At www.achrnews.com, The NEWS’ Extra Edition page is home to hundreds of online-exclusive service and maintenance, technical, and business-management articles. Here are some of the best.

Superheat and Subcooling Made Simple

The purpose of this article is to provide a simple explanation of these terms for those who desire a concise understanding, as well as a review for those who understand the terms but want to take another look. An understanding of these terms is essential to understanding the air conditioning and refrigeration mechanical-refrigerant cycle as well as being necessary to trouble-shoot problems.

Practical Ice Maker Troubleshooting Tips

Ice maker troubleshooting is always easier when you have the service manual for the machine. If you can’t get the manual, all of the newer machines have a good set of explanations somewhere, on the front cover or in the control panel area, about what the indicator lights mean with regard to what part of the operational cycle the machine is in, or what error code is being displayed.

Understanding Hot Gas Bypass

Hot gas bypass is recommended when the load on an evaporator varies and operation of the air conditioning system is desired at lower than design conditions. Additionally, hot gas bypass is used when the evaporator coil is designed for comfort cooling (latent and sensible loads) versus precision cooling (all sensible loading). If return air conditions will be 72°F/50 percent rh or lower, the unit should incorporate the hot gas bypass option.

Basic Principles of Refrigeration

If you are like most of us in the HVAC industry, you are a hands-on person — you don’t want to mess with a lot of theory, but just get in and get the job done. But a refrigeration system is different from most. Unless you understand the basic principles covered in this article, you will never understand refrigeration.

Troubleshooting the Refrigeration Cycle for Mechanical Problems

The core of a refrigeration system is the compressor. The refrigeration compressor needs to be properly maintained and requires periodic inspection and testing. Unfortunately, the compressor is often ignored until it malfunctions or stops running altogether. This article describes how to troubleshoot a compressor and the associated problems that can cause a system to fail prematurely.

Publication date: 7/1/2013 

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