4.26 quadrillion BTUs. That’s the amount of site energy (energy used at the location being air conditioned) consumed by AC units in the year 2016. Source energy (energy generated at electrical plants) used by AC units that same year was triple that (around 12.8 quadrillion BTUs).
By 2050, energy consumption for air conditioning in OECD countries is expected to reach four times what it was in 2010. That doesn’t even include countries like China, where air conditioner sales reached 214 million units in 2019 – an increase of over 500% since 2000.
What does this mean? Many more people are using air conditioners now than were a few years ago. While this is mostly a positive sign of increased living standards and economic development, it also brings with it a troubling rise in energy consumption. Not only is this energy expensive, it creates an environmental concern that could quickly spiral out of control.
Until recently, many people in developing countries haven’t had the means to purchase air conditioners. Other regions may have lacked the electrical infrastructure to support a large number of people using air conditioners for climate control.
Now, all of that is changing. Places all around the world (especially cities) are experiencing more extreme temperatures. As of 2019, the average number of days (globally) that require air conditioning has increased by 15% since 2000.
As air conditioning becomes more available to everyone, the HVAC industry is beginning to face unique challenges regarding product efficiency and emissions. Although many organizations have made significant strides toward improving our efforts on this front, there is still more work to be done from both governments and AC manufacturers. If air conditioning is going to continue being a growing part of our everyday lives, we will need to focus on creating better refrigerants and energy efficient technology for all seasons.
The Two-Part Problem
Developing countries are gaining greater access to air conditioners than ever before. In fact, global demand for AC units is expected to triple by 2050. At that point, the estimated number of total AC units worldwide will be about 5.6 billion.
In many ways, this is a good thing for both the industry and the world. It means that more people are able to have comfortable living spaces, and air conditioning technology is being put to good use all around the globe. While this is a big win for global living standards, it also presents a challenge to decarbonizing our energy sources in order to stave off the worst effects of climate change.
The problem arises in the way energy consumption and emissions from air conditioners affect our atmosphere. Air conditioners are contributing to a significant amount of greenhouse gas emissions in two distinct ways.
Problem # 1: Direct Emissions from Refrigerants
The first problem with modern air conditioning is the emissions from certain refrigerants. Although the AC industry has made some progress in creating new refrigerants that do not directly contribute to the depletion of the ozone layer, today’s most commonly used refrigerants still present problems for the atmosphere.
To understand this, we first need to understand GWP.
GWP (Global Warming Potential) is a scientific standard developed to show the long-term impact of different gasses on the environment. It measures the amount of energy emissions that will be absorbed by 1 ton of gas over a certain length of time. GWP is important for understanding the impact of air conditioners on the environment because it shows how refrigerant emissions can be absorbed into the atmosphere and remain there.
Used as a base model, Carbon Dioxide (CO2) has a GWP of 1 regardless of the time elapsed. While many of us are familiar with the impact of CO2 on the environment, consider that some of the most common refrigerants used today have a GWP 1,000 times more destructive than CO2.
This only accounts for direct emissions, or emissions that occur when the refrigerant escapes directly from the unit into the air. While this problem is easy to visualize, the larger issue comes from indirect emissions. This is much more difficult to tackle.
Problem # 2: Indirect Emissions From Burning Fossil Fuels
To understand the full scope of the issue, consider that the energy required to run your air conditioning unit isn’t just what appears on your electric bill (site energy). It is also the source energy generated at power plants that is then routed to your building to run your AC unit.
Because electricity diminishes as it travels from the power plant to its final destination, power plants need to produce around three times more electricity than is actually consumed at the site level.
Source energy is the EPA’s preferred measurement for energy consumption because it provides a more complete picture of how much total energy is used by a building or site overall.
In total, heating, ventilation, and air conditioning account for 26.6% of total energy use in the United States, according to the U.S. Department of Energy.
And we aren’t just talking about energy costs here, either. We’re talking about the total amount of emissions from burning fossil fuels (gas, coal, oil, petroleum, etc.) to create the energy which runs all the air conditioners across the world.
Think of it this way: In 2020, 60% of the electricity in the United States was generated by burning fossil fuels. In China, where air conditioner use is growing much faster, it was 78%.
This in turn creates harmful emissions that either destroy the ozone layer or prevent heat from escaping the atmosphere. Since these emissions are not the direct result of any AC unit itself, they are referred to as indirect emissions.
According to the U.S. Department of Energy, 74% of the CO2-equivalent emissions associated with AC use are the result of indirect emissions caused by generating electricity.
Indirect (and direct) emissions include much more than the energy from cooling systems alone. About 48% of homes in the United States are heated by natural gas (a fossil fuel). This is closely followed by electricity at 37%.
If something isn’t done to address the issue with air conditioning emissions damaging the environment, the entire world faces a problem that compounds on itself. More air conditioners means more emissions. More emissions means a hotter planet, which then increases demand for air conditioners and so on. The problem only gets worse unless we make some changes.
While the burning of fossil fuels to produce electricity is a much bigger part of the problem, this issue needs to be addressed by our society as a whole. Decarbonizing our power sources is a big change that is already set in motion.
In the HVAC industry, we need to focus on improving our designs to be more environmentally healthy for use at the site level. We can start by using cleaner refrigerants and energy-efficient technology such as heat pumps. We can then work on making them affordable and available to be more widely adopted by consumers.
Using Better Refrigerants
Moving forward, one of the main goals for improving air conditioning technology is to implement new and cleaner refrigerants that are still feasible to use on a large scale. While the most widely-used refrigerants today do not deplete the ozone layer, we still need to find a cooling solution with a low GWP.
