Ventilation apparatus

Abstract

A ventilation apparatus (30, fig 1) comprises an air intake channel (38, fig 4) extending between an air intake inlet (46) and an air intake outlet 48, an air exhaust channel (40) extending between an air exhaust inlet 50 and an air exhaust outlet 52.The intake channel and the exhaust channel are separated from each other, and a heat recovery structure (42, fig 6) including at least one heat exchanger element 54 projects into each channel. The intake and exhaust channels separation may be via a wall 44 and the heat exchanger element(s) projects therethrough. The heat exchanger element may comprise a plurality of 2 to 3mm thick parallel plates spaced apart between 6mm and 10mm. The intake inlet and intake outlet may face orthogonal directions and / or the exhaust inlet and exhaust outlet may face orthogonal directions. The intake inlet and exhaust outlet may face opposite directions and the intake outlet and exhaust inlet may face the same direction. At least one of the inlets and outlets may include one or more moveable dampers (56a) or louvres (56b) adjustable in response to sensor information. The apparatus may pass through a building wall and operates passively or actively using a fan.

Description

The invention relates to a ventilation apparatus with a passive heat recovery mechanism, particularly a passive or natural ventilation apparatus, and a building comprising such a ventilation apparatus. The invention is designed for use in residential, commercial, and industrial buildings. Buildings require ventilation to provide fresh air for occupants and to expel stale air, which can contain pollutants and excess humidity. It is known to use ventilation equipment to improve air quality inside a building. According to a first aspect of the invention, there is provided a ventilation apparatus comprising: an air intake channel extending between an air intake inlet and an air intake outlet; an air exhaust channel extending between an air exhaust inlet and an air exhaust outlet, wherein the air intake channel and the air exhaust channel are separated from each other; and a passive heat recovery structure including at least one heat exchanger element arranged to project into the air intake channel and the air exhaust channel. The ventilation apparatus is designed for installation in a building. The air intake inlet and the air exhaust outlet are directly connected to an exterior environment of the building. The air intake outlet and the air exhaust inlet are directly connected to an interior environment of the building. This allows air to enter the building through the air intake channel and exit the building through the air exhaust channel in windy conditions, creating a pressure differential between the air intake channel and the air exhaust channel. Preferably the ventilation apparatus is configured as a passive or natural ventilation apparatus. It will be appreciated that the air intake channel may function as an air exhaust channel while the air exhaust channel may function as an air intake channel depending on the wind conditions (such as wind direction relative to the air intake inlet and the air exhaust outlet) at the time. The passive heat recovery structure provides a medium for heat exchange between the air flowing in the air exhaust channel and the air flowing in the air intake channel. This allows the use of waste heat to increase the temperature of the air entering the building which in turn reduces the ventilation heat loss and building's energy consumption for heating purposes. Furthermore, a ventilation apparatus comprising such a passive heat recovery structure is easier and cheaper to install and operate than a ventilation apparatus comprising an active heat recovery device requiring wiring and power supply or than a ventilation apparatus comprising a fan-driven device such as seen in mechanical ventilation with heat recovery (MVHR) systems. This is particularly useful for multi-storey or multi-room buildings where other forms of ventilation are not feasible, as it eliminates the need for complex and expensive ductwork, thus reducing installation costs. The invention is suitable for rooms or spaces that are not allowed to have cross-flow ventilation or openings on opposite sides of the room or space, such as rooms with only one outdoor-facing wall or single-aspect rooms. Further, the invention can operate as a single integrated unit without relying on other ventilation devices or techniques. The configuration of the invention therefore results in a ventilation apparatus with waste heat recovery capabilities, thereby providing a sustainable and energy-efficient building solution that improves maintenance of good indoor air quality and comfortable temperature with a more compact, discreet and easily installed system. The air intake channel, the air exhaust channel and the passive heat recovery structure may be built as an integrated unit, which makes it easier to install in buildings. For example, the ventilation apparatus may include a housing that includes both the air intake channel and the air exhaust channel, wherein the passive heat recovery structure may be arranged in the housing. This allows the ventilation apparatus to be built as a self-contained unit with its own air intake channel, air exhaust channel and passive heat recovery structure. Each self-contained unit can be designated as a module in a modular system in which one or more modules can be added or removed to suit changing ventilation needs or building expansions. This is beneficial for buildings with varying occupancy levels or buildings that undergo frequent layout changes, such as modular homes or temporary structures. The configuration of the or each heat exchanger element may vary. In embodiments of the invention, the or each heat exchanger element may be configured as a cross-flow heat exchanger element. In further embodiments of the invention, the or each heat exchanger element may be configured as a static heat exchanger element. That is to say, the or each static heat exchanger element is fixed, i.e. immovable. By removing the need for actively moving parts in the passive heat recovery structure, this not only reduces the energy consumption of the ventilation apparatus but also reduces the maintenance requirements of the ventilation apparatus. In still further embodiments of the invention, the air intake channel and the air exhaust channel may be separated by a wall. The or each heat exchanger element may extend through the wall so as to project into the air intake channel and the air exhaust channel. In such embodiments, the wall may be made of a thermally conductive material. This provides another medium of heat exchange between the air flowing in the air exhaust channel and the air flowing in the air intake channel. The or each heat exchanger element may be arranged to extend from the air intake inlet to the air intake outlet within the air intake channel. The or each heat exchanger element may be arranged to extend from the air exhaust inlet to the air exhaust outlet within the air exhaust channel. This improves the efficiency of heat transfer between the or each heat exchanger element and the air flowing inside the air intake channel and / or the air exhaust channel. The shape of the or each heat exchanger element may vary depending on the heat exchange requirements of the ventilation apparatus. The passive heat recovery structure may include a plurality of heat exchanger elements arranged to project into the air intake channel and the air exhaust channel. The number of heat exchanger elements in the passive heat recovery structure may vary depending on its heat transfer requirements. In a preferred embodiment of the invention, the or each heat exchanger element may be configured as a plate element. This provides a larger surface area for heat transfer between the or each heat exchanger element and the air flowing inside the air intake channel and / or the air exhaust channel. The heat exchanger elements may be configured as plate elements that are arranged in parallel between the air intake inlet and the air intake outlet and / or between the air exhaust inlet and the air exhaust outlet. The heat exchanger elements may be configured as plate elements spaced apart from each other. For example, the plate elements may be spaced part by a gap of 6mm to 10mm. A thickness of the or each plate element may vary. For example, the or each plate element may have a thickness of 3mm. The configuration of the ventilation apparatus may vary. The air intake inlet and the air intake outlet may be arranged to face orthogonal directions. The air exhaust inlet and the air exhaust outlet may be arranged to face orthogonal directions. The air intake inlet and the air exhaust outlet may be arranged to face opposite directions. The air intake outlet and the air exhaust inlet may be arranged to face the same direction. At least one of the air intake inlet, the air intake outlet, the air exhaust inlet and the air exhaust outlet may include one or more air dampers or louvres. The orientation of the or each air damper or louvre relative to the corresponding air intake inlet, air intake