GB2356451A

GB2356451A - Air heating means for a simulated solid fuel fire

Info

Publication number: GB2356451A
Application number: GB9919970A
Authority: GB
Inventors: Richard Colley; Arthur PURTON
Original assignee: BURCO DEAN APPLIANCES Ltd
Current assignee: BURCO DEAN APPLIANCES Ltd
Priority date: 1999-08-24
Filing date: 1999-08-24
Publication date: 2001-05-23
Anticipated expiration: 2019-08-24
Also published as: GB2356451B; GB9919970D0

Abstract

Air is heated in a simulated solid fuel fire by a primary air heater of a first type and a secondary air heater of a second type which is operable independently of the primary air heater. The primary air heater may comprise a heat exchanger (5) forming part of the room central heating system, and a fan (6). The secondary air heater may comprise an electric fan heater (9) positioned in the canopy (4) overlying the solid fuel facade (3) of the fire. The electric fan heater may accordingly be operated when the central heating system has been turned off, or in addition to the central heating system to supply extra heat.

Description

2356451 A HEATING UNIT The present invention relates to a heating unit and

particularly, but not exclusively, to a domestic heating unit or "fire".

Although central heating is installed almost universally in domestic properties there is still a great demand for floor standing heating units, or "fires", both to supplement the local heat output of a central heating system and also to provide an attractive focal point for a living area. For instance, solid fuel burning fires are still in wide use and "living flame" gas fires which simulate coal or log burning fires have become very popular. A disadvantage with such real fuel burning fires is that a chimney or other flue is required for extracting fumes and these are not always present where a fire may be desired, particularly in modem homes.

One possible solution to the above problem is provided by the heating unit disclosed in British Patent No. 2083903. This is floor standing unit which may be incorporated into a conventional central heating system. The unit includes a decorative fagade which simulates a solid fuel burning fire but the heat is actually supplied from a water to air heat exchanger designed to receive hot water from a central heating system in much the same way as an ordinary radiator. The heat exchanger is housed in the base of the unit and an electrically powered fan is provided to draw air into the unit and blow it over the heat exchanger and through an outlet located in the front of the unit to simulate the radiating effect of a real fire. The heating unit may be installed at any point in the central heating system and does not require a chimney or a flue.

The heating unit described above works well and has proved very popular. It does however have a shortcoming in that it only operates when the central heating system is switched on, which is not always desirable.

It is an object of the present invention to obviate or mitigate the above disadvantages.

According to the present invention there is provided a heating unit comprising a primary air heater of a first type and a secondary air heater of a second type different from said first type, wherein said secondary air heater is operable independently of said primary air heater.

2 A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. I is a schematic front view of a heater in accordance with the present invention; Fig. I a is an illustration of the control panel of the heater of Fig. I and; Fig. 2 is a schematic cross-section through the heater of Fig. 1.

Referring to the drawings, the illustrated heater is designed as a domestic "fire". It is suitable for installation in fireplaces (but does not require a chimney or flue) as a focal point of a living area. The illustrated heater comprises a floor standing unit I including a lower heat exchanger housing 2 above which is located a fagade 3 which simulates a log burning fire and which is covered by a canopy 4 which mimics that conventionally included in real ftiel burning fires to channel the fumes to a flue or chimney.

The housing portion 2 has a front grill 2a behind which is located a hot water convector heat exchanger 5 assisted by a fan 6. The heat exchanger 5 may for instance be a heating coil such as that described in British Patent No. 2083903 mentioned above, or a finned radiator arrangement. Other possible arrangements will be apparent to the skilled person. The electric fan 6 is located behind the heat exchanger 5 and operates to draw relatively cool air into the unit 1 through an inlet 8 located at an upper rear portion of the unit I and blow the air out through the heat exchanger 5 and the front grill 2a (thereby simulating the radiating effect of a real fire).

The decorative fagade 3 may be of any conventional form for example comprising simulated logs which are lit by a varying or "flickering" light source. The light source may for instance be provided by coloured light bulbs which illuminate the logs through rotating vanes (which might for example be driven by electric motors or be powered by heat rising from the light bulbs). Other forms of decorative fagade (which will generally be designed to simulate a real fire) could of course be used, although this is not essential to the operation of the invention.

The above-described features of the heater are essentially known. Where the heater in accordance with the present invention differs from the prior art is in the provision of a secondary heat source, namely an electric fan heater 9, mounted under

3 the canopy 4 in front of a grill 10. In this example the electric fan heater is a 1.5Kw unit comprising a fan 9a and a resistance heating element 9b.

