Indoor air remains dry, even during the rainy season. You will never have to worry again about mold or dew condensation.
Shirasu has a moisture absorptive property which absorbs moisture when the indoor humidity is high, and releases the moisture when the indoor humidity is low, maintaining a comfortable level of humidity.
During peak summer humidity, this absorptive property holds down the indoor humidity, reducing the temperature and thereby cutting electric power consumed by air-conditioners.
Also, by discouraging dew condensation, it can prevent the appearance of mold or mites caused by humidity.
Formaldehyde absorption and discharge test
How effective are Shirasu's humidity-conditioning properties?
The data below confirms how Shirasu’s humidity-conditioning properties keep indoor air comfortable.
A 15 × 15 cm section of wallboard plastered with Shirasu was placed in a 10 liter desiccator set to 93% humidity (and temperature of about 30ºC).
At the end of the moisture absorption test, the Shirasu wallboard section was promptly placed in a 10 liter desiccator set to 17% humidity (and temperature of about 23ºC).
During the moisture absorption test, the humidity reached 54% (a comfortable level) after 30 minutes, then leveled off at about 45% after 60 minutes. During the moisture release test, the humidity reached 25% after 35 minutes, 27% after 80 minutes, 28% after 250 minutes, then changed gradually thereafter. Although Shirasu seems less effective at releasing moisture than absorbing moisture, our results suggest a slow release of moisture over an extended period. Shirasu may be so slow to release moisture because the cavities in the shirasu particles are so effective at capturing and retaining water that they impede the ability of the circulating air to rise to the humidity of the shirasu in the room.
The humidity-conditioning properties of Shirasu enable it to absorb the humidity of moist indoor air, making rooms feel more comfortable in hot weather. When the indoor air becomes dry, Shirasu releases the humidity stored within the wall. These properties let users raise their air-conditioning temperature setting in summer and live comfortably without air-conditioning for a longer period of the year. Shirasu can also eliminate the need for clothes driers, since even in wet weather, laundry can be dried quickly indoors without leaving any unpleasant lingering laundry odors. In addition, Shirasu’s outstanding deodorizing property purifies indoor air and eliminates the need for air purifiers. Shirasu helps keep the indoor air environment comfortable without the need for energy-consuming appliances.