The Climate Menace Hidden in Plain Sight

Join daily news updates from CleanTechnica on e mail. Or follow us on Google News!

A primer on refrigerants and their impacts on local weather change.

Refrigerants are in every single place. They’re in our air conditioners and warmth pumps, in our fridges — even in our automobiles! But, regardless of this ubiquity, refrigerants are an oft-neglected topic inside electrification methods regardless of their main contribution to the greenhouse impact.

Maybe this disregard stems from the notion that refrigeration is both a secular or overly technical topic. Many sources are dense and chock-full of acronyms.

On this article, I’ll hopefully persuade you that refrigerants could be a fascinating topic, and one which’s important to know if we’re critical about decarbonizing our buildings.

I’ll begin with some refrigerant fundamentals, then dive into just a few big-picture questions, together with: How has the refrigerant business advanced over time? How widespread are leaks and why are these leaks problematic? And, lastly, how a lot do refrigerants contribute to constructing sector emissions?

What makes a (good) refrigerant?

Refrigerants are fluids that may be simply heated right into a vapor (evaporated) after which cooled again to a liquid (condensed) again and again. “Easily” means boiling at a really low temperature — we’re speaking colder than -25°F for a lot of widespread refrigerants.

You may be asking — what’s the purpose of all this evaporating and condensing? Briefly, it permits refrigerants to seize warmth and transport it from one place to a different. As an example, they absorb warmth from inside your fridge and dump it outdoors.

Refrigerants will also be used to maneuver vitality for thermal storage. For warmth pump water heaters, refrigerants soak up warmth from the encircling air and channel it right into a scorching water storage tank. Refrigerants make the magic of warmth pumps potential — by transferring warmth reasonably than creating it, warmth pump methods can function at greater than 300% effectivity!

Ideally, refrigerants are additionally low- or non-flammable, low- or non-toxic, don’t deplete the ozone layer, and aren’t horrible for the local weather (extra on this later). There are millions of probably usable refrigerants, however solely a pair dozen that meet these standards.

Are refrigerant leaks widespread? If that’s the case, why does it matter?

Refrigerant leaks are by no means factor. At finest, they’re a ache for constructing homeowners and a possible indication of a defective system. At worst, they will severely injury the ozone layer and contribute to international warming.

So, how a lot do refrigerant methods leak? This query is advanced — leakage varies based mostly on components like tools sort, set up high quality, and upkeep (or lack thereof).

Grocery retailer fridges are among the many worst offenders, dropping 30% of their charge every year on common. Variable refrigerant circulate (VRF) methods are one other potential concern. Whereas much less liable to leaks (estimated 6% annual loss), VRF items include giant volumes of refrigerant. So, even a small proportion leak equals numerous refrigerant within the ambiance.

An annual leakage price of 4% is typical for each warmth pumps and chillers. Whereas 4% won’t sound like rather a lot, needless to say these items proceed to lose refrigerant over their decade-plus lifespan.

It’s not life like to fully stop leaks from taking place. That’s why it’s important to transform to lower-emission alternate options. That means, when leaks occur, they don’t contribute so considerably to international warming.

How a lot do refrigerants contribute to local weather change?

It relies upon.

Some refrigerants are dramatically worse than others by way of local weather injury. That injury is denoted by two metrics: Ozone Depletion Potential (ODP) — i.e., how good a refrigerant is at tearing aside the ozone layer — and World Warming Potential (GWP), which measures a chemical’s potential to lure warmth within the ambiance. For GWP, carbon dioxide (CO2) is used because the baseline and has a GWP of 1.

Fortunately, ozone-depleting refrigerants have largely gotten the ax. In 1987, in an inspiring instance of nations coming collectively to unravel a human-caused downside with the local weather, world leaders agreed to ban halons and chlorofluorocarbons (CFCs) — the refrigerant teams with the highest RIP. Hydrochlorofluorocarbons (HCFCs), a bunch of refrigerants with weaker ODP, had been lastly phased out as of 2020. Fashionable HCFCs like R22 can now not be produced or imported to the U.S., however could also be used from recycled or stockpiled capability.

Okay, that was numerous acronyms. Any straightforward mnemonic is that refrigerants with “CFC” within the title launch chlorine molecules that tear aside the ozone layer.

Hydrofluorocarbons (HFCs), refrigerants commercialized in the 1990s to switch CFCs, are probably the most generally used refrigerants at the moment. Whereas they don’t injury the ozone, HFCs usually have 1000+ GWP; probably the most potent amongst them exceed 10,000.

The graphic under shows some generally used HFCs and HCFCs, in addition to some low-carbon alternate options.

There are billions of cooling home equipment internationally, and most use HFCs. Left unchecked, emissions from these units alone may contribute 0.3–0.5°C of world warming by 2100.

Not-so-fun reality: Leaking one 12-oz can of R134a is like burning 110+ gallons of gasoline!

Fortuitously, 197 countries agreed to constrict HFC manufacturing by way of the 2016 Kigali Modification. Whereas this pact is a good first step, implementation and enforcement on the country-level continues to be vital. The U.S. is main by instance by way of the 2020 American Innovation and Manufacturing (AIM) Act.

Below AIM, the EPA will try to curtail HFC consumption by 85% over the subsequent twelve years. There’s an essential milestone arising at first of 2025: new warmth pumps and air conditioners can not use refrigerants with GWP higher than 750. Which means that producers should discover a replacement for the ever-present R410A (which far exceeds that threshold with a GWP of two,088). It should doubtless get replaced by R454B (the blue bar within the graphic above) in lots of functions.

In my subsequent article, I’ll talk about among the accessible low-GWP refrigerants. I’ll additionally clarify why the transition away from HFCs shall be far tougher than it was for CFCs.

Noah Gabriel is a Venture Supervisor at New Buildings Institute (NBI). At NBI, Noah manages a number of initiatives involving cutting-edge warmth pump water heater (HPWH) analysis and deployment. Noah is a subject professional on HPWH load shifting and leads the demand response element of the Superior Water Heating Initiative.