• SkillCat Team

Purpose of Refrigerant Blends

Updated: 7 days ago

EPA 608 Core Chapter 22 (Take full course for free)

In this module, we will introduce refrigerant blends and discuss how to use them in HVAC practices. Skip to quiz!

1. Overview of Refrigerant Blends

As we discussed in the previous module, refrigerants used in the past were found to be harmful to humans and the environment. These refrigerants were phased out in the US and internationally.

After they were phased out, CFC and HCFC refrigerants could no longer be used. So what happens to equipment that operated on those refrigerants? This is why refrigerant blends were created.

During the time before CFCs and HCFCs had to be fully phased out, the industry developed refrigerant blends. Refrigerant blends were developed to match properties of the refrigerants originally used.

Refrigerant blends contain a mixture of two or more refrigerants. Generally, a refrigerant blend will contain two refrigerants.

If it contains three refrigerants, the term for that is a ternary blend.

For example, R-407c is a ternary blend of three HFC refrigerants. It contains:

  • 23% R-32

  • 25% R-125, and

  • 52% R-134

Refrigerant blends are standardized by manufacturers and have their own ASHRAE numbers. R-407c, like we just discussed, is a unique ASHRAE number.

2. Can Technicians Create Their Own Blends?

Refrigerant blends are manufactured by companies like Honeywell or DuPont. Blends are made to have specific properties in specific ratios. Otherwise they won’t work in an HVAC system.

Technicians cannot mix their own refrigerants. Mixing your own refrigerant is illegal and the technician is subject to fines.

If technicians mix refrigerants, the resulting refrigerant is basically a mixture with unknown quantities. The mixture can no longer be used.

This is because this mix will have different properties than what the equipment was originally designed for.

Mixing your own refrigerants would be the same as mixing your own gasoline to put into your car. You wouldn’t do that because your car is a complex machine that needs a specific blend of chemicals to run. HVAC systems are the same way.

If the technician mixes their own refrigerants, this

  • Creates unpredictable temperature changes, and

  • Places stress on equipment

All of this can cause equipment to fail and not work properly.

Putting this mix into an HVAC system will also void the warranty of the equipment. This because it goes against the manufacturer’s guidelines for use.

These reasons are why technicians should never mix their own refrigerants.

If technicians accidentally mix their own refrigerants and sent the mixture to be reclaimed, the reclaimer may:

  • Refuse to accept it, or

  • Destroy the refrigerant at the owner’s expense.

It is very expensive to destroy refrigerant.

4. Conclusion

In this module, we discussed how were the refrigerant blends developed and the properties of different refrigerant blends.

Question #1: Refrigerant blends take on the ASHRAE number of the main refrigerant in the blend.

  1. True

  2. False

Scroll down for the answer...

Refrigerant blends have their own ASHRAE numbers. These numbers are different from the ASHRAE numbers of the refrigerants that make up the blend.

Question #2: What is a ternary blend?

  1. Three refrigerant blends combined

  2. Three refrigerants blended together

  3. Three replacement refrigerants

  4. None of the above

Scroll down for the answer...

A ternary blend is a refrigerant blend that contains three refrigerants.

Question #3: Technicians can make their own EPA approved refrigerant blends.

  1. True

  2. False

Scroll down for the answer...

Technicians cannot make their own blends.

Question #4: Which of the following are reasons to not mix your own refrigerants?

  1. It is illegal

  2. It can cause equipment failure

  3. The resulting mix has unpredictable temperatures

  4. All of the above

Scroll down for the answer...

All of these are reasons why technicians cannot mix their own refrigerants.

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