How did it go?
Ice ready for loading!
Our first experiment took place in Nelson, New Zealand on February 19th at 8am.
We had our ice delivered to the boxes by commercial chiller truck.
The air temperature was 16 degrees both outside & inside the Ice Boxes.
Equal amounts of ice were loaded into each Ice Box. The slabs were really heavy to load.
While loading the second hand bath cradles we cracked the acrylic bath in the High Performance Box. We taped over this crack with window seal tape so the bath didn't leak water into the floor of the Box.
Once both Boxes were loaded with Ice we shut the doors 7 locked them at the same time.
We enjoyed clear sunny skies and a high temperature of 20 degrees C.
The Ice Boxes were located at a local shopping centre beside key sponsor Mitre10 Mega Nelson.
They were in a large car park facing due north & set 4 meters apart so that neither box could shade the other box.
Ice in bath cradles.
We were pretty excited to monitor both boxes at least twice a day.
Typically we checked them first thing in the morning & then during peak traffic times & temperatures.
Over the course of two weeks in February we had an average temperature high of 21.2 degrees.
We had one day of rain & another overcast day.
The highest temperature was 22 degreesC on the 24/05/2026. On that day the code box reached an internal temperature of 24degreesC. The High Performance Box only reached 13degreesC.
On most days the difference in temperature of the boxes was 11degreesC which we found pretty amazing.
We were really glad that the ice was sitting in baths. The baths were plumbed outside and the trap created an airtight seal so no air could enter the Boxes.
You could look under the boxes & see a steady stream of drips coming out from melting ice. It made for quite a large puddle under one Box in particular.
How it looked on day 9...
After one week it was pretty obvious which box was going to win. The puddle under the Code box was showing how much ice was melting inside it.
It then became a waiting game to see how long the ice would actually last for...
Day 8 was a gloomy overcast day. It was only 17degreesC outside.
Inside the Code box there was only a couple of pieces of small ice left (half the size of a rugby ball)
The code box was 18degreesC.
The High Performance Box held reasonable ice and was 9degreesC.
Day 9 & it was all over!
Zero ice in the Code Box & an internal temperature of 32degreesC.
The high performance box was 14degreesC.
We brought in some scales & a fish bin to weigh the remaining ice in the High Performance box. There were 3 pieces left which weighed a total of 84.6kg
We left the ice inside the High Performance box to see how long it would last.
On day 15 we packed up the boxes & trucked them to Christchurch for round two.
There was still a 9 kg piece of ice left on day 16. Very impressive stuff!