Air displacement device for oven

Abstract

An air displacement device 200 deflects an air flow from a fan (108, fig 3A) of an oven (100, fig 3A) towards a top side (104, fig 3A) of the oven, and displaces air in the interior volume of the oven to reduce a volume of air to be heated. The air displacement device may comprise a body portion 210 and a ramp portion 220, with a lip 240 at a lower end of the ramp portion and a deflector portion 230 connected to the body portion. One or more fins 218, 219, 228, 229 may be disposed on a top side of the body portion, and / or on a ramp slope side of the ramp portion, to guide the air flow towards a centre plane of the device. A method of using the air displacement device comprises disposing the device on a bottom of an oven and operating the oven.

Description

Field of disclosure The present disclosure relates to a device for displacing air in an oven. Background Ovens for heating food function by heating air within an interior volume of the oven to a selected target temperature. Food is placed within the oven and the air in the interior volume heats the food by conduction e.g. contact between the air and the food transfers heat from the air to the food. Reducing the time taken for an oven to reach a selected target temperature may increase the efficiency of the oven and / or the amount of time the oven is needed to be operated to cook food. Accordingly, reducing the time taken for an oven to reach a selected target temperature may reduce total energy consumption of the oven and / or the cost of operating the oven to cook food. Summary The present invention is defined by the appended independent claims. Optional features are set out in the dependent claims. An aspect of the disclosure provides an air displacement device, for displacing air in an oven, the air displacement device configured to: deflect an air flow from a fan of the oven towards a top side of the oven; and, displace air in the interior volume of the oven to reduce a volume of air to be heated in an interior volume of the oven. Advantageously, the air displacement device reduces the amount of air to be heated in the interior volume of the oven which may reduce the time taken to heat the air in the interior volume of the oven to a target temperature and / or reduce the total energy required to heat air in the oven to the target temperature and / or reduce the total energy required to maintain air in the oven at the target temperature. The air displacement device may comprise a body portion configured to displace air in the interior volume of the oven to reduce the volume of air to be heated in the interior volume of the oven. The air displacement device may comprise a ramp portion connected to the body portion, wherein the ramp portion is configured to deflect an air flow from the fan of the oven towards a top side of the oven e.g. to deflect the air flow towards a centre of the oven. The ramp portion may be configured to guide an air flow from a fan of the oven along the ramp portion from a lower edge of the ramp portion to an upper edge of the ramp portion. The ramp portion may be configured to reflect an air flow from a fan of the oven away from a ramp slope surface of the ramp portion towards a top side of the oven e.g. to deflect the air flow towards a centre of the oven. The air displacement device may comprise a lip disposed at a lower end of the ramp portion, wherein the lip is configured to prevent liquids flowing down the ramp slope surface from flowing off the air displacement device. The air displacement device may comprise a deflector portion connected to the body portion, wherein the deflector portion is configured to deflect an air flow from a fan of the oven towards a top side of the oven. The deflector portion may be configured to induce circular motion of an air flow from a fan of the oven. The ramp portion may be connected to the body portion at a back end of the body portion and the heat deflector portion may be connected at a front end of the body portion wherein the back end of the body portion is opposite the front end of the body portion. The air displacement device may be configured to deflect air blown from a fan of the oven from a lower part of the oven to a higher part of the oven wherein: the ramp portion may be configured to guide air blown from a fan of the oven along the ramp portion from a lower edge of the ramp portion to an upper edge of the ramp portion so that an air flow is provided across the body portion from the back end of the body portion towards the front end of the body portion; and, the deflector portion may be configured to deflect the airflow across the body portion upwards away from the air displacement device. The air displacement device may comprise one or more body fins disposed on a body top side of the body portion wherein each of the one or more body fins is configured to deflect air towards a centre plane of the air displacement device wherein the centre plane is perpendicular to the body top side. Preferably a first body fin is provided disposed between a body first side and a centre plane of the air displacement device and a second body fin is provided disposed between a body second side and a centre plane of the air displacement device. The air displacement device may comprise a body fin disposed on a body top side of the body portion wherein the body fin is configured to deflect air (e.g. an airflow provided by a fan of an oven) towards a centre plane of the air displacement device wherein the centre plane is perpendicular