Reefer Precool Time Estimator — Half-Cooling-Time Model (USDA AH-66)

Source: USDA Agriculture Handbook Number 66, The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks — precooling / half-cooling-time chapter. The half-cooling model: each "half-cooling period" removes half of the remaining temperature difference between product and cooling air. 3 periods ≈ 7/8 cool; 4 periods ≈ 15/16 cool.

Load & Cooling Inputs

Commodity (optional — informational only)

Pulp temp at load

Core / pulp temperature of the product as it arrives at the dock.

Target transit temp Desired pulp temp before / at load-out (same unit as above).

Cooling-air temp Supply air temp from the cooling unit or reefer trailer.

Cool to fraction

Cooling method

Forced-air

Half-cooling ~1–4 h. Fans pull cold air through vents / stacked pallets.

Room cooling

Half-cooling ~10–20 h. Static cold room, no forced airflow.

Hydrocooling

Half-cooling ~0.25–0.5 h. Cold water immersion / shower.

Half-cooling time (H_c) for this load

0.1 h 2.0 h 4 h

Depends on airflow rate, package venting, product size/shape, and pallet stacking — set from your equipment's typical performance or a prior cool-down log. This is the single biggest source of uncertainty in the estimate.

Estimated Time to 7/8 Cool

—hours

⚠ Estimate only

Cooling Curve — Pulp Temp vs. Time Pulp temp Air temp Target fraction

Fraction-Cooled Math (shown)

How this tool works

Reefer Precool Time Estimator runs entirely in your browser. Inputs are evaluated with rules and constants taken from Half-Cooling-Time Model (USDA AH-66) (Freight & logistics). Nothing is uploaded to a server for the calculation itself.

Enter the values that match your load, vehicle, or scenario.
Results update live — treat them as a cited reference, not legal or professional advice.
Open the primary source linked at the top of this page before you rely on a number for compliance.

Use Copy link to share this page (including query parameters when the tool supports them) or Print for a dock/packet copy.

FAQ

What is half-cooling time?

Each half-cooling period removes half of the remaining temperature difference between product pulp and cooling air (USDA AH-66 model). Three periods ≈ 7/8 cool.

Can I cite this in a claim or customer email?

You can share the link and the underlying public source. Do not present the tool as legal, medical, or insurance advice.

Can I cite this in a claim or customer email?

You can share the link and the underlying public source. Do not present the tool as legal, medical, or insurance advice.