Cooling systems and their refrigerants are the unsung heroes behind our fresh food, cool homes and offices, and smoothly operating technology. These refrigerant-based systems can also perform as heat pumps, which are a cost-effective lower emissions option compared to traditional fossil fuel-based HVAC heating systems. As the role of refrigerants expands in modern HVAC systems, replacing traditional hydronic (water-based) systems, it is important to understand the impact of refrigerants as potential greenhouse gases.  

As a result, regulatory organizations have been actively setting thresholds to reduce the environmental impact of refrigerant systems and are redefining the types of refrigerants that can be used in new and existing systems in a push to lower their Global Warming Potential (GWP). GWP represents how much more energy a compound will absorb compared to CO2. The higher the GWP, the worse the compound is for the environment.  

The role of refrigerant-based systems is expanding and can be a big part of the effort to decarbonize our buildings. This makes it essential for building developers, designers, and owners to understand the role of refrigerants and how to align with current regulations and systems. 

The Role of Refrigerants in Heating and Cooling 

Refrigerants are chemicals that change from liquid to gas at specific temperatures and pressures, absorbing and releasing heat in the process. This makes them ideal heat transfer mediums for Direct Expansion (DX) cooling systems and heat pumps. 

Heat pumps work by transferring heat from one place to another. This is a similar process to how refrigerators work. When you put your hand on the back of a refrigerator, you feel heat being expelled. The heat is transferred from inside the refrigerator to the outside, making the interior colder. It's essentially a giant heat pump! 

Heat Pumps as a Sustainable Solution 

In recent years, heat pumps have emerged as a key technology for electrifying buildings. In many climates, they provide both heating and cooling more efficiently than traditional air conditioning units and gas boilers. While gas systems have a lower upfront cost, they burn natural gas to produce energy. Alternatively, heat pumps use electricity to move heat already present in the environment, requiring less input energy, giving them a higher efficiency. 

For example, heat pumps can achieve efficiencies of 300-400%, meaning they produce three to four times more energy than they consume (COP—coefficient of performance). This efficiency translates to lower energy use and reduced GHG emissions. Heat pumps can significantly improve building efficiency, lower utility bills, and support sustainability goals. 

Updated Regulations for Refrigerants 

In 2020, the U.S. Congress passed the American Innovation and Manufacturing (AIM) Act to help industries transition to environmentally friendly refrigerants. The act aimed to reduce their overall production and consumption by 85% by 2036 and paved the way for the EPA to develop specific GWP requirements for refrigerants. Starting in 2025, all refrigerants for residential and light commercial systems must have a GWP below 700.  

This is a significant shift from traditional refrigerants that developers will need to comply with. For instance, the common refrigerant R-410A has a GWP of 2,088, HFC-23 of 13,800, and Freon 404A of 3,920. Alternatively, newer refrigerants like R-1233zd and R-1234ze have GWPs of less than 10, making them ideal substitutes to gradually replace these older options. 

What This Means for Building Owners 

Building owners must proactively manage their HVAC systems to align with AIM. Here are key steps to consider: 

1) Conduct Audits: Understand when your HVAC system will need replacement. 

2) Create a Capital Improvement Plan: Plan for upgrades and replacements with heat pumps and low GWP refrigerants. 

3) Review Incentives: Explore current incentives and alternative funding options to lower your cost of capital.

4) Understand New Standards: Recognize how new refrigerants require updated systems, such as new piping and coils. 

What This Means for MEP Designers 

Mechanical, electrical, and plumbing (MEP) designers must educate themselves on the new refrigerants and their specific design requirements. Some new refrigerants, like R-1234ze, have a flammability rating of A2L, which is mildly flammable but manageable with proper installation and maintenance. Organizations like ASHRAE and UL have already published standards to ensure the safety of systems using these refrigerants. 

What This Means for Local Jurisdictions 

Local authorities having jurisdiction over heating and cooling systems must familiarize themselves with updated regulations to ensure compliance and safety. This knowledge will help streamline the transition to low-GWP refrigerants and heat pump systems in local communities. 

Emerald is Helping Companies Adapt 

Adapting to these changing regulations is not a burden; it's an opportunity to improve your building's efficiency and reduce greenhouse gas emissions. These go hand-in-hand to improve building resiliency and be a valuable part of your sustainability strategy — such as achieving green building certifications. 

At Emerald Built Environments, we understand this process and have helped several clients capitalize on the opportunity. Here are a couple of examples: 

National Retailer

We collaborated with the design team of a national equipment retailer on a new build. Our role was to explore HVAC system options, ultimately resulting in them choosing a Variable Refrigerant Flow (VRF) system. Combined with an assessment of value engineering options for exterior shading devices, the project achieved energy savings of 40% better than the code minimum. 

Madtree – The Alcove 

We worked with the design team to explore energy savings options for a historic structure renovation. We focused on non-structural components like VRF and window systems to maintain the historic aesthetic. This led to an energy efficiency 12% better than code. 

Building a Sustainable Future with Refrigerants 

Refrigerants play a vital role in the path to decarbonization. By adopting heat pumps and low-GWP refrigerants, buildings can significantly reduce both direct and indirect GHG emissions while lowering long-term energy costs. Combined, these are an impactful, often cost-effective, and achievable way to improve building sustainability. We frequently recommend them as an early step in our sustainability roadmap service for developers. 

Emerald Built Environments has helped many companies streamline their buildings to reduce energy efficiency through individualized strategies. Learn how we can help you identify areas of energy savings and implement solutions.