Electric and hydronic radiant heating panels are appropriate for all buildings. They
are commercially available in the configurations required to provide heating for all
building types. The characteristic features of radiant heating panels are common to
both hydronic and electric radiant heating systems. Key radiant panel features
include lack of dust, noise, odor, maintenance, and impact on relative humidity.
Electric radiant systems exhibit the control flexibility characteristic of electricity,
including very fast-acting systems.Temperature setback and thermal storage is also
possible over a broad range of comfort requirements. Electric utility rate structures
often are an important factor in economic analysis for electric radiant panel systems.
The local Public Utility Commission has historically overseen electric rates, which
differed by use and customer classification. In some areas, the rates in a given class
were flat all year long. In other areas, the rates per kilowatthour were fixed, but different
during different seasons and varied by time slots over a 24-h period.
With deregulation and the associated industry dynamics, real-time pricing is likely
to become more common. In fact, in areas where electricity charges in relation to
system-wide demand—real-time pricing—are in place, users have the option (indeed,
incentive) to schedule electric consumption when rates are most attractive.With realtime
pricing the rates may change frequently and fluctuate widely. Real-time pricing
eliminates the rate stability and predictability that are characteristic of time-of-day or
peak and off-peak time periods during which flat rates are either high or low.
Identification of the daily time periods with low and stable rates is an important
factor in determining the thermal storage potential of a radiant system. Building
mass retention of radiant heat or cool enables a level of thermal sailing that could be
important under a condition of power interruption necessary to gain the full benefit
of time-of-day rates or real-time pricing.
Electric radiant heating panels generally consist either of discrete manufactured
panels, modules, or fixtures ready for electrical connection on-site, or of terminated- component heating elements consisting of cable, wire, or assembled mats. In some
cases, terminations are field constructed. Electric radiant panels and component
products are described in some detail in Chap. 2 of this section because these components
are integral to the radiant panel. Hydronic mechanical systems, such as boilers,
geothermal heat pumps, and combination heaters are not part of the radiant
hydronic panel, but are discussed in Chap. 3 of this section in terms of characteristics
that could influence radiant panel performance and control.
Hydronic systems involve a broad selection of radiant panel configurations.Traditional
high-mass systems are most common.The growing interest in radiant hydronic
heating has spurred the development of many new radiant panel approaches. Innovations
include small-diameter capillary-style mats, interconnected routed aluminumcovered
plywood flooring, routed plywood flooring, and under-floor-suspended or
heat conduction plate–routed hydronic tubing. The proponents of each of the many
system and design options provide information about important features of their system.
The literature identifies features and benefits that manufacturers believe give
their system a performance, installation, or cost advantage.
Warm-air radiant heating involves the routing of heat transfer ducting through the
concrete floor or slab. Figure 1.1 shows a common approach using air for floor heating
and cooling.The heated or cooled air may be in a closed system, or all or part of
the air may pass through the space being conditioned to provide supplemental heating
or ventilation on its way back to the furnace. Systems like this have been developed
for many different types of building using either the floor or the ceiling, or both.
Panel design methodology is governed by the same opportunities for output
maximization as other radiant systems. However, the air dynamics of such a system
where the air usually flows into the room and out through a return in a manner
similar to a forced-air system are beyond the scope of this Handbook. Application
of this approach to duct routing provides floor warming in buildings with concrete
floors that might be uncomfortable with ceiling delivery of warm air convection
heat.
Radiant heating has long been especially valued for its successful use in very specific
situations in conjunction with conventional heating. For the most part, unless
part of a carefully engineered project, the installation of radiant heating or cooling
has usually occurred as a retrofit to solve a comfort, operational, or energy cost
problem. In fact, hybrid or combination radiant heating or cooling offers not only
comfort, but also economic operating benefits.The use of radiant systems in combination
with other systems is covered in detail in Sec. 7 of this Handbook.
Electric and hydronic radiant heating panels are appropriate for all buildings. They
are commercially available in the configurations required to provide heating for all
building types. The characteristic features of radiant heating panels are common to
both hydronic and electric radiant heating systems. Key radiant panel features
include lack of dust, noise, odor, maintenance, and impact on relative humidity.
Electric radiant systems exhibit the control flexibility characteristic of electricity,
including very fast-acting systems.Temperature setback and thermal storage is also
possible over a broad range of comfort requirements. Electric utility rate structures
often are an important factor in economic analysis for electric radiant panel systems.
The local Public Utility Commission has historically overseen electric rates, which
differed by use and customer classification. In some areas, the rates in a given class
were flat all year long. In other areas, the rates per kilowatthour were fixed, but different
during different seasons and varied by time slots over a 24-h period.
With deregulation and the associated industry dynamics, real-time pricing is likely
to become more...
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© 2009 McGraw-Hill Companies, Inc. (The)
