Central Ventilation systems are ideal for new buildings, where the central unit is positioned in a cupboard, laundry or in the ceiling space, and ducts run through the ceiling or roof space to the wall or ceiling vents. Some of these vents then extract stale and unwanted air from rooms such as bathrooms, kitchens, walk-in robes and laundries, while other vents supply fresh air to rooms such as lounge and dining rooms, bedrooms, study rooms and other habitable spaces.

There are two main types of ventilation systems in buildings: extraction-only air systems and supply/extract air systems.

The simplest and cheapest method for ventilation is an extraction-only air system. This is the system you will recognise from almost all houses in Australia - unwanted air is removed from areas such as the kitchen, bathroom and toilet. But the air that is extracted and pushed out from the building must then be replaced somehow... and this replacement air from outside has traditionally just seeped its way into the building via the small openings and cracks around windows, doors, ceiling & roof, etc.

Now in theory this simple and cheap way works, but the air that is getting sucked into the house through all the openings and cracks is costing us money. In winter this air is cold, and therefore we have to pay to heat it up... and the same is true in summer - the air coming in is hot, and we have to pay to cool it down.

But unlike an extraction-air system, a supply/extract system first strips the unwanted extract air of its thermal energy, and then it transfers the majority of this energy to the fresh air that is being supplied into the building. This is a Central Heat Recovery Ventilation system.

So for example in winter the outside air may be 7°C, but inside your home it's a comfortable 21°C. A simple extraction-only air system would exhaust to the outside 21°C air from your house, and then draw in 7°C air from outside... which can be uncomfortable for those inside, but most of all costs you money to heat up this cold air to 21°C again. However, a supply/extract air system would in this situation extract the heat from the stale 21°C air first, and only then exhaust it at ~9°C. The fresh incoming cold air from outside would be at 7°C before it passes through the special crossflow heat exchanger, but then it's supplied into your home at 19°C... meaning you don't experience discomfort and you dramatically save on your heating bills, while having high quality (and filtered) fresh air supplied throughout your home.

It's important to remember that heat recovery ventilation systems do not actively heat or cool your home - they only help you keep more of the energy you already have in your home while enjoying clean fresh air and minimising your energy bills.

Central Heat Recovery Ventilation systems are great for:

• Energy efficient homes that don't want to waste energy (and pay for the wasted energy too)
• Air-tight homes that require fresh air supply (to keep O2 levels right, and minimise CO2 and other pollutant build-up)
• For people and families that suffer from asthma and allergies (the fresh air is filtered before it enters your home)
• Reducing the potential of mould and other pathogens (replacing the air within the building and reducing moisture build-up)

EnergyLabs offers you ready to go and complete installation kits - making it easy for you to install (with no missing parts) and get your heat recovery ventilation system up and running:

SMALL heat recovery ventilation systems are suitable for homes with a habitable floor area of 80 – 125m² with 6x fresh air supply inlets, and 3x stale air extraction outlets.

MEDIUM heat recovery ventilation systems are suitable for homes with a habitable floor area of 125 – 180m² with 9x fresh air supply inlets, and 6x stale air extraction outlets.

LARGE heat recovery ventilation systems are suitable for homes with a habitable floor area of 220 – 280m² with 14x fresh air supply inlets, and 8x stale air extraction outlets.

X-LARGE heat recovery ventilation systems are suitable for homes with a habitable floor area of 280 – 350m² with 17x fresh air supply inlets, and 10x stale air extraction outlets.