Articles by John Tomczyk

The Professor: Superheat

By John Tomczyk
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Superheat is probably the most talked about yet misunderstood technical term used by service technicians in the field. Superheat is a measured value. What can be done with it?


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The Professor: Suction Line Accumulators

By John Tomczyk
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There are times when low evaporator heat loads, just ended defrost periods, failing or misadjusted mechanical valves, or simply lack of system maintenance can cause compressor floodback. If there is no way to prevent these periods of liquid floodback to the compressor, a suction line accumulator is needed on the system.


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The Professor: Frosted Compressor Head

By John Tomczyk
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Many service technicians believe that frost on a suction line or on the compressor’s head itself indicates there is liquid refrigerant coming back to the compressor. Is this really true? 


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The Professor: Systematic Troubleshooting an Oil-Logged Evaporator

By John Tomczyk
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Systematic troubleshooting using a system check sheet is still the best method for the conscientious service technician to pinpoint hard-to-find system problems. This article explores how evaporators can become oil logged, and includes symptoms with explanations of a system with an oil-logged evaporator.


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The Professor: Condensing Temperatures and Condensing Splits

By John Tomczyk
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The three functions of the condenser are desuperheating, condensation, and subcooling. Read to find out more about what the Professor has to say about these three topics. 


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The Professor: Hard Ice vs. Soft Ice

By John Tomczyk
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Homes, restaurants, and businesses rely on clear, clean ice for many applications. Ice is considered a food source, and the water that makes the ice must be of good quality; but what it is the difference between hard and soft ice? Read to find out. 


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The Professor: System Check Sheets

By John Tomczyk
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While my last series of columns explored liquid subcooling in a refrigeration system, this article will compare subcooling amounts in a refrigeration system incorporating an overcharge of refrigerant, a dirty condenser, and air in the system.


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The Professor: The Needed Amount of Condenser Subcooling

By John Tomczyk
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The amount of condenser subcooling needed is system dependent. The more pressure drops — friction and static — associated with the lines and accessories that carry the liquid in the system, the more need there will be for liquid subcooling to prevent liquid line flash gas.


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The Professor: Why Is Condenser Subcooling Needed?

By John Tomczyk
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Condenser subcooling ensures that there is a liquid seal at the condenser’s bottom so the liquid line or receiver will not be fed with vapors. This condition prevents any noncondensables, like refrigerant vapor or air, from leaving the condenser’s bottom and entering the receiver or liquid line.


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The Professor: The Importance of Liquid Subcooling

By John Tomczyk
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This is the first of a three-part series covering the importance of liquid subcooling in a refrigeration or air conditioning system.


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NEWSMakers: Jeff Nusz

Jeff Nusz, president, Reitmeier HVAC Services, Tualatin, Oregon, joins the program to discuss how he modernized his website and gained new clients and more money because of it. We’ll go through the process of the change and much more.  Posted on Aug. 1.

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