Product review (2 stars): Great idea, but needs improvement to operate efficiently.
Soaks up a lot of water but restricts air flow when fully loaded and spongy material expands. I had to add a wood block between the plastic wick enclosure and front of humidifier to prevent air draft from pulling wick over on its side. Slows air flow by adding resistance to air draft. May or may not put added strain on humidifier fan motor, but definitely slows evaporation. Great concept to use spongy material but need to find way to improve air flow.