Cold Room Cooling Load & Size the Refrigeration in TR
Cools fruit
Enter produce mass, specific heat, temperatures, pull-down time and a safety margin to get the product heat load, cooling kW, tons of refrigeration and recommended TR— so the room actually holds temperature.
Size your cold room
Next: specify a plant of about 3 TR so it pulls the produce down within 24 h with margin for door openings and respiration heat.
This is the product (sensible) pull-down load only; real plants must also add transmission, infiltration, respiration, fan, lighting and personnel loads — the +20% here is a starting margin, not a full audit.
Cold room cooling load — key facts
- Product heat
- mass × specific heat × temp drop
- Spread over
- the pull-down time
- Sized in
- tons of refrigeration (TR)
- 1 TR
- ≈ 3.517 kW
- Field heat
- removed to storage temp
- Safety margin
- ≈ 10–30%
- Undersized
- room never holds temperature
- Privacy
- Runs in your browser; nothing uploaded
Size the plant for the heat, not for the room's walls alone
A cold room is only as good as the refrigeration behind it, and that plant is sized in tons of refrigeration from the heat it must remove. The dominant part is usually pulling the produce down from field heat to storage temperature — mass × specific heat × temperature drop — over the pull-down time, plus a safety margin for doors, fans, lights and respiration. Get this wrong and the room never holds temperature, so produce ripens and spoils.
This tool gives the product heat load, cooling kW, tons of refrigeration and a recommended TR from your produce mass, specific heat, temperatures, pull-down time and margin. Use it to scope a new cold store, check an existing plant, or decide how fast you can load fresh produce. Pair it with the Cold Storage Capacity, Shelf-Life and Precooling Time tools to design the whole cold chain.
Right-size the plant
Tons of refrigeration from the real load.
Hold temperature
Avoid an undersized room that never cools.
Remove field heat
See the heat to pull produce down fast.
Build in headroom
Safety margin for doors, fans and hot days.
Frequently Asked Questions
What is a cold room cooling load?+
The cooling load is the total heat that must be removed from a cold room to bring produce down to storage temperature and keep it there. A room's refrigeration is sized in tons of refrigeration (TR) from this heat. The biggest part is usually cooling the produce from field heat to storage temperature, so undersizing the plant means the room never holds temperature.
How is the load calculated?+
The main product heat load = mass × specific heat × temperature drop (field temperature minus storage temperature), spread over the pull-down time. Convert that heat to a cooling rate in kW, then to tons of refrigeration, and add a safety margin for door openings, lighting, fans, respiration and infiltration. The result is the recommended TR for the room.
What is a ton of refrigeration (TR)?+
One ton of refrigeration is the rate of cooling equal to melting one short ton of ice in 24 hours — about 3.517 kW. Refrigeration plants are rated in TR, so converting your cooling load into TR tells you directly what size condensing unit or chiller the cold room needs.
Why does pull-down time matter?+
The same amount of heat removed quickly needs a bigger plant than removed slowly, because cooling rate is heat divided by time. A short pull-down time (cooling a fresh load fast to protect quality) raises the TR; a longer time lowers it. The pull-down time you enter sets how hard the refrigeration must work.
What is field heat and why remove it fast?+
Field heat is the warmth produce carries in from a sun-exposed crop — it can be well above storage temperature. Removing it quickly slows ripening, respiration and decay, extending shelf life. The temperature drop from field heat to storage temperature is the core of the product heat load.
What goes into the safety margin?+
Beyond cooling the produce, a cold room gains heat from wall and door infiltration, opening doors, lights, fan motors, packaging and the produce's own respiration. A safety margin — often 10–30% — covers these and gives headroom for hot days and peak loading, so the plant isn't sized right at its limit.
What happens if the plant is undersized?+
An undersized plant runs continuously yet never pulls the room down to set point, so produce stays warm, ripens and spoils, energy bills climb and the compressor wears out early. Sizing for the real product heat load plus a sensible margin is far cheaper than chasing temperature with a plant that can't keep up.
Does specific heat depend on the produce?+
Yes — different produce holds different amounts of heat per kilogram per degree. High-moisture fruits and vegetables have a high specific heat (often around 3.6–4.0 kJ/kg·°C above freezing), while drier goods are lower. Enter the specific heat for your commodity so the product heat load reflects what you're actually cooling.
Are the figures precise?+
They give a solid sizing estimate for the dominant product load plus a margin. A full design also accounts for transmission through insulation, exact air changes, and equipment heat in detail. Use this to scope the TR you need, then have a refrigeration engineer confirm the final plant — the calculator gets you to the right ballpark fast.