operating, the integrated fan of that device draws air in through the inlet 122 into the return ducting section 121 and through the heating device 115 where the air that enters the heating device 115 is heated. The heated air is pushed through the connecting ducting section 123, the coil 116 and into the delivery ducting section 124 where it exits the ducting 120 through the outlets 130 and 131 of the branches 125 and 126.

[0096] The flow of air through the ducting 120 is continuous, by virtue of air being drawn into the return ducting section 121 and being discharged out of the delivery ducting section 124. The temperature inside the building space slowly increases as the air within the building space cycles through the heating device 115. Once the temperature within the building space reaches the desired temperature, adjustments to the fan speed, or the heat output of the heating device 115, or both can be made to maintain the temperature.

[0097] Importantly, the heated air that exits the heating device 115 is not subject to any cooling by passage or travel through the coil 116, because the cooling device is inoperative or disabled and so there is not flow of chilled water to the coil 116.

[0098] In the alternative, when the temperature within the building space 112 is to be cooled, then the heating device 115 is rendered inoperative or is disabled, but the fan is operated. This causes air to flow through the ducting 120 in the same manner as during the heating cycle and thus air flows through the heating device 115 and the coil 116 as described above. However, in order for a cooling function to take place, the chiller 117 supplies chilled water through the delivery conduit 128 to the coil 116 and air that is delivered into the coil 116 via the fan of the heating device 115 is cooled for discharge into the building space 112 via the delivery ducting section 124. Again, the air within the building space 112 is cycled through the ducting 120 by the fan of the heating device 115 until such time as the temperature within the building space 112 reaches the set or desired cooled temperature. Once that temperature has been reached, the temperature of the chilled water can be adjusted, as can the flow of air through the coil 16 to maintain the cooled temperature.

[0099] It has been established that the system of the invention, such as illustrated in FIG. 4, can provide rapid initial temperature reduction within a building space. Testing has been conducted to compare a system employing a conventional refrigerated air-conditioning unit to a unit according to the invention in which a water chiller that was about 40% smaller in terms of kW output compared to the conventional refrigerated air-conditioning unit, was installed. The results of that testing are illustrated in FIG. 5 and show that temperature cooling from an initial temperature of 31 C. to a lower temperature of 26 C. occurred more quickly and at a lower energy output in the system according to the invention as compared to a system incorporating a conventional refrigerated air-conditioning unit.

[0100] The attached table of FIG. 5 gives the actual testing data of a rudimentary test that the applicant has undertaken and compares a conventional air-conditioning unit known as a 12 kW air-conditioner to the 7 kW unit referred to above. The table of FIG. 5 shows that use of the water chiller was able to reduce the building space temperature from 31 to 26 within 3 minutes. That compared to 6.1 minutes for the refrigerated air-conditioning unit. Moreover, the water chiller had an energy usage of 0.17 kW/h as compared to the air-conditioning unit power usage of 0.37 kW/h.

[0101] The testing of the table in FIG. 5 was conducted with the water chiller 117 being pre-cooled which provided very fast initial cooling.

[0102] In relation to heating, the systems according to the invention can use heating devices which are already in use in heating systems for domestic dwellings and commercial buildings and it is expected that the heating capacity of a system according to the invention will be in line with the heating capacity of units already in existence.

[0103] The heating and cooling system 110 is expected to provide the significant advantages as stated earlier herein in relation to improved energy efficiency and lower running costs, reduced capital cost, reduced maintenance cost environmental benefits.

[0104] Where any or all of the terms comprise, comprises, comprised or comprising are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.

[0105] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.