Cob: cob/ thermalMass

[Darel Henman]

The problem with trom walls is that they will radiate more heat out
through the windows during night time which is many hours more that day
light time in the winter, and there is no temperature controll.

Your water idea sounds better as it has more thermal capacitance.  If
you keep the tank in an insulated area you could heat it up to say  150
degree F or so and store it there for a cloudy day.  Open a little hatch
to the heat room to let heat out faster.  Just some ideas.

Darel

"Matthew HALL(SED)" wrote:
> 
> If you try to make a storage heater using cob with heated elements buried deep inside it the
> expansion/contraction of the water-carrying vessel (steel pipe?) will crack and ultimately destroy
> the cob. Fired clay pipes may solve this, eg recycled underground pipes if you can find them.
> 
> How about a trombe storage heater? If you are not familiar with the trombe wall concept here goes...
> Place a thick thermal mass wall (eg cob) a short distance behind plain glass and paint the surface
> of the wall black. The direct sunlight will heat the black wall intensely, and the backscattered
> infrared radiation emitted by the glass will also provide an intense heating effect of the earth
> mass wall.
> 
> Now
> Perhaps you could incorporate a storage/water heater within a trombe wall concept, the effect of
> thermal expansion would not be so severe and possibly not cause cracking if the heat had to travel
> through the earth mass first to get to the water to heat it, see what i mean? I envisage a sealed
> water container within the earth mass wall.
> Comments?
> Cheers
> Matthew