Cool boxes · rigid and passive
A box that publishes its hours or a box that publishes its weight — which figure decides it?
Two rigid passive boxes, both without any power connection, both publishing dimensions rather than leaving you to guess. Beyond that they fill in opposite lines: Brisby publishes the longest cooling figure in this hub and no weight, Kreher publishes the only empty weight in this hub and no cooling figure. Neither publishes an insulation thickness, and neither publishes the conditions behind a retention claim.
| Compared on | 22 litre passive box with four 450 ml ice packs in the lid | Polarbox, 20 litres, rigid passive box, 1.3 kg stated |
|---|---|---|
| Box type | Rigid passive box — stated as passive and without power, with four ice packs built into the lid | Rigid passive box — stated as passive, with a removable lid and no power connection |
| Capacity | 22 litres — stated, with dimensions of 27.5 × 44.5 × 38.3 cm | 20 litres — stated, 45 × 30 × 29 cm outside and 41 × 26 × 26 cm inside |
| Insulation type | PU/PP construction — stated food-safe and BPA-free, with four 450 ml ice packs integrated into the lid | Styrofoam in a washable plastic shell — both stated |
| Insulation thickness | Not published | Not published — inside and outside dimensions are both published, which is not a stated wall thickness |
| Ice retention | Up to 40 hours cold and up to 18 hours warm — both stated, with the four supplied ice packs | Not published — reliable cooling is claimed, with no figure |
| Ice retention conditions | Not published — the figure is tied to the four supplied ice packs, with no fill ratio or ambient temperature | Not published — no retention figure is published, so there are no conditions behind one |
| Closure and seal type | Not published — the lid carries the ice packs, and no gasket, latch or catch is described | Removable lid — stated; no gasket, latch or catch is described |
| Carry arrangement | A sturdy carry handle — stated; the box is stated water-repellent and compact | Adjustable faux-leather shoulder strap and rounded edges — stated |
| Empty weight | Not published | 1.3 kg — stated for the 20 litre box; the 12 litre version is stated at 1 kg |
Each tick belongs to its own line and nothing more. The row of ticks is not a score: the two verdicts underneath settle the page, because these two answer different questions on the trail.
The Brisby publishes the longest cooling figure on this shelf, up to 40 hours cold and 18 warm, and its own listing ties that figure to the four 450 ml ice packs built into its lid rather than to the box alone. It is the larger of the two at 22 litres, and it never says what it weighs empty.
The Kreher is the only cool box in this hub with an empty weight on the page, 1.3 kg for the 20 litre size, and the only one to publish inside and outside dimensions together. It publishes no cooling figure at all, so the thing it is bought for is the thing its listing declines to quantify.
Not really, and the Brisby listing is unusually clear about why: the figure is quoted with the four supplied ice packs in the lid. No fill ratio, ambient temperature or ice quantity accompanies it, and the Kreher publishes no figure to set beside it. Hours from different listings are not the same measurement twice.
No listing in this hub does except one soft bag, which is compared on another page. Kreher comes closest by publishing inside and outside dimensions together, but the difference between two boxes is a wall, not a thickness of insulation, and this site does not perform that subtraction on the maker’s behalf.
Rigid passive box · 22 litres · 27.5 × 44.5 × 38.3 cm · four 450 ml ice packs built into the lid · 40 h cold and 18 h warm stated · PU/PP
The longest cooling figure published in this hub at 40 hours, and the listing itself says the number rests on the four ice packs built into its lid.
Best for: A weekend where the box is packed once and opened rarely, and the ice packs are frozen properly beforehand.
≈ 60 €
Rigid passive box · 20 litres · 45 × 30 × 29 cm outside and 41 × 26 × 26 cm inside · Styrofoam in a washable plastic shell · 1.3 kg stated · shoulder strap
The only box in this hub that publishes an empty weight, and the only one to publish inside and outside dimensions together — 1.3 kg, 20 litres of rigid Styrofoam.
Best for: A beach day or a car trip where a light, wipe-clean rigid box on a shoulder strap beats a soft bag.
≈ 41 €
Prices in these summaries were read on the dates each review gives. The live figure sits beside every product.
