Eutectics and insulation11 / 26

GEBHARDT recommends 24 hours for its eutectic plates; depending on the cooling technology it ranges from 8 to 24 hours. The freezer must run at least 5 °C below the melting point.

Do not treat 2-8 °C as universal; base plate choice on product protocol and measured route performance.

In the ATP IR class the average K value of the body is at most 0.40 W/m²K. Thin sections at corners and in the lid channel pass more heat than that average; where they sit and how much heat they pass, in numbers.

A logger may represent the coolant, box air or part of the load; purpose and route validation determine the position.

Putting packs on top is not a rule by itself: heat direction, product sensitivity, separators and closure set the layout, and the position is verified in a recorded trial.

The heat entering a box is K, surface area and temperature difference multiplied, and it comes out in watts. The result gives an order of magnitude and a starting point for plate count and duration.

Water appears when moist air meets a surface below its dew point. Work out the dew point and note where the water shows, and the source can be told apart.

Five steps, each with its limit: checking the box, bringing the product to temperature, working out how much coolant the load needs, placing it, and recording the closure.

Plate temperature and surface can vary by model. Plan the task using manufacturer instructions, suitable protective equipment and a clear handling route.

Do not assume a fixed gap; use product instructions, container model, packaging and measured load trials.

First protect people from slips and contact. Isolate the plate and affected load for product-specific assessment.

Do not treat label volume as usable load. Measure packs, cold sources and closure clearance in a sample, then record the layout.

Inspect the zip line empty and loaded; record gaps, trapped lining and seam damage, then verify the sample in use.

ATP splits insulation by the k coefficient: at most 0.70 for IN and 0.40 W/m²K for IR. IR is mandatory for the sub-zero refrigerated classes.

The same bag gives a different time when fill, product temperature, ice packs and openings change. One logged trial on your hardest route gives your own hours.

The ATP definition of insulated equipment, its K-value classes and a six-hour route calculation show where a soft bag stops being enough. Product temperature limits come from the same ATP guide.