On Mar 12, 10:56*am, "Ed Pawlowski" wrote:
wrote in message

...





On Thu, 11 Mar 2010 22:13:04 -0500, "Ed Pawlowski"
wrote:

wrote
Sure, thermodynamics requires things to be symmetrical, that way. *;-)
However, the time ramping up and down are inefficient. *Waiting for the
ramp
up, your cold. *On the way down, you've wasted that heat. *Nothing for
nothing.

Where is the heat wasted?

Heat loss is proportional to the temperature difference. *If you leave the
difference higher, longer, the loss is more than it would have been if the
temperature came down more quickly. *Nothing for nothing.

If the house is constantly losing heat on a cold
day, the heat from the radiator is just helping to maintain it for a
longer
time between cycles. *The perfect system it to balance the heat loss with
the heat makeup of the radiators to maintain a perfect temperature all the
time.

The higher the temperature (difference) the higher the loss.

OK, that is true and complies with the laws of physics. *But where is the
waste? *If I keep my house at 70 with copper, I use the same heat as keeping
my house at 70 with cast iron, cast aluminum, or hollow chicken bones. *70
degrees is 70 degrees and it takes the same Btu to maintain that temperature
over outside ambient no matter the source.

Only way you'd have waste from the higher heat loss is if the temperature
inside overshot the thermostat. That is the fault of system design or bad
equipment, not the heat transfer material. *Cast iron allows for a nice
steady heat.

I don't see any loss.- Hide quoted text -

- Show quoted text -

The loss arises through the overshoot. If you have a sytem that can
exactly matches heat requirements its possible to make very
significant savings.10-15% would be pretty typical.