On Wed, 30 Jul 2003 18:05:49 +0100, "IMM" wrote:



Actually yes, but first let me make the point that I did say *can* be
less expensive, not *would* be. It would depend on the circumstances
I am sure.

There was, on average, a 3-5% lower
use of gas when setback was used.

What about comparison to optimised start and stop?

That was with optimised start and stop. The controller does that
anyway when ramping between two temperatures whether it has been
completely off or just at a lower set point.


In the 1960s the electricity
boards had a slogan "Lag It And Leave It", saying lag a cylinder and
leave
the immersion heater on 24/7. Under tests this was slagged as highly
uneconomical. Switching the immersion on when needed or on a clock was
proven to be far more economical.

At that point it probably did. WIth today's insulation, and I have a
100mm layer around my cylinder,

The point is that the older cylinders can be equated to heating systems. Not
so much today.


Probably. Really with decent insulation on the cylinder, whether the
timer would allow the water to be heated 24*7 or just 16*7 becomes
largely irrelevant.


..andy

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