Refrigerants and the LEED Green Associate Exam: What You Need to Know

The LEED Green Associate exam will almost certainly test you on refrigerant management and the Montreal Protocol. For example, this is an example of a question that could appear on the test:

Which of the following refrigerants has the highest global warming potential (GWP)?

a) Carbon dioxide

b) Hydrochlorofluorocarbons (HCFCs)

c) Chlorofluorocarbons (CFCs)

d) Hydrofluorocarbons (HFCs)

e) Ammonia

(See answer at the bottom of the page).

Refrigerants are chemicals that are used in HVAC systems and refrigerators to cool the building or items inside the refrigerator. Common refrigerants include chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). However, these refrigerants have been found to deplete the ozone layer and expedite global warming. Therefore, in the late 1980s, the United Nations developed the Montreal Protocol, which is an international treaty that mandates the phase-out of CFCs (the most harmful) by 2010 and the phase-out of HCFCs (the second most harmful) by 2030.

Ozone Depleting Potential and Global Warming Potential

Ozone Depleting Potential, or ODP, and Global Warming Potential, or GWP, are both ways to measure the impact of refrigerants on the atmosphere. It is important to note that ODP is more harmful to the environment than GWP, so refrigerants with higher ODP are considered worse than those with high GWP.

For the exam, you will need to memorize the following refrigerants and their corresponding levels of ODP and GWP (listed in order from most harmful to least harmful:

1) CFCs: High ODP, Medium-High GWP

2) HFCs: Low ODP, Medium GWP

3) Hydrofluorocarbons (HFCs): Zero ODP, Highest GWP

4) Natural Refrigerants/Hydrocarbons (HCs): Zero ODP, Low-Zero GWP

Examples of natural refrigerants: Water, CO2, Ammonia, Propane, Butane, Isopentane, etc.

5) Natural Ventilation: Zero ODP, Zero GWP

It is important to remember the order from worst (CFCs) to best (natural ventilation) for the environment. Keep in mind that although HFCs have the highest GWP, they are not the most harmful, because ODP is worse than GWP (and CFCs and HCFCs have higher ODP).

Refrigerants and LEED Rating Systems

Since they are harmful to the environment, LEED addresses refrigerants in both an Energy and Atmosphere prerequisite (Fundamental Refrigerant Management) and optional credit (Enhanced Refrigerant Management), meaning that it is mandatory for projects to restrict their use of harmful refrigerants, but they have the option to go above the minimum requirement and earn points for further reducing the amount.

For the test, you should know the general requirements for the both the prerequisite and the credit.

Energy and Atmosphere (EA) Prerequisite 3: Fundamental Refrigerant Management (Required)

New buildings: Zero use of CFC refrigerants in HVAC & refrigeration

Existing building: CFC phase-out before project completion

Exception: If it's not economically feasible, reduce CFCs to 5% or less.

EA Credit 4: Enhanced Refrigerant Management (Optional, worth points)

Do not install fire suppression systems with CFCs, HCFCs, or halons AND

Option 1: Do not use refrigerants OR

Option 2: Choose refrigerants for HVAC & refrigeration with low ODP and GWP according to this formula:

LCGWP + LCODP x 10^5 < 100

where LCGWP stands for life cycle global warming potential and LCODP stands for life cycle ozone depletion potential.

Answer: D