North Gosford townhouses
summer 3pm wind rose for williamtown airport
winter 3pm wind rose from williamtown airport

Natural Ventilation on the Central Coast

What is Natural ventilation design on the Central Coast?

Natural cross ventilation refers to the process of using natural air flow to ventilate indoor spaces. This is typically achieved by strategically placing windows or other openings in a building to allow for the flow of air through the space. Cross ventilation relies on the natural movement of air currents, which can be influenced by factors such as wind direction, building orientation, and temperature differences between the interior and exterior of the building. Cross ventilation can be an effective way to improve indoor air quality, regulate temperature and humidity, and reduce the need for mechanical ventilation such as fans or air conditioning. It is particularly useful in hot and humid climates, where the flow of air can help to cool and dehumidify indoor spaces. To maximize the benefits of natural cross ventilation, it is important to design buildings with this goal in mind. This may involve selecting building materials that are conducive to air flow, such as porous or breathable materials, and placing windows and other openings in locations that will promote air circulation.  The best way to achieve natural ventilation is to place windows directly opposite each other with a building depth of no more then 6m, if this is not possible then corner windows are the next best thing.


The orientation of a house is an important consideration in natural ventilation design, as we generally want to maximise natural ventilation in summer when cooling is required and minimise it in winter when it is not as desirable. The windroses to the left show the wind spped and direction in summer and winter at Williamtown airport. These show that natural ventilation from the south east is the best direction in summer. Williamtown airport is the closest source of windroses for the central coast, it is still quiet a distance away so it is really important to look at the site and see which direction the trees have bent the trees to give a more accurate wind direction.

Using Height:

Natural ventilation using height known as stack ventilation refers to the process of using the natural tendency of warm air to rise and cool air to sink to create airflow through a space. This can be achieved by designing a building with a tall central atrium or other vertical space, and strategically placing openings at the top and bottom to allow for natural air movement. The warm air in the building will naturally rise, creating a stack effect that draws in cooler air from outside through the lower openings. This cool air will then circulate through the space, helping to regulate temperature and improve indoor air quality. 

Using a Labyrinth under a building:

A labyrinth under a building is a type of ventilation system that uses a series of interconnected tunnels or passageways to create a path for air to flow through the building. This approach is particularly useful for buildings with limited space or access to outdoor air, such as underground structures or buildings located in dense urban areas. The labyrinth Is commonly located beneath the building and consists of a series of narrow tunnels or passages that are designed to slow down and filter the air as it moves through the system. The labyrinth may include features such as baffles or filters to remove impurities from the air and may be lined with materials such as clay or concrete to enhance its structural integrity. The air is typically drawn into the labyrinth through a series of intake vents located at the bottom of the building and is then circulated through the labyrinth before being released into the building through exhaust vents at the top. The labyrinth design creates a convoluted path for the air to follow, which slows down the flow and increases the amount of time that the air spends in contact with the labyrinth walls. This allows the system to filter and condition the air before it enters the building more effectively.

Under floor air conditioning:

Under floor air conditioning (UFAC) is a system that delivers conditioned air to a building through a network of ducts and diffusers located in the floor, rather than in the ceiling or walls. This approach provides several benefits over traditional heating, ventilation, air conditioning (HVAC) systems, including improved energy efficiency, better indoor air quality, and greater flexibility in building design. In a UFAC system, the air is typically drawn in from outside and conditioned by a central air handling unit before being distributed through the underfloor ducts. The air is then released into the space through diffusers located in the floor, typically at the base of partitions or other structures. This creates a draft-free and uniform airflow that helps to maintain consistent temperatures and improve indoor air quality. UFAC can also be easily adapted to changes in building layout or occupancy, as diffusers and ducts can be added or removed as needed. In addition, UFAC systems can be more energy-efficient than traditional HVAC systems, as the air is delivered closer to the occupied zone, reducing the amount of energy required to move the air around the space. This can result in lower energy costs and a reduced environmental impact. 

Using a thermal exchange:

Thermal exchange in ventilation refers to the transfer of heat between the air that is being circulated through a building and the surrounding environment. This process can occur naturally through open windows or other forms of natural ventilation, or it can be facilitated by mechanical ventilation systems. During thermal exchange, warm air from inside the building is expelled through an exhaust vent or other opening, while cooler air from outside is drawn in to replace it. As the air moves in and out of the building, heat is transferred between the indoor and outdoor environments, helping to regulate the temperature and improve indoor air quality. Mechanical ventilation systems can be designed to facilitate thermal exchange by using heat recovery systems, which capture and transfer heat from the exhaust air to the incoming fresh air. This helps to reduce the energy required to heat or cool the incoming air, resulting in lower energy costs and a reduced environmental impact.

Airtight construction: 

The building envelope is constructed to be airtight to prevent heat loss through air leakage. This is achieved through the use of specialized tapes, sealants, and membranes. 

Energy-efficient windows: 

High-performance windows are used to minimize heat loss and gain through the glass. AVS is a local window manufacturing company that provides ThermalHeart windows which are double glazed windows with a thermal break so that heat is not lost through conduction to the outside.

Heat recovery ventilation: 

A mechanical ventilation system is used to provide fresh air to the living space while recovering heat from the exhaust air. Heat on is a local provider of heat recovery systems.

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