Articles by John Tomczyk

The Professor: Going Chlorine-Free in Retrofits

Ferris State University’s Commercial Refrigeration Laboratory has gone totally chlorine-free. By replacing the refrigerant HCFC-22 that was in two medium-temperature commercial refrigeration cases in the laboratory, the students in the associate degree program in HVACR can boast that the lab is now chlorine-free.
Read More

The Professor: Restricted TXV Metering Device

This article explores how a restricted metering device will affect system performance and efficiency. The system is a commercial refrigeration system with a TXV as the metering device. The refrigerant being used is HFC-134a. Very similar results will occur if an automatic expansion valve (AXV) is used.
Read More

The Professor: Symptom Variations With Different Devices

Symptoms for a refrigeration system with an overcharge of refrigerant are (a) high discharge temperatures, (b) high condenser subcooling, (c) high condensing pressure, (d) higher condenser splits, and (d) slightly higher evaporator pressures. However, these are for a system with a conventional TXV. What if the system has an automatic expansion valve or a capillary tube?
Read More

The Professor: Advanced Leak Detection

My Oct. 4 column discussed leak detection and provided details on basic detection methods. This column looks at more advanced methods. The Oct. 4 column outlined various classes of leaks with standing leaks as the most common. This article begins with a discussion of how to test for pressure-dependent leaks.
Read More

The Professor: Basic Leak Detection Methods

Every environmentally conscious service technician should spend time learning how to check for refrigerant leaks in refrigeration and/or air conditioning systems. Ozone depletion, global warming, and the increasing price of refrigerants are forcing technicians to become better and more thorough leak detectors.
Read More

Multimedia

Videos

Image Galleries

2015 HARDI Fly-In

Highlights from HARDI's Congressional Fly-In in Washington, D.C. Post date: May 28, 2015.

Podcasts

NEWSMakers: Kevin Conrad
Kevin Conrad, president, Kevin Conrad Heating and Cooling Inc., Nantucket, Massachusetts, breaks down working in the New England climate, the benefits of insulation foam, and more.


More Podcasts

ACHRNEWS

NEWS 06-29-15 cover

2015 June 29

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe

Online Reviews

Do you track online review sites like Yelp to look for comments on your company’s performance?
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