Product review (1 stars): Does not perform well or last
These MD1-0002 replacement filters are supposedly compatible with ALL Vornado humidifiers but this is not the case for Evap1 model.

Vornado recently reduced the thickness of MD1-0002 filters from 2" to 1 1/2", a very noticeable difference and results in a poor fit with Evap 1 housing.  These thinner filters also have noticeably worse moisture output per day.

The newer, thinner design of MD1-0002 filters will last you approx 3-4 weeks of continuous use.  Be prepared to go through several filters each season.

Here are some numbers:  Assuming the humidifier season runs from 12/1 - 4/1 and continuous use of your Vornado humidifier during the season, you will run through approx 9 - 12 filters per humidifier.  At a cost of $12.99 each filter set, that is $117 - $156 per humidifier per season.

For the same cost of running 1 Vornado humidifier per season, you are better off buying 3 or 4 of the Crane humidifiers for the same money and place them in each of your bedrooms.  The Crane humidifiers work great and do not require any filter replacements.

The Crane is the top rated humidifier on Consumer Reports vs. Vornado models which are near the bottom.