[Strawbale] PEX, Concrete Slab, Fear of Death (by contractor)

[Speireag Alden]

On 2007, Dec 26, at 17:37, David Neeley wrote:

> There seems to be a general consensus that a three-string bale wall  
> house
> represents about R30 to R40 (depending on many factors and who was  
> doing the
> testing, it appears). If you couple this with superior insulation  
> in the
> attic (seeing that the roof structure is responsible for about 65%  
> of the
> heat gain or loss in a typical house) and decent windows and doors,  
> the
> house should hold temperatures very well--and the lag times of a  
> hydronic
> system would be difficult at best to deal with. Adding in the high  
> cost of
> the system, and I cannot think it would be a worthwhile investment.

     Everyone always says that hydronic systems are expensive.  Mine  
cost about $1000, ten years ago, for everything including the  
heater.  It has one zone, and an on/off switch, and a brass  
circulating pump.  Currently, the heat source is the same 30-gallon  
electric tank heater which supplies the taps.

     When the floor is running, as we say, the tank heater gets drawn  
down and find equilibrium at about 110°F.  As soon as the floor stops  
running, the tank goes back up to its set-point of 145°F and thereby  
sterilizes its contents.  I did all the work myself.  When it's  
bitterly cold outside, the floor is toasty warm.

     I have a very massive floor, far more than is probably best for  
response time (over a foot of mass), and when I get caught  
unexpectedly by cold conditions (as when someone leaves a door  
swinging, for instance) I find that the response time is an hour or  
so.  In the meantime, a cup of tea and a sweater hold me over nicely.

-Speireag.