thinking about a black plastic cover/wrap over that. I was also thinking of turning it into a growing wall, but that requires more engineering than I am prepared for. If I do get around to planting that wall, it can be a year round feature. Otherwise, it has to come down in summer.
after about two hours post install part of the front thermal bank on the greenhouse wall in front of my primary living space, photos directly above, I did a touch test - the incomplete wall on the right is hot, the bottle filled (partially) wall on the left is puts out significantly less degrees as I touch the mesh against the bottles and touch the plastic above and around the bottles... so, the bottles are trapping the heat... this is good! I may or may not put another layer of plastic over the bottle side of the wall to make a giant bottle heat soaking pillow. I probably will.
Pia Jensen wrote:If I do get around to planting that wall, it can be a year round feature. Otherwise, it has to come down in summer.
after more contemplation - I can plant Moringa inside the fence - close to it for tying it to the fence for more security in the wind (Moringa I know has been weak in heavy winds) and Maracuya on the outside dam to create a living wall that can stay up year round. The plants will shade the plastic bottles (slowing breakdown), the sun will get absorbed and released to the plants and soil.... Maracuya may be too sensitive (wind and cold exposure on the exterior away from the bottles), but it's the only vine type I have growing right now. And, they need a new space that is strong enough to handle the beast without damage.
no....I was thinking the result would be similar to double pane glass. If I fill them with sand or water, I'll need more structural support. Do you think the heat will dissipate rapidly without a filler?
I've been thinking off and on to hang material (canvas if I can find it here) at both ends of the space between the bottle wall and the house to create a sort of "mud room" heat trap. Also thinking of planting a medium sized philodendron at the end (in pic below - where the yellow "material" is hanging), the philly would be right in front of that and behind the big rock, up against the house wall like the Charlie plant is.
There was a friend's house in Nor Cal that had an attached greenhouse with an entry via the house into the greenhouse - the heat transfer was awesome. This is what I am thinking. Should I still endeavor to fill the bottles with something (lightweight, not water or sand... plastic bags, for example).
Dale Hodgins wrote:The wall will store heat according to its thermal mass. A very light wall can't store much. Water stores 5x as much heat in a given weight of material compared to cob.
Water heat capacity=1
Cob heat capacity=.2
ah, thank you for the data comparison. I found this research on thermal water wall via cers.engr.psu.edu/files_public/winning%20papers/2011/UG_Ramal.doc "Thermal analysis of a discarded plastic bottle solar water" wall
and I have an idea.. because I don't want to use limited resources constructing a structurally sound water-load-bearing wall (!!) because other priorities are using those resources, I can fill larger bottles, put them on the ground at the back wall of the greenhouse, under the emtpy water bottle wall.... cloak them in black plastic and snug them up against rocks there.... to sink heat into the rocks and emit heat in the night up through the wall?