# Cold Chain Cooling Load Calculator

> Estimate the refrigeration load of a chilled store from wall heat gain, product pull-down, internal loads and air-change allowance, in kW and tons.

Category: Logistics & transport · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/cold-chain-cooling-load-calculator

A cold room’s cooling load is the heat leaking through its walls (U × A × ΔT), plus the heat removed from warm product, plus lights, fans and people, with allowances for door openings and a safety margin.

Also called: Cold room heat load calculator, Cold storage refrigeration calculator.

## Inputs
- Inside length (unit m; default 6)
- Inside width (unit m; default 4)
- Inside height (unit m; default 3)
- Panel U-value (unit W/m²·K; default 0.25)
- Design outside temperature (unit °C; default 35)
- Room set-point (unit °C; default 2)
- Product loaded per pull-down (unit kg; default 2000; optional)
- Product specific heat (above freezing) (unit kJ/kg·K; default 3.6)
- Product entering temperature (unit °C; default 25)
- Pull-down time (unit h; default 12)
- Lights, fans and people (unit W; default 500; optional)
- Air-change and door allowance (unit %; default 15; optional)
- Safety factor (unit %; default 10; optional)

## Results
- Refrigeration load
- Refrigeration tons
- Wall, floor and ceiling gain
- Product pull-down load
- Internal loads
- Air-change allowance
- Enclosure surface area

## Formula

```
Q_walls = U × A × (T_out − T_in);  Q_product = m × c × (T_product − T_in) ÷ t;  Q = (Q_walls + Q_product + Q_internal) × (1 + Air%) × (1 + Safety%);  TR = kW ÷ 3.5169
```

Where:
- A: 2 × (L·W + L·H + W·H), all six inside faces
- m, c: product mass and specific heat
- t: pull-down time in seconds
- 1 TR: 12,000 BTU/h = 3.5169 kW

## Worked example
1. Area = 2 × (24 + 18 + 12) = 108 m²; walls = 0.25 × 108 × 33 = 891 W.
2. Product = 2,000 × 3.6 × 23 = 165,600 kJ over 43,200 s = 3,833 W.
3. Subtotal = 891 + 3,833 + 500 = 5,224 W; +15% = 6,008 W; +10% = 6,609 W.
4. 6.61 kW ÷ 3.5169 = 1.88 TR.

**Result:** The 6 × 4 × 3 m chiller needs about 6.6 kW (1.9 TR) of refrigeration.

## What the result means

Use this as a first sizing check. Product pull-down usually dominates for rooms receiving warm product; transmission dominates for long-term storage of pre-cooled goods.

## Assumptions and limits
- Product is cooled but not frozen (sensible heat only).
- Floor heat gain uses the same U-value and outside temperature as the walls.
- Latent heat of freezing, product respiration, defrost heat, solar gain and humidity are not included.
- Final equipment sizing should be done by a refrigeration engineer using the full load method.

## Questions

### Can I use this for a freezer?

Only for the part above freezing. Freezing product releases latent heat that this tool does not model, so the load would be badly underestimated.

### Why a safety factor?

It covers uncertainty in the inputs and lets the system recover after door openings. Typical allowances are set by your engineer.

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_Quantities are estimates. Confirm requirements with your engineer or supplier before ordering materials._

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/cold-chain-cooling-load-calculator