Gary Collier said the following to Mike Ross on the subject of
power source/pump (23 Jan 98  11:53:27)
 GC> O.K. I am intriqued. Does this system work with a system where the
 GC> heat source is below the heat exchanger???
Yes, a gravity hot water system must have its heat source at a lower
level than the radiators because it depends on the difference in the
density between hotter and colder water. The heated water rises because
it is less dense and cooler water sinks because it is denser.
The radiators transfer heat to the ambient air which cools the heated
water. This can create an appreciable flow which depends on the
temperature difference of the heated and radiator cooled water.
It can be a 1 pipe or 2 pipe system. The 1 pipe type must have a larger
gauge because the hot and cold water create opposing flows in the same
pipe. A 2 pipe type only has flow in 1 direction so the gauge can be
smaller.
 GC> I have had experience with radiant baseboard heating, but the heat
 GC> source was always above the heat exchanger or at same level
It must have been a mechanically circulated system or perhaps steam.
 GC> ...in my
 GC> case the heat exchanger is going to be at least 15 feet above the heat
 GC> source. Please describe your system if it would be applicable.
See the ascii sketch in my reply to Jim Dunmyer for a rough idea of
what a simple gravity hot water system may look like.
... Ice Storm of '98 refugee.
--- Blue Wave/DOS v2.30
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