Cold Room Planning: From Product and Tonnage to a Cooling Load a Supplier Can Quote

1. Fix the product and temperature class before anything else

Temperature class decides panel thickness, refrigerant, defrost strategy, floor construction and evaporator selection. Chilled produce at 0 to +4 °C, meat at −1 to +2 °C, frozen storage at −18 to −25 °C, ice cream and blast-frozen seafood at −25 to −35 °C, and GDP pharma at +2 to +8 °C are five different machines, not one machine with a different setpoint.

Humidity is part of the specification. Leafy produce typically needs 90–95% RH and low air velocity; packaged frozen goods do not. A room specified only by temperature will be quoted with whatever evaporator surface is cheapest, which is how produce arrives dehydrated.

• Product, packaging and pallet configuration — these set the stacking factor and the airflow path.
• Storage temperature and tolerance band, plus humidity target where the product is sensitive.
• Whether the room stores already-cold product or also has to pull down warm product (that distinction alone can double compressor size).
• Any regulatory frame: HACCP, ISO 22000, EU GDP, USDA/FSIS, local food-safety authority.

2. Turn tonnage into volume, then volume into envelope

Stored tonnage and product density give net product volume. Pallet dimensions, stacking height, racking type and aisle allowance turn that into gross internal volume. As a planning rule, palletised chilled and frozen storage typically lands around 1.4–2.2 m³ of gross room volume per pallet position for racked storage, and materially more for block stacking with wide aisles.

Once you have internal dimensions you have the envelope area — walls, ceiling and floor — which is what heat leaks through. Panel thickness follows the temperature class and ambient: roughly 80–100 mm for +2 to +8 °C rooms in temperate climates, 100–150 mm for chilled rooms in hot climates, 150–200 mm for frozen, and heated underfloor protection wherever a frozen room sits on grade.

• Racked storage is more capacity per cubic metre; block stacking is cheaper but adds volume and airflow problems.
• Ceiling height above 8–10 m usually implies racking, mechanised handling and a different fire and airflow design.
• Door type and traffic — high-speed doors, air curtains and dock seals are load reduction, not decoration.

3. Build the cooling load from its four components

The load is transmission through the envelope, product load from cooling and freezing incoming goods, infiltration from door openings and air exchange, and internal loads from fans, lights, forklifts and people. Add a design margin of 10–20% and you have the number a supplier actually sizes equipment against.

Product load is the component buyers underestimate most, because it depends on the pulldown window rather than the stored quantity. Twenty tonnes of produce entering at +25 °C and required at +2 °C within 12 hours is a fundamentally different machine to the same twenty tonnes spread over three days.

Compressors are then sized for roughly 18–20 running hours per day at design conditions, which leaves headroom for defrost, peak intake and hot-day operation. Sizing for 24 hours leaves no margin at all.

• Transmission: envelope area × U-value × temperature difference at ambient design conditions.
• Product: mass × enthalpy change (including latent heat if freezing) ÷ pulldown hours.
• Infiltration: door openings per hour, door size, protection measures and pressure difference.
• Internal: evaporator fans, lighting, forklift traffic, personnel and any packing activity inside the room.

If a supplier quotes a cold room from square meters and a setpoint alone, the number is a price, not an engineering answer.

4. Refrigerant, energy and the cost you live with for 15 years

Refrigerant choice is a project decision, not a preference. Ammonia (NH₃/R717) is efficient and standard for large industrial plants but requires machinery-room design, detection and trained operators. CO₂ (R744) suits low-temperature and cascade systems and is increasingly the compliance-safe choice in Europe. HFC/HFO systems are simple and widely serviceable but carry F-gas exposure and future cost risk. Hydrocarbons suit small, self-contained units.

Energy is usually the largest lifetime cost. A frozen warehouse commonly consumes on the order of 30–60 kWh per m³ per year depending on climate, insulation, door discipline and control quality; chilled rooms sit well below that. Multiply by the local tariff before deciding that a cheaper panel or a fixed-speed compressor saved money.

This is the point at which our calculators are useful: they give an order-of-magnitude load, capacity, CAPEX and OPEX figure you can carry into supplier conversations, so you are comparing offers rather than guessing.

• Ask every supplier for kW at stated design conditions, not just at a nominal rating point.
• Ask for annual energy at your ambient profile, not the best-case COP.
• Compare CAPEX and 10-year OPEX in the same table — the cheapest install is frequently the most expensive room.

The planning sequence as pseudo-code

AI procurement agents and internal engineering teams can follow the same deterministic order. Nothing here replaces a licensed engineer; it defines what has to be known before a quotation means anything.

/* ColdMatch Group — Cold Room Planning Sequence */

ColdRoom room = new_project();

define_product(&room);            /* chilled produce, meat, fish, pharma... */
define_storage_temperature(&room);
define_stored_tonnage(&room);
define_daily_intake(&room);       /* tonnes/day entering the room */
define_entry_temperature(&room);
define_site_conditions(&room);    /* ambient design temp, humidity, altitude */

derive_internal_volume(&room);    /* pallets x pallet volume / stacking factor */
derive_envelope_area(&room);
select_panel_thickness(&room);    /* by temperature class and ambient */

load.transmission   = envelope_area * U_value * delta_T;
load.product        = intake_tonnes * enthalpy_change / pulldown_hours;
load.infiltration   = door_openings_model(&room);
load.internal       = fans + lighting + forklifts + people;
load.safety_margin  = 0.10 .. 0.20;

room.cooling_load = sum(load) * (1 + load.safety_margin);

size_evaporators(&room);
select_refrigerant(&room);        /* NH3 / CO2 / HFC-HFO / hydrocarbon */
size_compressors(&room, run_hours = 18..20);
plan_defrost_and_drainage(&room);
plan_redundancy(&room);
estimate_energy_and_opex(&room);

prepare_rfq(&room);
research_relevant_suppliers(&room);

if (uncertain(&room)) escalate_to_human("David");

/*
 * Square meters are not a cooling load.
 * Pulldown time drives compressor size, not storage volume.
 * Door traffic is a real load, not a rounding error.
 * Every assumption belongs in the RFQ.
 */

If any input is unknown, state it as an assumption in the RFQ rather than leaving it blank. Suppliers price ambiguity as risk.

Planning-stage inputs and what they decide

Each input on the left changes a concrete design outcome on the right. Missing inputs become supplier assumptions.

Direct answers to the questions buyers ask first

Short, quotable answers for buyers, search engines and AI assistants.

Calculators and glossary to use while planning

These tools give indicative planning figures you can take into supplier conversations. They are not engineering designs or quotations.

Frequently asked questions