This credit can be fairly difficult to understand at a glance. So let’s start by getting some common misconceptions out of the way.

One common misconception is that this credit specifies or prohibits a certain refrigerant type. That was true in early versions of LEED (and is still the case in the prerequisite, EAp3).

Another misconception is that this credit solely concerns refrigerants’ ozone-depleting and global-warming potentials (ODP and GWP), and that a refrigerant like R-410A automatically complies because it has low ODP and GWP numbers. But the credit requirements also include other variables, such as the ratio of coolant charge to cooling capacity for a given compressor unit, and this credit considers the life of the unit and the refrigerant leakage rate. R-410A, for example, may be compliant in some scenarios but not in others. 

Two main requirements

To earn this credit, you’ll need to:

• Select systems that reduce the harmful environmental impacts of refrigerants (or avoid them entirely).
• Prohibit installation and use of fire suppression systems with CFCs, HCFCs, or halons. 

The credit is about reducing the environmental impact of refrigerants in space conditioning and large-scale refrigeration systems in project buildings. It deals with two environmental impacts of concern: depletion of the ozone layer, and greenhouse gas emissions. EAc4 is more comprehensive than EAp3: Fundamental Refrigerant Management, which only concerns the use of ozone-depleting CFCs in equipment.

All permanently installed HVAC&R equipment with more than 0.5 lbs of refrigerant—including chillers; unitary HVAC equipment (split and packaged); room and window air-conditioners; computer, data center, and telecom room cooling units; and commercial refrigeration equipment—is addressed by this credit.

The credit also addresses fire suppression systems that contain ozone-depleting substances, including CFCs, HCFCs, or halons. Halon production was banned in the U.S. in 1994, as it is many times more ozone-depleting than CFCs and HCFCs.

Why it matters

While ozone is an unwanted pollutant at ground level (it’s a key component of smog), in the upper atmosphere a sparse layer of ozone plays a critical role in filtering out harmful ultraviolet rays from sunlight.

The Montreal Protocol on Substances that Deplete the Ozone Layer—the world’s first global environmental protection treaty—prescribed a complete phase-out of CFC-based refrigerants by 1995, and of HCFCs by 2030 in developed countries. As a result, environmentally preferable refrigerants are becoming more widely available for new systems.

Thinking ahead to earn the credit

From an environmental perspective, the best way to earn this credit is to avoid the use of refrigerants altogether, by using either passive or evaporative cooling strategies, or with absorption chillers (see Related Products in the right column). 

If neither of these is an option for your project, earning this credit will be more about the selection of mechanical equipment and associated refrigerants. 

The best way to determine credit compliance is to run compliance calculations as soon as an HVAC system is proposed. Not all compressor units have to be in compliance individually; this credit calculation uses a weighted average based on cooling capacity (in gross ARI-rated ton). Leakage rates and coolant charge are as important as GWP and ODP factors in influencing credit calculations.

If your project already has designed an HVAC system and now wants to change the refrigerant to meet the credit, you will find that it may not be as simple as swapping out the coolant or the compressor unit for a more environmentally benign choice. Rather, your entire HVAC system may have to be resized to accommodate the different capacities and efficiencies of the newer units.

A centralized plant helps

This is a relatively easy credit to obtain if your project has a centralized cooling plant, with a favorable “coolant charge to cooling capacity” ratio. But even for projects with smaller, more dispersed units, this credit should be achievable if you consider the credit requirements early.

Because requirements are based on the average refrigerant impact per ton of capacity, a low-performing system can be offset by high-performing systems, or a building with a large amount of heat pumps can still comply if the cooling capacity of the heat pumps is high enough.

That said, there are some project types where meeting these requirements will be more difficult. Supermarkets and restaurants with high volumes of commercial refrigerators need to carefully plan how to design HVAC&R systems to earn the credit.

Ironically, some of the refrigerants that can help earn this credit are used in systems with poorer energy efficiency, resulting in increased greenhouse gas emissions. (CFCs were super-efficient, they just happened to be toxic and destroyed the ozone layer.) The life cycle of operational efficiency and refrigerant performance is not covered by this credit, but leakage and direct environmental impact are. Any loss of efficiency is a trade-off that has to be accounted for in EAc1.