Frequently Asked Questions

PolyFrost can only be applied by a professional paint shop that has completed our training and follows our Standard Operating Procedures (SOPs). You can work with one of our certified application partners trained by ChillSkyn, or apply it in-house after training. Contact us to identify an application partner near you or to finds out about our application certification for your team.

PolyFrost is rolled and sprayed on with standard spray equipment, much like paint. A trailer can be coated in under 12 hours, with no downtime beyond the application window. This works on new builds and on trailers already in service.

PolyFrost works on sun-exposed roofs and surfaces where heat load drives energy use, discomfort or product risk. ChillSkyn trials and deployments include: refrigerated trailers, deep freeze trailers, aluminum dry boxes, air-conditioned containers, passenger buses, broadcast trailers, traffic signal cabinets and components in the power distribution network.

PolyFrost’s performance has been verified three ways: Mesilla Valley Transportation Solutions (MVTS) Certified third-party testing, laboratory testing to ASTM and EN standards, and controlled field pilots across North America, South America and Europe.

PolyFrost is a roll and spray-applied passive daytime radiative cooling (PDRC) coating from ChillSkyn that lowers the surface temperature of sun-exposed roofs, such as reefer trailer roofs, and outdoor electrical equipment, without using any power. It reflects incoming sunlight and radiates heat away to the sky, so less heat reaches the trailer interior, reducing the refrigeration unit runtime and the reliance on HVAC. PolyFrost has been validated in field pilots across North America, South America and Europe.

Passive cooling is any way of lowering temperature such as shading, ventilation, or reflective surfaces, without electricity, fuel or moving parts. Passive daytime radiative cooling (PDRC) is a type of passive cooling that works even in direct sunlight. A PDRC surface does two things. It has high solar reflectance, so it reflects most incoming sunlight and absorbs little heat. It also has high thermal emissivity, so it radiates heat as infrared light through the atmosphere’s transparent window (8–13 µm) to the cold of outer space. ChillSkyn’s PolyFrost GFX is a spray-applied PDRC coating. It reflects up to 97% of sunlight, has up to 94% emissivity, and lowers roof surface temperatures by up to 50 °C (90 °F) with no power.

Passive daytime radiative cooling (PDRC) is a way of cooling a surface in direct sunlight with no energy input. A PDRC material reflects most of the sun’s energy and emits heat as infrared radiation through the atmosphere’s 8–13 µm window to outer space. This lets the surface shed more heat than it absorbs, even at midday. PDRC coatings such as ChillSkyn’s PolyFrost reflect up to 97% of sunlight and emit heat with up to 94% emissivity.

No. PolyFrost has zero power draw: no wiring, no controller and no equipment to run. It is a coating, so once it is applied it works continuously, with nothing for drivers or fleets to operate.

Yes. Passive cooling uses no electricity or refrigerants, and instead of adding heat to its surroundings, the surface sends heat out to space as infrared radiation. PolyFrost also reduces emissions indirectly: by cutting transport refrigeration unit (TRU) runtime, it cuts the diesel a trailer burns by up to 510 gallons per trailer per year. Less diesel means lower greenhouse gas emissions.

No. In side-by-side trials, PolyFrost roofs ran 10–15 °C (18–27 °F) cooler than standard white polyurethane paint on passenger buses in Mexico (June 2026). In Illinois (June 2025), PolyFrost ran up to 24 °C (43 °F) cooler than another commercial reflective roof coating. PolyFrost is engineered for high solar reflectance (88–97%) and heat emission, so a coated roof rejects most sunlight and keeps shedding heat. Unlike white paint, PolyFrost can cool a surface below the surrounding air temperature.

No. Reflecting sunlight is only part of how PolyFrost cools. It pairs very high solar reflectance (88–97%) with high emissivity (up to 94%), so it rejects sunlight and also sheds the heat it does absorb as infrared. A surface that does only one of these, such as aluminium, runs hotter. In a June 2025 trial in Pachuca, Mexico, a bare aluminum roof reached up to 70 °C while a PolyFrost roof measured 18–20 °C.

Across ChillSkyn’s controlled pilots, PolyFrost-coated trailers ran their TRU engines on average about 17% less than control trailers in start-stop mode. A 76-day North Carolina trial measured 20% less TRU load in the daytime and 17% at night. A June 2026 Mississippi trial measured about 15% less on average despite high humidity, and field trials in Santa Catarina, Brazil measured 19% on average. Results are strongest in dry, high-solar climates.

High-speed operation is when a TRU’s diesel engine runs at higher RPMs, usually to pull the box down to setpoint or to handle a heavy heat load. These hours burn more fuel and put more wear on the engine and compressor. PolyFrost reduces high-speed TRU hours. Across cold and frozen pilots, coated trailers ran in high-speed mode on average about 50% less than baseline. ChillSkyn’s June 2026 Mississippi trial measured a 78% decrease in high-speed TRU hours.

