This is the second in my ‘personal cooling’ series. Previously I posted about a personal evaporative coolerwhich worked well but I wanted to take it to the next level. The basic idea is to use a water pump and some kind of tubing to circulate cold water around the body, taking your excess body heat away and cooling you down. This type of water cooling is extremely efficient and cools the body far more effectively than a fan. I’m continuously working on improving the design and will update this page with new revisions.
Latest design – 3rd Revision
This design uses a micro water pump, plastic tubing and a small water resistent travel case. The total cost comes in at under $5 and the whole device can be put together in about 15 minutes. Two holes were drilled into the top of the case for routing the tubing. A soldering iron was used to melt a small slot into the plastic closure for the power cable to exit. Due to the smaller water container, the cooling effect lasts for about 30 minutes before the water needs to be replaced. 3rd Revision in action:
One of the major hurdles I had to overcome was finding a water pump small enough to make my idea portable and power efficient. After much searching, I finally struck gold with a ‘Zen Garden’ desktop water fountain. The device sits on your office desk and circulates water through the garden. I was able to remove the water pump and use it on my project. I’ve used a hand soap bottle as my water container. The cap of the bottle was modified to route the incoming and outgoing water pipes and the power connector for the water pump. You wear the plastic tubing around your neck and down the front of your core body. Once the power is applied, the pump immediately starts circulating water around the tubing, cooling your body and absorbing your excess heat. The constant circulation ensures that the excess heat of your body is immediately mixed with cooler water. You can increase the cooling capacity by adding ice cubes. After a couple of hours, the water will have warmed up – at that point you simply pour the warm water away and refill it at your cold water faucet. 2nd Revision in action:
Original/Proof of concept
In my original version, I used copper tubing, some sheet aluminum, a fish tank water pump and some plastic tubing. The copper transfered heat (or cold) very well and acted as a great heat sink but the aluminum produced a poor thermal transfer. The whole device is quite bulky but does provide good cooling and a high capacity, meaning the water/ice can last up to a whole day.