outlet, air exhaust inlet or air exhaust outlet may vary. Preferably the or each air damper or louvre of the air intake inlet and / or the air exhaust outlet may be arranged to be at an angle of 20 degrees to 35 degrees with respect to a horizontal plane, and / or the or each air damper or louvre of the air intake outlet and / or the air exhaust inlet may be arranged to be at an angle of 20 degrees to 50 degrees with respect to a vertical plane. Such orientation of the or each air damper or louvre may be preferably set during a ventilation mode or operation of the ventilation apparatus. The or each air damper or louvre may be fixed, i.e. immovable. It will be understood that the or each fixed air damper or louvre may be provided in all, some or one of the air intake inlet, the air intake outlet, the air exhaust inlet and the air exhaust outlet. Alternatively the or each air damper or louvre may be movable to adjust its orientation. Changing an orientation of the or each air damper or louvre changes airflow rate and speed inside the air intake channel and / or the air exhaust channel, as well as rate of heat transfer to / from the passive heat recovery structure. It will be understood that the or each movable air damper or louvre may be provided in all, some or one of the air intake inlet, the air intake outlet, the air exhaust inlet and the air exhaust outlet. At least one of the air intake inlet, the air intake outlet, the air exhaust inlet and the air exhaust outlet may be completely closed or shut off, for example during very cold or unfavourable weather conditions. This may be carried out by adjusting the orientation of the or each damper to fully close at least one of the air intake inlet, the air intake outlet, the air exhaust inlet and the air exhaust outlet. The or each air damper or louvre may be manually movable. Additionally or alternatively the ventilation apparatus may include a controller programmed to adjust an orientation of the or each air damper or louvre. In embodiments of the invention, the ventilation apparatus may include a controller programmed to dynamically adjust an orientation of the or each air damper or louvre responsive to real-time environmental information received by the controller. The realtime environmental information may include, but is not limited to, building occupancy information and patterns, weather forecasts and air quality indices. The controller may be configured to receive the real-time environmental information from an external source, such as a server or the internet. In further embodiments of the invention, the ventilation apparatus may include a controller and at least one environmental sensor. The or each environmental sensor may be configured to monitor an environmental condition outside or inside a building. For example, the environmental condition may be an indoor air quality parameter including, but not limited to, temperature, humidity and pollutant level. The controller may be programmed to dynamically adjust an orientation of the or each air damper or louvre responsive to a change in environment sensed by the or each environmental sensor. In still further embodiments of the invention, the ventilation apparatus may include a controller programmed to dynamically adjust an orientation of the or each air damper or louvre to: balance a volumetric flow rate of air flowing through the air intake channel with a volumetric flow rate of air flowing through the air exhaust channel; and / or regulate air pressure at the air intake outlet and the air exhaust inlet. It will be appreciated that controller functions described above and throughout the specification may be performed by the same controller or by different controllers. In embodiments of the invention, the ventilation apparatus may include a solar energy harvester. The solar energy harvester may be configured to supply power to one or more electrical components of the ventilation apparatus, such as the controller and / or the or each environmental sensor. The solar energy harvester may include, or may be coupled to, a rechargeable battery or other energy storage device. In further embodiments of the invention, the ventilation apparatus may be at least partially made of a solar transparent material, such as glass. This allows the use of solar energy to heat up the air inside the air intake channel and / or the air exhaust channel, as well as the or each heat exchanger element. In still further embodiments of the invention, the ventilation apparatus may include at least one air circulation device (e.g. a fan or another type of air blower) operable to force air to flow through the air intake channel and / or the air exhaust channel. This allows the ventilation apparatus to continue operation in low wind or no wind conditions. The at least one air circulation device may be powered by the solar energy harvester. According to a second aspect of the invention, there is provided a building comprising a ventilation apparatus according to any one of the first aspect of the invention and its embodiments, wherein the air intake inlet and the air exhaust outlet are directly connected to an exterior environment of the building, wherein the air intake outlet and the air exhaust inlet are directly connected to an interior environment of the building. The ventilation apparatus may be retrofitted to an existing building or may be installed as part of a new building construction. In a preferred embodiment of the invention, the ventilation apparatus is arranged to project out of the building, typically a sidewall or fagade or rear or roof or angled surface of the building. More preferably, the ventilation apparatus is arranged to project out of the building by at least 75mm. The features of the ventilation apparatus of the invention are designed to provide a compact ventilation apparatus that can be readily integrated into various building architectures, whether it is a modern glass facade or a traditional brick wall. This flexibility broadens the range of potential applications, from residential homes to commercial and industrial buildings. This compactness is crucial in urban environments where space is at a premium. In addition, a building may comprise a plurality of ventilation apparatus. The features of the ventilation apparatus are compatible with a modular design approach that allows for flexibility in terms of scalability and customisation. One or more modules (i.e. the ventilation apparatus) can be added or removed based on the specific ventilation requirements of the building, thus making the system adaptable to different sizes and types of buildings and ventilation requirements. Moreover, the ventilation apparatus of the invention can be designed for easy installation and seamless integration into a building, allowing it to fit harmoniously within the existing structure and aesthetics. This can be achieved through specific design elements like standard connection points and pre-assembled modules. The ventilation apparatus's exterior components can be finished in a variety of colors and textures to match the building's external appearance. This ensures that the system does not significantly affect the building's structural integrity or require extensive modifications during installation, thereby reducing installation labour, cost and materials. It will be appreciated that the use of the terms "first" and "second", and the like, in this patent specification is merely intended to help distinguish between similar features, and is not intended to indicate the relative importance of one feature over another feature, unless otherwise specified. Within the scope of this patent application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, and the claims and / or the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and all features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. Preferred embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings in which: Figure 1 shows assembled and exploded views of a ventilation apparatus according to an embodiment of the invention; Figure 2 shows the ventilation apparatus of Figure 1 when installed in a sidewall of a building; Figure 3 shows a housing of the ventilation apparatus of Figure 1; Figure 4 shows a cross-section of the ventilation apparatus of Figure 1; Figures 5 and 6 illustrate a working principle of the ventilation apparatus of Figure 1; Figures 7 to 10 show alternative configurations of the ventilation apparatus; Figure 11 shows an exemplary configuration of a controller of the ventilation apparatus; Figure 12 shows a field test facility comparing the performance of the ventilation apparatus with and without a passive heat recovery structure; Figures 13 to 16 illustrates wind conditions and performance results when comparing the performance of the ventilation apparatus with and without a passive heat recovery structure; and Figures 17a to 17d show computational fluid dynamics modelling results. The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic form in the interests of clarity and conciseness. Conventionally there is a broad spectrum of ventilation technologies, including singlesided natural ventilation, mechanical ventilation