How To Fix a Refrigerant Leak In an AC Unit?

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Refrigerant Leak In an AC Unit

You may have a refrigerant leak that must be fixed if your air conditioner has stopped blowing cold air, is blowing warm air, or is simply not cooling as effectively as it once did.

A common cause of AC refrigerant leaks is a clogged condensate drain line. 

You can fix a leaking refrigerant by accessing the condensate drain pipe, cleaning the pipe, and draining the filters. However, if the leak persists, contact a professional HVAC expert with the knowledge and tools to diagnose the problem and repair your AC unit.

Here is the information you need about AC refrigerants, leakage symptoms, and possible solutions.

What Is Refrigerant?

What Is Refrigerant?

An air conditioner uses a chemical substance called AC refrigerant. After passing through the compressor and evaporator, the refrigerant’s purpose is to absorb heat and produce cool air.

A functioning AC refrigerant determines how effectively an air conditioner can cool your home.

Sometimes referred to as Freon, it is a coolant essential to its capacity to chill your house or place of business.

All air conditioning units have refrigerant inside their copper coils to cool your home to the temperature you set on the thermostat.

How Does Refrigerant Work?

When refrigerant absorbs heat from interior air, it transforms from a low-pressure gas to a high-pressure liquid.

Next, the refrigerant is sent outside through air conditioning components, where it is exhausted to the outside by a fan that blows hot air over the coils.

After cooling down, the refrigerant transforms back into a low-pressure gas.

The low-pressure gas is compressed due to the refrigerant’s ability to remove heat from the indoor air. It then passes through the coils of the AC unit, where it cools and turns into a high-pressure liquid.

The refrigerant, a fluid, draws cool air into your home or place of work by absorbing heat from the outside. The refrigerant then cools, returning to a gaseous state and restarting the cycle.

Although Freon is a specific gas that is being used less and less due to environmental concerns, the phrase has come to be used by many to denote any HVAC refrigerant.

How Much Refrigerant Is in A Home Air Conditioner?

How Much Refrigerant Is in A Home Air Conditioner?

The General Principle

The usual rule applied when estimating the amount of refrigerant in a household air conditioner is 2-4 pounds per ton of cooling.

Recharging a 3-ton air conditioner with a 35-foot line set from empty level, for instance, would require 6 to 12 pounds of refrigerants. 

AC Size

The size of your air conditioning machine substantially influences the quantity of refrigerant required to produce cool air.

So, naturally, the larger unit necessitates a longer liquid line on the line set, necessitating a larger capacity.

Size and Length of Copper Line Set

More refrigerant is required the farther apart the evaporator and condenser coils are from one another.

Therefore, the proper amount of refrigerant, following the distance between these two essential components, is pre-installed in air conditioning units at the factory.

Evaporator Coil Size

For more effective cooling, many homeowners would like larger evaporator coils. This, however, also implies that your unit requires more refrigerant within.

Systems Type

Comparing split systems to packaged units, more refrigerants may be required. Since this sort of A/C has indoor and outdoor components, several factors must be considered, including the line set and coils. A skilled installer can decide on each of them.

How To Check Home AC Refrigerant Level?

How To Check Home AC Refrigerant Level?

Here are a few straightforward methods to check the AC refrigerant levels.

Test Soap Method

This method is the earliest and least expensive to locate an AC system leak. Put a water and soap solution around the region if you suspect coolant is seeping there.

You’ll notice bubbles, which will indicate the leak. However, this approach might be ineffective if the leak is tiny.

Utilize A Leak Detector Electronic

This gadget, which contains a virtual leak indicator, is also known as a sniffer. If a leak is found, it may also make noise.

Although numerous electronic leak detectors are on the market, they might not be reliable, especially in windy conditions.

Checking the Coolant Levels

You will need a digital thermometer, paper, a pen, and a refrigerant slider to calculate superheating and subcooling.

1. Identify the Type Of Refrigerant First

The type plate on your installation will provide these specifics. It contains information on the number of plates, the type of gas, the number of circuits, and the possibility of global warming.

2. Examine the Pressure

Pressure gauges that show discharge suction pressure and high or low pressure are almost always present in AC systems.

Check the discharge and suction pressures in the paperwork if your system doesn’t already have one.

3. The Temperature At Which Evaporation And Condensation Occur.

At various pressures, refrigerants have varied evaporation and condensation temperatures.

A slider for refrigerant controls this. Set the slide to “dew” to get the evaporation temperature. Set the slide to “bubble” to get the condensation temperature.

4. To Gauge the Environment’s Temperature At the Installation, Use a Digital Thermometer.

Calculate the suction pipe’s superheating temperature. You can take a temperature reading before the expansion valve to determine the subcooling.

5. Do the Superheating And Subcooling Calculations.

You can compute the superheating and subcooling now that you have all the relevant information.

First, subtract the evaporation from the suction pipe temperature to obtain superheating.

