An insulated container is a thermally insulated transport and storage container based on ISO standards that passively protects the interior from extreme outside temperatures, frost, heat, and condensation. These are typically decommissioned refrigerated containers (reefers without an active cooling unit) featuring industrial-grade polyurethane (PUR) sandwich insulation, or standard shipping containers that have been retrofitted with insulation. They are ideal for use as frost-free storage, workshops, or equipment rooms without the high energy consumption of active cooling.
Passive thermal insulation provides reliable, energy-efficient protection for stored materials against the elements:
Can a heater or air conditioning unit be retrofitted into an insulated container?
Yes. Because the building envelope is extremely well insulated (very low U-value), even a small electric convector or a compact split-system air conditioner with minimal power consumption is sufficient to heat the interior to over 20 °C, even in freezing temperatures.
Does condensation form inside an insulated container?
No. Unlike uninsulated steel containers, the polyurethane insulation core prevents the inner wall from cooling down, which stops moisture from the air from condensing (protection against condensation).
Why is a former reefer better as an insulated container than a self-insulated shipping container?
Factory-built reefers feature seamless, industrially foamed PUR walls with no thermal bridges. This keeps the exterior width compact while eliminating the need for additional construction. Retrofitting DIY interior walls wastes valuable floor space and, if not done perfectly, is prone to hidden mold growth behind the insulation.