Justin McGar writes a good article on the sourceable.net website about a new technique using water that can build more energy-efficient homes. Do you have any views?
Houses Made of Water Are the Future for Energy Efficiency
An increased awareness of energy consumption, and the financial costs involved, is likely to see households continue to engage in energy saving practices. But would you build a house with water in the quest for energy efficiency?
Using an approach coined ‘liquid engineering,’ a Hungarian architect has come up with a multi-functional panel system which he believes is the answer to a more sustainable, more comfortable and energy efficient home.
Climate change has been identified as one of the biggest issues facing the nation and the world. Results from the 2007-08 Environmental Views and Behaviours component of the ABS Multipurpose Household Survey showed that nearly three quarters (74 per cent) of Australian adults were concerned about climate change. This, in addition to concerns about rising energy costs, has led to greater attention being focused on ways in which households and individuals can reduce their carbon footprints.
In Australia, most homes use a third to half of their energy for heating and cooling with these also being responsible for a similar proportion of greenhouse gas emissions. Around 30 per cent of heat is lost through ceilings and another 10 to 20 per cent through walls, unless they are well insulated.
Matyas Gutai says his Allwater panels can save as much as 40 per cent in energy costs.
Typical structures built of brick or concrete have good heat storage capacity, which is crucial for a good indoor environment and comfort, but unlike light structures, they are expensive to build.
Water is not only a good collector of heat but a superb distributor. By inserting a sheet of water between the inner layers of his innovative panels, Gutai’s solution is equal to a thick brick or concrete wall when it comes to heat mass.
The house is actually able to reheat itself. When it is hot, any excess heat is stored either in the foundations of the building or in external storage. It can then be brought back to the walls when the temperature drops. The internal environment can be adjusted to suit using a similar monitoring system to central heating.
“Water House works just like planet Earth,” said Gutai. “Solid, fluid and gas work together and all serve the purpose they are best in. Air insulates, soil gives geometry and water provides thermal storage and distribution.
“Water House is not simply an improvement of the classic model; it is a completely new type of structure. Fluid infill is not only a superb heat storage opportunity, it is also perfect for heating and cooling, and also distributing to maintain an ideal thermal balance indoors.”
Compared with conventional heating methods, for example gas, where energy consumption is 100 per cent and the saving is 0 per cent, or even gas plus geothermal heating system which saves about 20 per cent and energy costs drop to 80 per cent, Allwater panels in conjunction with either geothermal or solar panels can supply the complete energy needs of the building – both heating and cooling – and save another 20 per cent.
Beyond improved energy efficiency, there are a number of other advantages to the system. Water only enters the structure at the end of construction making the panels easy to assemble, and these panels are “light during construction, heavy during operation.” In addition, the ability to not only collect heat but transport heat means its fire resistance is much higher than conventional structures.
Gutai got the idea for the water house when he visited the open air hot baths of Tokyo, while studying at University 12 years ago.
Despite the freezing snow outside the pool, he remained comfortably warm inside it and thus he has his eureka moment, realising the importance of the water’s surface temperature and its potential use in architecture.
There have been plenty of structural challenges to overcome, however, such as what happens when it’s so cold outside that the water freezes, or what happens when one panel breaks.
“We now mix the water with natural solvents, which do not cause pollution but lower the freezing temperature to an acceptable level. This practically means, that even if the reheating technology fails, the water cannot freeze,” Gutai told CNN. “In case of cold climates, like in Hungary, we also add some external insulation to the structure, to protect it from freezing.”
If the panel were to break, specially designed joint units allow slow flow but block faster flows, sealing remaining panels instantly from the damaged one. The effect, Gutai explained, is based on fluid dynamics, and not computers or monitoring systems. This minimizes the chance of failure.
Constructing houses in this way is moderately more expensive than traditional designs but the increased cost up front is offset by the reduction in energy costs. This, coupled with collaborative research with manufacturers to help reduce production costs, could pave the way to water being the green building material of the future.