Home and Leisure Technology for Environmental Efficiency


  1. Introduction
  2. Water Saving
  3. Heating
  4. Building
  5. Home Theatre
  6. Transport

    See Also

  7. Eco-House
  8. Smart Apartment
  9. Author


The Spring Home and Leisure Show was on in Canberra so I went along to see that energy and water efficient technologies they had. Also there were some interesting building and transport options. I was particularly on the lookout for local products and there were several which deserve more attention world wide. Here are the ones I thought interesting.

Water Saving

Perpetual Water Grey Water Treatment System

Perpetual Water is a system for treating graywater so it can be reused in the home and garden. The water can be used for watering the garden, flushing the toilet, even water clothes (but not for drinking). Greywater is the used water from washing in the home. It is a lot easier to treat and reuse than the wastewater from the toilet (called blackwater).

The perpetual water system is a large computer controlled box at the back of the house, which does all the filtering of the water.

Grey water from your shower, bath, handbasin and laundry is collected ...

The Grey water is in the settling tank for 7 1/2 hours. A settling agent is added to the water which aids the contaminants in the water (such as dirt, detergent, sand, hair, lint) to settle to the bottom, leaving clear water at the top of the tank. ...

The clear water from the settling tank is then pumped through Perpetual Waters patented filtration process to complete the cleaning and treatment process. ...

To allow safe storage of the purified water, a very small amount of chlorine is then added before the water is stored in a reuse tank ready for use by your household.

From: Perpetual Water, 2006

Fencewell Water Tank in a Fence



Fencewell is a rainwater tank made up of pipes stacked to form a fence. The idea is that instead of a water tank taking up space in your backyard, it can form the boundary of the property and also save the cost of a fence. It looks a lot better than it sounds.

The pipes are heavy duty PVC. They are stacked on a frame and can be painted to blend in. Because of the use of pipes, the system is inherently modular. It can be built on sloping ground (difficult for a normal tank) and separate sections can be used for different water uses:


Fencewell Diagram

Fencewell water storage system has three sections

  1. Top section is well suited for uses such as, toilet flushing, laundry and evaporative cooling.
  2. Middle section is appropriate for outside the home, garden, car washing, or topping up your pool.
  3. Bottom pipe is a built-in 'first flush' to collect leaf litter, dirt and fumes.

From: How it works, Fencewell, 2006

Toroid Water Tanks

Toroid Water Tank

Donut Water Tank

Tankmasta has a remarkable donut shaped water tank. This is a donut two and a half metres wide holding 3,000 liters of water. The tanks are made out of one piece of molded plastic with built in reinforcing ribs and designed to be buried. There is a larger oval shaped model holding 5,000 l called The Bagel.

Aerated Wastewater Treatment System

Aquanova Tank

Aeration Tank

Everhard Industries showed their Aquanova Aerated Wastewater Treatment System. This has two plastic tanks which wastewater from the house is treated in. Unfortunately ACT Government regulations discourage the use of these systems in the city. They could be used to save water and reduce the load on the sewage system if the regulation were changed to allow home wastewater treatment systems. If you think this is a good idea you might want to send a note to Mr Simon Corbell, ACT Minister for Planning.

The Aqua Nova is a two tank system which provides the very latest in aerated wastewater treatment through a multi stage digestion process using naturally occurring bacteria and enzymes.

In the primary stage, treatment is anaerobic, where bacteria thrive in an oxygen free zone, and the breakdown of solid waste is performed. From here the waste is sent to the second stage where air is continually supplied to bacteria providing aerobic treatment to complete the total digestion process.

At this point the wastewater passes through a clarifying process into the disinfection chamber where any remaining pathogenic bacteria are destroyed. Finally the now clean, clear and disinfected water is delivered by an integral submersible pump with automatic level control to a selected irrigation system in the landscaped garden beds or other dispersion areas.

From: Aqua-Nova, 2006


SolarHeart Gas Boosted Solar Hot Water System

Gas Boosted Solar System

Gas Boosted Solar System

Solahart displayed their Streamline Closed Circuit Gas Boosted solar hot water system. This is designed for Canberra's subzero winters. In cold conditions the water in a solar panel can freeze, destroying it. This closed circuit system uses anti-freeze (like in a car).

During cloudless periods it is difficult for solar systems to keep water hot. The Streamline system has an instant gas heater attached to the tank to heat the water, when needed. The unit isn't pretty, being a large water tank with a gas heater stuck on the side, but should get the job done.

There are plenty of books on Solar Hot Water Systems, but keep in mind that DIY is not a good idea in the area.

WarmTrace Heated Water Pipe

WarmTrace Heated Water Pipe


Jim Bishop, from Active Solar Hot Water, showed me the WarmTrace Self-Regulating Heating Cable. This is used where you have a long run of pipe between your hot water tank and the tap. It keeps the water in the pipe warm, so that you don't have to run the tap for a minute before hot water arrives.

WarmTrace looks like a fat, flat electrical cable. It contains a resistive element which gets warm when current is put through it. Jim cuts you a length of the cable which is then taped along your hot water pipe, between the tank and the tap. Insulation is then wrapped around the pipe, and the cable plugged into an ordinary power point. A few watts of electricity is used to warm the pipe. The cable is manufactured from a material which automatically regulates the temperature.

A WarmTrace system replaces the complex recirculation network of return pipes, circulating pumps and balancing valves. ... self-regulating cable automatically maintains desired water temperatures. Changes in pipe diameters, flow rates and use patterns will not affect the design. Even variations in ambient or water temperature are compensated for as the cable adjusts its heat output along the entire length of a heat-traced pipe.

... heating cable is cut to length and installed directly on the supply piping under conventional thermal insulation with ordinary hand tools. Kits for power connection, end termination and splicing, plus other accessories, are designed for quick and easy installation. ...

From: HSX Product Specifications, Thermon

Heating cable appears to be commonly used in the USA and Europe. There are products available on-line and books describing how to install them. But keep in mind these may not meet local building codes.

Obviously it would be better to put the hot water system closer to the taps and not use electricity to heat the pipe. But if you are stuck with a system a long way away this could save the problem of cold and wasted water.

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