Refrigerated electric units for cargo vans: a guide for converters

Why van conversions shifted to electric power

The way last-mile cold-chain operations work has changed. Grocery platform orders, meal-kit subscription deliveries, and pharmacy distribution all send small, fully loaded vans into city centers at the same time that cities are tightening rules on diesel noise and emissions—including idling at the curb. In this context, a refrigeration unit driven by the van's engine has two structural flaws: it stops cooling the moment the engine turns off, and it makes the van idle while parked in a loading bay. Fully electric 12 V and 24 V refrigeration units solve both. The compressor runs off the battery, the engine stays off, and the box maintains temperature throughout a multi-stop route.

For upfitters, fleet operators, and the distributors who supply them, the technology choice is now less about "whether to go electric" and more about "which electric solution." This is the selection process we use with our conversion partners.

Three drive architectures, three use cases

• Engine-driven units draw power from the chassis engine, either directly or via PTO. Cooling output is high and pull-down is fast, but cooling stops when the engine stops. They still make sense for long intercity routes with few stops.
• Electric standby adds a mains-powered module to an engine-driven unit, enabling overnight pre-cooling at the depot. Useful when vans return to a base with 220 V or 380 V hookups.
• Fully electric 12 V / 24 V units run the compressor entirely from the vehicle's electrical system or a dedicated battery pack. This is the format that urban delivery and EV-chassis conversions are standardizing on, and the one our product line focuses on. See our refrigeration units for cargo vans and trucks line for current models.

Matching unit size to box volume

Refrigeration load has two components: heat leaking through the walls, and heat entering every time the door opens. For urban multi-stop operations, the second component dominates, and it's the one most often underestimated.

Our engineers use these ballpark figures for a preliminary calculation: for medium-temperature (0 to +8°C) applications, allocate approximately 80 to 100 W of cooling per cubic meter of box volume, then add an allowance for door openings based on the number of stops per shift. For frozen cargo at -18°C, the requirement typically doubles or more. Insulation quality determines the baseline: a properly built box uses 60 to 80 mm polyurethane foam at a density of around 40 kg/m³, yielding a K-value of approximately 0.024 W/(m·K). You shouldn't specify a unit sized for a 10 m³ box for a 15 m³ box just because the price looked better. Our high-capacity refrigeration units cover the larger boxes where this margin issue becomes costly.

Two acceptance tests turn spec-sheet claims into something you can hold a supplier accountable for. Pull-down from +25°C to -18°C on an empty box should take approximately 45 minutes. And the supplier should provide performance data at +30°C ambient, not +25°C, because your customers' vans operate through summer afternoons, not laboratory mornings.

Electrical integration derails more conversions than cooling performance

A battery-driven unit is only as reliable as the power system behind it. These are the checks we run before signing off on a conversion:

• Alternator capacity. A rule of thumb among upfitters is at least 150 A on the chassis to simultaneously power the unit, the van's own electrical loads, and the battery; anything less and the system will slowly deplete.
• Battery capacity. Two 12 V 110 Ah deep-cycle batteries are a common baseline for maintaining temperature during loading and short stops. For all-day engine-off operation, conversions shift to dedicated LiFePO4 packs sized in kWh based on the unit's average power draw.
• Wiring and protection. DC compressor inrush at startup is the critical stress point; undersized cabling manifests as nuisance cutouts months later.

Units in our range, such as the professional auto refrigeration units and the industrial-grade vehicle refrigeration units, are built around variable-speed DC compressors, which reduce both average current draw and startup stress, and we publish the power draw figures that conversion shops need for their electrical designs.

What to require from your supplier

The difference between a unit that lasts a decade of deliveries and one that fails in its second summer rarely shows up in the brochure. Ask for the vibration rating, because a compressor that passes bench testing may not survive cobblestones at speed. Ask about how spare parts and gaskets are stocked in your region. Ask for the refrigerant declaration, as low-GWP transitions are affecting transport refrigeration too. And ask for reference conversions with comparable box volumes and stop counts. A supplier who answers these four questions with documentation rather than adjectives is one you can build a program around.

For conversion partners evaluating electric refrigeration for 2026 programs, our team prepares load calculations and electrical specifications on a per-project basis. Start the conversation through the contact page.