systems, windcatchers / wind towers, mechanical ventilation with heat recovery (MVHR.) systems, and other natural ventilation solutions such as background ventilators. Background ventilators are a simple and subtle form of ventilation, commonly used in residential buildings: • These systems provide a constant, low-level background ventilation. They typically consist of small vents or grilles installed in the external walls or windows of a building. • By allowing a steady trickle of fresh air, background ventilators help in reducing indoor pollutants, moisture, and the risk of condensation and mold growth. • These ventilators are unobtrusive, require minimal maintenance and do not consume energy like mechanical systems. • Background ventilators do not actively control indoor air quality or temperature. They provide basic ventilation but are not effective in removing large volumes of stale air quickly or in responding to varying indoor air quality needs. • Unlike more advanced ventilation systems, background ventilators do not include any mechanism for heat recovery, which can be a significant disadvantage in terms of energy efficiency, especially in colder climates. Single-sided natural ventilation is a commonly used ventilation strategy in buildings, particularly in residential settings. It involves rooms with openings, like windows or vents, on one side of the building that serves as the same opening for both the inlet for incoming fresh air and the outlet for outgoing stale air. This method has been traditionally used due to its simplicity and cost-effectiveness. However, it comes with several limitations: • The effectiveness of single-sided ventilation heavily relies on external factors such as wind direction, wind speed and temperature gradients. This reliance often results in inconsistent and unpredictable ventilation rates. • Unlike mechanical systems, single-sided natural ventilation provides little control over the amount and direction of airflow. This can lead to issues like draftiness in windy conditions or inadequate ventilation in still air. • Due to its unpredictability, single-sided ventilation can struggle to maintain consistent indoor air quality and thermal comfort. This is especially problematic in urban areas where buildings can block natural airflow and in regions with extreme weather conditions. • In very hot or cold climates, the reliance on natural ventilation can lead to higher energy consumption for heating or cooling, as the building cannot be sealed as effectively as with mechanical systems and does not incorporate heat recovery. Mechanical ventilation systems, in contrast, use powered fans and ductwork to control air movement within a building. These systems are designed to provide a more consistent and controllable indoor environment and can be found in both residential and commercial buildings. They include a range of technologies, from simple exhaust fans to sophisticated MVHR (Mechanical Ventilation with Heat Recovery) systems. Key aspects include: • Mechanical systems allow for precise control over airflow rates, speeds and direction, ensuring consistent and adequate indoor air quality and temperature regulation. • MVHR systems recover heat from the outgoing air to warm the incoming fresh air, reducing heating demands in colder climates. • These systems typically require more complex installations, including ductwork. They also consume electricity to power the fans, which can add to operational costs. • Mechanical ventilation can be adapted to a wide range of building types and sizes, and is particularly advantageous in densely populated areas or buildings where natural ventilation is insufficient. Mechanical ventilation with heat recovery (MVHR) systems combine mechanical ventilation with energy recovery. Key aspects include: • MVHR systems use fans to supply fresh air into a building while simultaneously extracting stale air. The core of the system includes a heat exchanger that transfers heat from the outgoing air to the incoming air, minimising heat loss. • By recovering heat that would otherwise be lost, MVHR systems can reduce the energy required for heating, leading to lower energy bills and reduced carbon emissions. • These systems provide consistent and controlled ventilation, which helps to maintain optimal indoor air quality, reducing issues like dampness and mold growth. • MVHR systems require careful design and installation, often involving ductwork throughout the building. Regular maintenance is also needed to ensure efficient operation and air quality. • MVHR systems are particularly effective in well-insulated and airtight buildings, where natural ventilation is limited. They ensure a continuous supply of fresh air without the significant heat loss associated with opening windows in such environments. Windcatchers and wind towers are a traditional architectural approach to natural ventilation and cooling, particularly prevalent in hot and arid regions. Modern adaptations have been integrated into contemporary building designs across various climates. Key aspects include: • Windcatchers are designed to capture and channel wind into a building, often through a roof-mounted structure. They utilise both wind-driven and stack ventilation principles, where wind-induced pressure and thermal buoyancy create airflow within the building. • These systems typically do not require electrical power for operation, making them energy-efficient and environmentally friendly. They harness natural wind and temperature gradients to ventilate and, in some cases, cool the interior spaces. • While effective in moderate to hot climates, windcatchers can be less efficient in cold climates. The introduction of cold air during winter can lead to discomfort and increased heating demands, making them less suitable for year-round use in such regions. • Integrating windcatchers into a building's design requires careful planning and architectural consideration. They can be more challenging to retrofit into existing structures due to their size and the need for roof modifications. • Windcatchers are most effective in areas with consistent wind patterns. In urban settings or regions with variable wind conditions, their performance can be significantly diminished. Other natural ventilation solutions utilise and enhance the natural airflow within a building without relying on mechanical systems. They are similar to single-sided ventilation and, while these systems are energy-efficient and eco-friendly, they often struggle with providing consistent and controlled ventilation. Their performance is heavily influenced by external factors like wind speed, direction, and temperature differences. In regions with extreme weather or in densely built urban environments, the effectiveness of these natural ventilation solutions can be significantly reduced. The invention provides a building ventilation solution in the form of a ventilation apparatus that merges efficient air circulation with energy-saving heat recovery in a single, streamlined system, so as to provide consistent and controllable ventilation, overcoming the limitations of traditional natural and mechanical ventilation systems, while also being environmentally sustainable, energy-efficient and cost-efficient. The invention combines the following key features that sets it apart from conventional solutions: a) A dual-channel airflow system The dual-channel airflow system is engineered to provide a more stable and controllable ventilation process, which is an improvement over the unpredictability of single-sided natural ventilation, where airflow depends heavily on external factors like wind direction and speed, and temperature differences between the inside and outside of the building. The system efficiently manages the intake of fresh outdoor air and the expulsion of stale indoor air, ensuring a balanced air exchange. This is particularly beneficial in maintaining good air circulation and indoor air quality with less dependence on requiring favourable external weather conditions, a challenge often encountered in some natural ventilation solutions. b) Passive heat recovery The passive heat recovery feature of the invention sets it apart from typical MVHR systems. Instead of using fans, it utilises the natural principles of heat exchange to recover and transfer heat from the outgoing stale air to the incoming fresh air. The source of the heat in the outgoing stale air may be from internal heat sources inside the building, such as heating systems, solar gains, occupants, electrical appliances, cooking equipment and lighting. This passive approach significantly lowers energy consumption as it does not rely on mechanical components like fans, which are standard in conventional MVHR. systems. The reduction in energy use not only lowers operational and maintenance costs due to fewer moving parts but also decreases the overall carbon footprint of the building. By recovering heat, the invention helps maintain a comfortable indoor temperature, an aspect that is particularly valuable during colder months. This feature helps in reducing the heating load on other building systems, leading to further energy savings. c) Versatility and