Oil-logging is often a major cause of low-side restrictions, and there are many ways in which evaporator and suction lines inside tubing can become oil-logged.
When installing or repairing a refrigeration system, technicians should look for opportunities to slightly modify the system (without changing its design) to make it more serviceable.
Troubleshooting the high side of a refrigeration system will often give service technicians valuable information. That’s because what happens in the condenser is a direct reflection of what is happening in the rest of the refrigeration system.
According to the Environmental Protection Agency (EPA), a typical food retail store leaks an estimated 25 percent of refrigerant, or approximately 1,000 pounds, annually.
The homeowners of a medium-sized house complain of reduced airflow coming from their registers during the summer. Their air conditioner is a 4-ton (48,000 Btuh), R-22 split system with the A-coil in the plenum of the furnace located in the basement. The evaporator has an orifice for a metering device, and the condensing unit is located on the east end of the house.
A critical step in the installation of a built-up (field-piped) refrigeration system is the startup and commissioning of the equipment, which simply means verifying the operation of the system and its components. Although this seems obvious, it is a step that is occasionally skipped or done too quickly to be effective.
Many air conditioning and refrigeration systems have their condensing units located outdoors for two main reasons. First, this takes advantage of the cooler outdoor ambient temperatures to reject the heat absorbed in the evaporator section, and second, to reduce noise pollution.
Many single-phase compressors require a start capacitor to assist in starting the motor. These capacitors will occasionally fail, causing a compressor to fail to start.