A heat pipe is a sealed self-contained, liquid evaporating
condensing system, usually shaped like a cylinder. Heat
is transferred from the hot incoming gas to the evaporator
section of the heat pipe. The local vapour pressure increases
and evaporated fluid flows along the pipe to the condenser
section. The vapour pressure is lower here, so the liquid
condenses and the heat is released to the cold gas. The
liquid then returns to the evaporator by a combination of
capillary action and gravity.
Passive Operation
No energy input is required to operate the Heat Pipes.
When two air streams pass through the Heat Pipes, (one
air stream at one end, and another air stream at the other
end), the temperature difference between the two air streams
activates the Heat Pipes and causes them to exchange heat
by “Heat Pipe action”. Heat Pipe action is
a much more powerful heat transfer mechanism than convection
flow. Heat Pipe action utilizes the heat capacity available
when the working fluid changes phases, from a liquid to
a vapor and back again.
Long Life
There is nothing in the Heat Pipes to wear out! The Heat
Pipes are passive. They have no moving parts (unless they
come equipped with a bypass damper.) To guard against
corrosion, the Heat Pipes can be ordered with a baked
epoxy coating or other protective coating. The Heat Pipes
are fabricated with a multitude of charged circuits. Under
normal operations, there is no reason for these ever to
leak. If some inadvertent mechanical damage were to occur
on one circuit to cause it to leak, there would be little
effect on performance even if the leak was not repaired.
Furthermore, because the tubes in Heat Pipe Technology
Heat Pipes are copper, leaks can be fixed. Most other
Heat Recovery Heat Pipes are fabricated with aluminum
tubes which are very difficult to repair.
Isolated Air Streams
Dividing plates to separate the two air streams are an
integral part of Heat Pipe Technology Heat Recovery Heat
Pipes. The copper tubes carrying the Heat Pipe working
fluid are expanded into the mating holes in the dividing
plates, assuring an excellent seal to prevent cross contamination.
Minimum Maintenance
Since the Heat Pipes have no moving parts (apart from
any dampers), the only maintenance recommended is periodic
cleaning. A coil cleaner may be applied for this purpose
just as for any cooling coil.
Minimum Size
Heat Recovery Heat Pipes from Heat Pipe Technology take
up much less space than other heat recovery schemes. They
are also generally considerably thinner than other heat
pipes. A six-row Heat Recovery Heat Pipe can be fabricated
with a thickness of as little as 7 inches.
Summer and Winter
The same Heat Pipe can be used for both summer cooling
and winter heat recovery without any changeover mechanism.
The temperature difference between the air streams activates
the energy recovery.
