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Home » Authors » John Tomczyk

Articles by John Tomczyk

Refrigerant Cylinders

Don’t Mistake a Restricted Liquid Line for an Overcharge

Technicians must distinguish between the two when servicing refrigeration systems
John Tomczyk
October 28, 2020
Distinguishing between a restricted liquid line and a system overcharge in a commercial refrigeration system is very important for service technicians.
Read More
The Professor John Tomczyk

Overcharge Symptoms Differ Due To Metering Devices

TXVs, AXVs, and capillary tube systems will have varying evaporator pressures
John Tomczyk
September 23, 2020
There are varying types of symptoms that can occur when a refrigeration system has an overcharge of refrigerant.
Read More
The Professor John Tomczyk

Worn Rings and Leaky Valves Can Cause Problems

Diagnosing the issue in refrigeration and air conditioning systems can be tricky
John Tomczyk
August 28, 2020
Worn compressor rings and/or leaky compressor suction or discharge valves can cause a lack of cooling in refrigeration and air conditioning systems.
Read More
Dirty Air Filters Can Cause Serious Air Conditioning System Problems

Dirty Air Filters Can Cause Serious Air Conditioning System Problems

Air conditioners should have filters cleaned or replaced before starting for the season
John Tomczyk
August 9, 2020
One important but often overlooked piece of equipment is the air filter, which protects the evaporator from dirt and lint.
Read More
Absolute pressure refrigerant gauge.

Refrigerant Density Can Affect Compressor Capacity

Service techs can make adjustments to optimize performance
John Tomczyk
July 3, 2020
Let’s look at how the density of refrigerant entering the compressor’s cylinders affects the mass flow rate of refrigerant through the compressor.
Read More
How to Prepare Equipment for Long Shutdowns

How to Prepare Equipment for Long Shutdowns

Precautions must be taken for refrigeration and air conditioning systems
John Tomczyk
May 26, 2020
Long shutdowns can wreak havoc on refrigeration and air conditioning systems if certain steps are not taken.
Read More
FROSTlines

Liquid Refrigerant, Dense Vapors Can Damage Compressors

To prevent these conditions, the proper amount of superheat must be set at the TXV
John Tomczyk
May 2, 2020
Refrigeration and a/c compressors are vapor compressors, meaning they are designed to compress refrigerant vapor, not liquid refrigerant.
Read More
Frosted Evaporator Coil

Don’t Confuse a Frosted Evaporator Coil With Refrigerant Overcharge

Never add or subtract refrigerant from a system until the problem is determined
John Tomczyk
April 8, 2020
Technicians often confuse symptoms of a refrigeration system that has a frosted evaporator coil with a system that is overcharged with refrigerant.
Read More
FROSTlines

Don’t Mistake Liquid Line Restriction For an Undercharge of Refrigerant

Ensure there is no restriction before adding refrigerant to system
John Tomczyk
March 9, 2020
In a refrigeration system, service technicians often confuse a liquid line restriction with an undercharge of refrigerant.
Read More
Compressor Discharge Temperature

Compressor Discharge Temperature Reflects How Equipment is Operating

Keep an Eye on Discharge Line Temps
John Tomczyk
February 10, 2020
The compressor’s discharge temperature can tell the service technician what is going on inside a refrigeration or air conditioning system.
Read More
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