Five Uses of Antifreeze

by Jessica Clifton

Antifreeze is an additive used to decrease the freezing point – and increase the boiling point – of any water-based liquid.

Antifreeze is made using any one of four main agents mixed with water: methanol, glycerol, ethylene glycol and propylene glycol, and each of these agents can be put to different use. You probably know it best for its use in engines, so let’s start with that:

  1. Antifreeze as a car engine coolant

The words ‘coolant’ and ‘antifreeze’ are generally used interchangeably, even though they appear to have the exact opposite meanings. That’s because the chemical is used in car engines to both prevent the engine’s cooling system from freezing, and prevent it from overheating. Clever stuff. It means that the water in your car’s engine won’t freeze in normal cold weather conditions – if it did, it could cause serious damage to your radiator – neither will it overheat in warm weather, with similarly damaging (and expensive) results.

Happily, the antifreeze in your car also protects against engine corrosion, prevents scale build-up, lubricates any moving parts it comes into contact with, and helps to get your car to its optimum operating temperature as quickly as possible, which reduces air pollution.

  1. Heating, ventilation and air conditioning systems

Heating, ventilation and air conditioning (HVAC) systems are an integral part of modern residences, office buildings and hospitals, as well as submarines and ships. Antifreeze can be used in HVAC systems to help prevent pipes from freezing, bursting and causing damage. It also reduces the risk of scale build-up and corrosion. Typically, glycol is the agent used in these systems as it is non-toxic.

Exterior of apartment building

  1. Antifreeze in solar water heating systems

With the use of solar energy on the increase, it’s important to maintain these systems properly. Antifreeze is used in solar water heating systems as a heat transfer fluid, providing protection from freezing, and damage to the system, in colder climates. But beware! Don’t try and add or change it in your solar water heating system yourself – these systems are pressurized and any maintenance is best left to the professionals.

  1. Clear ice from a driveway 

Snowfall and freezing temperatures can lead to perilously icy driveways, but antifreeze is on your side to help clear that ice rather than using salt, which can corrode the underside of your car as well as damage your garden. Using a non-toxic antifreeze (propylene glycol), clear as much snow as possible before spraying diluted antifreeze over the icy areas.

  1. Don’t use antifreeze as a windscreen de-icer!

Our fifth and final use of antifreeze is more of an anti-use – but it’s an important one. The onset of winter and frosty mornings is a sign to set your alarm clock 10 minutes earlier so you have time to defrost your car before your journey begins. It might sound like a good idea to use antifreeze in place of your normal screen wash, but it isn’t. Antifreeze can not only damage your car’s paintwork, but it can also have harmful effects on the environment due to its toxicity.

A car windscreen, which should not be de-iced with antifreeze

Benefits of Antifreeze

  • High boiling point
  • Low freezing point
  • Stability over a range of temperatures
  • High specific heat and thermal conductivity and improved heat transfer
  • Low viscosity
  • Chemically inert
  • Reduction in repairs to thermostats, radiators, and water pumps
  • Save time and money in maintenance
  • Anti-corrosion protection
  • Compatibility with rubber and plastics


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