On March 30th, Laura Burkhart (of SLIM) came to my home and we built Chill Box V0.1. This is the version she will be showing at the Maui Agricultural Festival this saturday (April 2). It is a simple, no electronic control version. It consists of a styrofoam ice chest filled with cold water, a small fountain pump, a short length of 1/2″ plastic tube and a U of copper pipe (+fittings).
The initial build went pretty easy. Laura and her partner arrived about 9am and (after feeding horses) we reviewed the parts she had brought. She had some 1/2″ copper tube, a styrofoam cooler and a small fountain pump. I realized there was no easy way to connect the pump to pipes, and that my torch had gone awol. So we made a quick road trip to the Haiku Hardware Store for parts. We initially tried the Ohana Greenhouse & Garden Supply in Haiku center, which specializes in hydroponics, etc. Their selection for grow lights, fertilizers, etc was pretty wide, but not so good for tubing, and nothing for copper. I think the staff had been sampling produce from gardens too… at 10am! Haiku Hardware was very helpful and had just about everything we needed. Laura bought a foot of 1/2″ plastic tube, some calk and some fittings to attach the tubing to copper pipe. I picked up a burner for my butane bottles, some flux + brush, solder and a small pipe cutter. Always nice when a project adds to your tool box!
Back at the garage, we cut a couple 18″ lengths of pipe, guesstimated a center length and then got to sweating the copper joints. Its been quite a few years since I soldered copper pipe, but most of the basics came back quickly. I did forget a few things – like wear long pants and socks. Solder drips sometimes and hot splatter stings. The resulting joints are not professional work but do hold water. Once we had the U assembled, I pushed the ends into the styrofoam to mark the location for holes. I used a short remnant pipe to push thru the styrofoam, drilling the holes. It made a nice blow pipe too – although it took a strong wind to clear the foam plugs. I was about to calk the U in place when I remembered we needed to add the nipple. This required sweating a threaded fitting on one end of the U. Once that was done, I had to widen one hole to accept the new fitting. Then we screwed on the nipple and used some silicone calk to seal up the holes. Since the outgoing hole was now bigger than the pipe, I used some of the styrofoam chunks to help fill the hole. I let it dry overnight.
This morning (March 31, 2011), I brought the unit out to the lanai (porch for you mainlanders), filled it with water and plugged in the pump…. WoooHoo! it pumped water and no leaks from joints. Next I got some ice packs from the freezer and dumped them into the water. I added a bunch of ice chips too, so as to quickly reduce the water temperature. The packs and chips raised the water level above the holes in sides of cooler – and immediately started running out from below the outgoing end. I guess I had not completely sealed that hole. I will add a bit of silicone, but first I wanted to let it run and see if it would condense water….. 20 minutes later I went back out to check and LO! Condensation!!
Ok so V0.1 works!! Couple things need changing:
- re-calk the pipe holes
- shorten the pipes. Current 18″ length is pretty long
- add insulation on legs of pipe so as to keep condensation over the end/garden
Here are some pictures of the build:
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Next up will be:
- Showing Chill Box v0.1 at Maui Agricultural Festival Saturday April 2
- working the electronics & sensors
We have a planning meeting scheduled for tonight (Thursday) at the offices of Brian Thomas.
Update: Here’s Laura and Devon showing the box at the fest: