Heat pumps are crucial for heating and cooling systems widely used in residential and commercial spaces. It is essential to select the appropriate refrigerant for heat pumps as it affects the system’s energy efficiency, environmental impact, safety, and cost. The two commonly used refrigerants in heat pumps are R290 and R32, which have different characteristics and applications. The functionality and suitability of heat pumps primarily depend on the type of refrigerant they use. This article explores the differences between R290 and R32 heat pumps.
What is R290?
R290 is a hydrocarbon refrigerant also known as propane. It is used as a refrigerant in various cooling and heating applications, including heat pumps, air conditioning, and refrigeration systems. R290 has a low Global Warming Potential (GWP) of 3, which is significantly lower than the standard of 150, making it an environmentally friendly alternative to most other refrigerants such as R22 and R410A. It also has a high latent heat of vaporization, meaning it can absorb a significant amount of heat energy during evaporation, making it an efficient refrigerant.
However, R290 is flammable, so specific safety measures must be taken during installation, maintenance, and disposal processes to prevent fires. Despite its flammability, R290 is increasingly being used as a refrigerant in various applications due to its low environmental impact and high efficiency.
What is R32?
R32 is a refrigerant commonly used in air conditioning and heat pump systems. It belongs to the Hydrofluorocarbon (HFC) refrigerant series, which means it is chlorine-free and has a lower Ozone Depletion Potential (ODP). R32 has a Global Warming Potential (GWP) of 675, significantly lower than many other refrigerants used in the past.
It is also more energy-efficient than some other refrigerants, helping to reduce the operational costs throughout the system’s lifecycle. R32 is non-flammable, but significant inhalation may cause slight toxicity. Due to its low environmental impact and high energy efficiency, R32 has become a popular choice for global air conditioning and heat pump systems.
Differences between R290 and R32 Heat Pumps
The refrigerant brings unique performance characteristics to heat pumps, resulting in differences between them. The main differences between these heat pumps are reflected in the following aspects:
Refrigerant Properties
The two heat pumps use different refrigerants. For example, R290 (also known as propane) has lower Global Warming Potential (GWP) and Ozone Depletion Potential (ODP) compared to R32. R290 has a GWP of 3 and ODP of 0, while R32 has a GWP of 675 and ODP of 0.
Efficiency
R32 has a higher volumetric cooling capacity compared to R290, meaning R32 heat pumps are more efficient in terms of cooling power per unit volume of refrigerant. The volumetric cooling capacity of R32 is approximately 87% higher than R290. R290 systems require compressors with higher displacement to maintain the same cooling load.
Safety
R290 is flammable, requiring specific safety measures during the installation and maintenance of R290 heat pumps. On the other hand, R32 is non-flammable but may cause slight toxicity with significant inhalation. If safety is a concern, make sure you have the proper setup for your preferred heat pump.
Availability
R32 has a broader application in heat pumps compared to R290, making R32 heat pumps potentially easier to obtain and find replacement parts for compared to R290 heat pumps.
Cost
Due to the lower GWP and ODP values, R290 generally has a lower cost compared to R32. Therefore, R290 heat pumps tend to be cheaper than R32 heat pumps. However, the cost of the heat pump itself can vary depending on the manufacturer, size, and features.
Operating Pressure
R32 operates at higher pressures compared to R290. This makes it more suitable for larger systems requiring higher pressures, but it also makes it more challenging to operate and maintain compared to R290 heat pumps.
Environmental Impact
Although R290 has a lower GWP than R32, it is still a hydrocarbon refrigerant that can contribute to smoke formation if leaked into the atmosphere. On the other hand, R32 is a hydrofluorocarbon refrigerant that can contribute to global warming if released.
Efficiency at Lower Temperatures
At lower outdoor temperatures, R290 heat pumps have higher Coefficient of Performance (COP) compared to R32 heat pumps, making them a better choice for cold climates. On the other hand, R32 heat pumps perform better at higher outdoor temperatures.
Energy Consumption
Due to higher efficiency, R32 heat pumps generally consume less energy compared to R290 heat pumps. This can lower the operational costs throughout the system’s lifecycle and potentially offset the initial higher price.
Noise Level
R32 heat pumps are often quieter than R290 heat pumps due to lower working pressures and smoother operation. This can be an important consideration in residential environments where noise levels can be a concern.
Factors to Consider When Choosing Between R290 and R32 Heat Pumps
The choice between R290 and R32 heat pumps depends on various factors, including specific applications, regulatory requirements, safety concerns, and personal preferences. When choosing between these two options, several factors need to be considered:
When to Use R290 Heat Pumps:
R290 heat pumps may be a good choice for heating and cooling systems in the following scenarios:
When you need a medium-sized heat pump: R290 is suitable for medium-sized heating and cooling systems, such as residential, small businesses, and offices. Its high energy efficiency and low operating costs make it an attractive choice for these applications.