to the body top side. The air displacement device may comprise a plurality of body fins disposed on a body top side of the body portion wherein each of the body fins is configured to deflect air (e.g. an air flow provided by a fan of an oven) towards a centre plane of the air displacement device wherein the centre plane is perpendicular to the body top side. When air touches a side of the oven, heat may be lost from the air in the oven to the side (e.g. by conduction). Advantageously, body fins may prevent or reduce the amount of air touching the sides of the oven (and therefore the heat loss) and thereby may increase the efficiency of the oven. The air displacement device may comprise one or more ramp fins disposed on a ramp slope side of the ramp portion wherein each of the one or more ramp fins is configured to deflect air towards a centre plane of the air displacement device wherein the centre plane is perpendicular to the ramp slope side. Preferably a first ramp fin is provided disposed between a ramp first side and a centre plane of the air displacement device and a second ramp fin is provided disposed between a ramp second side and a centre plane of the air displacement device. The air displacement device may comprise a ramp fin disposed on a ramp slope side of the ramp portion wherein the ramp fin is configured to deflect air (e.g. an air flow provided by a fan of an oven) towards a centre plane of the air displacement device wherein the centre plane is perpendicular to the ramp slope side. The air displacement device may comprise a plurality of ramp fins disposed on a ramp slope side of the ramp portion wherein each of the ramp fins is configured to deflect air (e.g. an air flow provided by a fan of an oven) towards a centre plane of the air displacement device wherein the centre plane is perpendicular to the ramp slope side. When air touches a side of the oven, heat may be lost from the air in the oven to the side (e.g. by conduction). Advantageously, ramp fins may prevent or reduce the amount of air touching the sides of the oven (and therefore the heat loss) and thereby may increase the efficiency of the oven. The air displacement device may comprise a heat resistant coating disposed over at least part of the air displacement device. An aspect of the disclosure provides a method of use of the air displacement device of any of the preceding claims, the method comprising: disposing the air displacement device on the bottom side of an oven; operating the oven to provide an air flow from a fan of the oven. Recipes typically do not instruct food to be placed below the middle of the oven (e.g. closer to the bottom side than to the top side). Therefore, it is not a disadvantage that the bottom of the oven (e.g. the part of the oven closer to the bottom side than the top side) does not reach the target temperature. However, the bottom of the oven is still heated up (just not to the target temperature) and so the energy used to heat the bottom of the oven is essentially superfluous (e.g. is not used in cooking). As the bottom of the oven does not reach the target temperature and the bottom of the oven is not typically used for cooking, the air displacement device may be disposed on the bottom side 103 of the oven to deflect an air flow from a fan of the oven towards a top side of the oven and displace air in the interior volume of the oven to reduce a volume of air to be heated in an interior volume of the oven. Advantageously, the air displacement device reduces the amount of air to be heated in the interior volume of the oven which may reduce the time taken to heat the air in the interior volume of the oven to a target temperature and / or reduce the total energy required to heat air in the oven to the target temperature and / or reduce the total energy required to maintain air in the oven at the target temperature. The method may comprise: disposing the air displacement device on the bottom side of the oven, wherein the ramp is disposed opposite the fan of the oven; operating the oven to provide an air flow from the fan of the oven towards the ramp portion of the air displacement device. The disclosure is described in relation to an oven with a fan (e.g. a fan assisted oven) however, it will be appreciated that one or more air flows will be present in an any type of oven (e.g. due to convection etc.) and that aspects of the disclosure may displace air in the interior volume of the oven to reduce a volume of air to be heated in an interior volume of the oven thereby increasing the efficiency of the oven. Brief description of drawings Figure 1A illustrates a schematic perspective view of an oven 100; Figure 1B illustrates a schematic plan side view of the oven 100; Figure 2A illustrates a perspective view of an air displacement device 200; Figure 2B illustrates a schematic plan side view of the air displacement device 200; Figure 2C illustrates a schematic top plan view of the air displacement device 200; Figure 3A illustrates a schematic plan side view of the air displacement device 200 disposed within the oven 100; Figure 3B illustrates a schematic top plan view of the air displacement device 200 disposed within the oven 100 illustrated in Figure 3A; Figure 4 illustrates a graph 400 indicating oven temperature (y-axis) versus time (x-axis) for an oven without the air displacement device 200 disposed therein; Figure 5 illustrates a graph 500 indicating oven temperature (y-axis) versus time (x-axis) for an oven with the air displacement device 200 disposed therein; In the drawings