efficiency The design of the invention is such that it can be seamlessly integrated into different types of buildings, from residential to commercial structures. Its adaptability makes it a viable option for both new constructions and retrofitting projects. The system's versatility extends to its ability to be scaled and tailored to meet the specific ventilation requirements of different buildings, accounting for factors like size, occupancy, and geographic location. By improving air quality and thermal comfort while reducing energy consumption, the invention contributes to the overall efficiency of buildings. This efficiency is crucial in the context of increasing environmental concerns and the drive towards more sustainable building practices. A ventilation apparatus according to an embodiment of the invention is shown in Figure 1 and is designated by the reference numeral 30. The ventilation apparatus 30 is for installation in a sidewall or fagade or rear or roof or angled surface of a building 32, e.g. underneath or above a window 34 of the building 32. Figure 2 shows the ventilation apparatus 30 installed underneath the window 34 as seen from the inside and outside of the building 32. The ventilation apparatus 30 comprises a housing 36, an air intake channel 38, an air exhaust channel 40 and a passive heat recovery structure 42. As shown in Figures 3, 4 and 5, the air intake channel 38 and the air exhaust channel 40 are formed as separate channels in the housing 36, with a divider wall 44 separating the air intake channel 38 and the air exhaust channel 40. The air intake channel 38 extends between an air intake inlet 46 and an air intake outlet 48. The air exhaust channel 40 extends between an air exhaust inlet 50 and an air exhaust outlet 52. The positions of the air intake inlet 46, the air intake outlet 48, the air exhaust inlet 50 and the air exhaust outlet 52 in the housing 36 are arranged as follows: • The air intake inlet 46 and the air exhaust outlet 52 are arranged on opposite sidewalls of the housing 36 to face opposite directions; • The air intake outlet 48 and the air exhaust inlet 50 are arranged on the same sidewall of the housing 36 to face the same direction; • The air intake inlet 46 and the air intake outlet 48 are arranged on adjoining sidewalls of the housing 36 to face orthogonal directions. • The air exhaust inlet 50 and the air exhaust outlet 52 are arranged on adjoining sidewalls of the housing 36 to face orthogonal directions. In use, the ventilation apparatus 30 is installed in the sidewall or fagade or rear or roof or angled surface of the building 32 so that the air intake inlet 46 and the air exhaust outlet 52 are directly connected to an exterior environment of the building 32, while the air intake outlet 48 and the air exhaust inlet 50 are directly connected to an interior environment of the building 32. Preferably the housing 36 is arranged to project out of the sidewall or fagade or rear or roof or angled surface of the building 32, e.g. by at least 75mm, so that the air intake inlet 46 and the air exhaust outlet 52 are located outside the building 32. Preferably the air intake outlet 48 and the air exhaust inlet 50 are flush with an inner wall of the building 32. The air intake channel 38 and the air exhaust channel 40, separated by the divider wall 44, form a dual-channel airflow system. Figures 3 and 4 shows the dual-channel airflow system in action, illustrating the intake of fresh air from the outside environment into the building 32 simultaneously with the expulsion of stale, warm air from inside the building 32 to the outside environment. This is enabled by the placement of the air intake inlet 46, the air exhaust outlet 52 and the divider wall 44 that results in a pressure differential being formed between the air intake inlet 46 and the air exhaust outlet 52 when wind blows across the ventilation apparatus 30. The size, shape and dimensions of the air intake channel 38, the air exhaust channel 40 and the divider wall 44 are chosen to optimise airflow within the channels 38,40, accounting for factors such as airflow dynamics and noise reduction. The air intake inlet 46 is the entry point for fresh outdoor air. It is strategically located to capitalise on natural airflow patterns and pressure differentials, enhancing the dualchannel airflow system's efficiency in drawing in fresh air. The air intake inlet 46 may include an air filter to purify the incoming air, effectively removing pollutants, allergens and particulates, thereby enhancing the indoor air quality. The air exhaust outlet 52 is the exit point for stale indoor air, which is typically warmed by internal heat sources inside the building 32, such as heating systems, solar gains, occupants, electrical appliances, cooking equipment and lighting. The air exhaust outlet 52 not only plays a role in removing air that is high in humidity, CO2 levels, and indoor pollutants but also works in coordination with the air intake inlet 46 to achieve a balanced exchange of air, thereby maintaining an equilibrium that prevents negative or positive pressure scenarios within the building 32. Positioning the air intake channel 38 and the air exhaust channel 40 side by side facilitates the effective expulsion of indoor air without the need for the air exhaust inlet 50 to be located higher than the air intake outlet 48. Furthermore, the side-by-side configuration of the air intake channel 38 and the air exhaust channel 40 facilitates a compact and efficient design, allowing for a more streamlined integration into various building types. By having the housing 36 project out of the building 32, the air intake inlet 46 and the air exhaust outlet 52 are spaced away from the sidewall or fagade or rear of the building 32, preferably by at least 75mm. The greater the distance of the air intake inlet 46 and the air exhaust outlet 52 from the building 32, the higher the achievable pressure differential between the air intake inlet 46 and the air exhaust outlet 52. The extent to which the housing 36 projects out of the building 32 is limited by other factors, such as structural and aesthetic factors. It will be appreciated that the air intake channel 38 may function as an air exhaust channel while the air exhaust channel 40 may function as an air intake channel depending on the wind conditions (such as wind direction relative to the air intake inlet 46 and the air exhaust outlet 52) at the time. As a result the dual-channel airflow system provides continuous air circulation in the presence of wind flow to ensure that indoor air is continually refreshed, thus enhancing the quality of indoor air and promoting a healthier indoor environment. The dual-channel airflow system is integrated with the passive heat recovery structure 42 as follows. The passive heat recovery structure 42 is arranged in the housing 36 and includes a plurality of heat exchanger elements. In the embodiment shown in Figures 5 and 6, the heat exchanger elements are configured as plate elements 54. The plate elements 54 are arranged to extend through the divider wall 44 of the housing 36 so as to project into the air intake channel 38 and the air exhaust channel 40. In a preferred embodiment, the plate elements 54 are arranged to extend from the air intake inlet 46 to the air intake outlet 48 within the air intake channel 38 and to extend from the air exhaust inlet 50 to the air exhaust outlet 52 within the air exhaust channel 40. The plate elements 54 are arranged in parallel between the air intake inlet 46 and the air intake outlet 48 and between the air exhaust inlet 50 and the air exhaust outlet 52. The plate elements 54 are spaced apart from each other, preferably by a gap of 6mm to 10mm. A thickness of each plate element 54 may be several millimetres, e.g. 2-3mm. The plate elements 54 are fixed in place, i.e. static. In this way the plate elements 54 are arranged as cross-flow heat exchanger elements which together combine to define a cross-flow heat exchanger. When air streams flow separately in the air intake and exhaust channels 38,40, the air streams flow past the plate elements 54 in the respective air intake and exhaust channels 38,40. The cross-flow heat exchanger elements absorb heat from the outgoing warm air flowing in the air exhaust channel 40 and transfers the heat to the incoming cooler air flowing in the air intake channel 38. In the process, the incoming air inside the air intake channel 38 will effectively absorb heat from the outgoing air inside the air exhaust channel 40 via the cross-flow heat exchanger elements, thereby pre-warming the incoming air before it is introduced into the building 32. The arrangement of the cross-flow heat exchanger across and within the air intake and exhaust channels 38,40 therefore facilitates efficient heat transfer to the incoming fresh air from the outgoing exhaust air, without mixing the two air streams inside the air intake and exhaust channels 38,40 (see Figure 4). This setup enables the ventilation apparatus 30 to passively recover waste heat from the exhaust air during the ventilation process, thereby minimising ventilation heat loss, optimising energy efficiency, while preventing mixing