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RSES COVID-19 Resources

Together We’ll Make It Through COVID-19

The onslaught of the COVID-19 virus poses a once-in-a-generation challenge to the HVACR industry on multiple levels. How do HVACR contractors keep their businesses going as their customers shut down? Are residential customers afraid of letting service technicians into their homes? How do you protect your service techs from the virus? How do you get personal protective equipment when even hospitals are having a difficult time? How do you protect your elderly or otherwise susceptible customers from service techs who may have come in contact with the virus and either be carriers or have the virus on their clothing? How do you advise commercial clients on best practices for operating their HVAC systems during the crisis?

Fortunately — and rightly so — HVACR contractors have been deemed essential businesses that must continue to operate even as the virus has shut down much of the U.S. economy. Supermarkets and convenience stores continue to operate, and our refrigeration customers are depending on us. It’s still cold enough that residential customers need their heating systems, especially in the northern tier, and will need air conditioning if this continues into summer. Hospitals will need particular care to keep, for example, negative pressure rooms operating properly.

There are limits to what we can do with the tools that we have at hand. Filtration, biocides and UV lighting can help, but not completely. Nevertheless, there’s much that we can do. There’s plenty of good advice that we can give our customers. There are plenty of services that we can offer that will be helpful.

And, so, to help you, we’ve assembled all of the information that we can find from our archives and from other industry sources to serve as a helpful guide during these difficult times. We’ll be adding to it as more information becomes available. We hope that these resources will help you survive and recover from the current crisis. In the meantime, be careful, sanitize surfaces in your office and trucks (especially your phone), and wash your hands thoroughly and often. Together we’ll make it through COVID-19.



How To Stay Safe As A Contractor During COVID-19 Pandemic

U.S. Department of the Treasury Assistance for Small Businesses

Coronavirus Emergency Loans Guide and Checklist for Small Businesses and Nonprofits

Air Handler Retrofit Turns Regular Hospital Rooms into Negative Pressure ICU Rooms

ASHRAE Epidemic Task Force Established

Minnesota Document Shows Hospitals How to Set-Up Stop-Gap Negative Pressure Rooms

Goettl Air Conditioning Donates UV Germicidal Lights to All 600 Employees

HVAC Contractors Guide to COVID-19

Proactive Measures to Avoid and/or Mitigate Exposure to Construction Impacts Arising From COVID-19

Advice to Contractors: COVID-19 Prevention & Control Plan

Toolbox Talk: The Coronavirus Pandemic

ACCA Requests HVACR Workers Be Considered Essential Service Providers in Pandemic

Can Air Purifiers Protect You from the Coronavirus?

School HVAC Systems and COVID-19

HVAC Systems Don’t Spread COVID-19

ASHRAE Offers Course on the Role of HVAC Systems on Infection Control



UV Light: A Tool for IAQ Solutions

Putting UVC Under a New Light

Getting Clean and Green with UVC Technology

Product Focus: PPE

Improving iAQ: A Balancing Act

Understanding IAQ Tool Characteristics

Filtering Down to the Nitty Gritty

Balanced Efficiency in Air Filters

Using UVC to Control Microbial Contamination

 Shining Light on UVGI Installations

What Every Tech Should Know About IAQ



RSES' Service Application Manual (SAM) is the oldest living reference manual available that contains literally thousands of pages of technical data, equipment analyses and evaluations, field application instruction, regulations, good practice codes, business development guidance and more.  Access to the hundreds of SAM chapters currently available is a member benefit, however, we have compiled a list of some of our Educational & Examining Board members' favorites for you to review for FREE. Following are just a few samples of the chapters available in our archive. Take a look at the complete Table of Contents.

