Recent scientific testing on DOWNWOOL® by GRÜEZI BAG has shown that as humidity increases the level of loft, and thus insulation increases, extending performance and comfort.
Grüezi Bag had its unique DownWool insulation tested in a complex test procedure for its fill power to see what happens as the humidity increases.
The renowned testing institute Hohenstein Laboratories GmbH & Co. KG exposed DownWool to 23°C and a relative humidity of between 50% to 90%, monitoring and measuring the change in volume (fill power). The humidity was kept constant for a whole day and the change in volume was observed.
Counter intuitively, the volume of DownWool insulation increases rather than decreases as the humidity increases. At 90% humidity, the volume increased by almost 30% compared to 50% humidity.
The result is that the insulation value increases rather than decreases due to the increasing fill power, which adds to the comfort of the end user. The explanation is that wool absorbs the humidity and swells up. This means that more air is trapped and the insulation increases.