Hi..I have been exploring an idea of using continuous loops / rings of a pipe/tube within a "planter drum" and flowing a liquid through it to heat the Soil up to around 75 degrees F....
I have found a tubing that I think could work ..Its an under floor Alloy/Pex heating pipe/tube @ $1.20 metre on NZ's version of Ebay...
http://www.trademe.co.nz/a.aspx?id=1096180568
I would be very grateful if anybody could help me here ...with my limited knowledge this could be an ideal tubing for me although its not copper.....So I asked the seller for advice on how many rings or loops he would suggest I use within the planter drum which is 450mm wide with a depth of 350mm..(his reply is in the Questions and Answers Link) ....He suggested at least 10 hoops?? Well this is away above what I had been thinking especially as water in the soil would conduct the heat from the tubing...
Looking at costs ... One ring / hoop would equal around 1.350 metres or $1.70 and here am I hoping to keep my cost to well below $10 a drum for tubing...
I would be extremely grateful for any comment on how many hoops I would need ..It would be of great help to me.....Thanks Ron...