System efficiency more important than GWP
USA: Lower GWP refrigerants are important in reducing the contribution of refrigeration and air conditioning on climate change, but operators should not neglect improving system efficiency or reducing leaks.
So says Jordan Smith, executive director of GlobalFact, the Global Forum for Advanced Climate Technologies backed by a number of major refrigerant producers.
“There is no question that GWP matters and that the industry should be supporting all efforts to invent and test new, lower GWP solutions,” says Smith. “However, GWP is not the only piece of the carbon impact equation. Frankly, it’s not even the most important piece. Operators should focus on improving system efficiency, including reducing leaks.”
He recognises that operators are relying on the mantra that lower GWP leads to lower carbon emissions to make critical business decisions, and that, for the busy operator, digging deep into system operations to improve efficiency is daunting.
“A straightforward directive like “lower your GWP” is simple,” says Smith. “And simple solutions are enticing, especially when they are proven to work. Without a doubt, converting to a lower GWP refrigerant can help a business meet its environmental goals. But importantly, it’s not the only way to meet those goals.
“In fact,” he argues “it’s not even the best way.”
Jordan Smith lists leak management and peak efficiency from correctly installed and maintained systems as critical.
“Refrigerant GWP is only harmful to the environment if it leaks. If it does not leak, a refrigerant’s GWP has no environmental impact whatsoever. What matters more, and it matters regardless of leak rate, is energy consumption. For residential systems, leaks account for as much as 3% of a system’s total environmental impact. Indirect emissions from energy consumption account for 97% or more.”
Reducing leaks is also closely tied to system efficiency. A leaky system that contains less than a full charge will run less efficiently.
“Inefficient systems consume more energy, resulting in increased carbon-equivalent emissions. Put simply, the increased efficiency of a low-leak system goes much farther in reducing carbon impact than merely switching to a lower GWP refrigerant.”
Poorly installed HVACR systems lose as much as 40% of their expected efficiency. “The climate impact of this poor installation is double the impact of a properly installed system that leaked 100% of its refrigerant, regardless of the refrigerant’s GWP,” says Smith.
“Finally, leak rates don’t magically improve over time,” he says. “Without proper attention, leaks can get worse. Addressing them head on and quickly will reduce direct emissions and, more importantly, reduce indirect emissions by way of increased system efficiency.”