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Getting marine cold room design right is what allows a crew to eat safely through a voyage that can last weeks or even months — a subsystem that rarely gets the attention the galley itself does. Wärtsilä’s own encyclopedia defines provision stores simply as “refrigerated stores intended to preserve perishable foods for shipboard use,” and getting this subsystem wrong means both a food-safety risk and an unhappy crew.

A proper cold room project has to bring together four separate disciplines at once: temperature zoning and food-safety standards, capacity calculation based on crew size and voyage length, insulation and construction detail, and — increasingly strict in recent years — refrigerant regulations. This guide covers all four, backed by verifiable sources rather than invented numbers.

1. Why Marine Cold Rooms and Provision Stores Matter

A shore-based business that runs low on stock simply calls its supplier. A ship doesn’t have that option — it has to make do with whatever provision is on board until the next port call, which on some cargo routes can be 20-30 days or more away. That single constraint turns cold room capacity and temperature control from a “nice to have” into an operational necessity.

The consequences of a poorly designed or undersized cold room system:

• Food safety risk: Exceeding temperature tolerances — especially for meat, fish and dairy — puts crew health directly at risk.
• Inspection non-conformity: Findings during the periodic inspections required under MLC 2006 can turn into a Port State Control detention or deficiency record.
• Provision waste: Poor capacity planning either leaves the store undersized or oversizes it and wastes valuable below-deck volume.
• Regulatory exposure: Systems still running on legacy refrigerants can fall outside MARPOL and EU F-Gas rules, creating real problems for future servicing and spare parts (see Section 5).

2. Temperature Zones and Food Safety Standards

The reference framework for shipboard food-storage temperatures is the Maritime Labour Convention (MLC 2006), Regulation 3.2 (Food and Catering). MLC 2006 requires inspections of the food stores, cold rooms and galley — under the authority of the master — at intervals not exceeding seven days, with findings recorded in the ship’s official log book.

2.1 The Chill Zone

2.2 The Freezer Zone

MLC 2006 guidance defines freezer temperature as -18°C or colder; short-term deviations to -15°C are considered acceptable. Frozen goods should also be received at -18°C or colder.

2.3 Dry Stores and Vegetable Stores

Not all fruit and vegetables belong in a cold room — some items (bananas, garlic, mature potatoes) should be kept at room temperature. For produce, a “cool room” up to 10°C is generally acceptable. Dry stores should be cool (~10°C), dry, well lit and ventilated; items should never be stored directly on the deck and should instead sit on shelving or grating.

3. Capacity and Volume Calculation

A commonly used starting point for cold room sizing is the daily per-person consumption reference data published in Wärtsilä’s own engineering encyclopedia. These figures are meant for early design/quotation stages; final sizing should be refined against the actual menu, crew/passenger profile and voyage route.

3.1 Daily Per-Person Consumption Data

Source: Wärtsilä Encyclopedia, “Provision stores”. Note: dry provisions are expressed as shelf area (m²), while chilled/frozen provisions are expressed as volume (m³) — the two should not be confused.

3.2 Worked Example

Applying these reference coefficients directly, the approximate chilled + frozen volume required (excluding dry-store shelf area) for a few crew/voyage combinations works out as follows:

4. Insulation and Construction Detail

Cold room panel thickness is driven by the target temperature differential. The following ranges are common practice in general cold-storage engineering:

Source: general cold-storage engineering practice (manufacturer guidance published for land-based facilities) — used here as a reference for marine projects; it is not a maritime-specific table mandated by any classification society.

Marine-specific factors to add on top of this:

• Salt-air corrosion: A stainless steel (AISI 304/316L) panel facing, rather than galvanised sheet, meaningfully extends service life.
• Ship motion: Panel locking/joint systems need to tolerate roll and vibration — some standard land-based locking profiles are not adequate here.
• Proximity to machinery spaces: If the cold room sits next to the engine room or the galley cooking line, the resulting ambient heat gain should push both panel thickness and compressor capacity upward accordingly.

5. Refrigerant Selection and Regulations

Refrigerant choice is no longer just a performance question — it is now a compliance question under both international and EU law. Two regulations are essential reading for any new cold room project:

5.1 MARPOL Annex VI, Regulation 12 — Ozone-Depleting Substances

5.2 The EU F-Gas Regulation

On EU-flagged vessels, high-global-warming-potential (GWP) HFC refrigerants are subject to:

• A ban, in force since 1 January 2020, on using GWP>2,500 HFCs (such as R-404A, R-507, R-422D) for servicing.
• A 2030 target of a 79% overall cut in HFC use, phased through progressive quota reductions.
• A mandatory periodic leak test for systems above 5 tonnes CO2-equivalent.
• For existing R-404A systems, the recommended path is retrofitting to a lower-GWP alternative such as R-407F, which cuts quota consumption by roughly 53%.

6. Classification Society Approval

Refrigeration plant is assessed under the vessel’s main classification society’s machinery rules. At Lloyd’s Register, for example, fitting reliquefaction or refrigeration equipment triggers the mandatory RMC(LG) notation, with construction and testing carried out against the relevant sections of LR’s Rules.

Other societies — DNV, Bureau Veritas, Türk Loydu and others — have equivalent refrigeration-plant requirements within their own machinery rules; the exact part/chapter reference varies by society, vessel type and plant size.

7. Installation Rules

• Door gaskets should use a heated gasket profile in the freezer zone to prevent icing
• Door hinges and latches should be self-closing and rated for ship motion (roll/pitch)
• Floor insulation should be treated as its own detail, to prevent heat/moisture transfer into the space below
• The compressor/condenser unit should be positioned as far as practical from the heat load of the galley cooking line
• Interior lighting should use vapour-proof fittings
• The alarm system (temperature deviation, door left open) should signal to the galley or the bridge
• Post-installation, both the classification society survey and the initial MLC 2006 inspection should be scheduled

8. Periodic Maintenance and Inspection

9. Where We Deliver

Only Maritime designs, fabricates and installs custom marine cold room and provision store systems from our production facility in Kocaeli/Gebze, Turkey — serving new-build and refit projects at Turkish shipyards as well as international owners and yards, including retrofit work to bring existing systems into line with current refrigerant regulations. Get in touch with your crew/passenger count, voyage profile and current refrigerant setup, and we’ll scope a solution for your project.

10. Frequently Asked Questions