How Air Conditioning & Heat Pump Evaporator Coils (Cooling coils) are Cleaned
January 18, 2012Evaporator coil cleaning often requires cutting refrigerant lines, removal of the coil and other components for cleaning, and reinstallation, pulling a vacuum on the refrigerant lines, and recharge with refrigerant. Such service and repair may involve significant expense, although there are some “in place” cleaning methods using foams and sprays that are a simpler procedure. See DIRTY COIL CLEANING PROCEDURES for details of this topic.
FROST BUILD-UP – Frost Build-up on the Evaporator Coil in an Air Conditioner
The ice or frost formed on a cooling coil in an air conditioner air handler unit is usually caused by an improper refrigerant charge, possibly by inadequate air flow across the cooling coil, or by a thermostatic expansion valve (TEV) or other air conditioner or heat pump control defect.
Ice blocks air flow through the coil, thus reducing air conditioner output; if the ice formation is extreme nearly all of the airflow across the coil is blocked and the air conditioner system runs but does not produce cool air flowing into the occupied space.
Frost and ice can also form on refrigerant tubing at other locations, and frost and ice can form inside air conditioning duct work itself, leading to troublesome leaks into the building.
Details of what causes frost on air conditioning equipment, what problems that creates, and how to diagnose and repair icing or frost on cooling coils or other air conditioner parts are provided at FROST BUILD-UP on AIR CONDITIONER COILS. There we discuss locations and causes of condensate, frost or ice formation in air conditioning systems, air handlers, compressor/condensers, refrigerant lines, and in air ducts.
Note that frost formation at some cooling coils (not air conditioners or dehumidifiers) may be normal. We discuss frosting and non-frosting cooling coil types and coil defrosting methods further at Frosting vs. Non-Frosting Types of Evaporator Coils
