Articles by John Tomczyk

The Professor: Net Oil Pressure

Many larger compressors in the refrigeration and air conditioning field have forced-oiling systems. These compressors are usually over 5 hp. They contain an oil pump located at the end of the compressor’s crankshaft. The crankshaft is actually connected to the oil pump and supplies power, which turns the oil pump.
Read More

The Professor: Systematic Troubleshooting

The problem we are going to deal with here pertains to a restricted liquid line after the receiver. Provided is a service checklist. Assume that the refrigeration system is a TXV/receiver system, employing a filter drier and sight-glass. The system has R-134a as the working refrigerant.
Read More

The Professor: Retrofit R-438A

There is an estimated 900 million pounds of HCFC-22 installed in refrigeration and air conditioning systems in the United States. This article covers one of the leading refrigerant blend candidates for retrofitting R-22 systems for both a/c and refrigeration applications.
Read More

The Professor: Variable-Frequency Drives

The HVACR industry is one where both centrifugal pumps and fans are used on an ongoing basis. Because of this, HVACR systems are huge energy consumers. Creating higher-efficiency systems offers a tremendous opportunity for great electrical and monetary savings. Many of these savings can be achieved through the use of variable-frequency drives.
Read More

The Professor: Retrofitting R-22 Systems

As mentioned earlier, most new systems will be manufactured with R-410A. However, the question of what is the best retrofit refrigerant blend for existing R-22 systems is often asked by technicians and equipment owners. There is no one quick-fix solution or answer to this question. The answer depends on several key factors.
Read More

The Professor: Explaining the R-22 Phaseout

With so much talk these days about HCFC-22, I thought I’d offer a back-to-basics look at this refrigerant that has been so popular for so long - but now is facing phaseout.
Read More

The Professor: Comparing HFC-134a to R- 12

HFC-134a is the alternative refrigerant of choice to replace CFC-12 in many medium- and high-temperature stationary refrigeration and air conditioning applications. However, R-134a is not a direct drop-in refrigerant for R-12. Retrofit guidelines must be followed carefully when converting a system from R-12 to R-134a.
Read More

The Professor: Replacement Blend HFC-410A

This article is the first in a series focusing on refrigerants and refrigerant blends. This month’s article will concentrate on the HCFC-22 air conditioning replacement refrigerant blend HFC-410A, better known as R-410A.
Read More

The Professor: Restricted Airflow Over an Evaporator

There are a number of ways that the airflow over an evaporator can become restricted. Anytime the evaporator coil sees reduced airflow across its face, there will be a reduced heat load on the coil. No airflow will cause a lot of the refrigerant in the coil to remain a liquid and not vaporize.
Read More

The Professor: Defrost Termination/Fan Delay Controls

The defrost termination/fan delay control is a temperature-activated, single pole-double throw switch controlled with a remote sensing bulb. The control can be an adjustable type. One example of the installation of an adjustable defrost termination/fan delay control is on a walk-in freezer’s evaporator.
Read More

Multimedia

Videos

Image Galleries

2014 World Energy Engineering Congress

Scenes from the 2014 World Energy Engineering Congress in Washington, D.C.

Podcasts

NEWSMakers: Matt Barga

Matt Barga, portfolio manager — a/c and coils, Ingersoll Rand, discusses how the company is working to comply with the new energy conservation standards for heat pumps and air conditioners that go into effect on Jan. 1, 2015. Posted on Dec. 19.

More Podcasts

ACHRNEWS

NEWS 12-22-14 cover

2014 December 22

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe

HVAC TECHNICIAN SHORTAGE

In order to bring more people into the trade and produce more technicians, what should the industry do?
View Results Poll Archive

HVACR INDUSTRY STORE

2015.jpg
2015 National Plumbing & HVAC Estimator

Every plumbing and HVAC estimator can use the cost estimates in this practical manual!

More Products

Clear Seas Research

 

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

DON'T MISS A THING

Magazine image
 
Register today for complete access to ACHRNews.com. Get full access to the latest features, Extra Edition, and more.

STAY CONNECTED

facebook icontwitter iconyoutube iconLinkedIn i con