Up to 510 gallons of diesel per trailer per year. That figure applies a measured runtime saving of about 17% to a trailer running 3,000 TRU hours a year at about 1 gallon per hour. Actual savings depend on a fleet’s runtime hours, TRU fuel burn, climate and duty cycle.

Yes. A PolyFrost roof keeps emitting heat after sunset. In a 76-day North Carolina trial, TRU load fell 20% in the daytime and 17% at night.

Yes, although results are strongest in dry, high-solar climates. A June 2026 Mississippi trial measured about 15% less TRU runtime despite high humidity. In a 20-day passenger bus trial in Mexico that spanned the rainy season, the cooling benefit held through rainfall.

Temperature-related spoilage usually comes from heat the refrigeration unit can’t remove fast enough, or from gaps in cold-chain handling. Solar heat load makes the TRU run longer and harder, so cutting it with PolyFrost reduces that strain. Across ChillSkyn’s cold-chain pilots, temperature deviation around setpoint was roughly 5–20% tighter (about 10% on average), and coated trailers recovered to setpoint 30–60% faster after a door opening or defrost.

Reefer compressor hours follow heat load, so the most direct fix is to reduce the heat the unit must remove. Cutting solar heat at the roof, limiting door-open time and keeping insulation and seals in good condition all help. Fewer run hours mean less wear on the compressor and engine, longer service intervals and higher resale value. PolyFrost cuts solar heat at the roof, and in ChillSkyn’s pilots it reduces TRU runtime by about 17% on average.

The most direct way to cut reefer diesel is to reduce how long and how hard the TRU runs. Practical steps include reducing solar heat gain on the roof, pre-cooling trailers and cargo before loading, minimizing door openings, and avoiding unnecessary high-speed operation. PolyFrost addresses the roof heat load and saves up to 510 gallons of diesel per trailer per year.

Solar heat gain comes largely through the roof and sun-facing walls. Options include reflective roof coatings, well-maintained insulation, shaded staging, and passive daytime radiative cooling coatings. PolyFrost is a PDRC coating: it reflects 88–97% of incoming solar energy, emits heat back to the sky, and cuts roof surface temperature by up to 50 °C (90 °F) with no power.

Reducing solar heat on the roof pays back every year in service. PolyFrost is a one-time coating with no power draw. PolyFrost’s payback period ranges between 8–24 months, depending on setpoints, climate, cargo, driver behavior and diesel cost. Over six years, a 15–20% runtime reduction is worth roughly $21,000–$28,000 per trailer in total quantified value.

No. PolyFrost does not replace a refrigeration unit. PolyFrost is a coating that augments refrigeration units: it cuts the solar heat reaching the trailer, so the TRU has less heat to remove and runs less. The unit still holds the setpoint and does the pull-downs. In ChillSkyn’s controlled pilots, coated trailers ran their TRUs 5–25% less than control trailers, about 17% on average, and recovered to setpoint 30–60% faster after a door opening or defrost.

Typical payback on PolyFrost is 8–24 months, depending on setpoints, climate, cargo type, driver behavior, diesel cost and other operating factors. Payback is shorter for trailers that run many hours, run in hot lanes, or run at higher diesel prices.

Read our white paper Más allá del ahorro de combustible: la economía completa de reducir las horas del equipo de refrigeración for the full story.

PolyFrost works on aluminum, steel, composite panels, and pre-painted surfaces. ChillSkyn has been field validated on bare aluminum trailer roofs, composite bus roofs, air-conditioned containers and broadcast trailers.

PolyFrost is built to withstand the impact, abrasion and flexing a trailer roof sees in service, and has been tested to ASTM and EN standards. With the PolyFrost Bonding Primer on aluminum, it withstood 11 J of impact (ASTM D2794). With the Guard topcoat, it showed no wear-through after 9,000 Taber abrasion cycles (ASTM D4060) and withstood 40 L of falling sand (ASTM D968). It is flexible enough to move with the panels as they flex. Adhesion held the top rating (0) under EN ISO 2409, including after 24 hours of water immersion. It also resists the abrasion of roof snow removal common in northern climates.

Yes. PolyFrost cools most in strong sun, so its effect is smaller in winter, when solar heat is lower. Depending on the setpoint, extra cooling in cold months is not a drawback for refrigerated trailers.

PolyFrost is tested to ASTM and EN standards for impact, abrasion and adhesion, and has been in field service on trailers and buses since 2024. Contact ChillSkyn for durability data and warranty terms for your application.

Contact ChillSkyn to schedule a pilot trial for your fleet, through the contact page or at info@chillskyn.com.