How Does Refrigerant Work?

If you’ve ever heard the term “refrigerant” but aren’t exactly sure what it is or how it works, don’t worry – you’re not alone. HVAC systems have a lot of moving parts that can be confusing for homeowners who aren’t familiar with how they work. This includes refrigerant and the refrigerant lines, which work together to transfer heat to either cool or heat your home.

We’re here to help you better understand your HVAC system, so let’s break down how refrigerant works and why regular maintenance is key to avoiding problems with refrigerant lines.

What Is Refrigerant and How Does It Work?

Refrigerant is often called the “lifeblood” of a heat pump or air conditioning system because it’s responsible for transferring heat to heat or cool your home. It circulates through copper coils, changing between gas and liquid states as it moves through the evaporator coil (inside the air handler) and the condenser coil (outside). The refrigerant absorbs and releases heat, moving it between inside and outside your home to cool or heat the air.

In cooling mode, refrigerant starts in the evaporator coil inside the air handler, where it absorbs heat from the indoor air and turns it into a low-pressure, cool gas. The compressor then pressurizes this gas and sends it to the condenser coil outside, where it releases the heat and condenses back into a liquid. After passing through the expansion valve, the refrigerant’s pressure and temperature drop before it returns to the evaporator coil to repeat the cycle.

In heating mode, a heat pump reverses the refrigerant flow using a reversing valve. This allows the system to extract heat from the outdoor air (even in cold temperatures) and transfer it indoors, where the refrigerant releases heat through the evaporator coil to warm your home. 

Although it may be cold outside, there’s still enough heat in the air to warm your home, but only up to a certain point. Traditional heat pumps begin to lose efficiency when temperatures drop below freezing, but leading HVAC manufacturers are now developing advanced heat pumps designed to function even in sub-zero temperatures.

Common Issues with Refrigerant

Refrigerant leaks are bad news for your system, its efficiency, and the environment. Here are some common problems to look out for that are associated with refrigerant issues:

• Refrigerant Leaks: Over time, leaks in refrigerant lines or connections can cause the system to lose refrigerant, resulting in reduced heating or cooling efficiency, poor temperature control, and higher energy bills.
• Dirty Coils: When the evaporator or condenser coils get dirty, airflow and heat transfer are restricted. This forces the refrigerant to overheat or underperform, leading to inefficiency and poor comfort levels.
• Frozen Evaporator Coil: Low refrigerant levels or blocked airflow can freeze the evaporator coil, preventing the refrigerant from absorbing heat properly and reducing cooling performance.
• AC or Heat Pump Blowing Warm Air: Low refrigerant levels prevent the system from absorbing and releasing enough heat, causing it to blow warm air during cooling mode and leaving your home uncomfortable.
• Short Cycling: Low refrigerant levels can cause short cycling, where the system turns on and off too frequently. This reduces efficiency and puts extra strain on components.
• High Energy Consumption: Improper refrigerant levels – either too high or too low – can make the system work harder than needed, resulting in higher energy costs and increased wear on the system.
• Compressor Issues: When refrigerant levels are low, the compressor has to work overtime. This can potentially cause overheating, damage, or even complete failure over time.

How Regular Maintenance Can Prevent Refrigerant Issues

To keep your air conditioner or heat pump running smoothly and efficiently throughout the year, it’s important to schedule regular maintenance with a trusted HVAC technician – once a year for your AC and twice a year for your heat pump if you use it for both heating and cooling. Regular tune-ups help prevent problems before they arise, helping you avoid expensive repairs or premature replacement.

During a maintenance visit, the technician will clean and adjust key components, check refrigerant levels, and inspect for any leaks. Catching refrigerant leaks early can reduce your system’s performance and, if left untreated, harm the environment.

Why Are They Changing Refrigerants?

The HVAC industry is gradually shifting away from R-410A, a refrigerant that’s been widely used since 2010, due to its negative environmental impact. While R-410A is being phased out to reduce global warming potential, starting in 2025, all newly manufactured air conditioners and heat pumps will switch to a more eco-friendly refrigerant called R-454B. R-454B offers lower global warming potential, making it a more sustainable choice for the future.

However, R-410A should still be available for several years to come, so if your current system develops a refrigerant leak or requires a recharge, technicians will be able to find it and make repairs. Contact a qualified technician to determine whether repairing your existing system or replacing it with a more energy-efficient model that uses R-454B would be the best choice for your home and budget.

R-22 was commonly used in older HVAC systems manufactured before 2010, but it has been phased out due to its harmful environmental impact. Although you can still find recycled R-22, it's expensive, so if your system runs on it, it might be time to think about upgrading to a more energy-efficient model.