What is Superheat, and Why Does it Matter?

Have you ever heard the term superheat? Unless you study thermodynamics, or you’ve been reading our website, or talking to our technicians, then probably not. Don’t feel alone though. It’s sad to admit, but many heating and air conditioning companies don’t even know what superheat is, why it’s important, or even how to check it. This is another, of many, reasons why AirPro is the most trusted heating and air conditioning company in Eastern Arkansas!

What is Superheat?

Superheat is the only truly accurate way to measure the refrigerant (freon) levels in your air conditioning system.

Technically speaking, superheat is the temperature of a gas or vapor, above the boiling point for that liquid.

Let’s take water, for example. Under normal conditions (at sea level, etc) water will boil at about 212 degrees Fahrenheit. When we heat water to this temperature, it results in a physical change of state in which the water turns from a liquid into a gas (steam). If we continue to heat this gas — the steam — it will cause it to go above water’s boiling point of 212 degrees. This increase in temperature, above 212 degrees, would be the superheat. In other words, if we increased the temperature from 212 to 215 degrees, we would have superheated the steam 3 degrees.

How does Superheat Apply to Air Conditioning?

Given the above example, where water boils at 212 degrees, you may have wondered what this has to do with air conditioning. One of the key things to making your air conditioner work is the liquid refrigerant inside of it, often called freon. This refrigerant, unlike water, has an extremely low boiling point. Where water boils and turns into a vapor (gas), at 212 degrees, most refrigerants boil at a frigid negative 40 degrees Fahrenheit, or colder!

Inside of your air conditioning system, liquid refrigerant is pumped through copper tubes into a piece of equipment known as an evaporator coil. At the same time, a fan passes hot air from inside of your house through this same evaporator coil. Since the air from your house is much hotter than the refrigerant’s boiling point of around -40 degrees Fahrenheit, as it passes through the evaporator coil, the refrigerant starts to boil and is converted into a gas. As this happens, the gas “absorbs” the latent heat from the air, resulting in the air being cooled down before being delivered back into your home.

The path of refrigerant in your air conditioning system

Why is Superheat Important to Me, the Customer?

As a customer, the main thing you should know is that superheat is the only truly accurate way to measure the refrigerant (freon) levels in your air conditioning system.

Having the precise amount of refrigeration that your air conditioning unit requires is crucial. If you don’t have enough, your system can’t function correctly. If you have too much, there is a risk of liquid freon being transported back to the compressor, resulting in permanent damage!

By measuring the superheat of your air conditioner’s refrigerant, a skilled technician can ensure that your system has the precise amount of refrigerant needed to operate correctly.

Let AirPro Inspect and Service Your Air Conditioner Today

Letting AirPro check your superheat and service your air conditioner is a great way to ensure that it’s running safely, and at peak efficiency. Don’t wait until it’s too late — schedule to have your air conditioner inspected and serviced today!

Click Here to request this service

6 Comments on “What is Superheat, and Why Does it Matter?”

  • Robby Sclafani January 16th, 2013 7:23 am

    I work for Hill Phoenix in CA, I came across your superheat write up and wanted to say thank you. So many young techs have no idea what it is, and I have shared this with a lot of techs.

    Thank you guys
    Great work!!
    Robby Sclafani
    Journeyman technician

  • Poelee Polly September 19th, 2013 7:31 am

    Thank u so much. I gained a lot of knowledge.
    Thank u.

  • Kadav October 1st, 2013 4:54 am

    Well explained in simple way

  • vic January 19th, 2014 10:33 am

    Thanks , its always good to do alittle refreshers course on superheat. Ive been in the refrigeration business for years

  • Raul CastaƱeda March 28th, 2014 8:11 am

    Thanks for the refresher. Only a good company would explain that to a customer

  • evaporatormanufacturer April 10th, 2014 6:04 am

    I read your blog.. its amazing. you having very good content. very helpful to all.

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