like reference signs indicate like elements. Specific description Figure 1A illustrates a schematic perspective view of an oven 100; Figure 1B illustrates a schematic plan side view of the oven 100. The oven 100 comprises: a back side 101 comprising a vent 111; a front side 102; a bottom side 103; a top side 104; a first side 105; a second side 106; a heating element 107; and, a fan 108. The six sides 101 to 106 are arranged to provide a cuboid. The cuboid provided by the six sides 101 to 106 delimits an interior volume 109. The back side 101 is connected to the bottom side 103, the top side 104, the first side 105, and the second side 106. The front side 102 is connected to the bottom side 103, the top side 104, the first side 105, and the second side 106. The bottom side 103 is connected to the back side 101, the front side 102, the first side 105, and the second side 106. The top side 104 is connected to the back side 101, the front side 102, the first side 105, and the second side 106. The front side 102 is a door which is openable to provide access to the interior volume 109 e.g. the door 102 can be opened to permit items, such as food, to be placed within the interior volume 109. The heating element 107 and fan 108 are separated from the interior volume 109 by the back side 101 e.g. the back side 101 is disposed between the interior volume 109 and the heating element 107 and fan 108. The heating element 107 is configured to heat air close thereto e.g. the heating element 107 heats up in response to an input and heats air close to the heating element by conduction. The heating element 107 may be an ohmic wire configured to receive a current, wherein when the heating element receives the current (either alternating or direct) the wire heats up. The fan 108 is a fan (e.g. an axial fan) configured to provide an airflow 158. The fan 108 comprises blades which rotate about a rotational axis. When the blades rotate around the rotational axis and air flow is provided parallel to the rotational axis. In the example shown in Figure 1B, the rotational axis is parallel to the bottom side 103 and the top side 104. The vent 111 is disposed in the back side 101. The vent 111 is one or more holes configured to permit air to flow from the fan 108 to the interior volume 109. The air flow 158 provided by the fan 108 passes through the vent 111 into the interior volume. Air is heated by the heating element 107 and moved into the interior volume 109 by the fan 108. The air heated by the heating element 107 heats air in the interior volume (e.g. by conduction). The airflow provided by the fan is indicated by arrows 158. As illustrated in Figure 1B, in an empty oven (e.g. an oven with nothing disposed in the interior volume 109) the air flow 158 moves generally from the back side 101 of the oven to a front side 102 of the oven. The air flow 158 moves from the fan 108, through the vent 111 into the interior volume 109. Air is heated by the heating element 107 and moved into the interior volume 109 by the fan 108. The air flow spreads out in the interior volume 109 of the oven 100 to heat the air in the interior volume 109 (e.g. by conduction). In this manner air in the interior volume 109 is heated by the airflow 158. Often the whole interior volume of the oven is not required for cooking. For example the food placed in the oven has a volume much smaller than the interior volume 109. Therefore, the entirety of the interior volume 109 is not required for cooking food and it is unnecessary to heat all of the air in the interior volume 109. Figure 2A illustrates a perspective view of an air displacement device 200; Figure 2B illustrates a schematic plan side view of the air displacement device 200; Figure 2C illustrates a schematic top plan view of the air displacement device 200. The air displacement device 200 comprises: a body portion 210; a ramp portion 220; a deflector portion 230; a lip 240; a first body fin 218; a second body fin 219; a first ramp fin 228; and, a second ramp fin 229. The air displacement device 200 is configured to deflect air towards a top side 104 of the oven 100. The air displacement device 200 is configured to displace air in the interior volume of the oven 100 to reduce a volume of air to be heated in an interior volume 109 of the oven 100. The air displacement device 200 is a volume delimited by surfaces. The surfaces deflect an air flow provided from a fan 108 of the oven 100 towards a top side 104 of the oven 100. The volume of the air displacement device 200 displaces air in interior volume 109 of the oven 100 (e.g. the device reduces the amount of air that can fill the interior volume of the oven). The body portion 210 is configured to displace air in the interior volume 109 of the oven 100 to reduce the volume of air to be heated in the interior volume 109 of the oven 100. The body portion has a volume which displaces air from the interior volume 109 of the oven 100. The body portion 210 has a cuboid shape e.g. it is a rectangular prism. The ramp portion 220 has a wedge shape e.g. it may be a triangular prism, for example, an irregular triangular prism as illustrated in Figures 2A and 2B. The combination of the body portion 210 and the ramp portion 220 provides an element which is a trapezoidal prism. In the particular example shown in Figures 2A and 2B the combination of the body portion and the ramp portion is a right-angled trapezoidal prism. The body portion 210 comprises: a body bottom side 213; a body top side 214; a body first side 215; a body second side 216. The