How Does a Cold Setting Work on a Blow Dryer

A blow dryer is a versatile tool that many of us rely on for styling our hair. While most people are familiar with the hot settings for drying and shaping hair, the cold setting often remains a mystery. 

Have you ever wondered how the cold setting on a blow dryer works? In this comprehensive guide, we’ll delve into the science behind the cool shot feature, exploring its benefits, functionality, and practical uses.

The Science Behind Heat and Cold

Before we dive into the specifics of how the cold setting on a blow dryer works, let’s first understand the basics of heat and cold and their effects on hair.

Heat: When you use the hot setting on a blow dryer, the heating element inside the dryer generates the warm air. This warm air helps to open the hair cuticle, allowing moisture to escape and speeding up the drying process. Heat is also instrumental in styling hair, as it helps to shape and set the hair into your desired style.

Cold: In contrast, the cold setting on a blow dryer emits a stream of cool air. This cool air helps to close the hair cuticle, sealing in moisture and creating a smooth, shiny finish. Additionally, the cold air helps to set the style in place, making it last longer.

how does a cold setting work on a blow dryer

How Does the Cold Setting Work on a Blow Dryer?

Now that we understand the basic principles of heat and cold let’s explore how the cold setting on a blow dryer functions:

  1. Cooling Element: Inside a blow dryer, there is a component known as a Peltier device or thermoelectric cooler. This device utilizes the Peltier effect, which involves transferring heat from one side of the device to the other when an electric current is applied. One side of the device becomes cold, while the other side becomes hot.
  2. Airflow Control: When you activate the cold setting on a blow dryer, the airflow is directed over the cold side of the Peltier device. As the air passes over the cold surface, it is cooled down before being emitted from the dryer’s nozzle.
  3. Closing the Cuticle: The cool air helps to rapidly lower the temperature of the hair, causing the hair cuticle to contract and close. This closure of the cuticle helps to seal in moisture, making the hair appear smoother and shinier.
  4. Setting the Style: In addition to sealing the hair cuticle, the cold air also helps to set the style in place. By cooling the hair quickly, the cold setting on a blow dryer can help to lock in the shape and structure of your hairstyle, making it last longer throughout the day.

Benefits of Using the Cold Setting:

Now that we understand how the cold setting on a blow dryer works let’s explore some of its key benefits:

  1. Seals in Moisture: The cold air helps to seal the hair cuticle, preventing moisture loss and leaving the hair hydrated and healthy-looking.
  2. Adds Shine: By closing the cuticle, the cold setting creates a smooth surface that reflects light, resulting in shinier, more lustrous hair.
  3. Sets the Style: Using the cold setting after styling helps to set the hair in place, making your hairstyle last longer and reducing the need for additional styling products.
  4. Soothes the Scalp: The cool air can provide a refreshing sensation, making it ideal for soothing an irritated scalp or calming frizz.

Practical Uses of the Cold Setting:

The cold setting on a blow dryer has a variety of practical uses beyond simply sealing the hair cuticle and setting the style. Here are some creative ways to incorporate the cold setting into your hair care routine:

  1. Setting Curls: After curling your hair with a curling iron or rollers, use the cold setting on your blow dryer to set the curls in place for long-lasting hold.
  2. Taming Frizz: If you struggle with frizz or flyaways, use the cold setting to smooth down the hair cuticle and reduce frizz.
  3. Refreshing Second-Day Hair: On days when you don’t wash your hair, use the cold setting to revitalize and re-style your hair without adding excess heat.
  4. Cooling Down: After using hot styling tools or spending time in the sun, use the cold setting on your blow dryer to cool down and soothe your scalp and hair.


The cold setting on a blow dryer is a versatile and underrated feature that offers a range of benefits for your hair. By understanding how the cold setting works and incorporating it into your hair care routine, you can achieve smoother, shinier hair with long-lasting style. So, the next time you reach for your blow dryer, don’t overlook the cool shot button – it may just become your new favourite hair styling tool.

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