Open, Closed & Isolated Systems



Systems refer to any parts of the universe being studied.

If you are conducting an experiment in a beaker, then the system you are studying is in the beaker.

The system is subject to surrounding factors such as air temperature and pressure.

Thermodynamics involve the study of heat energy exchange between a system and its surroundings.

There are three types of thermodynamics systems. Based on the possible heat and matter transfer, they are classified as open, closed or isolated systems.


Types of Thermodynamic Systems

Types of thermodynamic systems

Open Systems

open, closed, isolated thermodynamics systemsYou may have heard of open systems and closed systems. An open system is one that freely allows energy and matter to be transferred in an out of a system.

For example, boiling water without a lid.
Heat escaping into the air.
Steam (which is matter) escaping into the air.

Closed Systems

closed system thermodynamics
A closed system, on the other hand, does not allow the exchange of matter but allows energy to be transferred.

It allows heat to be transferred from the stove to the water

Heat is also transferred to the surroundings

Steam is not allowed to escape

Example of a closed system – a pressure cooker.

Nb: If a system is 100% closed, it is in danger of exploding. That's why pressure cooker should be designed with safety mechanisms to prevent the system from over-pressurzing by allowing steam to escape when needed.

Isolated Systems

This system is completely sealed
Matter is not allowed to be exchanged with the surroundings
Heat cannot transfer to the surroundings

Thermoflask - isolated system - thermodynamicsExample – A thermoflask is an isolated system

Find the isolated systems below:

14 thoughts on “Open, Closed & Isolated Systems

    1. Hi Onalenna, thanks for your question. It’s very hard to find examples of isolated system in nature because isolated systems don’t exist in nature. However, the universe is considered an isolated system but that is based on the assumption that there is no other universe adjacent to this one that we’re living in and our universe is not exchanging energy and matter with any “surroundings”. Here’s one of an isolated system in physics that is quite abstract in concept –

      1. Correct – there is no isolated systems in nature. But the universe could be considered an isolated system as the universe has not been observed to exchange energy or matter with something outside of it.

    1. See the definitions:
      An open system can exchange matter and energy.
      A closed system can exchange energy (e.g. heat) but not matter.
      An isolated system cannot exchange energy or matter.

      So, if your system is open, it lets both heat and matter out. It can be turned into an isolated system if the system is completely closed and insulated so neither heat or matter can escape. However, there are no truly isolated systems in the world. Some matter or heat will always escape from a container. In the case of a science experiment in school, you can assume a system such as the coffee cup calorimeter as an isolated system so that you can do your calculations, but really it is not an isolated system.

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