AN EVAPORATOR UNIT FOR AN AIR CONDITIONING SYSTEM

Abstract

An evaporator unit for an air conditioning system (1), the unit comprising an evaporator coil (7), a sensor (12) in to detect the liquid level in a reservoir and a pump for pumping condensate from the housing. At least one UV LED (6,8) is arranged to radiate light onto the evaporator coil (7) and/or the sensor (12). An LED driver (13) supplies electrical power to the LEDs. A single electrical power connection (14) is connectable to a mains power source to supply mains power to the pump; wherein the LED driver (13) is connected to the electrical power connection supplying power to the pump.

Claims

1. An evaporator unit for an air conditioning system, the unit comprising a housing; an evaporator coil; an airflow path defined through the housing from an air inlet to an air outlet and passing over the evaporator coil; a reservoir for collecting condensate form the air passing over the evaporator coil; a sensor in the reservoir to detect the liquid level in the reservoir; a pump for pumping condensate from the housing; at least one UV light emitting diode (LED) mounted in the housing and arranged to radiate light onto the evaporator coil and/or the sensor; an LED driver to supply electrical power to the LEDs; a single electrical power connection connectable to a mains power source to supply mains power to the pump; wherein the LED driver is connected to the electrical power connection supplying power to the pump.

2. An evaporator unit for an air conditioning system according to claim 1, wherein the at least one LED and LED driver are removably attached within the housing and the electrical connection from the LED driver to the electrical power connection supply power to the pump is in the form of a removable plug which plugs into a socket associated with the electrical power connection supplying power to the pump.

3. An evaporator unit for an air conditioning system according to claim 1 or claim 2, wherein the LED emits light with a wavelength of from 100 to 280 nm.

4. An evaporator unit for an air conditioning system according to claim 1, wherein the LED emits light with a wavelength of from 200 to 280 nm.

5. An evaporator unit for an air conditioning system according to claim 1, wherein the LEDs are arranged to radiate light onto the evaporator coil and are provided in an adhesive strip.

6. An evaporator unit for an air conditioning system, the unit comprising a housing; an evaporator coil; an airflow path defined through the housing from an air inlet to an air outlet and passing over the evaporator coil; a reservoir for collecting condensate form the air passing over the evaporator coil; a sensor in the reservoir to detect the liquid level in the reservoir; a pump for pumping condensate from the housing; and at least one UV LED positioned to radiate onto the sensor.

7. An evaporator unit according to claim 6, further comprising a sensor module in which the sensor and UV LED are mounted, such that, in use, the light from the UV LED is incident on the sensor.

8. An evaporator unit according to claim 7, wherein the sensor module is mounted in a lid of the reservoir.

9. An evaporator unit according to claim 7, wherein the sensor module has a power lead with a plug at the end furthest from the module.

10. An air conditioning system comprising an evaporator unit according to claim 7.

Description

[0019] An example of an evaporator unit in accordance with the present invention will now be described with reference to the accompanying drawings, in which:

[0020] FIG. 1 is a schematic front view of a known unit with LEDs fitted;

[0021] FIG. 2 is a similar view showing a unit according to the present invention;

[0022] FIG. 3 is a schematic drawing of a conventional power supply;

[0023] FIG. 4 is a similar view of the power supply according to the present invention;

[0024] FIG. 5 is a perspective view of a reservoir for use in the unit;

[0025] FIG. 6 is a plan view of the reservoir;

[0026] FIG. 6A is a cross section through line A-A in FIG. 6;

[0027] FIG. 7 is a side view of a sensor module used in the reservoir; and

[0028] FIG. 8 is a top view of the sensor module.

[0029] The evaporator unit, shown in FIG. 1 is well known in the art and is designed to be mounted on an internal wall of the room. This connects to a compressor unit external of the building to create a refrigeration circuit as is well known in the art. The invention may equally be applied to a ceiling or floor mounted unit or a freestanding unit.

[0030] The unit comprises a housing 1 which is mountable to a wall and has a duct 2 to provide external connection for an air intake, the pipe (not shown) for the discharge of condensate and a 230 volt mains power supply connected to the pump 3. The pump is configured to pump condensate from a reservoir 4 once the level exceeds a predetermined amount.

