Green building is resource efficient,
contributes to a healthy environment, and provides a healthy home for
occupants. According to the EPA, most Americans spend up to 90% of
their time indoors. Home design includes many amenities people feel
they need to make them happy and comfortable in their home. A home
should also ensure that sources of indoor pollutants are limited, and
those that exist will be diluted or removed from the space.
Because of the amount of time people spend
inside, indoor air quality is important. Indoor air problems are
usually caused by gases or particles. Many building materials and
building designs contribute to indoor air problems. Outside sources
can also become indoor pollutants if carried in on shoes or located
next to fresh air returns for the house. Ventilation provides fresh
air to dilute concentrations of pollutants and to carry them outside.
Inadequate ventilation can add problems by allowing moisture and
temperature levels to rise.
|
Air conditioning unit in a computer room
Note the
water stain and collected debris
on interior
of access door.
 |
Here, the plenum space
shown with mold growth. |
Why use Radiant
Cooling?
Most Air Conditioning systems use the
principle of forced air (HVAC). In forced air systems warm room air is
recirculated, chilled, and blown back into space.
With the increase use of PCs and other
technology, higher and higher heat loads need to be removed from those environments. To
remove this additional heat, a higher volume of cooled air is blown
into the working environment to maintain a comfort, making draft-free
cooling with chilled, primarily air increasingly more difficult. An
additional problem that came to light in the 1970's through 1980's is
known as "sick building syndrome"
A new Air
Conditioning Concept!
Hydronic Radiant Cooling
Technology enables air conditioning to occur in a completely different
way that solves both problems. Radiant Cooling ceiling panels
(drywall, plaster or metal finish) contains
chilled water at 62ْ F of cool temperature running through the
capillary tubes that are bonded to the non-visible reverse side of the
panels.
The ceiling panel functions as
heat exchangers between the room air and chilled water.
The ceiling absorbs heat from
heat sources in a room and exchanges it with the circulating chilled
water. The chilled water is then pumped to a chiller, recooled, and
return to the ceiling.
Radiant Cooling
and
DOAS
(Dedicated Outdoor
Air System)
Since air quality
must be maintained and Karo Capillary Tube System removes only
the sensible heat from the space, Karo Capillary Tube System
are used in
conjunction with a reduced ventilation system requirement.
The ventilation
system not only ensures the air quality to recommended levels but also
it regulates the latent or moisture load of the space.
To prevent high
humidity levels within a room, the supply air, must be drier than that
of the supplied space, especially in light of additional sources of
moisture in the room. Consequently, outdoor air must be
dehumidified which is usually done by cooling to a dew point
approximately 59ْ F (15 Cْ ) .
If the environment is dry, the ventilation system is used to humidify
the air. Since the ventilation system used to maintain the Indoor Air
Quality and to regulate the latent load of the space, the air flow
required is small
(NO NOISE-NO DRAFT) relative to conventional
cooling systems.
The best results
are usually attained attained with a
DOAS (Dedicated Outdoor Air
System)
with no recirculation of air.
The DOAS typically
supplies the air through outlets near or at the floor temperatures
below that of the room air which provides for a uniform layer of
outside air to the ceilings where it can be exhausted.
With this
reduction in air flow and the fact that Karo Capillary Tube System
operates at a relatively high surface temperature (mean of 61ْ
F or 16ْ C), radiant cooling is a more
comfortable way of cooling a space than a conventional systems.
Therefore in a radiant cooling ceiling application, the
Karo Capillary Tube System
provides most of the sensible load while the DOAS (Dedicated
Outdoor Air System) provides ventilation and air moisture control
with no recirculation of air.
Reasons to Change
Some people, especially children, elderly, and those with allergies
are particularly sensitive to indoor pollutants. Adverse health
effects may include respiratory, neurological, and skin conditions,
impairment of brain function (mental retardation in children), lung
disease and cancer. To reduce these effects, apply a "systems
approach" where the interaction of all elements of the building site,
building envelope, mechanical systems, and occupants are considered.
Save Energy!
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