New Additions | Posted April 3, 2020:

  • The Capillary Tube and Its Application to Small Refrigerating Systems: It is the purpose of this chapter to present a simplified explanation of the capillary tube and to describe simply and in a straightforward fashion the steps to be taken in making a conversion.
  • Capillary Tubes: Theory and Practice: This chapter covers the importance of the cap tube as a refrigerant control vs. what you only may see as a slender copper tube with a small inside diameter.
  • Thermostatic Expansion Valves - Part 1: This chapter covers the theory of operation, proper selection, and application of thermostatic expansion valves (TEVs).
  • Thermostatic Expansion Valves - Part 2: This chapter covers knowing how to apply, install and service the thermostatic expansion valves (TEVs).
  • Evacuation of a Refrigeration System: The purpose of this chapter is help the service technician thoroughly understand the use of vacuum as a service “tool” to properly prepare a refrigeration or cooling system to receive its charge of refrigerant. The various sizes and types of vacuum pumps will be reviewed and followed by a brief discussion of the fundamentals of vacuum.
  • Plotting the A/C Cycle on a Pressure-Enthalpy (Mollier) Diagram: This chapter covers a discussion of how physical characteristic curves, or pressure-enthalpy diagrams, can be developed for stable refrigerants.
  • Using the PT Chart as a Service Tool: The purpose of this chapter is not only to explain the pressure-temperature relationship, but also to illustrate how a P-T chart can be used to thoroughly analyze a refrigeration or air conditioning system
  • Pressure-Enthalpy Charts and Their Use: his chapter will help you become familiar with the properties of both liquid and vapor in order to understand the refrigeration cycle. These properties are the key to understanding and using refrigerant pressure-enthalpy diagrams. Sample diagrams are in this chapter.
  • The Psychrometic Chart and Its use: In this chapter, the basic fundamentals of psychrometry as well as several examples of its use to the Service Engineer are covered.
  • Electronically Commutated Motors Part 1: This chapter is intended to provide the reader with the history and background on electronically communicated motors (ECMs.) Part 1 in a series.
  • ECMs Part 2: Constant-Airflow ECMs: This SAM section is dedicated to providing the reader with an understanding of current Constant-Airflow ECMs including their operation, application and benefits, installation and setup, troubleshooting and repair.


Like what you are reading? Parts 3 and 4 (along with hundreds more Chapters) are available to RSES Members. Sign up today!


  • Fundamentals of Indoor Air Quality: Topics covered in this chapter are as followed: “Sick Building Syndrome”, humidification, air filters, dilution ventilation, carbon dioxide, fungi, general service guides.
  • Refrigeration and Air Conditioning Trade Safety for Construction, Service and Maintenance Workers: By adhering to the legal responsibilities and recommended practices outlined in this chapter, labor and management can work together to reduce or eliminate many injuries and improve the health and safety of all who work in the refrigeration and air conditioning industry.
  • Venting of Category IV Appliances: It is the intent of this chapter to highlight the basic procedures that can help the technician prevent costly or possibly even deadly mistakes. All systems must be vented in accordance with the manufacturer’s specifications and all local codes. The technician must read and follow the manufacturer’s instructions for the equipment being installed.
  • Residential Electronic Ignition Systems: Information contained in this chapter is generic in nature. It may or may not illustrate a given manufacturer’s recommendations for a particular product. Always follow manufacturer’s instructions, specifications, and service/safety practices.


Posted March 31, 2020:


  • Understanding Electrical Schematics Part 1: The purpose of this chapter if to familiarize technicians with symbols and conventions commonly used in schematic diagrams, thereby making it easier to identify components and their related circuits.
  • Understanding Electrical Schematics - Part 2: This chapter deals with a wiring diagram for a packaged gas/electric system, which is a relatively complex heating and cooling unit. Many of schematic symbols currently used and recognized by the HVAC/R industry are at the end of this
  • Residential Electronic Ignition Systems: Information contained in this chapter is generic in nature. It may or may not illustrate a given manufacturer’s recommendations for a particular product. Always follow manufacturer’s instructions, specifications, and service/safety practices.
  • Refrigerant Piping: The purpose of this chapter on refrigerant piping is to point out some of the precautions to be taken which affect the life and efficiency of refrigerating equipment, and to offer some helpful suggestions in piping design, selection and erection.
  • Principles of Refrigeration – Part 1: This chapter is the first part in a series on the principles of refrigeration covering saturation, temperature and pressure, superheat, vapor pressure, liquids other than water, temperature difference, pumping superheated vapor, pressure drop in the suction line and salvaging the refrigerant.
  • Principles of Refrigeration – Part 2: This chapter is the second part in a series on the principles of refrigeration covering saturation, temperature and pressure, superheat, vapor pressure, liquids other than water, temperature difference, pumping superheated vapor, pressure drop in the suction line and salvaging the refrigerant.
  • Principles of Refrigeration – Part 3: This chapter will cover the process by which the refrigerant vapor that is boiled off in the evaporator is salvaged and reconverted into a liquid, so that it can be used over again, rather than wasting it to the atmosphere.
  • Principles of Refrigeration – Part 4: This chapter covers the fundamentals of refrigeration utilizing a simple mechanical system with a closed cycle. Topics covered include temperature, moving heat, change of state, heat capacity, sensible heat, vapor pressure, saturation, latent heat, net refrigeration, superheat, the compressor, capacity.