[0031] The conventional unit has been fitted with a first array 6 of the UV-C LEDs arranged above an evaporator coil 7 and a second array 8 arranged below the evaporator coil 7. These are supplied on adhesive strips that are adhered in place within the housing.

[0032] Preferably the UV LED emits light with a wavelength of from 100 to 280 nm which is the germicidal part of the spectrum. More preferable the LED emits light with a wavelength of from 200 to 280 nm, as this is the more effective part of the germicidal spectrum. This is the UV-C part of the spectrum (although some of the emitted light may have a wavelength outside of that range).

[0033] The wiring for this conventional unit is shown in FIG. 3. As shown, the pump 3 and LED driver 5 have their own separate 230 volt power supplies. The first power supply 10 supplies the pump via live 10A, earth 10B and neutral 10C lines. The second power supply 11 supplies power to the LED driver 5 via live 11A, earth 11B, and neutral 11C lines. This second power supply needs to be installed subsequently by an electrician.

[0034] The LED driver 5 supplies power to the LED strips 6, 8, while the pump receives signals form a sensor 12 to control the flow of the condensate from the reservoir.

[0035] As shown in FIG. 2, the present invention uses the same basic set up of the unit. One of the strengths of the invention is that it can readily be incorporated into an existing unit. Rather than requiring the fitting of a second 230 volt power supply, the unit now uses the existing power supply as the LED driver is combined into the same unit 13 as the pump. As shown in FIG. 4, the two power supplies 10, 11 are replaced by a single power supply 14, having live 14A, earth 14B, and neutral 14C lines. In practice, the power supply for the LED driver is provided with a plug which plugs into a corresponding socket in the pump housing or elsewhere to complete the power supply to the LEDs 6, 8.

[0036] The unit may be sold without the LED strips 6, 8 in place. These can be fitted either by an air conditioning engineer at the time of installation, or can be fitted later. This simply requires the LED strips to be fixed in place, for example, using an adhesive mounting and the LED driver to be plugged into the socket. Alternatively, the LED strips and driver may be preinstalled in the unit prior to installation.

[0037] In either event, the unit can be installed by an air conditioning engineer without the involvement of the electrician.

[0038] The reservoir 4 and sensor 12 are shown in greater detail in FIGS. 5 to 8.

[0039] The reservoir comprises a tank 20 closed by a lid 21. A number of components are mounted in the lid 21.

[0040] This includes a sensor module 23 comprising a capacitive sensor 24 as disclosed in WO2020/120971 and a UVLED 25 mounted in the module next to the capacitive sensor. The sensor may alternatively be a thermistor or float switch. The emitted light 26 is depicted schematically in FIGS. 6A and 7. In practice this is emitted with a beam angle of 120 and will therefore impinge on most of the sensor and the bottom of the tank 20.

[0041] This serves two purposes. Firstly, it will keep the sensor 24 clean. Secondly, it will reduce or avoid a build up of sludge and bacteria in the tank 20. The bottom of the tank can be damp and cold which leads to slime building up when cold, and that can block a pump. Also, the slime dries out into flaky matter floating about in the condensate which again can block the pump.

[0042] Leading from the sensor module is a flex 27 via which power is transmitted at low voltage to the sensor 24 and UVLED 26. The flex 27 terminates at a plug 28. This is plugged into a socket in the pump housing as described above. The pump housing may have two sockets if separate UVLEDS are also provided for the coil as described above.

[0043] The sensor module 24 is therefore very easy to install, making is economical to introduce the UVLED into an area where it has not previously been provided, thereby providing the above advantages.

[0044] The tank 20 has a pair of inlets 29 via which condensate enters the tank 20, only one of which is used in any given application while the other is capped. Similarly there are a pair of alternative outlets 30 out of which the condensate is pumped by pump 3 to a drain when the level reaches an upper limit as detected by the sensor 12. The presence of two inlets 29 and outlets 30 allows the reservoir to be fitted into various different housing configurations. A vent 31 is provided in the lid.