EPA Regulations for HVAC Technicians - Part 2
- SkillCat Team
- Sep 16
- 6 min read
EPA Type 1 Chapter 1
SNAP Substitutes
In this module, we will discuss how the SNAP program affects our use of refrigerants. We will also take a look at why SNAP considers a refrigerant acceptable or unacceptable and specific examples in each category.
SNAP Background
Recall that SNAP stands for the Significant New Alternatives Policy and it is implemented by the EPA. The SNAP program was developed to evaluate new alternatives to replace phased-out refrigerants.
New alternatives that are accepted under SNAP are less harmful to the environment. These accepted refrigerants do not deplete the ozone layer and have low global warming potentials.
The SNAP program classifies a refrigerant as either:
Acceptable,
Unacceptable, or
Acceptable under use conditions.
SNAP looks at the use of refrigerants in different types of appliances. For example, SNAP evaluates refrigerants for use in chillers, ice rinks, industrial AC, and many other end-uses.
For Type I, we care about the refrigerants that SNAP considers acceptable for small appliances since that is what Type I is. So this means we will look at the substitutes SNAP considers acceptable for new household refrigerators or freezers.
Note that SNAP approves substitute refrigerants for new appliances. Manufacturers of new appliances factory charge the appliances with acceptable substitute refrigerants. This means that older appliances can still contain refrigerants that is not acceptable as a substitute under SNAP.
Unacceptable Substitutes
Unacceptable substitutes generally are older refrigerants or blends including older refrigerants that are harmful to the environment.
HFC blends were used in the industry as a transition away from CFCs and HCFCs. Recall that under the Kigali Amendment of the Montreal Protocol, HFC refrigerants are also being phased out because they have high global warming potentials.
Under the SNAP program, refrigerant blends containing only HFCs are generally not acceptable as of January 2021. This means you will not see HFC or HFC blends in new refrigerators but you may see them in older ones.
An example of an HFC blend is R-404a, which is a blend of:
44% HFC-125,
4% HFC-134a, and
52% HFC-143a
Since all three components of R-404a are HFC refrigerants, R-404a is considered an HFC blend.
This is why R-404a is designated by the SNAP program as an unacceptable substitute for use in household refrigerators and freezers. Because the EPA labels it as an unacceptable substitute, you will not see R-404a used in new household refrigerators and freezers.
As of January 20211, other unacceptable substitutes for new household refrigerators and freezers include:
R-407c, and
R-410a
Recall that both R-407c and R-410a are completely HFC blends. This is why the SNAP program considers them unacceptable substitutes. So we will not see either of these refrigerants in new household refrigerators and freezers.
Acceptable Substitutes
Acceptable substitutes are generally newer refrigerants that are:
Non-ozone depleting, and have
Low global warming potential.
Acceptable substitutes include:
Hydrocarbons, and
Certain refrigerant blends
Recall that hydrocarbons such as propane (R-290) and isobutane (R-600a) are considered natural refrigerants. They do not contain chlorine so they are non-ozone depleting. They also have a global warming potential of 3, which is very low.
For new household refrigerators and freezers, SNAP approves the use of hydrocarbons under certain use conditions. The concern with hydrocarbons is that they are highly flammable. Use conditions set by the EPA are set to deal with the risk of hydrocarbons being flammable.
The SNAP program issues the following use conditions for using hydrocarbons as a substitute:
The maximum charge is 2 lbs,
Permanent labels are needed, and
Pipes and service ports need to be marked red.
Hydrocarbons are used as a substitute in new household refrigeration appliances only. They are not approved for retrofitting existing appliances because of safety concerns around their high flammability.
Refrigerant blends that are acceptable substitutes generally have much lower global warming potential than the refrigerants they are replacing.
For example, R-450a is an acceptable substitute for household refrigerators and freezers under the SNAP program. R-450a is a blend of
42% HFC-134a, and
58% HFO-1234ze.
R-450a is an alternative to R-134a. Although R-450a contains an HFC refrigerant, it is also blended with an HFO refrigerant, which gives it a lower global warming potential than R-134a. The GWP of R-450a is 547, which is a 60% reduction from the GWP of just R-134a.
To summarize, unacceptable substitutes are generally refrigerants that have high GWP-like blends that are made of completely HFCs. Some refrigerant blends containing HFC refrigerants are considered acceptable because they have much lower global warming potentials than the refrigerants they are replacing.