between the two air streams to ensure the purity and quality of the incoming air. This separation is critical for maintaining healthy indoor air standards. The air intake and exhaust channels 38,40, the air intake inlet and outlet 46,48 and the air exhaust inlet and outlet 50,52 are preferably made of lightweight and / or durable materials. Robust materials like reinforced plastics or lightweight metals could be used to ensure they withstand environmental exposures while not adding excessive load to the building structure. The material selection for air intake and exhaust channels 38,40 may also take into account noise reduction to minimise any sound from the airflow, thus enhancing the comfort of the indoor environment. Each plate element 54 is made of a material with high thermal conductivity, such as a metallic material, for efficient heat transfer. Preferably the material of each plate element is chosen to provide lightweightness, durability and resistance to wear under continuous thermal cycling. Non-limiting examples of such materials include advanced alloys or composites that can withstand long-term heat exposure and corrosion. The spacing between the plate elements 54 is selected to strike a balance between maintaining a good rate of airflow and achieving effective heat transfer. The divider wall 44 may be made from materials with high thermal conductivity, thereby allowing heat to transfer from the warmer outgoing exhaust air to the cooler incoming air. The air intake and exhaust channels 38,40 are preferably constructed using lightweight, durable materials, like plastic or aluminum, which are resistant to corrosion and damage from environmental conditions. Preferably eco-friendly or recycled materials are chosen for the air intake and exhaust channels 38,40, the air intake inlet and outlet 46,48, the air exhaust inlet and outlet 50,52 and the plate elements 54. By recovering waste heat from the exhaust air which would normally be lost, the ventilation apparatus 30 reduces the heating requirements of the building 32, thus providing energy savings and building maintenance cost reductions. This is particularly useful in colder climates where heating demands are high. Each one of the air intake inlet 46 and the air exhaust outlet 52 includes louvres 56a, while each one of the air intake outlet 48 and the air exhaust inlet 50 includes air dampers 56b. The orientation (i.e. angle) of each air damper 56b or louvre 56a relative to the corresponding air intake inlet 46, air intake outlet 48, air exhaust inlet 50 or air exhaust outlet 52 may vary. The air dampers 56b act as airflow regulators for the air intake and exhaust channels 38,40 while the louvres 56a provide protection from the elements such as rain and snow. The indoor-facing air dampers 56b are angled away from one another to prevent undesirable mixing of outflowing stale air with inflowing fresh air ('air short-circuiting') and efficiently distribute the incoming air throughout the space inside the building 32. Meanwhile, the outdoor-facing louvres 56a are angled downward to prevent precipitation and other outdoors elements from entering the air intake and exhaust channels 38,40. Each louvre 56a of the air intake inlet 46 and the air exhaust outlet 52 may be arranged to be at an angle of 20 degrees to 35 degrees with respect to a horizontal plane. Each air damper 56b of the air intake outlet 48 and the air exhaust inlet 50 may be arranged to be at an angle of 20 degrees to 50 degrees with respect to a vertical plane. In some embodiments the louvres 56a in the air intake inlet 46 and the air exhaust outlet 52 may be fixed, i.e. immovable. In other embodiments the air dampers 56b in the air intake outlet 48 and the air exhaust inlet 50 may be movable to adjust its orientation (i.e. angle). By changing an orientation of the air dampers 56b, airflow rates and speeds inside the air intake channel 38 and the air exhaust channel 40 can be adjusted to control the level of ventilation though the channels 38,40. Such adjustment may be made in response to changing internal and external environmental conditions. This functionality allows for dynamic control over ventilation, ensuring optimal indoor air quality and thermal comfort at all times. The the air dampers 56b in the air intake outlet 48 and the air exhaust inlet 50 may be moved manually by a user. Additionally or alternatively the ventilation apparatus 30 may include a controller 58 (such as a computer or a microprocessor), as shown in Figure 11, which is programmed to dynamically adjust an orientation of the air dampers 56b. Such adjustment may be responsive to real-time environmental information received by the controller 58. The real-time environmental information may include, but is not limited to, building 32 occupancy information and patterns, weather forecasts and air quality indices. The controller 58 may be configured to be in communication with an external source 60 so that it can receive the real-time environmental information from the external source 60, such as a server or the internet. The ventilation apparatus 30 may further include at least one environmental sensor 62 to monitor an environmental condition outside or inside the building 32. For example, the environmental condition may be an outdoor air quality parameter or an indoor air quality parameter including, but not limited to, temperature, humidity and pollutant level (CO2 level). When the at least one environmental sensor 62 senses a change in environment (e.g. a change in temperature, humidity and / or pollutant level), the controller 58 dynamically adjusts the orientation of the air dampers 56b of at least one of the air intake outlet 48, the air exhaust inlet 50 and the air exhaust outlet 52 in order to adjust the airflow rates and speeds inside the air intake and exhaust channels 38,40. In some embodiments, the ventilation apparatus 30 may include a user interface (e.g., a graphical user interface) that allows for manual overrides and preferences, giving occupants control over their environment. In embodiments employing a plurality of ventilation apparatus, the controller 58 may be configured as a central controller that is programmed to dynamically adjust an orientation of the air dampers 56b of each one of the ventilation apparatus. To optimise the performance of the ventilation apparatus 30, the controller 58 dynamically adjusts an orientation of the air dampers 56b to adjust the airflow rates and speeds in the air intake channel 38 and the air exhaust channel 40 in order to: • balance a volumetric flow rate of air flowing through the air intake channel 38 with a volumetric flow rate of air flowing through the air exhaust channel 40. This balancing helps maintain a stable indoor air pressure,; • regulate air pressure at the air intake outlet 48 and the air exhaust inlet 50. This is to prevent either negative pressure or positive pressure from building up within the building 32, thereby providing comfort and structural integrity. The controller 58 therefore provides the ventilation apparatus 30 with the capability to autonomously respond to changing conditions, enhance energy efficiency and ensure excellent indoor air quality and thermal comfort, thereby reducing the need for user intervention. This is particularly useful for integration into or with a smart building management system for automated climate control, air quality monitoring and energy management. Further optional features of the ventilation apparatus 30 include: • The ventilation apparatus 30 may include a solar energy harvester (e.g. solar panels). As shown in Figure 7, solar panels 64 may be formed on the front and top of the housing 36 of the ventilation apparatus 30. The solar energy harvester may be configured to supply power to one or more electrical components of the ventilation apparatus 30, such as the controller 58 and / or the or each environmental sensor 62. This is suitable for buildings in regions with significant sunlight and for sustainable, energy-efficient projects. • The ventilation apparatus 30 may be at least partially made of a solar transparent material, such as glass (like double-glazed or low-E glass). For instance, as shown in Figures 8 and 9, part of the housing's walls, ceiling or front may be made of a solar transparent material 66 to allow solar energy to heat up the air inside the air intake channel 38 and the air exhaust channel 40 as well as the plate elements 54. The solar transparent material traps solar radiation like a small greenhouse, heating up the ventilation apparatus's internal space and passive heat recovery structure 42. This is not only beneficial in colder climates but also could add to the aesthetic appeal and can be customised for different looks. • The ventilation apparatus 30 may include at least one air circulation device (e.g. a fan or another type of air blower) operable to force air to flow through the air intake channel 38 and / or the air exhaust channel 40. This allows the ventilation apparatus 30 to boost airflow in low wind or no wind conditions. Since the ventilation apparatus 30 is primarily operated as a passive or natural ventilation apparatus 30, the at least one air