HVAC heating, ventilation, air conditioning & refrigeration system component identification guide: This article lists and explains the function of the basic components of an air conditioning or heat pump systems and provides detailed inspection, diagnostic, and repair advice. We include photographs to assist readers inrecognizing cooling system defects. Example home inspection report language is provided to describe common air conditioning system components and their defects. If your air conditioning or heat pump system has lost its cooling capacity or won't start see REPAIR GUIDE for AIR CONDITIONERS. See How to determine the cooling capacity of air conditioning equipment if the system seems to be working but is inadequate to cool your building. At What are the Parts of an Air Conditioning System and How do Air Conditioners Work? we explained the main parts of an air conditioning system and we described the sequence of steps that make an air conditioner work to cool indoor air.

Below we begin a more detailed A/C system inspection list of air conditioning system components. If your air conditioning system is not working properly, see REPAIR GUIDE for AIR CONDITIONERS The air conditioning system (and heat pump) components introduced here are discussed in detail and are illustrated by photographs and drawings throughout this website using the links at the left of these pages. We explain how to inspect, diagnose, repair, or select, purchase, and install air conditioning systems or their individual parts and components. These components are discussed in detail and are illustrated by photographs and drawings throughout this website using the links at the left of these pages. Above we show two typical compressor/condenser units outdoors. The main internal components of the compressor/condenser unit are listed below: Compressor motor - on residential units this is normally a hermetically-sealed motor-compressor combined in a single unit like the Carrier(TM) unit shown

If a ductless split-system is installed an outside compressor/condenser unit is still required, typically containing the very same functions but perhaps more compact, looking like the Sanyo(TM) unit shown at above right. An air conditioning compressor is a specialized pump which draws refrigerant gas back to the compressor/condenser unit from the in-building air handler and evaporator coil. ac dc unitThe compressor compresses the returning low-pressure refrigerant gas to a high pressuresmallest window ac unit available (and high temperature) form.york ac parts diagram In a "split" air conditioning system, multiple indoor evaporator coils and blower units may be served by a single outdoor compressor unit such as the Sanyo unit shown

at the top of this page. That unit was handling the compressor/condenser function for two wall-mounted, ductless indoor cooling units, one of which is shown in the right hand photo at "List of Indoor Components" above. Split systems like this do not make use of ductwork. Sketch of the condenser coil courtesy of Carson Dunlop Associates. Condensing coil receives high pressure refrigerant gas from the compressor and cools this refrigerant gas back to a liquid state. Electrical controls: shut-off switch(es) for service at the unit are provided to permit maintenance and repair of the equipment. Circuit breaker(s) at the electrical panel protect the circuit supplying power to the air conditioning system. Fan an outdoor cooling fan in the compressor/condenser unit moves outdoor air across the condensing coil to cool it and assist in condensing the high pressure, high temperature refrigerant gas back into a liquid. It is this process which completes the transfer of heat through the refrigerant from indoor air to outdoor air

as the compressor/condenser unit compresses and then cools the refrigerant back to a liquid. : these pipes, typically made of copper, include a low-pressure "suction line" which returns low pressure refrigerant gas from the indoor evaporator coil (cooling coil) outlet to the outdoor compressor motor inlet. The high pressure refrigerant line connects the compressor outlet to the outdoor condensing coil inlet (gas) and further connects the condensing coil outlet to the indoor thermal expansion valve which meters high pressure refrigerant into the "low-side" evaporator coil (cooling coil) in the air handler unit in the building. are usually present on the refrigeration lines near the compressor. These valves permit testing the condition of the air conditioning system and permit removal, replacement, or additions to the refrigerant in the system. This photograph of a split system compressor/condenser outdoor unit shows four refrigerant lines and their sets of service ports.

larger diameter copper pipes are the low pressure or suction lines and the smaller diameter pipes are the high pressure lines returning refrigerant to the indoor cooling units. The screw caps visible at the piping connectors where they enter the unit can be removed to provide access to special connecting valves to which the service technician can connect her set of gauges to measure system operating pressures on these lines. unless you're a trainedYou may lose refrigerant or contaminate the system, leading to improper system operation or a costly Continue reading at A/C INSPECTION CHECKLIST - OUTDOOR UNIT or select a topic from the More Reading links or topic ARTICLE INDEX shown below. Or see AIR CONDITIONING & HEAT PUMP SYSTEMS - homeThere are various types of air conditioners like window air conditioner, split air conditioner, packaged air conditioner and central air conditioning system. This series of articles describes all types of air conditioners.