andrew neil

Hi Joseph
thinking more hitech using calcium chloride hexhydate (Galaubers Salts. There is a dude on this forum Rich that is trying to do exactly same as me. ie; ringing the GH with black HDPE black drums to provide nightly heat. Call me a newbie but I need to keep ambient night time temps above freezing. Outside it will get to minus 5C. Also looking at simplistic bubblewray. btw its a twin wall polycarb structure.
Any constructive thoughts greatly appreciated
andrew

Hi Richard
I am endeavouring exactly to same as yourself. Paraffin is way too exxy in comparison wondering how your expriment has gone with calcium chloride?
Very egaer to know any plusses and/or pitfalss. I live in southern canberra, australia and its about to get cold
cheers andrew

Hi all
Im new to this site and have done cursory searches for PCMs (phase Change Materials)
In a nutshell I am constructing a 3 x 8m poly carb twin wall “glasshouse” and am going to need to exothermically pump heat back into it especially on winter cold nights where it gets down to -5C.
The idea is to line the house inside perimeter with 25L black drums (stacked x2 high, 200L drums in the corners) and use PCMs to seep heat back into it in the wee hours. Read; tropical plants and orchids!
I am looking at Calcium Chloride crystals (Damp Rid) or Octadecane paraffin. They are quite a lot of other chems that are not volatile that are suitable but I won’t go into it initially.
Just simply interested in peoples thoughts and experience with this scenario. (expansion rates, latent heat absorbency, quantities in suspension, additives, vermiculite, perlite etc)
Hopefully some of you may have already gone down this track and can shed some light on this quite confusing arena (unless you are a chem engineer!)
many thanks,
andrew