Articles by John Tomczyk

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What’s the Latest with R-410A?

What was once an alternative refrigerant is now an industry mainstay
John Tomczyk
July 3, 2017
R-410A entered the scene as the replacement HFC-based, binary refrigerant blend for R-22 in “new” light commercial and residential air conditioning and heat pump applications.
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R-134A MOLECULE

What’s Happening With R-134a?

Here are some alternatives to replace the venerable but high-GWP refrigerant
John Tomczyk
June 5, 2017
R-134a has a global-warming potential (GWP) of 1,430. This means it traps 1,430 times as much heat per kilogram as carbon dioxide does over a 100-year period. Because R-134a has such a high GWP, the U.S. Environmental Protection Agency (EPA) listed R-134a as an “unacceptable” refrigerant for certain refrigeration and air conditioning applications under its Significant New Alternatives Policy (SNAP) program.
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Refrigerant

What’s the Latest with R-404A?

As another industry workhorse feels the GWP crunch, contractors look at alternatives
John Tomczyk
May 1, 2017
R-404A is being used by OEMs in new equipment and also on retrofitted equipment. However, because of its high global-warming potential (GWP), the U.S. Environmental Protection Agency (EPA), under its Significant New Alternatives Policy (SNAP) program, has listed R-404A as an “unacceptable” refrigerant in a number of retail food refrigeration categories and in vending machines end-uses.
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Tomczyk

Oil in the Evaporator — Not Very Slick

An evaporator internally saturated with refrigerant oil causes many system headaches
John Tomczyk
April 3, 2017
In a perfect scenario, the oil in a refrigeration or air conditioning system would stay inside the compressor’s crankcase to lubricate the compressor’s moving parts. However, because of ever-changing heat loads on the system and varying system conditions there is no such thing as a perfect system in the real world.
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filter drier position

Inside Filter Driers

These valuable components keep systems clean but can become restricted themselves
John Tomczyk
February 6, 2017
Filter driers are designed to remove foreign materials, such as moisture, dirt, sandpaper grit, soldering flux, small solder beads, and acid from a refrigeration or air conditioning system. However, filter driers are notorious for becoming restricted from moisture, sludge, dirt, or oil that has entered the system from a poor service practice or extreme operating conditions.
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thermostatic expansion valve

The Symptoms of a Restricted TXV

How to identify when a liquid-line restriction is starving a system of refrigerant
John Tomczyk
January 9, 2017
A system with a restricted metering device will display the same symptoms as a system with a liquid-line restriction. This is because the TXV is actually part of the liquid line.
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ALCOHOL TREATS:

The Professor: Cheers to Frozen Alcohol Treats

A new process allows alcohol to be frozen at household freezer temps
John Tomczyk
November 7, 2016

A company has invented and patented a method for freezing edible alcohol products. The consistency of the products ranges from hard and solid through sorbet-like, and all stay frozen in the temperature range of 24°-28° without affecting taste, consistency, or alcohol content.


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One way to reduce the amount of extra refrigerant charge needed for condenser flooding is to split the condenser into two separate and identical condenser circuits – note the “summer/winter” and “summer” circuits.

The Professor: Controlling Head Pressure with a Split Condenser

A reliable way to reduce the extra refrigerant charge needed for condenser flooding
John Tomczyk
October 10, 2016

One method of head-pressure control during low ambient conditions is to use a mechanical hold-back or flooding valve located at the outlet of the condenser to hold back or flood liquid refrigerant in the condenser. This valve is often referred to as an open on rise of inlet (ORI) valve because it will start to throttle open on a rise in condenser pressure.


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There is a clear difference between hard ice (right) and soft ice. Photo courtesy of Ferris State University

The Professor: A Toast to Decorative Spherical Ice

Ice is a serious business, but it can also be fun and creative
John Tomczyk
September 12, 2016

Homes, restaurants, bars, 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. Good quality water will produce a crystal-clear, hard piece of ice.


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