Radiantec's energy efficient tubing was developed with grant support from the United States
Department of Energy. Considerable effort went into the design of a radiant heat exchanger tubing
that had optimal characteristics of service life, energy efficient heat transfer and minimal electrical
requirements for pumping. Flow through the tubing was optimized to be "slightly turbulent". Laminar
flow (which is very smooth) and fully turbulent flow (which requires excessive pump work) are
both to be avoided.
TECHNICAL INFORMATION
The amount of heat that a heat exchanger tubing puts out is directly
related to the surface area (size) and the thickness and conductivity of
the walls. Other factors such as the rate at which the heat can then be
carried away from the tube, are relevant as well.
"Workability" factors are very important to consider. The tubing must
not kink readily or require unusual skill or care during installation.
Service life and performance should never be sacrificed for very easy installation. Rubber radiant heat exchanger tubings are highly questionable.
Some degree of over design is often appropriate for safety and service life. However, the design of heat exchanger tubing always involves trade offs and gross over design in one area will usually compromise another. Waterline products are engineered for pressures of 100 psi at temperatures of 180° F They may be grossly over designed if a tubing will operate at 15 psi and 120° F.
Lower operating temperatures in a radiant heating system are important for energy efficiency, safety, long service life and compatibility with alternative energy. Energy efficient condensing heating units operate particularly well at low temperatures.
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