>With radiant floor, you can very effectively control the energy load by
>installing closer piping loops near the cool location of your building (
>windows, doors,...)
>
>There are only 3 fundamental types of heat transfer: Convection, Conduction,
>Radiation. While no heating system is 100% of a type, radiant floor heating
>is MAINLY radiant, convection & conduction are minimal.
>
>Michel de Spot. P.Eng. mdespot@xxxxxxxxxx
Loop as much as you want, the basic principle remains that the maximum
temperature of the slab, assuming that people might intend standing on it,
would be around 80-85 degrees F. And at this maximum temperature if there
is considereable heat loss through windows, it can be difficult to achieve
the proper input of heat to balance the heat loss without overheating the
space. One of the problems of old cast iron radiation was that with
gravity flow, the radiator were placed on interior walls and while the
thermal balance between heat loss and the heat added was achieved, comfort
conditions were not. If I hold onto the hot and neutral wire of an
electrical systems, a balance alos is achieved, but not comfort.
As for the transfer of heat into the space, while radiation is the major
intended means of thermal transfer, the fact remains that heat flows from a
higher intensity to a lower intensity, and with the floor surface 10 to 15
degrees warmer than the air temperature, there will be considerable thermal
transfer into the air. Perhaps this is most apparent when we realize that
a DBT thermostat typically remains the means by which we control the
radiant panel system.
Don't get me wrong. As an architect I am convinced that we should be
predominantly concerned with radiant transfer since this is a means of
thermal control with which we are responsible. Of course, it has also been
shown that under unstressed conditions, 60% of the body's heat loss is
through radiant transfer (see C. Mills). But my interest lead more to the
control of enclosing architectural assemblies - that is walls, roofs, and
floors and their proper design so that the interior conditions are
appropriate for human habitation. My tendency to reject active radiant
heating panels might also be somewhat influenced by what I interpret to be
the driving force behind this - avoidance of any imposition of the
mechanical systems on the architectural expression.
Mills suggested that through the use of reflective surfaces, a lower
interior temperature could be maintained. Now that is an inovative use of
radiant energy - using the human body as the means to control the human
body.
Obviously, there's no bias here.
David Lee Smith, Professor of Architecture
School of Architecture and Interior Design
University of Cincinnati
Cincinnati, Ohio 45221-0016
(513) 556 5291
DAVID.SMITH@xxxxxx
>installing closer piping loops near the cool location of your building (
>windows, doors,...)
>
>There are only 3 fundamental types of heat transfer: Convection, Conduction,
>Radiation. While no heating system is 100% of a type, radiant floor heating
>is MAINLY radiant, convection & conduction are minimal.
>
>Michel de Spot. P.Eng. mdespot@xxxxxxxxxx
Loop as much as you want, the basic principle remains that the maximum
temperature of the slab, assuming that people might intend standing on it,
would be around 80-85 degrees F. And at this maximum temperature if there
is considereable heat loss through windows, it can be difficult to achieve
the proper input of heat to balance the heat loss without overheating the
space. One of the problems of old cast iron radiation was that with
gravity flow, the radiator were placed on interior walls and while the
thermal balance between heat loss and the heat added was achieved, comfort
conditions were not. If I hold onto the hot and neutral wire of an
electrical systems, a balance alos is achieved, but not comfort.
As for the transfer of heat into the space, while radiation is the major
intended means of thermal transfer, the fact remains that heat flows from a
higher intensity to a lower intensity, and with the floor surface 10 to 15
degrees warmer than the air temperature, there will be considerable thermal
transfer into the air. Perhaps this is most apparent when we realize that
a DBT thermostat typically remains the means by which we control the
radiant panel system.
Don't get me wrong. As an architect I am convinced that we should be
predominantly concerned with radiant transfer since this is a means of
thermal control with which we are responsible. Of course, it has also been
shown that under unstressed conditions, 60% of the body's heat loss is
through radiant transfer (see C. Mills). But my interest lead more to the
control of enclosing architectural assemblies - that is walls, roofs, and
floors and their proper design so that the interior conditions are
appropriate for human habitation. My tendency to reject active radiant
heating panels might also be somewhat influenced by what I interpret to be
the driving force behind this - avoidance of any imposition of the
mechanical systems on the architectural expression.
Mills suggested that through the use of reflective surfaces, a lower
interior temperature could be maintained. Now that is an inovative use of
radiant energy - using the human body as the means to control the human
body.
Obviously, there's no bias here.
David Lee Smith, Professor of Architecture
School of Architecture and Interior Design
University of Cincinnati
Cincinnati, Ohio 45221-0016
(513) 556 5291
DAVID.SMITH@xxxxxx