Hydrocarbons are considered acceptable substitutes with use conditions, but existing systems cannot be retrofitted to use hydrocarbons. Equipment containing hydrocarbons must be marked with red to deal with the risk of their flammability.
Refrigerant Management
In this module, we will review retrofitting and discuss restrictions on using hydrocarbons in retrofit applications. We will also look at how mixed refrigerant affects appliances and talk about how to prevent the mixing of refrigerants.
Retrofit Refrigerants
Recall that retrofitting is the modification of systems components in order to use different refrigerants in the system. Generally, we retrofit systems that operated on phased out CFC or HCFC refrigerants in order to use new refrigerant blends.
For example, since R-22 is phased out, we could modify or retrofit an R-22 system to operate on a different refrigerant like R-407c. SNAP regulates what refrigerants are acceptable for retrofit, depending on the appliance’s category.
Make sure that the refrigerant you want to retrofit for is approved by SNAP as acceptable for use as a substitute in that category. For example, if we want to retrofit a household refrigerator containing R-22, we want to look for acceptable substitutes for retrofitting household refrigerators.
SNAP regulates the use of a refrigerant for retrofitting separate from new appliances. For example, SNAP can find a refrigerant acceptable as a substitute for retrofit purposes but not acceptable as a substitute for use in new appliances.
For the household refrigerators and freezers, SNAP deems R-407c:
Acceptable as a substitute in retrofit applications, but
Not acceptable as a substitute in new appliances
Alternative refrigerants that are labeled acceptable substitutes by the SNAP program may be used in existing systems. But these alternative refrigerants cannot be used without retrofitting or modifying components of the system. The system must first be modified to accommodate the alternative refrigerant.
A drop-in refrigerant is a refrigerant that can be used as a replacement for the original refrigerant without any modifications to the system. According to the EPA, there are no “drop-in” substitute refrigerants for R-22. We must retrofit a system in order to use another refrigerant in the system.
Remember that we cannot retrofit a system to operate on hydrocarbon refrigerants. This is because they are highly flammable and it would be dangerous if retrofit components failed. Hydrocarbons can only be factory charged.
Mixed Refrigerant
The thermal properties of a refrigerant allow the refrigerant to go through phase changes at specific temperatures and pressures. This needs to happen in order for the refrigerant to do its job of moving heat from one place to another.
Mixed or contaminated refrigerants can have unpredictable thermal properties. The unpredictable properties cause the compressor to operate inefficiently and can cause damage to components.
Imagine mixing diesel and regular gasoline together and then using the mixture in your car. This is essentially what is happening if we put contaminated refrigerants in our system.
Recall that refrigerant must be reclaimed to virgin specifications in order to change ownership. We need to send the refrigerant to an EPA-certified reclaimer to get the refrigerant reclaimed.
If you send mixed or contaminated refrigerant to be reclaimed, the reclaimer may either
Refuse to accept it, or
Charge you extra to try to remove contaminants from the refrigerant.
To prevent the mixing of refrigerants, we need to first check what refrigerant is contained in an appliance. If you are recovering the refrigerant, make sure that the recovery cylinder is used for the same refrigerant as what is inside the appliance.
For example, let’s say we check the appliance and see that it contains an R-22 refrigerant. We’ll need to make sure to recover the refrigerant using a recovery cylinder that is only used for R-22.
Recall that recovery cylinders can only be used for one type of refrigerant. For example, recovery cylinders previously used for R-12 cannot be used to recover R-22 refrigerant. This would contaminate the refrigerant you are recovering.
If you discover that refrigerant is mixed, you must turn it into a reclaimer to try to get it reclaimed. The reclaimer will access whether the refrigerant can be restored to virgin specifications for the refrigerant. If not, you will likely have to pay a fee for the reclaimer to destroy the refrigerant.
In this module, we looked at two refrigerant management practices: retrofitting and preventing the mixing of refrigerants. In order to use a different refrigerant in any system, the system must first be modified to operate on the new refrigerant.
We want to prevent the mixing of refrigerants because reclaimers can refuse to reclaim them or charge you extra. And mixed refrigerant can cause component failure so we don’t want that in our appliances anyway. If you discover any refrigerant is mixed, you must turn it into a reclaimer to try to reclaim it.
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