I recently purchased an evaporator humidifier, and I got to wondering if a drop of dishwashing soap in the water reservoir might help the evaporator pads soak up the water. This triggered my question here.
OK, I’ve heard from two chemists now on this issue (one in Fluther, one outside). The consensus seems to be that a small amount of soap will not affect the evaporation rate. Soap reduces the surface tension of water, allowing the water to clean better. “But”, according to one chemist, “the surface tension of a liquid does not affect the evaporation rate.” A lot of soap would just build up in the works in the machine, so I am not going to try it.