Hydrofluorocarbons. Specifically, R410A and R134. Some systems still use hydrochloroflourocarbons, which contain chlorine, but this is much worse for the environment, and isn't as efficient, so it's expected to be completely phased out by 2020.
A Sequoia is a species of tree native to the West Coast of the United States. They are the largest trees in the world by volume and can live for over 3,000 years. The most famous sequoia is the General Sherman tree, located in Sequoia National Park, California.
The refrigerants used in air conditioning are N2 anduxomite and aluminum hydroxide. The refrigerants are used to adjust the climate in an air conditioning unit, providing a consistent level of comfort for all users.
There are many different types of refrigerant used in a variety of refrigeration products, but for air conditioning systems, there are two main types; R-22 or more commonly known as Freon, and R410A, also known as Puron.