body front side 212 is connected to the body bottom side 213; the body first side 215 and the body second side 216. The body first side 215 is connected to the body bottom side 213 and the body top side 214. The body second side 216 is connected to the body bottom side 213 and the body top side 214. The body bottom side 213 is parallel to the body top side 214. The body bottom side 213 and the body top side 214 are separated by a height H. The body first side 215 is parallel to the body second side 216. The body portion 210 has a body back end 211 and a body front end 212. The body back end 211 is separated from the body front end 212 by the body top surface 214. The ramp portion 220 comprises: a ramp bottom side 223; a ramp slope side 227; a ramp first side 225; a ramp second side 226. The ramp bottom side 223 is connected to the ramp first side 225, the ramp second side 226, and the ramp slope side 227. The body portion 210 and the ramp portion 220 are connected. The ramp portion 220 is disposed at the body back end 211 of the body portion. The body bottom side 213 and the ramp bottom side 223 are contiguous and together form a device bottom side 203. The device bottom side 203 is a plane. The device bottom side 203 is configured to sit on a bottom side 103 of the oven 100. The body top side 214 and the ramp slope side 227 are contiguous and together form a device air flow surface. The device air flow surface is two rectangles joined obliquely at an edge of each rectangle. The air flow surface is configured to guide an air flow in the oven 100 (e.g. where the airflow is provided by the fan 108 of the oven 100) The body first side 215 and the ramp first side 225 are contiguous and together form a device first side 205. The device first side 205 is a plane. The body second side 216 and the ramp second side 226 are contiguous and together form a device second side 206. The device second side 206 is a plane. Figure 2C illustrates a centre plane 250 disposed parallel to and equidistantly from the device first side 205 and the device second side 206. The ramp portion 220 has a lower edge 222 and an upper edge 224. The lower edge 222 is adjacent (e.g. next to and in contact with) the device bottom surface 203. The upper edge 224 is adjacent (e.g. next to and in contact with) the body top surface 214. The upper end 224 has a height H above the body bottom side 203. The ramp slope surface 227 extends between the lower edge 222 and the upper edge 224. The ramp portion 220 is configured to deflect air towards a top side 104 of the oven 100. For example, from a lower part of the oven to a higher part of the oven e.g. from a first position to a second position wherein the first position is closer to the oven bottom side than the second position. The ramp portion 220 is configured to displace air in the interior volume 109 of the oven to reduce a volume of air to be heated in an interior volume 109 of the oven 100. The ramp portion 220 is configured to guide the airflow 158 from the fan 108 of the oven 100 along the ramp portion 220 from a lower edge 222 of the ramp portion 220 to an upper edge 224 of the ramp portion 220. For example, the ramp slope surface 227 is configured to guide the air flow 158 along the ramp slop surface 227 in a direction from the lower edge 222 to the upper edge 224. The ramp portion 220 is configured to reflect the air flow 158 from the fan 108 of the oven away from a ramp slope surface 227 of the ramp portion 220 towards a top side 104 of the oven 100. The first body fin 218 is disposed on the body portion 210. The first body fin 218 is disposed on the body top surface 214. The first body fin 218 is disposed between the body first side 215 and the centre plane 250. The first body fin 218 is a rectangular structure projecting from the body top surface 214. The first body fin 218 is disposed obliquely to the centre plane 250. The first body fin 218 is configured to deflect air towards the centre plane 250 of the air displacement device 200 wherein the centre plane is perpendicular to the body top side 214. The first body fin 218 is configured to deflect air towards the front end 212 of the body portion 210. The second body fin 219 is disposed on the body portion 210. The second body fin 219 is disposed on the body top surface 214. The second body fin 219 is disposed between the body second side 216 and the centre plane 250. The second body fin 219 is a rectangular structure projecting from the body top surface 214. The second body fin 219 is disposed obliquely to the centre plane 250. The second body fin 219 is configured to deflect air towards the centre plane 250 of the air displacement device 200 wherein the centre plane 250 is perpendicular to the body top side 214. The second body fin 219 is configured to deflect air towards the front end 212 of the body portion 210. The first ramp fin 228 is disposed on the ramp portion 220. The first ramp fin 228 is disposed on the ramp slope surface 227. The first ramp fin 228 is disposed between the ramp first side 225 and the centre plane 250. The first ramp fin 228 is a rectangular structure projecting from the ramp slope surface 227. The first ramp fin 228 is disposed obliquely to the centre plane 250. The first ramp fin 228 is configured to deflect air towards the centre plane 250 of the air displacement device 200 wherein the centre plane 250 is perpendicular to the ramp slope side 227. The first ramp fin 228 is configured to deflect air towards the upper edge 224 of the ramp portion 220. The second ramp fin 229 is disposed