circulation device can be low-powered. The at least one air circulation device may be powered by the solar energy harvester (which may include or be coupled to a rechargeable battery or other energy storage device) and / or may be configured to automatically turn on based on received information, e.g. a drop in airflow rate or speed, a drop in indoor air quality, which may be measured using one or more environmental sensors. • The ventilation apparatus 30 may include a telescopic or adjustable component 68 that can be extended or retracted to accommodate different wall depths. Different parts of the telescopic or adjustable component 68 as shown in Figure 10 that can slide over each other in order to extend or retract the telescopic or adjustable component 68. The telescopic or adjustable component 68 may be detachably connectable to the housing 36 (preferably the side of the housing 36 having the air intake outlet 48 and air exhaust inlet 50), which allows different telescopic or adjustment components to be used to fit various wall thicknesses and materials. Alternatively the telescopic or adjustable component may be permanently connected to, or integral with, the housing 36 (preferably the side of the housing 36 having the air intake outlet 48 and air exhaust inlet 50). The provision of the telescopic or adjustable component 68 results in a modular and flexible design approach that enables the ventilation apparatus 30 to be adapted for installation in various building walls. Figure 11 shows an exemplary configuration of the controller 58 for making real-time decisions based on a wide range of inputs, including environmental sensors (e.g., indoor / device sensors 62a, outdoor sensors 62b, occupancy sensors 62c) and external data from an external source 60 (e.g. external weather and air quality information). The motorized air dampers 56b are finely controlled for precise air management, and a user interface 70 allows for manual overrides and system monitoring. An experiment was performed by the inventors to compare the performance of the ventilation apparatus with and without the passive heat recovery structure. Figure 12 shows a field test facility 72 for obtaining the presented experimental results. The field test facility 72 was split into 2 equal rooms 74. Each room 74 is fitted with internal sensors for measuring speed and temperature. A weather station 76 is located on top of the field test facility 72. In the experiment, the housings of both ventilation apparatus are arranged to project out of the building in a southwardly direction. That is to say, the housings of both ventilation apparatus were facing the south. During the experiment, the wind was coming from between the south west and the south south west, which were the predominant wind directions in the field test location. Figure 13a shows the difference in airflow speeds of the incoming air in the ventilation apparatus ('Inflow'), the outgoing air in the ventilation apparatus ('Outflow'), the wind flowing through a first window measurement point at a window of the room 74 when the window is open ('Window 1') and the wind flowing through a second window measurement point of the same window when the window is open ('Window 2'). The first and second window measurement points are spaced apart by the same distance separating the air intake inlet 46 and the air exhaust outlet 52 for comparison purposes. Figure 13b shows the difference and fluctuations in airflow speeds of the incoming air in the ventilation apparatus ('Inflow') and the wind flowing through an open window ('Window'). The peak wind speed difference is indicated in Figure 13b. Figure 13c shows the weather conditions during the experiment. Figures 13d and 13c respectively show the outdoor wind speeds and directions during the experiment. Figures 14 and 15 compare the airflow speeds in the air intake and exhaust channels of both ventilation apparatus. Figure 16 compares the temperatures of the air stream inside the air intake channels of both ventilation apparatus. It was observed that the temperature of the intake air inside the air intake channel is higher for the ventilation apparatus with the passive heat recovery structure than the ventilation apparatus without the passive heat recovery structure, by up to a peak temperature difference of 5-6 degrees Celsius at certain time points. It was therefore demonstrated that the passive heat recovery structure is capable of transferring heat from the outgoing exhaust air to the incoming intake air, without requiring energy consumption. Figure 17a shows computational fluid dynamics (CFD) modelling results with a 3D view of the airflow streamlines and velocity distribution inside the test rooms 74. The results include a plot of the flow distribution in a horizontal plane in the test rooms 74 comparing the ventilation apparatus with and without the passive heat recovery structure 42. Reduced airflow speed is observed due to the addition of the passive heat recovery structure. Figure 17b shows CFD modelling results with a top view of the temperature distribution inside the test rooms 74. A higher indoor temperature is achieved in the left room 74 with the ventilation apparatus having the passive heat recovery structure 42 when compared to the right room 74 without the ventilation apparatus having the passive heat recovery structure 42. This is aided by pre-heating of the inflow air through heat recovery. Figure 17c shows CFD modelling results with a top view of the airflow streamlines in and around the test rooms 74. This shows the flow behaviour when the wind direction changed from 10 degrees (top) to 45 degrees (bottom). Figure 17d shows CFD modelling results which illustrate the influence of the spacing (6-10mm) between the heat exchanger elements 54 on the average intake air speed and the average intake temperature increase. The ventilation apparatus 30 of the invention addresses the following problems: • Inconsistency and unpredictability in natural ventilation: Single-sided natural ventilation is highly dependent on external factors such as wind speed and direction, leading to inconsistent and unpredictable airflow. The invention provides a controlled dual-channel airflow system that ensures a more consistent ventilation regardless of external conditions. • Energy usage intensity of mechanical ventilation systems: Mechanical systems, including MVHR, are effective in controlling indoor air quality but are energy-intensive due to their reliance on fans and electric components. The invention incorporates passive heat recovery, reducing the need for mechanical fans and thus lowering energy consumption. • Seasonal limitations of windcatchers and other natural systems: Systems like windcatchers can be less effective in cold climates, leading to increased heating demands. The passive heat recovery feature of the invention ensures that incoming air is pre-warmed, reducing the heating load and making it effective across different seasons. • Complexity and cost of installation in retrofitting: Integrating advanced ventilation systems into existing buildings can be structurally challenging and costly. The design of the ventilation apparatus allows for easier integration into various building types, including retrofit scenarios, without extensive structural modifications. The ventilation apparatus 30 of the invention has the following advantages: • Enhanced indoor air quality and comfort: By ensuring a more consistent supply of fresh air and effective expulsion of stale air, the invention improves indoor air quality and thermal comfort by pre-heating the incoming air. • Energy efficiency and reduced operating costs: The invention's passive heat recovery mechanism minimises energy loss, leading to lower heating costs and overall reduced operating expenses. • Environmentally friendly solution: Reduced energy consumption translates to a lower carbon footprint, aligning with environmental sustainability goals. • Flexibility and scalability: The invention can be adapted to a wide range of building sizes and types, making it a versatile solution for both new constructions and existing buildings. • Cost-effective solution for building owners: The invention's ease of installation and low maintenance requirements make it a cost-effective option compared to more complex mechanical systems, by reducing long-term costs and inconvenience for users. • Contribution to building regulations compliance: By improving energy efficiency and indoor air quality, the invention can help buildings meet increasingly stringent building regulations and standards. It will be appreciated that the above numerical values are merely intended to help illustrate the working of the invention and are not necessarily limiting on the scope of the invention. The listing or discussion of an apparently prior-published document or apparently prior-published information in this specification should not necessarily be taken as an acknowledgement that the document or information is part of the state of the art or is common general knowledge. Preferences and options for a given aspect, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, features and parameters of the invention.

