Polar King refrigerated trailers are towable walk-in coolers and freezers built for outdoor, over-the-road use, and NC Trailers sells, services, and supports them from its dealerships in Thomasville and Winston-Salem. If you run a catering company, a farm, an event business, or a restaurant that needs overflow cold storage, a Polar King gives you a true refrigerated box you can pull to the job. This guide covers how the trailers are built, the sizes in the lineup, what they need for power, and who gets the most out of one.
Key takeaways: Polar King builds refrigerated and freezer trailers with a seamless fiberglass exterior, and the company reports NSF and NATM certification for the line. The standard lineup comes in 8, 12, 16, and 20 foot lengths, and some models reach sub-zero temperatures. North Carolina Trailer Sales joined Polar King's dealer network in 2025 and handles sales, service, and support for the trailers.
What Is a Polar King Refrigerated Trailer?
A Polar King refrigerated trailer is a mobile walk-in cooler or freezer mounted on a trailer chassis and designed to hold a set temperature regardless of the weather outside. Polar King International, based in Fort Wayne, Indiana, began building walk-in coolers and freezers in 1982 and later carried that construction into its trailer division. That history shows in the product, because the trailer is built like a commercial walk-in first and a trailer second.
Built as a Cold Box, Not a Converted Cargo Trailer
The biggest difference between a Polar King and an insulated cargo trailer is the box itself. NC Trailers makes this point plainly in its own trailer guide: a dry cargo trailer with added insulation and a window air conditioner is not built to do the job of a purpose-built refrigerated unit. If you are weighing the two approaches, our comparison of insulated vs. refrigerated cargo trailers explains where each one fits and where it falls short.
Seamless Fiberglass Construction
Polar King uses a seamless fiberglass exterior, and the company says that design keeps the interior sanitary and independent of outside temperatures. A shell without exterior seams has fewer places for water to work its way in, which is why NC Trailers highlights that there are no seams to leak or rot. Polar King also says its one-piece fiberglass resists rust, corrosion, and deterioration. For a box that sits outside through North Carolina summers and wet winters, that matters more than any single spec.
Polar King Sizes, Temperatures, and Certifications
Polar King's standard trailer lineup comes in 8, 12, 16, and 20 foot lengths, and certain models offer sub-zero temperatures for freezer use. The table below summarizes what the manufacturer has published about the line, so you can narrow down a size before you visit. You can also browse refrigerated trailers in stock to see current units.
| Feature | What Polar King has published |
|---|---|
| Standard lengths | 8, 12, 16, and 20 foot units |
| Temperature range | 0°F to 50°F on compact units, with sub-zero capability on certain models |
| Power | All-electric. Compact 8 to 16 foot units are listed at 110V and 15 amps |
| Largest standard unit | PKM620, 6 by 20 feet, 220V, 9,400 pound capacity |
| Certifications | NSF certified, NATM certified, ISO compliant |
The PKM620 for High-Volume Operations
The PKM620 is the largest unit in Polar King's standard lineup at 6 by 20 feet, and Polar King describes it as the largest mobile cold storage walk-in in the industry. It has two full-size doors, one at the rear and one on the side, so a crew can load from two points instead of working around a single entrance. For an operation that moves product in and out all day, such as a large event or a busy harvest week, that second door saves real time.
Ground-Level Loading on the Avalanche Series
Polar King's Avalanche Series adds a ground-level loading system, which the company describes as the first on the refrigerated trailer market. Loading at ground level lets carts, dollies, and heavy containers roll straight in instead of being lifted into the box. If your crew loads heavy product often, ask about Avalanche availability when you call either location.
What Power Does a Polar King Need?
Polar King trailers are all-electric, so you plug them in instead of fueling a separate refrigeration engine. Polar King's profile with the North American Trailer Dealers Association lists its compact units at 110V and 15 amps, while the PKM620 steps up to 220V. Before you buy, confirm the power available where you will park the trailer, whether that is a barn, a commissary, a venue, or a farm stand.
Planning for Power at Events and Remote Sites
A site without shore power will need a generator sized to the trailer's published electrical requirement. Match the generator to that spec and walk through the plan with the NC Trailers team before your first event. Refrigeration that runs well on a dedicated circuit can struggle on an undersized power source, and a cooler that cannot hold temperature puts your product at risk.
Who Uses Polar King Refrigerated Trailers?
Polar King markets its trailers to foodservice, catering, agriculture, hunting, baking, and other temperature-sensitive work. NC Trailers names a similar mix of buyers on its own site: caterers, event companies, florists, farms, and restaurants running overflow storage. The common thread is product that has to stay cold away from a permanent building.
Catering, Events, and Restaurants
A caterer can stage food at a venue that has no walk-in, and a restaurant can add cold storage for a busy season without building onto the kitchen. Because the trailer moves, the same unit can serve a wedding on Saturday and sit behind the restaurant on Monday. Our guide to refrigerated trailers for event catering covers staging and setup at venues in more detail.
Farms, Florists, and Hunters
Farms use refrigerated trailers to hold harvested produce cold until market day. Florists keep arrangements fresh before weddings and events, and hunters use a cold trailer during the season. In each case, the trailer goes where the product is instead of the product traveling to a fixed cooler, which cuts handling and time out of the process.
Buying, Service, and Support From NC Trailers
North Carolina Trailer Sales, a trailer dealership with lots in Thomasville and Winston-Salem, joined Polar King's dealer network in 2025 to sell, service, and support the line. When the partnership was announced, NC Trailers President Johnny Shelton said in the announcement, as reported by the American Journal of Transportation, that "customers in central North Carolina finally have a go-to source for high-quality refrigerated trailers." That local support matters with refrigeration equipment, because a cooler that goes down in July needs a dealer close enough to diagnose it.
Financing a Polar King
NC Trailers offers traditional financing on Polar King refrigerated trailers through its online application. Applying before you visit tells you what your budget supports, so you can compare sizes with a real number in mind instead of guessing.
Find the Right Polar King for Your Business
A Polar King refrigerated trailer gives your business walk-in cold storage that travels, built with seamless fiberglass and backed by NC Trailers service in central North Carolina. Visit the Polar King refrigerated trailers page to see the lineup, then request financing or call the Thomasville or Winston-Salem location to talk through size, power, and how you plan to use it.
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