Static pressures are measured in an HVAC system and utilized to predict the
condition of a filter in the HVAC system. As the filter becomes clogged, the static
pressure can be expected to increase. Changes in the static pressure are determined
periodically, and utilized to predict the condition of the filter. A display provides
a user with an indication of the current condition of the filter, and a recommendation
to replace the filter once it reaches a predetermined condition.