Claims

1. A ventilation apparatus comprising:an air intake channel extending between an air intake inlet and an air intake outlet;an air exhaust channel extending between an air exhaust inlet and an air exhaust outlet, wherein the air intake channel and the air exhaust channel are separated from each other; anda passive heat recovery structure including at least one heat exchanger element arranged to project into the air intake channel and the air exhaust channel.

2. A ventilation apparatus according to Claim 1 wherein the or each heat exchanger element is configured as a cross-flow heat exchanger element.

3. A ventilation apparatus according to Claim 1 or Claim 2 wherein the or each heat exchanger element is configured as a static heat exchanger element.

4. A ventilation apparatus according to any one of the preceding claims wherein the air intake channel and the air exhaust channel are separated by a wall, the or each heat exchanger element extending through the wall so as to project into the air intake channel and the air exhaust channel.

5. A ventilation apparatus according to Claim 4 wherein the wall is made of a thermally conductive material.

6. A ventilation apparatus according to any one of the preceding claims wherein the or each heat exchanger element is arranged to extend from the air intake inlet to the air intake outlet within the air intake channel, and / or wherein the or each heat exchanger element is arranged to extend from the air exhaust inlet to the air exhaust outlet within the air exhaust channel.

7. A ventilation apparatus according to any one of the preceding claims wherein the or each heat exchanger element is configured as a plate element.

8. A ventilation apparatus according to Claim 7 wherein the passive heat recovery structure includes a plurality of heat exchanger elements arranged to project into the air intake channel and the air exhaust channel, wherein the heat exchanger elements are configured as plate elements that are arranged in parallel between the air intakeinlet and the air intake outlet and / or between the air exhaust inlet and the air exhaust outlet.

9. A ventilation apparatus according to Claim 7 or Claim 8 wherein the passive heat recovery structure includes a plurality of heat exchanger elements arranged to project into the air intake channel and the air exhaust channel, wherein the heat exchanger elements are configured as plate elements spaced apart from each other.

10. A ventilation apparatus according to Claim 9 wherein the plate elements are spaced part by a gap of 6mm to 10mm.

11. A ventilation apparatus according to any one of Claims 7 to 10 wherein the or each plate element has a thickness of 2-3mm.

12. A ventilation apparatus according to any one of the preceding claims wherein the air intake inlet and the air intake outlet are arranged to face orthogonal directions, and / or wherein the air exhaust inlet and the air exhaust outlet are arranged to face orthogonal directions.

13. A ventilation apparatus according to any one of the preceding claims wherein the air intake inlet and the air exhaust outlet are arranged to face opposite directions.

14. A ventilation apparatus according to any one of the preceding claims wherein the air intake outlet and the air exhaust inlet are arranged to face the same direction.

15. A ventilation apparatus according to any one of the preceding claims wherein at least one of the air intake inlet, the air intake outlet, the air exhaust inlet and the air exhaust outlet includes one or more air dampers or louvres.

16. A ventilation apparatus according to Claim 15 wherein the or each air damper or louvre is movable to adjust its orientation.

17. A ventilation apparatus according to Claim 16 including a controller programmed to dynamically adjust an orientation of the or each air damper or louvre responsive to real-time environmental information received by the controller.