on the ramp portion 220. The second ramp fin 229 is disposed on the ramp slope surface 227. The second ramp fin 229 is disposed between the ramp second side 226 and the centre plane 250. The second ramp fin 229 is a rectangular structure projecting from the ramp slope surface 227. The second ramp fin 229 is disposed obliquely to the centre plane 250. The second ramp fin 229 is configured to deflect air towards the centre plane 250 of the air displacement device 200 wherein the centre plane 250 is perpendicular to the ramp slope side 227. The second ramp fin 229 is configured to deflect air towards the upper edge 224 of the ramp portion 220. The deflector portion 230 is connected to the body portion 210. The deflector portion 230 is disposed at the body front end 212 of the body portion 210. The deflector portion is disposed on the body top side 214. The deflector portion 230 is a curved surface extending from the body top side 214. The curved surface is contiguous to the body top surface 214. Moving from the back end 211 of the body portion 210 to the front end 212 of the body portion 210, a normal vector to the surface is perpendicular to the device bottom side 203 until reaching the deflector portion 230. Moving along the deflector portion in the same direction, the normal vector to the surface is initially perpendicular to the device bottom side 203 and then the angle between the normal vector and the device bottom side 203 decreases (e.g. monotonically) from 90° to 0°. The deflector portion 230 Is configured to deflect air from a lower part of the oven to a higher part of the oven The deflector portion 230 is configured to deflect the air flow 158 from the fan 108 of the oven 100 towards the top side 104 of the oven 100 e.g. from the bottom side 103 of the oven 100 toward a top side 104 of the oven 100. For example, from a lower part of the oven to a higher part of the oven e.g. from a first position to a second position wherein the first position is closer to the oven bottom side than the second position. The deflector portion 230 configured to induce circular motion of the airflow 158 from the fan 108 of the oven 100. The curved surface is shaped (e.g. it may have a lateral crosssection of a quarter circle) to induce circular motion. The lip 240 is connected to the lower edge 222 of the ramp portion 220. The lip 240 is a rectangular surface disposed perpendicular to the device bottom side 203. The lip may be disposed obliquely to the device bottom side 203. The lip 240 is configured to prevent liquids flowing down a ramp slope surface 227 from flowing off the air displacement device 200. Liquids from food disposed above the air displacement device 200 may drip onto the air displacement device but will not contact the oven because the liquid is caught by the lip 240. Advantageously the liquid will not contact the bottom side 103 of the oven 100 which may avoid the need to clean the liquid from the bottom side 103 of the oven 100. Figure 3A illustrates a schematic plan side view of the air displacement device 200 disposed within the oven 100; Figure 3B illustrates a schematic top plan view of the air displacement device 200 disposed within the oven 100 illustrated in Figure 3A. The ramp portion 220 is disposed proximal to the back side 101 of the oven 100 e.g. proximal and opposite the fan 108 of the oven 100. The deflector portion 230 is disposed proximal to the front side 102 of the oven 100 e.g. proximal and opposite (e.g. in front of) the oven door. The volume of the air displacement device 200 displaces the volume of air in the interior volume 109 of the oven 100. This reduces the volume of air to be heated in the interior volume of the oven e.g. by the heating element 107 and fan 108. The air displacement device 200 provides a guide for an air flow 158 provided by the fan 108 of the oven 100. The air displacement device 200 guides the air flow 158 along the ramp slope side 227 thereby guiding the air flow 158 away from the bottom side 103 of the oven 100. The air displacement device 200 guides the air flow 158 from the fan 108 to the deflector portion which guides the air flow away from the bottom side 103 of the oven 100. The fan 108 of the oven 100 provides airflow 158. A first airflow is 158A is directed onto the ramp portion 220. The ramp slope surface 227 guides the first air flow 158A upwards from the lower edge 222 towards the upper edge 224 to provide a second air flow 158B. Peripheral parts 158B’ of the second air flow 158B are deflected by the first and second ramp fins 228 and 229 towards the centre plane 250 and towards the upper edge 224. The ramp slope surface 227 provides a second air flow 158B becomes a third air flow 158C across the body top side 214. Peripheral parts of the third air flow 158C’ are deflected by the first and second body fins 218 and 219 towards the centre plane 250 and towards the deflector portion 230. The body top side 214 provides the third part of the air flow 158C to the deflector portion 230. The deflector portion 230 deflects the third part of the air flow 158C to provide a fourth air flow 158D towards the top side of the oven 104. The deflector portion 230 deflects the third air flow 158C to provide a fifth air flow 158E which has a circular motion within the oven. The air displacement device 200 comprises a heat-resistant coating. The heat-resistant coating prevents damage of the device due to the heat within the interior volume 109 of the oven 100. The oven 100 is a fan-assisted oven but it will be appreciated that the air