Cold climates: R290 has higher Coefficient of Performance (COP) at low ambient temperatures, making it a good choice for heating applications in cold climates. It can provide reliable and efficient heating even at temperatures below freezing.
Environmentally friendly systems: As mentioned earlier, R290 has a very low Global Warming Potential (GWP) of 3, making it an excellent choice for environmentally friendly heating and cooling systems. It is also non-corrosive and non-toxic, making it a safe and reliable choice.
Residential and commercial facilities: R290 heat pumps can be used in residential and commercial applications such as homes, offices, and retail spaces. They can provide efficient and reliable heating and cooling while reducing the impact on the environment.
Retrofitting existing systems: R290 can be used for retrofitting existing heating and cooling systems that use other refrigerants. This can save energy and reduce environmental impact without the need to replace the entire system.
Why is R290 refrigerant a better choice?
R290 refrigerant is one of the newer alternatives on the market and comes with several advantages over Class I and Class II refrigerants. Let’s take a closer look at some of the reasons why this alternative is superior to others:
Environmentally Friendly:
R290 refrigerant poses significantly less harm to the environment. If released into the atmosphere, it does not contribute to ozone depletion like some other options. R290 can almost perfectly replace other refrigerants because its Global Warming Potential (GWP) is negligible, and its Ozone Depletion Potential (ODP) is zero. For decades, R134 and R404 were widely used commercial refrigerants. They have incredibly high GWP values, making them significant contributors to global warming. In contrast, R290 refrigerant is more environmentally friendly, making it a perfect substitute.
Cost-Effectiveness:
We live in a world where sustainability is crucial. Therefore, the foodservice industry also needs to take responsibility for maintaining our environment’s health. R290 refrigerant is the industry’s alternative solution, benefiting the planet while also saving money. Its heat-absorption capacity is 90% higher than previous generation products, resulting in faster temperature recovery and lower energy consumption. You can save money while knowing that you are not exacerbating global warming.
Compatibility:
One of the reasons why R290 refrigerant is so popular is its ability to be installed in many older models without the need to replace the entire system. This means spending less time and money while still benefiting from better technology. Additionally, R290 refrigerant has broad applications and can power commercial refrigeration systems for restaurants, food facilities, and food carts. The reasons for businesses to transition and start using R290 refrigerant models are evident.
Direct Atmospheric Discharge:
One of the most significant advantages of R290 is that it can be directly discharged into the atmosphere without the need for recollection and recycling. This eliminates the need for technicians to carry expensive tanks and accessories traditionally used when servicing old systems with R134 or R404. It results in a more manageable service for them, and you’ll pay much less for maintenance than before.
Recyclability:
R290 also has a good track record of being easily recyclable and reused for other purposes. This is good news for those who want to save money and repurpose what was once considered waste by-products.
Sustainability:
R290 will also become the new standard for manufacturing equipment in the future. This means that once the new standards are released and implemented, you won’t have to worry about expensive upgrades and replacements. It allows you to take a step towards a greener tomorrow.
Other refrigerants：
R410A and R32
R32 is considered a more environmentally friendly successor to R410A. Therefore, as we mentioned, manufacturers are gradually phasing out R410A. Producing R410A systems is not illegal, but OEMs must comply with regulated quotas and commit to reducing emissions. As mentioned earlier, a common misconception is that R410A depletes the ozone layer. The ODP (Ozone Depletion Potential) of both refrigerants is actually zero. The environmental difference lies in the GWP (Global Warming Potential). R32 has a GWP of 675, while R410A has a GWP of 2,088. For comparison, R-508B has a GWP of 13,396.
In addition, R32 is about 20% more efficient than R410A, reducing operational and maintenance costs. And what about recovery? R32 wins again because it is a single-component refrigerant, making it easier to recover.
However, R410A also has its benefits in certain situations. Many customers still require R410A because:
In the maritime industry, when dealing with ATEX zones, R410A is still the standard for most end-users. Therefore, they demand that installers and procurement companies purchase R410A air conditioning units.
R410A allows for transportation by air. R32 is prohibited from air transportation because it is considered hazardous. When customers are in a hurry, they often request R410A equipment.
R32 is still relatively new and has mild flammability. Not all countries and installers are familiar with R32, so they may not accept it in their projects.
Larger systems, such as VRF (Variable Refrigerant Flow) systems used for cooling buildings, require the use of R-410A instead of R32. If R32 leaks into small rooms inside buildings due to defects, the concentration of R32 in the air might exceed the lower explosive limit (LEL). This could create an explosive atmosphere, which we always strive to prevent.
