The United States of America put a stop to the use of ozone-depleting substances within MVAC, or motor vehicle AC systems, such as CFC or chlorofluorocarbon 12 during the middle of the 90s. Since that period of time, it’s HFC-134a that’s been the most widespread refrigerant in use within MVAC solutions. These refrigerants are synthesized fluorinated gases meant to replace the older ozone-depleting solutions that were extremely harmful to the environment.
However, most HFC refrigerants remain incredibly potent and harmful greenhouse gases that have a very high potential for global warming, or GWP. This led the government of the United States and the MVAC to start development on new alternatives that are going to be more eco-friendly and have far less potential for global warming. This is why no vehicles in the USA will continue using the old HFC–134a, beginning with the year 2021.
That’s just part of the story and it’s worth looking into the different alternatives to these harmful refrigerants that the country is planning to introduce. The same alternatives are going to be used in the heating and air conditioning industry, making it essential to familiarize yourself with them. This way, you’ll be able to give your customers the latest solutions that are just as effective for heating and cooling without being as harmful to the environment as the previous solutions.
SNAP – Significant New Alternatives Policy
The SNAP program of the Environmental Protection Agency has the task of reviewing the different potential substitutes to traditional refrigerants within a detailed framework for comparative risk analysis. They do this through a wide range of industrial applications that traditionally use ozone-depleting chemicals.
This program first evaluates and then lists all the different potential substitutes that have the potency to reduce adverse effects on the environment and human health. They evaluate the alternatives across several different categories, such as consumer and occupational safety and health, air quality effects, toxicity, flammability, GWP, and the potential for depleting the ozone layer.
The SNAP program lists all flammable refrigerants, with the exception of HFO-1234yf and HFC-152a as unacceptable for retrofit and new solutions. However, there are many other alternatives set for the future.
Eco-Friendly Alternatives
There are many low-GWP alternatives currently in development and set to replace all ozone-depleting refrigerants as soon as possible. All of the following three solutions are completely SNAP-approved and do not delete any portion of the ozone layer.
What’s more, they all have a much lower negative impact on our environment and climate system. Here are the most important characteristics of these three non-ozone-depleting refrigerant alternatives:
HFO-1234yf
- GWP 4
- Mildly flammable but sufficiently safe for daily use
- Use conditions include:
- Systems that implement this refrigerant have to conform to the requirements of SAE J639, including warning labels, a cutoff switch for the compressor, and devices for relieving pressure from the system.
Carbon Dioxide
- GWP 1
- This refrigerant works at a pressure which is five to ten times greater when compared to traditional refrigerants
- Use conditions include:
- There have to be mitigation devices and engineering strategies that will prevent the leak of this refrigerant in excess of 30,000 ppm over 15 minutes within a passenger-free area, or 40,000 ppm in a passenger-occupied area.
HFC-152a
- GWP 124
- Moderately flammable but sufficiently safe for use
- Use conditions include:
- Engineering devices and strategies have to be in place within the system to prevent the R-152a concentration greater than 3.7% v/v within the passenger compartment for the duration of 15 seconds from the moment the car ignition starts. Also, manufacturers have to respect the SAE Standard J2773.
