Air Filters and Screens
Each unit is equipped with return air filters. If the unit has an economizer, it will also have an outside air screen. If a manual outside air damper is added, it will also have an inlet air screen
Each of these filters and screens will need to be periodically replaced or cleaned.
EQUIPMENT DAMAGE HAZARD
Failure to follow this CAUTION can result in premature wear and damage to equipment
DO NOT OPERATE THE UNIT WITHOUT THE RETURN AIR FILTERS IN PLACE.
Dirt and debris can collect on heat exchangers and coils possibly resulting in a small fire. Dirt buildup on components can cause excessive current used resulting in motor failure.
Return air filters are disposable fiberglass filters. Access to the filters is through the lift-out filter access panel located on the rear side of the unit, above the indoor coil access panel. See Fig. 2.
Removing the Return Air Filters
Re-Installing the Access Panel
Outside Air Hood
Outside air hood inlet screens are permanent aluminum-mesh type filters.
Check these for cleanliness.
Source: Carrier (www.shareddocs.com)