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How to Determine AC Tonnage from Model Number


Are you currently browsing the aircon market and asking yourself; how to determine AC tonnage from model number and how many tons your aircon has? When it comes to buying a new air conditioner or assessing the AC tonnage of your existing AC unit, understanding the model number is crucial.

The model number of an air conditioner contains valuable information that can help you determine its power or tonnage per square footage. Understanding the precise tonnage of your air conditioner is essential for ensuring optimal cooling performance in your space.

In this blog, we will guide you in determining AC tonnage from the model number, equipping you with the knowledge and confidence to make informed decisions about your aircon needs.

How To Find the Model Number in an Air Conditioner

How to Determine AC Tonnage from Model Number

If you want to find the AC tonnage of your air conditioning unit, you first need to locate the model number on your air conditioning system. The tonnage of your AC is usually found on data plates or a plaque mounted on the outdoor or condensing unit. 

The data plate contains essential details about your AC unit, including its model number, heating capacities, energy efficiency ratings, square footage, square feet, and more.

The air conditioner’s model number typically consists of alphanumeric characters. While each AC unit manufacturer may use a slightly different format, some common patterns can be found across other brands. Determining the tonnage is essential in finding the right aircon size for your room. Finding the exact location may vary depending on the make and model of the air conditioner, but here are some familiar places to find the tonnage for the model number:

  1. Outdoor Unit: Check the outdoor unit’s sides, top, or back. The data plate is often located in a visible area for easy access.
  2. Condensing Unit: Look for the data plates on the condensing unit, typically located outside your home. It may be attached to the side or back of the unit.
  3. Indoor Unit: In some cases, the model number can also be found on the indoor unit of the air conditioner. Check the side panels, front cover, or inside the access panel.

How To Determine AC Tonnage From Model Number

Once you have found the model number, look for a two-digit number within it. This number is usually located towards the beginning or middle of the model number and corresponds to the tonnage of the AC unit. For example, if you see “1.5” in the model number, the AC unit’s tonnage is 1.5 tons.

If you are unable to find a two-digit number, don’t worry. Some manufacturers encode the tonnage information differently. In such cases, look for a number that is followed by a slash (“/”) or a hyphen (“-“) and another number. This combination represents the tonnage of the air conditioner. For instance, if you come across “1/1–5” or “1-5” in the model number, it indicates a tonnage range of 1 to 5 tons.

For residential aircon, you’ll find two even numbers divisible by 12. This number can range from 18 to 60. To determine the tonnage of your AC unit, divide this two-digit number by 12. ’12’ represents 12,000 BTU/hr or one tonnage of cooling capacity. Refer below for the corresponding tonnage based on the number and BTU information:

  • 18 = 1.5 tons
  • 24 = 2 tons
  • 30 = 2.5 tons
  • 36 = 3 tons
  • 42 = 3.5 tons
  • 48 = 4 tons
  • 60 = 5 tons

The rule of thumb in finding the right tonnage is following this simple AC tonnage calculation and referencing the chart. You can now accurately find the AC tonnage of your air conditioning unit.

It’s important to note that the tonnage of an AC is related to its cooling capacity, measured in the British Thermal Unit (BTU). One ton of cooling is equivalent to 12,000 BTU. Therefore, a 1.5-ton AC unit would have a cooling ability of approximately 18,000 BTU (1.5 tons x 12,000 BTUs/ton), and 2.5-ton AC has an exact BTU of 30,000.

What Is AC Tonnage and How Does It Relate to Cooling Capacity?

AC tonnage refers to the cooling capacity of an air conditioner and is measured in British Thermal Units (BTU) per hour. One BTU is the amount of heat produced by a birthday candle and is equivalent to the heat needed to raise the warmth of one pound of water by one degree. 

The capacity of an AC tonnage unit is determined by its size, which is measured in tons. Hence a larger unit may have a higher tonnage, kilowatts usage per square foot, to remove heat.  

The term “ton” or “tons” in this context represents the amount of cooling power an air conditioner can provide. One ton of cooling capacity is equivalent to the energy needed to melt one ton of ice within 24 hours, or it can also be comparable to the amount of heat an AC unit can remove within one hour. Hence, the larger the tonnage, the greater the cooling power of the AC unit.

To put it into perspective, one tonnage will efficiently cool 400 square feet of space. So, if you have a 1,200-square-foot home, you’ll need a three-tonnage AC unit.

Why Is AC Tonnage Important in an AC Unit?

AC tonnage matters as it is crucial for selecting the correct size air conditioner for your space. While bigger units may seem better in some situations, this is different for air conditioners. Buying an oversized system, like 2.5 tons for a small space, can lead to various issues such as:

  1. Short Cycling: An oversized AC unit will frequently turn on and off in short cycles, causing increased wear and tear on the system. This can result in more repairs and the need for premature replacement.
  2. Inadequate Dehumidification: Oversized AC units may cool the air quickly but must dehumidify the space adequately. This can leave you with a cool but damp and uncomfortable environment. You may lower the temperature to combat the excess moisture, leading to higher electricity usage.
  3. Unnecessary Expenses: Larger air conditioners cost more to purchase and operate at a higher cost. Opting for a bigger system when a smaller unit could adequately cool your home leads to unnecessary expenses.

On the other hand, an undersized unit is also problematic as it may need help to cool your space effectively, especially during the summer-long heat. 

If you’re still asking yourself, “Does my AC tonnage matter?” The answer to that is; Yes! Knowing the tonnage of your AC is vital in achieving the right balance between how many kilowatts per square foot and the size of your space is crucial for optimal comfort and energy efficiency.

How Do I Know if My AC Is 1 Ton or 1.5 Ton?

To determine if your air conditioning unit is one tonnage or 1.5 tons, you can find the AC tonnage on the model numbers on the air conditioner. The model number is typically found on a data plate or in the data plaque mounted on the outdoor or indoor unit of the AC system. Look for a double-digit number within the model number.

If the double-digit number is “12,” it represents a 1-ton aircon unit. One tonnage equals 12,000 BTU/hr (British Thermal Units per hour) of cooling power or capacity. However, if the double-digit number is “18,” it signifies a 1.5-ton AC unit. In this case, the air power is approximately 18,000 BTU/hr.

By checking the double-digit number in the model number, you can determine whether your AC unit is 1 ton or 1.5 tons. Remember, the tonnage of your AC indicates its heating and cooling capacities, with one tonnage being suitable for smaller spaces and 1.5 tons providing additional coldness for slightly larger areas. 

Final Thoughts

Determining AC tonnage from the model number is essential for selecting the appropriate size for your unit and ensuring efficient cooling in your space, especially in the Philippines, where the hot climate lasts for months. 

By decoding the model number, you can gain a general idea of the airconditioner’s approximate size and cooling ability per square foot. 

If you still can’t find the tonnage rating of your AC and how to read the AC model number, it’s best to consult an HVAC system professional and let them find AC tonnage for you.

Want to learn more about the best aircon brand for you? Read here and find out!

JP Reyes

JP has been in the aircon industry for almost as long as he has been alive. As a child JP would help his tatay fix aircon units at their junk shop in Cavite. After graduating UP in the early 2000's, JP then started his own Aircon servicing business and within 5 years had 10 shops in 8 different cities. Fast forward to today and JP brings all his experience and expertise online to give readers trustworthy advice and reviews about Air-conditioning buying, servicing, cleaning and repair in the Philippines.

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