Next, remove the discharge pipe temperature from the condensation temperature to get the subcooling.

What Causes Refrigerant Leak In AC?

What Causes Refrigerant Leak In AC?

Faulty Installation

Freon, often known as refrigerant, is a crucial part of air conditioners because it facilitates phase change (when a liquid converts into a gas).

Phase conversion aids in heat absorption, keeping your house comfortably cool. AC units in a closed coil system make a particular chemical compound repeatedly evaporate and condense.

Metal Corroding

An HVAC system may have serious complications as a result of erosion. For instance, it makes microscopic holes that let freon leak.

In addition, since outdoor air conditioners are standard, decay and other weather-related problems are more likely.

Additionally, formic acid corrodes copper pipes; the rate at which copper pipes corrode depends on their thickness. 

AC Unit Wear and Tear

Refrigerant leaks in air conditioners are frequently caused by age-related wear and tear. For example, your AC’s joints and connections may deteriorate over time.

Additionally, rubber seals around access fittings or service valves may deteriorate over time, allowing refrigerants to leak.

Furthermore, you will experience this problem earlier than anticipated if you put off or neglect HVAC repairs and maintenance for a long time.

Fabrication Errors

It’s a frequent assumption that if an air conditioning system is put in properly, there won’t be any problems while it’s brand new.

However, any mass-produced object could have manufacturing defects. Over time, flaws might cause a freon leak in the refrigerant lines.

In addition, increased energy costs and efficiency problems could indicate something is wrong.

If your new unit has flaws from the manufacturer, you’ll need to replace it. This is why having a home appliance warranty is essential.

For example, an air conditioner that is broken can be fixed or replaced with the help of a warranty.

Breach Leak

Pinhole leaks are little holes, sometimes called “Champagne leaks,” due to the tiny bubbles they produce in your AC coils.

As a result of deterioration over time, they typically develop in older units. The primary reason is certain acids, like formic, are created by volatile organic compounds (VOCs) that are usually found in the air.

Because they contain VOCs, products like air fresheners, glues, and paints can easily reach your indoor air conditioning system. These may chip away at the copper tubing in your air conditioner over time, producing minor leaks.


One crucial part of your air conditioner is the compressor motor, which is outside. If not adequately sealed, your outdoor unit may produce strong vibrations and weaken refrigerant lines.

Additionally, suppose your refrigerant lines were misconnected to begin with. In that case, even a slight vibration brought on by the system’s operation could wear holes in the copper coils, resulting in an AC refrigerant leak.

Physical Injury

Your outside unit could sustain damage from kids, pets, and lawnmowers. Additionally, lawnmowers may direct their trimmings at the outdoor unit, which could result in debris accumulation.

While playing, both children and animals may unintentionally strike or toss something.

Physical harm of all kinds may result from this. Put a protective barrier around your outdoor AC unit to guard against damage.

How To Fix Refrigerant Leak In AC?

condensate drain line

The blocked condensate drain line is a typical reason for AC refrigerant leakage. Condensation can escape because of this AC component.

Condensate drain pan clogs and leaks over time if water accumulates in the element near the condensate drain line.

1. Condensate Drain Pipe Access

Find the condensate drain pipe first, which is typically outside your house. Next, search the area around the outdoor unit for a white or copper pipe.

Look in your owner’s manual if you’re having trouble finding the pipe.

2. Clean Out the Pipe

Then, use a dry or wet vacuum cleaner to remove any obstruction by connecting it to the pipe’s end.

Or use other methods, such as vinegar, to clean the AC drain line

3. Changing the Filters

Continue to leak? Try changing the filters in the air conditioner.

You wouldn’t believe how much dirt and debris assemble on these filters over time, obstructing airflow to the evaporator coil and, you guessed it, causing leaks.

4. Make an Expert Call

Contact a qualified HVAC specialist with the knowledge and tools necessary to identify the problem and fix your AC unit if the leak problem continues.

How Much Does It Cost To Repair a Refrigerant Leak?

You should budget between $160 and 375 for a simple refrigerant top-off.

However, expect a more significant fee if the leak itself needs to be repaired.

For example, you could spend between $550 and $1,600 on air conditioning repair and refrigerant leak detection.

What Does Refrigerant Smell Like?

The majority of refrigerants are said to smell sweet or potentially like chloroform. Freon in high quantities can harm your organs and make breathing difficult. It can also create fluid buildup in your lungs.

Think of the copper coils as the veins of the air conditioner as the refrigerant passes through them.

Unfortunately, these copper coils can occasionally develop cracks and leak refrigerants.

As a result, you may be smelling a chemical called refrigerant, which has a sweet, chloroform-like aroma.

How Many Pounds of Refrigerant Per Ton?

The general rule is two to four pounds of refrigerant for every ton of your unit. Always double-check your unit’s specifications.

However, most residential air conditioners weigh between one and five tons. Therefore, anything weighing more than five tons is regarded as commercial grade.

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