Cob verify?

[Michael Saunby]

>
>     I invite any who has actually lived in a cob building (and 
understands
> the difference between insulation and thermal mass) to tell me 
differently,
> and why.
>


I've spent time in various buildings but never studied any of them with a 
great deal of scientific rigour but here are some observations and 
thoughts.

I've never lived in a cardboard box or an expanded polystyrene container 
but it's obvious to anyone that a small very well insulated container is 
easy and cheap to heat.  However if you want ventilation and a reasonable 
degree of temperature stability then just going for insulation isn't going 
to make for a comfortable living space.  In fact you've created a huge 
problem that can probably only be solved with a lot of technology - some 
sort of life support system is going to be needed for your plastic bubble.

The modern lightweight buildings with lots of insulation that I've lived in 
have required very responsive heating systems and have been unpleasant in 
warm weather - air conditioning is uncommon in the UK. Why are well 
insulated structures uncomfortable?  Because the heat is only in the air in 
the building so in winter it is lost when a door is opened. Okay there is 
heat retained in the water and metal of the heating system.

A cob building doesn't suffer huge temperature changes every time the doors 
or windows are opened because the walls are constantly taking heat from and 
return it to the air in the building  (it isn't just flowing one way!), 
which is where you get your own comfort (or discomfort from).

We've got things going on outside our house, so we have a need to go in and 
out. So thermal mass makes the house much more comfortable for our 
lifestyle.  Equally it avoids the need for high tech heating, a wood stove 
- which could be hard to use in a well insulated house works fine.

B.T.W. buildings are not only subject to conductive heating and cooling, 
when skies are clear radiative heating and cooling plays a big part.  A 
greenhouse (glasshouse) achieves temperatures way in excess of its 
surroundings with no heating so this idea of a building with high thermal 
mass achieving the mean of it's surroundings is surely untrue - it might 
even out the variations but you only have to consider the extreme of the 
other direction, a triple glazed house with huge windows to imagine how 
uncomfortable an over insulated  and inadequately shaded and ventilated 
building could be.  Unless your cob house is invisible then radiative 
heating and cooling will play a part.  You could position windows in order 
to gain or lose heat, the type and shape of roof will also play a part.


Also what is so different about "modern day" humans that they need "modern 
day" insulation, etc?

Michael Saunby