The U.S. Department of Energy states that if 100% of AC units started using near-zero GWP refrigerants, it would globally reduce the total emissions from air conditioning units by 26%.
With HCFCs like R-22 (aka Freon®) and HFCs like R-410A being phased out for new units, the AC industry is currently focused on HFO refrigerants like R1234yf, R1234ze(E), and R1233zd which have a GWP that is only four times higher than CO2.
Since 2008, manufacturers Honeywell and DuPont have developed a series of HFOs under the brand name Solstice. These refrigerants are meant to replace a variety of high-GWP refrigerants, even those used in cars. For instance, the Solstice L-41y (R-452B) was created to replace R-410A in most air conditioners and heat pumps.
At one point, R-410A was actually thought to be a suitable replacement for R-22. However, R-410A cannot be used in units designed specifically for R-22 because the operating pressures are too high for most compressors. This is one of the many challenges in adopting better refrigerants across the board. AC units need to be specifically designed to use better refrigerants if they are ever going to work properly.
Leveraging Heat Pump Technology
Currently, heat pumps fulfill only 5% of heating demand around the world. While the market for heat pumps is growing in many countries, we have yet to embrace this technology to its true potential. Heat pumps (and AC systems that use the same technology) provide a much cleaner solution for climate control at the site level.
Heat pumps work by absorbing heat from one location and blowing it (or pumping it) into another. Despite the name, heat pump technology can actually provide temperature control for all seasons. During the summer, your heat pump will absorb heat from the indoor space and pump that heat outside until the indoor temperature reaches the set point.
Believe it or not, this is the same technology used by many standard air conditioners. While heat pump designs have become much more efficient over the years (largely due to a shift toward inverter technology), there is not much difference in cooling efficiency between heat pumps and standard AC units.
The major advantage to using heat pumps comes during colder months. There is a unique opportunity to use heat pumps as a replacement for burning fossil fuels to heat our indoor spaces without sacrificing comfort. Instead of burning fuel, heat pumps absorb outside heat from the air, water, or ground (geothermal energy) and blow that heat through indoor space.
This is far more efficient than most other heating methods. Some even estimate that heat pumps consume 3 to 4 times less energy than gas heaters.
Although this doesn’t fix the source energy problem (the electricity powering your heat pump may still be generated from fossil fuels), it’s far less harmful than burning a fossil fuel like natural gas to heat your building directly.
Overall, heat pumps are a great way to cut down on emissions across the world that continue to harm the environment. So, why aren’t more people using this technology?
In many cases, the high upfront cost of installing a heat pump or replacing an existing system is the main obstacle to full adoption. Even when using a heat pump would save more money over time than a standard air conditioner, purchase costs for heat pumps are still too high in some markets for many to consider the investment. Newer heat pump models will need to become more affordable for consumers if the trend is ever going to change.
Working On a Solution Together
While this problem may be surprising to some, world organizations have been working on potential solutions for quite some time.
The Montreal Protocol
In one of the most significant examples of international cooperation to date, 197 nations unanimously ratified the 1987 treaty known as the Montreal Protocol. The agreement stated that participating countries would begin phasing out certain chemicals that were harmful to the ozone layer. This prevented the use of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons) as refrigerants in new AC units for many countries.
This agreement changed the air conditioning industry for good. After it was ratified, many countries started using HFCs (hydrofluorocarbons) to replace CFCs and HCFCs in new units. Because they do not directly deplete the stratospheric ozone layer, HFCs were thought to be an acceptable alternative.
However, the Kigali amendment was proposed in 2015 to phase out HFCs as well due to their high GWP. Countries now aim to reduce HFCs by 80-85% over the course of about 15 years. If adopted across the world, the amendment could prevent the warming of the planet by one half degree celsius this century alone.
The Global Cooling Prize
National governments aren’t the only ones working to change the industry. Organizations like RMI and Mission Innovation have partnered with the Department of Science and Technology and the Government of India to create the Global Cooling Prize.
The prize was an incentive for manufacturers around the world to create an affordable cooling solution that has five times less climate impact than residential HVAC technology commonly used today.
The first winner was the Daikin VRV, which was also the first air conditioner to use the refrigerant known as R-32 in residential models.
The second winner was GREE’s Zero Carbon Source cooling technology which uses a vapor compression refrigeration system for lower environmental impact.
Both of these inventions are great advancements in the fight to change air conditioning technology for the better. While there is still more research to be done, there is also great promise on the horizon.
Final Thoughts
The world has been changing in many ways, and we as an industry are now reaching a turning point. While we don’t believe this is the end of air conditioning overall, we do believe it’s time for the industry to adapt.
We are making progress, but there are still obstacles to widespread adoption of better refrigerants and heat pump technology. Part of the issue is awareness. Most people don’t understand the full scope of the impact air conditioning has on society or what they can do to change it. The problem of emissions and energy usage is worldwide, and it will take effort from multiple groups to get us where we need to be.
Still, the biggest obstacle to changing the heating and cooling industry is cost. While governments are phasing out poor refrigerants and manufacturers are updating designs, consumers are hesitant to purchase better units due to the high upfront cost.
Although the path ahead is still being paved, more efficient and affordable air conditioning solutions are already available in other forms. Many PTACs have heat pump technology built in, and the GREE ETAC2 series is high on the list for energy efficiency. As we continue to improve, making AC technology that is affordable for everyone will make sure we stay comfortable both in our homes and on this planet. Check out our store for new and refurbished models as well as replacement parts for your own PTAC units today.