Samuel Johnson Week 7
Hungarian architect Matyas Gutai has done the absurd – filling a small house’s walls with water (1). His goal is to reduce energy costs by storing heat in the walls. Traditional thermal masses like concrete and brick have worked in the past, but how does water walls compare and do they have a place in the market?
Water walls have the potential to reduce heating costs. The biggest advantage is its high specific heat capacity – it takes longer to heat up and cool down (2). This means water walls can radiate heat for longer periods of time and reduce the need for standard heating systems. In addition, water walls can take up less space than other thermal masses because of its efficient heat storage (3).
Unfortunately, the expense of water walls can add up fast. If the system were ever to leak or windows break water would soak into the walls creating a pricey clean up. Extra care must be taken to seal the system completely. Matyas Gutai also notes extra insulation needs to be added in colder climates to stop the walls from freezing (1), an accident that would ruin the system.
More importantly, water walls are only useful in certain climates. A leader in the passive solar design comments “If daytime highs are 50°F or less for months at a time… thermal mass won’t help much” (4). That significantly limits the use of water walls to warmer climates, a technology not very useful to the northern half of the U.S and many other Countries.
Thermal mass water walls can be costly to install and to use in colder temperatures, but its extraordinary heat capabilities ensures its place in the thoughts of designers. If installed with care in the correct climate water may have a place in the market.