RSES' Webinars are presented by some of the industry's most sought-after technical experts, sessions range from basic to advanced on topics spanning the HVACR spectrum. Participation in live webinars earns Members CEHs automatically, and webinars are recorded for future viewing. These live monthly events are available to Members free of charge, or as recordings in the Member-only area.

TODAY, we are offering the following webinars FREE to view for everyone during this difficult time. If you are looking to earn CEHs for these, please visit our Online Store and purchase the eLearning quiz that accompanies the presentation.


Basic Electrical Safety
June 17, 2020
Presented by Jeff Sloan






Commercial Building Connectivity – Smart Light Commercial HVAC Control Systems
June 16, 2020
Presented by Mark Bell, Gene, Shedivy, Rick Kloeppner
Handout 1; Handout 2; Handout 3




How Refrigerant Choices Influence System Architecture
May 20, 2020
Presented by Ron Vogl





How to Design for AWEF: Condensing Unit Choices and Options
April 28, 2020
Presented by Rex Martin





Evacuation Done Right
Wednesday, April 15, 2020 | 7 p.m. Eastern
Presented by Bryan Orr


 Refrigeration Systems Tricks & Tips
Wednesday, March 18, 2020
Presented by Joe Marchese, CMS, RCT

 Refrigerants & Service Training
Tuesday, May 14, 2019
Presented by Art Miller, CMS, RCT

 Principles and Applications
March 16, 2016
Presented by Brynn C. Cooksey, CMS, RCT

 Capacity in Residential Cooling
July 22, 2015
Presented by Bob Cone, CM


 Air Quality: The Latest Trends
September 17, 2014
Presented by Bill Spohn, PE
Carbon Monoxide Concentration Chart








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How Will the COVID-19 Pandemic Affect Your Business in the Next 8-12 Weeks

Increase  5 votes (71%)
Decrease  2 votes (29%)
Stay the Same  0 votes (0%)
Total Votes: 7

RSES is the leading education, training and certification preparation organization for HVACR professionals. RSES publishes various comprehensive industry training and reference materials in addition to delivering superior educational programs designed to benefit HVACR professionals at every stage of their careers through instructor-led training courses, online training for HVAC, educational seminars, interactive CD and DVD products, industry-related reference manuals, and helpful technical content through Service Application Manual chapters, the RSES Journal, the RSES Journal archives and feature articles, as well as web-exclusive features.

Beginning with basic theory and extending to complex troubleshooting, training courses covering refrigeration and air conditioning, heating, electricity, controls, heat pumps and safety may be conducted in a classroom environment or though self study. RSES publications may be purchased by schools, contractors, manufacturers or any other industry group wanting to conduct comprehensive training programs. Seminars covering air conditioning troubleshooting, electrical troubleshooting, compressor training, condenser training, refrigerant piping practices, DDC controls, and more are held in various cities across North America.

Select training programs offer Continuing Education Units (CEUs) and NATE Continuing Education Hours (CEHs).

In addition, RSES offers industry certification preparation materials for refrigerant handling (EPA Section 608), R-410A and North American Technician Excellence (NATE) examinations.

RSES’ monthly magazine, RSES Journal, serves HVAC contractors, service technicians, students, operations/maintenance managers, engineers and technicians who work in the residential, light commercial, commercial and institutional markets on air conditioning, warm-air heating, refrigeration, ventilation, electrical, ice machines, chillers, hydronic heating, piping, refrigeration control and energy management, building automation, indoor air quality and duct cleaning, and sheet metal fabrication equipment and/or systems.
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