Product review (5 stars): Holmes Filters
We use the Holmes tower humidifiers 2 in our home during the winter months even though we live in the south.  Any heating of the house takes out humidity and two much in the south makes mold.  That is why I like the stand alone model so that I can control the mositure instead of the heating unit to automacially pour it in.  I use these filters, a change out of 4, 2 times during the winter.