Short answer
The walls of a refrigerator or freezer are filled with rigid closed-cell polyurethane foam, foamed in place between the outer cabinet and the inner liner. The EPA counts about 10.7 million new U.S. refrigerators a year, each holding around 2 pounds of foam blowing agent. That same chemistry, sprayed on site instead of foamed in a factory, is closed-cell spray foam insulation; both have changed blowing agents from CFCs to today's low-warming options.
Key points
- The EPA's definition of appliance foam is "insulation foam in domestic refrigerators and freezers"; commercial refrigeration foam covers walk-ins, display cases, vending machines and refrigerated trucks.
- About 10.7 million new household refrigerators are made and sold in the U.S. each year, each with roughly 2 lb of blowing agent in its foam (EPA, 2016).
- The blowing agent has changed several times: CFC-11, then HCFC-141b from the mid-1990s, then HFCs and hydrocarbons; cyclopentane is now the most used worldwide.
- The DOE requires walk-in coolers to have at least R-25 and walk-in freezers at least R-32 in their panels.
- Building spray foam went through the same shift and now uses HFO blowing agents.
Why foam, and how it gets in the walls
A refrigerator is a box that has to hold a big temperature difference with thin walls, in a kitchen where every inch of space counts. Rigid polyurethane foam fits that job: millions of closed cells filled with a low-conductivity gas, filling the wall with no gaps.
The foam is made in place: the two liquid components go into the hollow space between the outer cabinet and the inner liner, expand to fill every corner and cure there. Spray foam on a wall does the same thing in the open air: two liquids mixed at the gun, expanding and curing in seconds.
Where you'll find it
The EPA, which regulates foam blowing agents under its SNAP program, lists the end uses:
| Category | What it covers (EPA) |
|---|---|
| Appliance foam | "Insulation foam in domestic refrigerators and freezers" |
| Commercial refrigeration foam | "Insulation for pipes, walls and metal doors in commercial refrigeration equipment, vending machines, coolers, buoyancy, and refrigerated transport vehicles" |
| Spray foam | Insulation sprayed on site in buildings |
Walk-in coolers and freezers, the rooms behind every grocery store and restaurant kitchen, are built from insulated panels with minimum R-values set by the Department of Energy: R-25 for coolers and R-32 for freezers.
The blowing agent story
The gas trapped in the cells does much of the insulating, which makes the choice of gas both a performance and an environmental decision. Refrigerators have gone through every stage of it, as the EPA documents:
- CFC-11. Older refrigerators "contained CFC-12 refrigerant and CFC-11 foam-blowing agent," both ozone-depleting.
- HCFC-141b, from the mid-1990s, as CFCs were phased out.
- HFC-134a, HFC-245fa and hydrocarbons, which replaced HCFC-141b. HFCs don't harm ozone but are strong greenhouse gases.
- Cyclopentane. "In 2011, GE became the first U.S. appliance manufacturer to adopt cyclopentane blowing agent," and cyclopentane blends "are the most globally used blowing agents in domestic refrigeration."
Building spray foam followed a parallel path, from HFCs to HFO blowing agents with a global warming potential near 1. Our HFO vs HFC article covers the EPA deadlines for buildings.
At the end of its life
The foam's blowing agent stays in the cells for decades, which is part of why the insulation keeps working. It also means old refrigerators still hold it when they're scrapped. The EPA has noted that because there were no federal requirements for foam recovery, the blowing agent in appliance foam "is emitted during shredding and landfilling." Its voluntary Responsible Appliance Disposal partners recover both refrigerant and foam; by 2016 they had processed nearly 6.5 million refrigerators and freezers.
What it means for a building
A refrigerator is the best everyday example of what closed-cell polyurethane does: a thin, continuous, bonded layer holding a big temperature difference for decades. Closed-cell spray foam brings that to a building's rim joists, basement walls, roof decks and metal walls, and seals the air leaks at the same time. The same family insulates LNG tankers at −261°F (LNG carriers) and rocket tanks at −423°F (spray foam on rockets).
Savings vary. Find out why in the seller's fact sheet on R-values. Higher R-values mean greater insulating power.
Want your building insulated the way your freezer is? Price My Project or call (814) 208-3478.
FAQ
What insulation is in a refrigerator?
Rigid closed-cell polyurethane foam, foamed in place between the outer cabinet and the inner liner.
Is refrigerator foam the same as spray foam insulation?
It is the same chemistry, rigid polyurethane made from two liquid components. Refrigerator foam is made in a factory; spray foam is mixed at the gun and sprayed on site.
What blowing agent is in refrigerator foam today?
Cyclopentane blends are the most used worldwide. U.S. refrigerators moved from CFC-11 to HCFC-141b in the mid-1990s, then to HFCs and hydrocarbons; GE adopted cyclopentane in 2011.