The Vanlifemag.de - test of the QOOL passive cooler
For testing, we used, in addition to the blue cooler, four red cold packs. Cooled down to at least minus 18 degrees, they are supposed to keep the contents (16 0.5-liter bottles or food for two people) at a temperature of minus 2 to plus 2 for seven days. Of course, this only works if the contents to be cooled have also been brought to this temperature beforehand.
If this is not the case, as in our test, the batteries have to cool it down. This is because we only cooled our 16 half-liter water bottles down to just over seven degrees in our fridge. The four cold packs had a temperature of minus 19 degrees at the start of the test. Seven days in the passive cooler So off we go with the batteries and the bottles into the box. The manufacturer points out that the best results are achieved when two batteries are placed on the side and two on top of the goods to be cooled. However, this is awkward to handle, especially if you often want to take something out of the box. We therefore put two batteries in the bottom of the box, the other two on the sides and put the bottles in with our wireless thermometer. Lid on and closed. On top we put a second radio thermometer so we can measure the outside temperature. We leave the box outside in a covered area that the sun doesn't reach directly but heats up during the day. We don't come close to the temperatures that are reached in a vehicle parked in the sun, but we approach the practice with such a box. Because when it comes to cooling, the temperature differences between day and night definitely play a role.
The next morning, we found that the bottles were actually cooled down further by the batteries. Not to plus 2 degrees, but at least to 4.3 degrees. As planned in our test scenario, we take out one bottle in the morning and one in the afternoon. On this first day, the weather is cloudy and the outside temperature is between 15 and 25 degrees. Day 3 of the test with the Qool passive cooler On day three, the temperature in the box has dropped even further. We measured 3.2 degrees. Unfortunately, our outdoor thermometer failed and won't report back today. But a look at another thermometer shows that the temperature is in a similar range as the day before. On day four, our outdoor thermometer reports back and shows just under 38 degrees in the afternoon. The indoor temperature rises from 3.8 in the morning to 4.7 in the afternoon. The next day the outside thermometer fails again, inside the temperature rises to 6.3 degrees, because it is again a hot day. On the fifth day we put the base station outside, because the second transmitter seems to have finally given up the ghost. It is not because of the batteries, which we have checked and replaced several times. Also today it is relatively hot. The temperatures climb from around 25 to a good 30 degrees.
Our bottles, which still have a temperature of 5.6 degrees in the morning, warm up to 6.1 degrees during the day, but surprisingly cool down again to 3.9 degrees in the evening. The last day. The interior temperature between the remaining bottles is 4.4 degrees, and we measure just under 32 degrees on the outside already in the morning. The removed water bottle fogs up, the water is pleasantly cool.
Conclusion of our test of the Qool passive cooler is therefore:
The Qool passive cooler passed our test without electricity. The Qool cooler kept our water bottles sufficiently cool over the seven days without electricity. It was clear that we could not reach the specified temperature of around two degrees, because we would have had to cool our bottles down further in advance. So the box couldn't do that at all. Nevertheless, it kept the temperature well over the test period. Of course, you have to make concessions if you open the box more often and especially if you put in unrefrigerated items. Then the cooling performance inevitably decreases. However, it is suitable without restrictions for an extended weekend trip with the camper van, and for the afternoon at the quarry pond anyway.
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