Kuruvilla Mathew

Vermifiltration systems rely on the biodegradation of organic matter in household wastewater to produce a humus filter. The humus filter in an appropriate design is capable of treating wastewater to a high secondary standard suitable for non-contact reuse purposes e.g. irrigation. The variable nature of household wastewater production and constitution may cause toxicity from particular wastewater constituents to the species that biodegrade the organic matter in vermifiltration systems. Due to this, this study was undertaken to assess the toxicity of one particular constituent, hypochlorite, to key species within the vermifiltration process. Hypochlorite and its by-products are present in many household products, especially disinfectants and household cleaners.

During the study, the key vermifiltration species, the worm Eisenia fetida, was subjected to a series of hypochlorite toxicity tests in solid phase mesocosms. The tests showed that the adult worms were relatively tolerant to hypochlorite toxicity, but the reproduction by the worms was impaired at a very low hypochlorite concentration. The overall risk assessment showed that hypochlorite and its main by-products total organic halogens and sodium chloride are unlikely to cause toxicity to E fetida from accumulation in a vermifiltration system, during normal household use.

A number of sustainable demonstration homes have been built in Perth over the last 5 years. This paper reports on data gathered at two of them, provides a comparative assessment and presents lessons learnt. The Subiaco Sustainable Demonstration Home (SSDH) is a collaborative effort between the local council and the building industry to create a house that uses fewer resources than normally built homes during its construction, use, and eventual demolition. Harvest Lakes, the first Housing Industry Association (HIA) GreenSmart estate in Western Australia, showcases ‘The Elements’ Sustainable Demonstration Home (ESDH) as an example of a possible sustainable future of residential construction and living. With a Passive Solar (PS) design based on a standard plan, ‘The Elements’ Sustainable Demonstration Home could easily be replicated in various other locations of Australia. Each house has been monitored for at least the last year using stand-alone temperature data-loggers to record the air temperatures in different rooms to give an indication of the effectiveness of the PS design in terms of maintaining temperatures within established Thermal Comfort thresholds. Results collected to date indicate that a PS building can be thermally comfortable, but it does require occupants to ‘drive’ them to maximise the benefits of the design.

This study concerns an investigation into the thermal performance and energy efficiency of prefabricated lightweight houses for peri-urban villages in the Perth Metropolitan region of Western Australia. Several styles of residence were selected for comparison, taken from the first three “lifestyle villages” constructed by National Lifestyle Villages Pty Ltd (NLV). NLV is committed to quadruple bottom-line sustainability and the aim is, therefore, to provide indicators of how old and new dwellings compared under the same external conditions. The buildings themselves are prefabricated and brought to site in two halves, framed in steel, clad with fibre-cement boarding, roofed in zincalume sheeting, floored in flooring grade particle board with applied fibre-cement sheeting. Although the basic design was developed using the passive principles of solar design and other energy conservation measures, they possess little thermal mass to augment the thermal efficiency. Research has indicated several feasible and low-budget innovative improvements to incorporate into future designs, and how best to modify and retrofit existing dwellings. NLV aims to provide homes for over 40,000 people in 100 villages throughout Australia by the year 2025. Any improvement in residential thermal performance can be translated not only into energy savings and greenhouse gas reduction on a significant scale, but can enhance comfort levels for residents whilst reducing their energy costs. This paper will present the data and report on the results of the investigations. Recommendations will be made for housing in proposed future villages with regard to requirements for other improvements such as innovative means of increasing internal thermal mass.

A number of sustainable demonstration homes have been built in Perth over the last 5 years. This paper will report on data gathered at two of them, provide a comparative assessment and present lessons learnt. A fundamental inclusion in a sustainable house is Passive Solar (PS) design. PS design is a simple methodology for the design of energy efficient buildings that can reduce the need for mechanical heating and cooling, therefore reducing the need for energy to operate active systems. PS design is a regionally specific design methodology whereby the general climate of a house site needs to be analysed to best ascertain what design features will be needed. In Australia, due to the extremes of conditions, house designs will vary greatly by state, which is also due to the established building industry. The uptake of this design rationale has been very slow, with houses mainly relying on air-conditioning. The design of a PS building follows several basic principles: Orientation, Glazing and Protection, Thermal Mass, Insulation, Ventilation and Zoning. A PS house uses a system of windows, walls and insulation to control the flow of energy to maintain temperatures at comfortable levels for occupation. Separate components are not monitored, just the capacity for the building to have stable internal air temperatures, which is what inhabitants will detect. The range of temperatures for Thermal Comfort (TC) is 18 to 28° Celsius. The Subiaco Sustainable Demonstration Home (SSDH) is a collaborative effort between the local council and the building industry to create a house that uses fewer resources than normally built homes during its construction, use, and eventual demolition. Harvest Lakes, the first Housing Industry Association (HIA) GreenSmart estate in Western Australia, showcases ‘The Elements’ Sustainable Demonstration Home (ESDH) as an example of a possible sustainable future of residential construction and living. With a PS design based on a standard plan, the ESDH could easily be replicated in various other locations around Australia. Each house has been monitored for at least the last year using stand-alone temperature data-loggers to record the air temperatures in different rooms to give an indication of the effectiveness of the PS design in terms of maintaining temperatures within established TC thresholds. Results collected to date indicate that a PS building can be thermally comfortable, but it does require occupants to ‘drive’ them to maximise the benefits of the design.