Top, Bottom or Wrapped: A Four-Pack Placement Test in a 20-Litre Box

Four identical 20-litre EPS boxes, four identical 1 kg gel packs each, four arrangements, and one 30 degree room for 36 hours. The payload was 8 kg of water bottles at 4 degrees, with a logger in the centre and another on the lid. All four packs on the bottom held the payload under 8 degrees for 21 …