[Strawbale] Sustainability of wood heat.

[activism98201 at verizon.net]

What about bamboo?


-Mark Nagel
Everett, WA


=====================
From: Sherwood Botsford <sgbotsford at gmail.com>

Speireag Alden wrote:
> On 2008, Feb 10, at 17:35, Sherwood Botsford wrote:
>
>   
>> I'm considering a PVC pipe + PE film greenhouse this summer.  What
>> should I be using for the frame instead?
>>     
>
>      Saplings between steel tubing joints?  Saplings between steel  
> tubing plates, such as are used sometimes for geodesic structures?
>
>      There's always ABS.  I'm using it for my drain pipe in the  
> addition, and so far so good...
>
>  
Ok, why is PVC so evil?  I know that it's obnoxious when burned.  I know 
it outgasses hydrochloric acid. I know that it's subject to UV 
degradation. (Needs to be painted.)  Depending on manufacturer, lead, 
cadmium or zinc is used to stabilize the plastic against thermal 
degradation.

Steel tubing is hard to bend, and substantially more expensive than 
(factor of 3) than pvc.
ABS hadn't occurred to me.  Is it flexible enough to put an 1/8 circular 
arc (45 degree) in 16 feet?
Pointer to using ABS pipe for structural purposes?

Greenhouse environments are very humid.  Wood doesn't last long in a 
warm humid environment.
A greenhouse frame with wood elements needs to be replaced every few 
years, or it has to be pressure treated.


I can put up a PVC framed greenhouse in a couple of days, at a cost for 
frame around 30 cents per square foot of ground covered. 

A viable alternative:
    Needs to be no more than twice as expensive.
    Needs to be no more than twice as long to set up.

OR

Convince me that PVC is sufficiently evil, and I'll postpone the 
greenhouse until I can do something different.