It's such a great time to stay comfortable with your Armstrong air conditioner. Have you ever wondered about its tonnage? How to find the tonnage in an Armstrong air conditioner and what does it mean? Don't worry! We did the research to answer these questions for you.

**The last two numbers in the model code of an Armstrong air conditioner indicate its tonnage when you divide the digits by 12. However, older units have a different format, in which the capacity is shown at the left of the dash.**

In this article, you'll figure out the tonnage of an Armstrong air conditioner. We'll provide ways to determine the right size of an AC and how significant the tonnage is. You'll get more relevant details ahead. So, join us in reading!

## How to Find Tonnage on an Armstrong Air Conditioner

In the HVAC world, tonnage means the capacity of an AC unit to change the temperature of the room. The British Thermal Unit, or BTU, is used to calculate tonnage.

The BTU measures how much energy a body needs to increase its temperature by one degree Fahrenheit. One tonnage is equal to 12,000 BTU. It is then shortened to fit in the model code. Instead of writing the conplete 12,000 BTU, manufacturers write only 12.

It's significant to know how to identify the tonnage of an Armstrong AC for proper sizing in an area. For instance, the model code is "4SHP16LS136P." The equation will look like this:

Tonnage = The last two numbers ÷ 12

= 36 ÷ 12

= 3

So, the tonnage in an Armstrong AC unit with model code "4SHP16LS136P" is 3. Which means that the unit has a capacity of 36,000 BTU.

However, shorter codes like "CJK24S-2C" are common on old units. The last two numbers in this example are 24 since there is a dash next to number 2. So, the tonnage will be calculated like this:

Tonnage = 24 ÷ 12

= 2

That's why the tonnage of the Armstrong AC unit with model code "CJK24S-2C" is 2, and the unit's capacity is 24,000 BTU.

However, you can rely on the RLA if you're unsure about the numbers you're looking at. RLA is usually printed on the compressor motor, and you can simply divide the amount by 5 or 6 depending on the unit. The amount you'll get will tell you the approximate tonnage requirement of an AC. Refer to user's guide about dividing RLA.

## What Happens if You Don't Follow the AC's Tonnage Requirement?

AC units do have some capacity when cooling down an area. It's significant to use an AC with the proper tonnage for more efficient temperatures. Consider the things below that you may encounter when you use an AC with inappropriate tonnage.

### Waste of Energy

If you use lower tons on a very large area, you'll lose a significant amount of energy. Keep in mind that an AC unit needs time to fill the area with the desired air temperature.

A 1-ton unit is capable of cooling down an area of 600 square feet. So, the formula for finding the right size of AC is to divide the area by 600.

Let's say you need to install an AC unit on an area of 1,700 square feet. The formula and computation should be as stated below:

Tonnage = Area ÷ 600

= 1,700 ÷ 600

= 2.83

Therefore, the area needs a 2.83-ton AC unit. However, there's no AC unit with exactly 2.83 tonnage. You can simply estimate the tonnage requirement closest to our computation, which is a 3-ton unit.

### Early AC Malfunction

If you try to run an AC with the wrong tonnage, its components and motors will struggle to adjust to the size of the area.

For an oversized AC, the thermostat will detect the temperature change too early and shut down the motors more often. In the case of an undersized AC, the motors may overheat while trying to cool the area without stopping.

Prolong your AC's lifespan by installing it to an appropriate area. Remember that broken motor is a serious issue on your AC.

### Unhealthy Air

Improper AC size is unhealthy. It's either you inhale a lot of processed air or the lack thereof. You don't want to risk your health by using the wrong AC size, especially in the hot season when you might get dehydrated due to extreme heat.

However, you may need to check if the area has proper ventilation. Right tonnage will be ineffective for a poorly ventilated area.

You can improve the ventilation by adding a fan to distribute the air throughout the area.

See this air circulator fan on Amazon.

## How Many AC Units Should You Have at Home?

Most homeowners use only one AC unit throughout their homes, which is just fine. But it's better if you do a proper calculation on how many AC units you could have, considering that you cover the entire area with appropriate tonnage.

For instance, let's say you have a two-story house. The first floor is 500 square feet, while the second floor is 350 square feet.

Since a 1-ton unit can cover up to 600 square feet, you can use a 1-ton unit on the first floor. You may be worried that a 1-ton unit is oversized for the first floor. But that is completely fine because the next tonnage is 1.5, which can cover up to 900 square feet. While the lower tonnage is 0.5, which can cover up to 300 square feet.

On the other hand, the area of 350 square feet is below the 1-ton unit capacity and could make the AC quite oversized. So, you can consider using a 0.5-ton unit for the second floor, which is good for an area of 300 square feet.

As a result, you may end up using a 1-ton unit alongside another 0.5-ton unit. Those should be two different AC units. However, factors like the location of the AC will matter for a two-story house. You may consult a technician to help you assess the AC's capacity.

Actually, you can use a single 1.5-ton unit to cover the entire house. If we sum up the two areas, we'll have 850 square feet. The closest tonnage for the combined area is 1.5, which is good for 900 square feet.

You should avoid choosing a 2-ton unit, simply because a 2-ton unit can cover 1,200 square feet, which is oversized for a total of 850 square feet.

The point of the given example is to measure the area before adding another unit of AC. You don't have to be exact on the tonnage unit. You just need to understand what tonnage unit is closest to the measurement of the area to avoid oversizing and undersizing.

## The Tonnage Is Correct But The Electric Bill Is High

Despite the fact that you learned how to estimate the tonnage requirement, your Armstrong AC may cause your electricity bill to be higher than usual. You need to evaluate the AC's condition to figure out the problem. See below for some ways to deal with this issue.

### Inspect the Wires

The wires connecting your AC to the main electric source can be the cause of a high electric bill. Make sure they're of the best quality and are not exposed.

Check the voltage compatibility of the AC as well. You can find it on the data sheet. It's important to avoid electric overload and incompatibility because that will raise the bill.

### Check the Refrigerant Level

A low refrigerant level may also cause the bill to soar. It's because the cooling ability is gone, and the AC is forced to continue the cooling cycle until the motors cannot function anymore. Check if the AC has enough refrigerant to perform well.

### Fix the Thermostat

A broken thermostat can display a false temperature reading, which will make you think that the desired room temperature is still not being achieved. You'll then end up extending the operation of the AC and increase the bill.

You need to fix the thermostat to avoid this from happening. Check if the batteries are working and keep the thermostat away from wet places.

You can also replace your thermostat if it's broken.

See this thermostat on Amazon.

## Conclusion

We've learned how to find out the tonnage of an Armstrong air conditioner. We provided some relevant examples for accurate tonnage computation.

Also, we realized that tonnage is significant in terms of energy efficiency, AC's condition, and health reasons. We included how many AC units you can add to your home by stating an example.

At the end of this article, we briefly explain why your AC might be raising the bill. Remember to monitor and maintain the AC's quality.

Did you enjoy reading it? Hold on, there's so much more to read!