18. A ventilation apparatus according to Claim 16 or Claim 17 including a controller and at least one environmental sensor, wherein the controller is programmed todynamically adjust an orientation of the or each air damper or louvre responsive to a change in environment sensed by the or each environmental sensor.

19. A ventilation apparatus according to any one of Claims 16 to 18 including a controller programmed to dynamically adjust an orientation of the or each air damper or louvre to balance a volumetric flow rate of air flowing through the air intake channel with a volumetric flow rate of air flowing through the air exhaust channel.

20. A ventilation apparatus according to any one of Claims 16 to 19 including a controller programmed to dynamically adjust an orientation of the or each air damper or louvre to regulate air pressure at the air intake outlet and the air exhaust inlet.

21. A ventilation apparatus according to any one of the preceding claims including a solar energy harvester, wherein the solar energy harvester is configured to supply power to one or more electrical components of the ventilation apparatus.

22. A ventilation apparatus according to any one of the preceding claims wherein the ventilation apparatus is at least partially made of a solar transparent material.

23. A ventilation apparatus according to any one of the preceding claims including at least one air circulation device operable to force air to flow through the air intake channel and / or the air exhaust channel.

24. A building comprising a ventilation apparatus according to any one of the preceding claims, wherein the air intake inlet and the air exhaust outlet are directly connected to an exterior environment of the building, wherein the air intake outlet and the air exhaust inlet are directly connected to an interior environment of the building.

25. A building according to Claim 24 wherein the ventilation apparatus is arranged to project out of the building.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS24 07 2527CLAIMS1. A ventilation apparatus comprising:an air intake channel extending between an air intake inlet and an air intake5 outlet;an air exhaust channel extending between an air exhaust inlet and an air exhaust outlet, wherein the air intake channel and the air exhaust channel are separated from each other, and wherein the air intake inlet and the air exhaust outlet face opposite directions; and10 a passive heat recovery structure including at least one heat exchanger elementarranged to project into the air intake channel and the air exhaust channel;wherein the ventilation apparatus is configured for installation in a building such that the air intake inlet and the air exhaust outlet are directly connected to an exterior environment of the building, the air intake outlet and the air exhaust inlet are directly 15 connected to an interior environment of the building, and the ventilation apparatus projects out of the building;wherein the air intake channel and the air exhaust channel function interchangeably depending on wind conditions; andwherein the ventilation apparatus, the air intake channel and the air exhaust 20 channel each have a rectangular profile.

2. A ventilation apparatus according to Claim 1 wherein the or each heat exchanger element is configured as a cross-flow heat exchanger element.25 3. A ventilation apparatus according to Claim 1 or Claim 2 wherein the or eachheat exchanger element is configured as a static heat exchanger element.

4. A ventilation apparatus according to any one of the preceding claims wherein the air intake channel and the air exhaust channel are separated by a wall, the or each30 heat exchanger element extending through the wall so as to project into the air intake channel and the air exhaust channel.

5. A ventilation apparatus according to Claim 4 wherein the wall is made of a thermally conductive material.

356. A ventilation apparatus according to any one of the preceding claims wherein the or each heat exchanger element is arranged to extend from the air intake inlet to the air intake outlet within the air intake channel, and / or wherein the or each heat24 07 25exchanger element is arranged to extend from the air exhaust inlet to the air exhaust outlet within the air exhaust channel.

7. A ventilation apparatus according to any one of the preceding claims wherein5 the or each heat exchanger element is configured as a plate element.

8. A ventilation apparatus according to Claim 7 wherein the passive heat recovery structure includes a plurality of heat exchanger elements arranged to project into the air intake channel and the air exhaust channel, wherein the heat exchanger elements 10 are configured as plate elements that are arranged in parallel between the air intake inlet and the air intake outlet and / or between the air exhaust inlet and the air exhaust outlet.

9. A ventilation apparatus according to Claim 7 or Claim 8 wherein the passive 15 heat recovery structure includes a plurality of heat exchanger elements arranged to project into the air intake channel and the air exhaust channel, wherein the heat exchanger elements are configured as plate elements spaced apart from each other.

10. A ventilation apparatus according to Claim 9 wherein the plate elements are 20 spaced part by a gap of 6mm to 10mm.

11. A ventilation apparatus according to any one of Claims 7 to 10 wherein the or each plate element has a thickness of 2-3mm.25 12. A ventilation apparatus according to any one of the preceding claims whereinthe air intake inlet and the air intake outlet are arranged to face orthogonal directions, and / or wherein the air exhaust inlet and the air exhaust outlet are arranged to face orthogonal directions.30 13. A ventilation apparatus according to any one of the preceding claims whereinthe air intake outlet and the air exhaust inlet are arranged to face the same direction.

14. A ventilation apparatus according to any one of the preceding claims wherein at least one of the air intake inlet, the air intake outlet, the air exhaust inlet and the air 35 exhaust outlet includes one or more air dampers or louvres.

15. A ventilation apparatus according to Claim 14 wherein the or each air damper or louvre is movable to adjust its orientation.24 07 2516. A ventilation apparatus according to Claim 15 including a controller programmed to dynamically adjust an orientation of the or each air damper or louvre responsive to real-time environmental information received by the controller.

517. A ventilation apparatus according to Claim 15 or Claim 16 including a controller and at least one environmental sensor, wherein the controller is programmed to dynamically adjust an orientation of the or each air damper or louvre responsive to a change in environment sensed by the or each environmental sensor.1018. A ventilation apparatus according to any one of Claims 15 to 17 including a controller programmed to dynamically adjust an orientation of the or each air damper or louvre to balance a volumetric flow rate of air flowing through the air intake channel with a volumetric flow rate of air flowing through the air exhaust channel.1519. A ventilation apparatus according to any one of Claims 15 to 18 including a controller programmed to dynamically adjust an orientation of the or each air damper or louvre to regulate air pressure at the air intake outlet and the air exhaust inlet.20 20. A ventilation apparatus according to any one of the preceding claims includinga solar energy harvester, wherein the solar energy harvester is configured to supply power to one or more electrical components of the ventilation apparatus.

21. A ventilation apparatus according to any one of the preceding claims wherein 25 the ventilation apparatus is at least partially made of a solar transparent material.

22. A building comprising a ventilation apparatus according to any one of the preceding claims, wherein the air intake inlet and the air exhaust outlet are directly connected to an exterior environment of the building, wherein the air intake outlet and 30 the air exhaust inlet are directly connected to an interior environment of the building.

23. A building according to Claim 22 wherein the ventilation apparatus is arranged to project out of the building.

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