Provision of the electric fan heater 9 overcomes disadvantages with the prior art mentioned above by providing a heat source which may be operated when the central heating system is not on and the heat exchanger 5 is thus not ftinctioning. In addition, the electric fan heater 9 may be operated together with the heat exchanger 5 to boost the heat output of the unit. This will be useful both in particularly cold circumstances and also to provide instantaneous output whilst the normal central heating system is warming up (for instance, the heater will generally include a low thermostat to prevent operation of the heat exchanger fan 6 until the heat exchanger has warmed up so that cold air will not be blown out of the fire when hot air is required).

Since the electric fan heater 9 is hidden behind the canopy 4 it does not detract from the appearance of the unit. Furthermore, positioning the electric fan heater 9 so that air is blown at a downwards angle over the fuel effect fagade 3 ensures that the hot air blown out by the fan simulates the radiating effect of a real fire.

Further details of operation of the heater will be described with reference to Figure I a which illustrates the unit's control panel 11, which is located on the lefthand side of the unit and is thus not visible in Figure 1. The control panel comprises top and bottom rotary knobs 12 and 13 and a two position on/off rocker switch 14.

The top rotary knob 12 has four possible positions which in rotating sequence are: a first "off' position; a second position in which the flame effect feature of the fagade 3 is activated; a third position in which the electric fan heater 9 is activated at a low heat setting; and a fourth position in which the electric fan heater 9 is activated at a high heat setting. The rocker switch 14 switches the heat exchanger fan 6 on and off and the lower rotary knob 13 controls the speed of the heat exchanger fan 6 which will typically have low, medium, and high settings.

The heat exchanger 5 and fan 6 may operate with or without the flame simulating feature. As mentioned above, a low thermostat is preferably included in the control circuitry to ensure that the fan 6 will not operate until the heat exchanger 5 has warmed up so that cold air will not be blown out of the unit. Varying the speed of the heat exchanger fan 6 effectively varies the heat output.

4 Since operation of the electric fan heater 9 is controlled by the other rotary knob, i.e. the knob 12, the electric heating fan may be turned on either together with the heat exchanger fan, or on its own when the heat exchanger is not operating. In the illustrated embodiment the fan heater has two possible heat output levels although of course in other embodiments more or less than two levels may be provided. With the control arrangement described, it is not possible to have the fan heater on unless the flame effect feature is also turned on. This is useful in providing a visual indication that the electric fan heater is on to reduce the likelihood of the fan heater being left on inadvertently.

In summary, the heater in accordance with the present invention has all the advantages of the heating unit disclosed in UK Patent No. 2083903 but has the additional advantage of providing a heat source that may be operated independently of a central heating system or together with a central heating system to boost the heat output from the heat exchanger.

Clearly many modifications can be made to the detail of the heater unit described above without departing from the present invention as set forth in the appended claims, such modifications will be readily apparent to the appropriately skilled person.

Claims

1. A heating unit comprising a primary air heater of a first type and a secondary air heater of a second type different from said first type, wherein said secondary air heater is operable independently of said primary air heater.

2. A heating unit according to claim 1, wherein the primary and secondary air heaters have different heat sources.

3. A heating unit according to claim 1 or claim 2, wherein the primary air heater comprises a heat exchanger for receiving a heated medium from a central heating boiler.

4. A heating unit according to claim 3, wherein the heated medium is hot water.

5. A heating unit according to claim 3 or claim 4, further comprising a fan for blowing air over the heat exchanger.

6. A heating unit according to claim 5, wherein the heat exchanger and the fan are housed within a housing which has an inlet for the passage of air into the housing and an outlet for the passage of air from the housing such that the fan causes a flow of air from the inlet to the outlet via the heat exchanger.

7. A heating unit according to any preceding claim, wherein the secondary air heater comprises an electric heating element.

8. A heating unit according to claim 7, wherein the electric heating element is a resistance heating element.

9. A heating unit according to claim 7 or claim 8, wherein the secondary air heater comprises a fan for blowing air over the heating element.

6

10. A heating unit according to claim 9 when dependent from claim 6, wherein the fan is arranged to cause air to flow from said inlet to a secondary outlet.

11. A heating unit according to claim 10, wherein the heat exchanger is located in a lower portion of said housing, above which the housing is provided with an outwardly-facing decorative portion simulating a burning solid-fuel fire, and the secondary air heater is located within a canopy which is positioned above said decorative portion.

12. A heating unit according to claim 11, wherein the secondary air heater outputs a flow of heated air in a direction having a downward component directed across said outwardly-facing decorative portion.

13. A heating unit substantially as hereinbefore described, with reference to the accompanying drawings.