Energy & Water Conservation



Because the water in a Japanese bath remains clean, it can be recycled in the laundry by the use of small pump, or where the levels are different, with pipes and taps. The water can also be used on the garden, of much benefit during dry weather and water shortages.


It is possible to maintain the temperature of a large vessel of heated water such as a bath with the appropriate insulation. An acrylic/polyester bath has its own insulation value and low thermal conductivity, akin to rubber. Surrounding the external surfaces with foil-lined insulation batts prior to fixing the lining in position will further reduce heat loss ( fibre on the inside, foil on the outside facing inwards ). It is surprising that this procedure has rarely been employed in bathrooms up to now.

A further and even more effective form of insulation is to cover the surface of the water and this is best achieved with an EVA/polyethylene foam sheet. Flexible, waterproof and available in various colours and thicknesses, it can be pre-cut by the supplier (Clark Rubber stores in Australia ) to fit tightly against the walls and corners at the depth of water usually required. They are highly effective at 12-15mm thickness and are easily stored and should be regularly scrubbed.

A third form of insulation is a rigid cover that sits on the bath ledge. In Japan, they are often of the roll-up plastic variety, easily cleaned and stored. Alternatively, and superior aesthetically, is the wooden cover that also fits on the ledge. It is preferably made in two parts of a lightweight wood, with handles. Cedar lining boards are ideal. Both the plastic and wooden lids are not as effective as the surface cover, but all these covers will prevent the steaming of the bathroom although the steam has its advantages on wintry nights.


The Japanese bath can be heated using gas, wood, electricity or solar energy and employing an instantaneous, circulatory or storage system. In Australia, the only system currently available has an electric heater connected to a spa.

The ideal heaters for a Japanese bath are the current fail-safe gas-fired circulating systems available in Japan. They are compact, efficient and entirely silent with a touch-pad thermostatic control.

It is possible to connect a hydronic gas hot water system to a Japanese bath but it must be installed by professionals and for safety reasons must not be in operation when the bath is being used.

It should be noted that while heating systems circulate the water, for health reasons, the bath should be emptied and cleaned daily. The bath water should never be reheated.