HVAC

Understanding Refrigerants and How They Work

Cincinnati Air Conditioning is more than just a luxury, it helps maintain productivity in the workplace and makes possible many modern medical/health services. It is also necessary for controlling humidity in humid climates.

Most AC systems are similar in their basic function, with a compressor, evaporator coil and condenser coil. Here’s a look at what each part does to remove heat from your house/room.

1. Refrigerant

HVAC

Refrigerant is a chemical substance that undergoes a series of reactions to cool your air and circulate it throughout your home. Known by the brand name Freon, it’s used in air conditioning systems and other electronic applications worldwide. However, many people don’t fully understand refrigerants and how they work.

Refrigerants are a mixture of liquid and gas, changing between the two phases as they circulate through your AC system. They have a very low boiling point, which allows them to absorb thermal energy (indoor heat) and transfer it to the outside air. Refrigerants are very dense, but they can evaporate and condense at high pressures. This cycle is what keeps your air cool, and it’s an essential part of your air conditioner.

When your system is working correctly, refrigerant flows through the evaporator coil indoors, where it absorbs heat from your home’s air and turns into a low-pressure gas. Then the refrigerant moves to the compressor, where it is highly pressurized. This process causes the liquid to vaporize, and it expels the heat outdoors, cooling your home’s air and turning back into a low-pressure gas.

The cycle repeats itself over and over, continuously absorbing and expelling heat to keep your home cool. Refrigerants are a vital part of your air conditioning, but they’re also fragile. They can break down and leak, causing your air conditioner to stop functioning. If you suspect that your refrigerant is low, contact a licensed HVAC technician. They’ll locate and repair any leaks, then add the right amount of refrigerant to your system.

While most refrigerants are considered nontoxic, some are being phased out in response to strict environmental regulations. For example, R-22, also called Freon, is being replaced with a newer refrigerant that does not deplete the ozone layer. Your HVAC professional will be able to explain the different refrigerants and how they affect your air conditioner’s efficiency. They’ll also discuss whether your air conditioning system can accommodate a new refrigerant. If not, you may need to consider replacing your unit.

2. Compressor

The compressor is one of the most vital components in an air conditioning system. It increases the pressure of the refrigerant and raises its temperature, so that it can absorb heat and cool the air. When the compressor fails, the entire air conditioner fails to cool your home.

A compressor is like a pump, in that it pumps gas or air from a smaller chamber to a larger chamber, but it can only do so with gases because liquids are not compressible. It requires energy, which can come from electricity or fuel, and it needs a control mechanism to keep the pressure stable.

An AC compressor has a motor that turns the crankshaft to press the pistons in the compression chamber. The resulting movement creates friction, and heat is generated by this process. This is why a compressor always runs on a fan to pull in ambient air, and it also helps to cool the compressor itself.

A hermetic compressor has a sealed housing that is hard to open, while semi-hermetic and open compressors allow for easy maintenance and repair. They have removable screws and covers, which can be removed to access the compressor motor and cylinders. Hermetic compressors are more expensive to purchase, but they last longer and are more efficient than semi-hermetic or open compressors.

Compressors need lubrication, which is provided by oil. Leaks in the compressor system can reduce lubrication, and this can lead to excessive wear. A professional inspection can help to determine the cause of these problems.

When the compressor is leaking, it will cause the refrigerant to have low pressure. This will prevent the system from cooling your home, and it may cause your ductwork to clog, which can result in poor air flow.

When the compressor is clogged, it can affect the air flow and increase your energy bills. A reputable HVAC technician can replace the compressor and address any issues that may be causing it to work harder than necessary. They can check for refrigerant leaks, valve problems, compressor stress, and electrical issues. They can also ensure that the suction line is the correct size for your air conditioner and that it is plugged in securely.

3. Coils

Coils are a vital part of your AC. They’re in direct contact with the air that passes through the system, and they have to be kept clean in order to work properly. Dirty coils force your system to work harder, which leads to higher electricity bills and eventual wear-and-tear on other components, like the compressor.

The copper coils in your evaporator and condenser units need to be cleaned regularly to ensure that heat is released efficiently. When the coils are dirty, the coolant can’t release the heat it has gathered, which makes your system work harder to get the job done and increases energy consumption.

Corrosion is the enemy of your AC coils, and it can take a toll on your energy bills and system efficiency. The corrosion comes from dirt, dust, and other pollutants in the air that come into contact with the coils. Dirty coils are also susceptible to damage from physical impact or abrasion.

The evaporator coils are especially sensitive to contamination. If they’re not cleaned often enough, they can become frozen, which inhibits heat transfer and makes your system work harder to cool your home. Frozen evaporator coils can also lead to a host of other problems, including high electricity bills and a burnt-out compressor.

There are several signs that you need to replace your evaporator or condenser coils, including a hissing sound, clanking noises, or puddles of liquid under your unit. These are all symptoms of a refrigerant leak, which can be caused by a dirty evaporator coil that has become clogged with ice and is blocking airflow or a broken compressor that is leaking at the copper lines.

The evaporator coils also need to be replaced when they start making your air conditioner produce a smelly or moldy odor. This is usually a sign that the coils are contaminated with old refrigerant or a chemical called chloroform, which can be toxic and requires professional attention as soon as possible. The newer R-410A refrigerant doesn’t have an odor, and any odors you might be experiencing are likely caused by a burning fan motor or another issue in your unit.

4. Thermostat

A thermostat is the command center for your heating and air conditioning system, monitoring and adjusting indoor temperatures to keep them consistent with your desired settings. While you may be familiar with the basics of a thermostat, there is much more to this simple wall-mounted device that makes it one of the most important parts of your AC.

Thermostats are not one-size-fits-all, offering a wide range of designs, features, and capabilities. Understanding how different types of thermostats work, and how they relate to your home, can help you choose the best one for your needs.

When a room’s temperature reaches a set point, the thermostat signals your air conditioner to activate and cool the space until it reaches your preferred setting. Once your desired indoor climate is achieved, the thermostat sends a signal to shut off your AC.

A good thermostat is key to ensuring your home remains comfortable, and that the performance of your AC system meets or exceeds your expectations. A poorly calibrated or functioning thermostat can waste energy, cause discomfort in your home, and even shorten the lifespan of your AC unit.

To understand how a thermostat works, it helps to look at the circuits inside of the device. Thermostats come in two varieties: digital and mechanical. The digital models use microprocessors to convert temperature readings into electrical signals. While the mechanical thermostats use coiled bimetallic strips to respond to temperature changes.

The power for the thermostat comes into the terminal labeled RC from the 24VAC transformer on your air conditioning system. The current passes through a mode switch controlled by the ball, which jumps the current onto a trace that connects to terminals marked G (for the fan) and Y (for the compressor). These relays then turn on the air conditioning system.

Thermostats have a significant impact on how well your AC system functions, but they can be easily damaged by improper installation or operation. If you’re experiencing an issue with your air conditioning, the first thing you should check is whether or not your thermostat is working correctly.