displacement device 200 is suitable for use with other types of oven. The air displacement device may be a trapezoidal prism, for example, a right-angled trapezoidal prism as illustrated in Figures 2A and 2B. The ramp portion may be trapezoidal prism, for example, a right-angled trapezoidal prism as illustrated in Figures 2A and 2B. In such examples, the ramp portion may be connected to back side of the cuboidal body portion as described herein. Figure 4 illustrates a graph 400 indicating oven temperature (y-axis) versus time (x-axis) for an oven without the air displacement device 200 disposed therein. The oven was operated to heat the air in the interior volume to a target temperature of 200 °C from room temperature (approximately 25 °C). Data indicative of the temperature of the oven was obtained from a plurality of temperature sensors disposed in different locations in the oven. The data obtained from each of the temperature sensors has been plotted relative to the axes and joined in sequence to provide a curve. Each curve is indicative of the temperature at a given time recorded by each of the temperature sensors. A first group of curves 401 are indicative of the temperature data obtained by temperature sensors disposed at a top side 104 of the oven 100 and in a middle portion of the oven (e.g. at a position approximately equidistant between the bottom side 103 and the top side 104 of the oven 100). A second group of curves 402 are indicative of the temperature data obtained by temperature sensors disposed at a bottom side 103 of the oven 100. The first group of curves 401 and the second group of curves 402 all have the same trend. The temperature of the interior volume 109 of the oven 100 increases with time. The first group curves indicate that the temperature of the air in the interior volume increases linearly from room temperature to the target temperature. The first group of curves 401 plateau upon reaching the target temperature. The first group of curves 401 reach the target temperature in approximately 13 minutes. The second group of curves 402 plateau at a temperature below the target temperature (approximately 20 °C less than the target temperature). Figure 5 illustrates a graph 500 indicating oven temperature (y-axis) versus time (x-axis) for an oven 100 with the air displacement device 200 disposed therein. The oven 100 was operated to heat the air in the interior volume to a target temperature of 200 °C from room temperature (approximately 25 °C). Data indicative of the temperature of the oven was obtained from a plurality of temperature sensors disposed in different locations in the oven. The data obtained from each of the temperature sensors has been plotted relative to the axes and joined in sequence to provide a curve. Each curve is indicative of the temperature at a given time recorded by each of the temperature sensors. A third group of curves 501 are indicative of the temperature data obtained by temperature sensors disposed at a top side 104 of the oven 100 and in a middle portion of the oven (e.g. at a position approximately equidistant between the bottom side 103 and the top side 104 of the oven 100). A fourth group of curves 502 are indicative of the temperature data obtained by temperature sensors disposed at a bottom side 103 of the oven 100. The third group of curves 501 and the fourth group of curves 502 all have the same trend. The temperature of the interior volume 109 of the oven 100 increases with time. The third group of curves 501 indicate that the temperature of the air in the interior volume increases linearly from room temperature to the target temperature. The third group of curves 501 plateau upon reaching the target temperature. The third group of curves 501 reach the target temperature in approximately 10 minutes. The fourth group of curves 502 plateau at a temperature below the target temperature (approximately 101 °C less than the target temperature). Therefore, using the oven 100 with the air displacement device 200 reduces the time taken for the top part of the oven to reach the target temperature compared to using the oven 100 without the air displacement device 200. Recipes typically do not instruct food to be placed below the middle of the oven (e.g. closer to the bottom side than to the top side). Therefore, it is not a disadvantage that the bottom of the oven (e.g. the part of the oven closer to the bottom side than the top side) does not reach the target temperature. However, the bottom of the oven is still heated up (just not to the target temperature) and so the energy used to heat the bottom of the oven is essentially wasted (e.g. is not used in cooking). As the bottom of the of the oven does not reach the target temperature and the bottom of the oven is not typically used for cooking, the air displacement device 200 may be disposed on the bottom side 103 of the oven 100 to deflect an air flow from a fan of the oven towards a top side of the oven and displace air in the interior volume of the oven to reduce a volume of air to be heated in an interior volume of the oven. The centre of the oven may be defined as the point or region within an interior volume of the oven which is furthest from each of the sides of the oven. For example, the centre of the oven may be the point equidistant between: top and bottom sides of the oven; front and bottom sides of the oven; and, first and second sides of the oven Other examples and variations of the disclosure will be apparent to the skilled addressee in the context of the present disclosure.

