Introduction to Refrigerants
Updated: 7 days ago
EPA 608 Core Chapter 15 (Take full course for free)
In this module, we will define refrigerant and also discuss different types of refrigerants.
1. What are Refrigerants?
Have you ever wondered how your refrigerator keeps your favorite ice cream cold?
Recall from our Refrigeration Cycle module that refrigerant absorbs heat from hot indoor air and transfers it outdoors. This is how air conditioning units provide cooling.
This is also how your fridge keeps your favorite ice cream cold. Your refrigerator makes use of the refrigeration cycle to transfer heat from the inside of your fridge to the outside. And the key to making this happen is the refrigerant.
A refrigerant is a substance or mixture that absorbs heat by using it to boil, changing phase from liquid to vapor.
We can choose from any number of substances to use as a refrigerant. Good refrigerants are cheap and have a low boiling point. Low boiling points are necessary because we need the refrigerant to boil at room temperature. Recall that boiling is what provides cooling.
But as we discussed in the Ozone module, some refrigerants are harmful to the environment. Some refrigerants are also more flammable or toxic than others.
That is why it is important to look at the properties of different refrigerants. We need to consider their effect on the environment as well as how safe they are.
2. Types of Refrigerants
CFCs were widely used in the mid 1900s before it was discovered that they were depleting the ozone layer. As we discussed in Key Regulations, these refrigerants were the first to be phased out.
We say pure refrigerants to distinguish from refrigerant blends, which consists of multiple refrigerants. Pure refrigerants are one substance only. We will discuss blends in a later module.
There are five major categories of pure refrigerants that we will cover for the EPA exam:
- Natural refrigerants
CFCs and HFCs are categories of refrigerants. This means there are multiple refrigerants that are CFCs or HFCs. Think of a category of refrigerants as a color. If something is blue, it could be sky blue or ultramarine or indigo.
If a refrigerant is a CFC, it could be any number of specific refrigerants. It could be R-11, R-12, et cetera. The list goes on. To reiterate, CFCs are a category of refrigerants, not one specific refrigerant.
In this module, we defined refrigerants and their types.
In the next module, we will delve further into CFCs and HFCs.