Many properties use smaller wall unit or window air conditioners, which are typically serviced by on-site maintenance personnel. Unit air conditioners work in much the same way as refrigerator. An evaporator coil cools the interior (in this case room), and the condenser coil releases the hot air outdoors. Refrigerant is moved by a pump through tubes between the two coils to transfer the heat. A fan blows the cool air into the room. Some simple maintenance tips can help keep the wall and window units work properly. Keep the filter and coils clean and replace the filter as recommended by the manufacturer. To clean, remove the inside grill, carefully take out the foam filter, and wash it in warm soapy water. If the filter extremely dirty, more than one washing may be needed. Be sure to rinse and allow the filter to dry before replacing. Filters that are no longer effective can be inexpensively replaced.

• Given the complexity and cost of such problems, managers should include specific inspections and actions relative to the plumbing system in their maintenance plans. Residents usually call management for repairs only after the plumbing has broken down or become a nuisance. Encourage residents to report all maintenance issues by calling the management office as soon as they discover a problem.

SANITARY SEWER SYSTEM

• The most common causes of sewer service line backups are improper disposal of household items, such as paper towels, sanitary napkins, disposable diapers, and cooking grease; garbage disposal misuse; and food debris, such as fruit and vegetable peelings, in kitchen sinks. Grease, roots and rags that are inappropriately discharged into the sewer system can also cause problems in sewer lines that are connected to main or city sewer lines.