Articles by John Tomczyk

Figure 1

What’s the Latest with R-410A?

What was once an alternative refrigerant is now an industry mainstay
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John Tomczyk
July 3, 2017
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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
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John Tomczyk
June 5, 2017
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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
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John Tomczyk
May 1, 2017
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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
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John Tomczyk
April 3, 2017
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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
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John Tomczyk
February 6, 2017
One Comment
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
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John Tomczyk
January 9, 2017
One Comment
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
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John Tomczyk
November 7, 2016
One Comment

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
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John Tomczyk
October 10, 2016
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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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