Claims

1. An air displacement device, for displacing air in an oven, the air displacement device configured to:deflect an air flow from a fan of the oven towards a top side of the oven; and,5 displace air in an interior volume of the oven to reduce a volume of air to be heated in the interior volume of the oven;the air displacement device comprising:a body portion configured to displace air in the interior volume of the oven to reduce the volume of air to be heated in the interior volume of the oven;10 a ramp portion connected to the body portion, wherein the ramp portion is configured to deflect an air flow from the fan of the oven towards a top side of the oven;wherein the air displacement device comprises at least one of:one or more body fins disposed on a body top side of the body portion wherein each of the one or more body fins is configured to deflect air towards a 15 centre plane of the air displacement device wherein the centre plane is perpendicular to the body top side; and,one or more ramp fins disposed on a ramp slope side of the ramp portion wherein each of the one or more ramp fins is configured to deflect air towards a centre plane of the air displacement device wherein the centre plane is 20 perpendicular to the ramp slope side.

2. The air displacement device of claim 1, wherein:the ramp portion is configured to guide an airflow from a fan of the oven along the ramp portion from a lower edge of the ramp portion to an upper edge of the ramp portion.

253. The air displacement device of any of claims 1 to 2, wherein: the ramp portion is configured to reflect an air flow from a fan of the oven away from a ramp slope surface of the ramp portion towards a top side of the oven.30 4. The air displacement device of any of claims 1 to 3, comprising:a lip disposed at a lower end of the ramp portion, wherein the lip is configured to prevent liquids flowing down the ramp slope surface from flowing off the air displacement device.16 06 235. The air displacement device of any of the preceding claims, comprising:a deflector portion connected to the body portion, wherein the deflector portion is configured to deflect an air flow from a fan of the oven towards a top side of the oven.

56. The air displacement device of claim 5, wherein:the deflector portion is configured to induce circular motion of an air flow from a fan of the oven.10 7.     The air displacement device of claim 6, wherein:the ramp portion is connected to the body portion at a back end of the body portion and the deflector portion is connected at a front end of the body portion wherein the back end of the body portion is opposite the front end of the body portion.15 8. The air displacement device of claim 7 wherein:the air displacement device is configured to deflect air blown from a fan of the oven from a lower part of the oven to a higher part of the oven wherein:the ramp portion is configured to guide air blown from a fan of the oven along the ramp portion from a lower edge of the ramp portion to an upper edge of 20 the ramp portion so that an air flow is provided across the body portion from the back end of the body portion towards the front end of the body portion; and,the deflector portion is configured to deflect the air flow across the body portion upwards away from the air displacement device.25 9. The air displacement device of any of the preceding claims, comprising:a heat resistant coating disposed over at least part of the air displacement device.

10. A method of use of the air displacement device of any of the preceding claims, the method comprising:30 disposing the air displacement device on the bottom side of an oven;operating the oven to provide an air flow from a fan of the oven.

11. The method of claim 10 using the air displacement device of any of claims 1 to 9,(Nthe method comprising:disposing the air displacement device on the bottom side of the oven, wherein the ramp is disposed opposite the fan of the oven;operating the oven to provide an air flow from the fan of the oven towards the5 ramp portion of the air displacement device.

Images