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Technical · Week 21 of 52

Cold room insulation in the tropics: why 150 mm panels pay for themselves

How panel thickness, door discipline and thermal mass reduce refrigeration and battery size in a solar cold room — and the design choices that cut the biggest cost, the battery.

In a solar cold room every kilowatt-hour you don't have to remove overnight is a kilowatt-hour of battery you don't have to buy. Insulation is the cheapest battery on the market.

Key facts

  • 150 mm polyurethane panels roughly halve heat gain compared with 75–100 mm panels in a 40 °C ambient.
  • A well-insulated, full frozen store holds temperature for hours with the compressors off — that thermal mass carries much of the night.
  • Doors are the leak: air curtains, strip curtains and a small ante-room cut infiltration losses by a third or more.
  • Pre-cooling by day plus good insulation lets the overnight battery be sized at 60–70% of daytime load.

Heat comes through walls, doors and product

Three sources: conduction through panels and floor, air infiltration each time the door opens, and the warm product you load. Panel thickness handles the first; door discipline and an ante-room the second; pre-cooling product before it enters the main store the third.

Thermal mass is free storage

Ten tonnes of frozen fish at −25 °C is an enormous cold reservoir. With 150 mm panels and closed doors, the store drifts only a degree or two over several hours. That is why our systems pull the room below set-point in the afternoon sun and let it coast — and why the battery can be a quarter of what a naive design demands.

Specifying it

Ask any supplier for panel thickness, floor insulation, door type and the design ambient temperature. If the quote assumes 25 °C ambient and 100 mm panels, the compressor and battery are undersized for a Lagos or Nouakchott afternoon.

Designing a cold room? Get the insulation spec right first.

Talk to Frontières Bay

Frequently asked

Containerised or built on site?

Containerised for speed and coastal sites; built on site for larger multi-room stores. Both get 150 mm panels.

What about the floor?

Insulated floors matter for frozen stores; chilled rooms can often sit on an insulated slab.

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