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Default Power cost of idle electric water heater

Jonathan Ball wrote:

...Take a 1-foot cube, 1 x 1 x 1. The volume is 1 cubic
foot, and the surface area is 6 square feet. An n x n
x n cube of 2 cubic feet will have n = (approx) 1.26.
The surface area is 6 x 1.25^2 = 9.52 sqare feet. The
volume has doubled, but the surface area has gone up by
LESS than twice.


A lovely explanation, but larger tanks lose more heat.


Not relative to volume.


Who cares about volume?

The RATE of heat loss is based on the ratio of the
surface area to the volume, and because the larger
vessel has a SMALLER ratio of surface area to volume,
it will lose heat at a slower rate.


I'm afraid you are wrong, my good man. The rate of heat loss
(vs temperature change) is directly proportional to the amount
of surface. This is known as "Newton's law of cooling."

Nick