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Chilled, frozen, blast: why cost per m² misleads

The same floor area can carry twice the installed cost depending on room temperature and daily turnover, because those two variables change the equipment rather than the building.

Published 2026-11-10 · 6 min read · All guides

Three rooms, three different jobs

Chilled storage, frozen storage and blast freezing are not three grades of the same thing. They work in different ways, and that is why their cost per square metre is not comparable.

Room type	What it does	Refrigeration duty
Chilled storage	Holds product above freezing	Replaces heat leaking in through the envelope
Frozen storage	Holds product below freezing	Replaces heat leaking in, at a larger temperature difference
Blast freezing	Removes heat from new product	Removes the product's own heat, in a short time

Chilled and frozen storage are maintenance duties. Blast freezing is a production duty, and its capacity is set by throughput rather than by room volume.

Why price per square metre misleads

The same floor area can carry a very different installed cost depending on room temperature and daily turnover, because both change the equipment rather than the building.

Variable	Effect on cost
Lower room temperature	Thicker panels, larger temperature difference, more compressor power
Higher daily turnover	Larger units, because product heat dominates the load
Longer storage period	More volume for the same throughput, but less installed capacity per tonne
Blast freezing on site	Separate high-capacity system, not a larger version of the storage system

Two rooms of identical area, one at 0°C and one at −25°C with daily blast freezing, can differ by a factor of two or more in installed cost.

What to settle before asking for a price

The quotation can only be as precise as the brief. These four items decide most of the cost, and none of them is a building dimension.

Item	Why it matters
Product and packing	Sets the room temperature, humidity and whether air movement damages the product
Room temperature per room	Sets panel thickness and evaporating temperature
Tonnage per room	Sets the envelope area and the stored mass
Daily intake and turnover	Sets the refrigeration capacity, which is usually the largest single cost

Given these four, a selection and an indicative price can be produced. Given only a floor area, any figure is a guess.

Cost questions

Why is a blast freezer so much more expensive per tonne?

Because it removes the product's own heat within hours rather than maintaining a temperature. That requires several times the installed capacity for the same stored mass.

Can a storage room be converted to blast freezing?

Rarely worth it. The equipment, the air movement and often the floor construction are different; converting usually costs more than building the right room.

Does a larger room always cost less per tonne?

Yes, up to a point: envelope cost per tonne falls with size, but the refrigeration capacity follows daily turnover, not volume. A very large room with low turnover is inefficient.