I. Introduction to Controlling
Humidity in Natatoriums
Twenty
years ago, humidity control for an indoor swimming
pool was to
bring in outside air while exhausting the warm humid
air outside with large exhaust fans. This process can
only work effectively when the outside air temperature
is cool and dry enough to allow for humidity control.
This type of system is the most expensive (in operating
costs) and an ineffective way of controlling humidity
in a pool enclosure, and cannot maintain the 50-60%
RH humidity levels required. When compared to conventional
ventilation or “waste ventilation” systems,
recycling and dehumidifying pool enclosure air with
a mechanical dehumidifier can save 50-75% on energy
costs, maintain the 50-60% RH required by ASHRAE, and
provide 100% room heating, air conditioning and pool
heating.
Humidity
control in an indoor pool enclosure is a complex endeavor
involving
many parties and disciplines. EPS, Inc. has taken a
very unique approach to high humidity envelopes. As
a design/engineering and consulting firm first and
foremost, our primary focus is on the initial design
of the structure (for new construction). Preventing
problems at the design stage is much lower than the
costs of correcting problems which occur “downstream”.
In order to ensure
the pool enclosure is protected from the damage caused
by excessive humidity and condensation, the building
envelope must be designed and must perform to a much
higher degree than structures intended for other uses.
To ensure a successful application of DRY-AIR Dehumidifiers
to your project, it is crucial that all of the parties
involved, from architects to builder to mechanical
contracting firms be aware of the importance of the
preventive measures that are taken in the planning
stages BEFORE applying dehumidification systems to
the equation.
II. Prevention of Condensation
Prevention of condensation
is perhaps the most important purpose of all for dehumidifying
an indoor pool enclosure. If condensation forms in
or on wood, plaster, or other porous materials, it
can cause warping, rot, mold, mildew, rust or simply
saturate the material until it loses its integrity.
Condensation, by
nature, is aggressive and will attack many materials
by leaching the minerals out of the surface it forms
on. Condensation, if allowed to form on ferrous materials,
will cause accelerated oxidation of the surface of
the metal. If left unchecked, condensation will ultimate
compromise the structural integrity of all metal components
and eventually lead to the failure of those components.
Building
considerations such as fenestration, moisture migration,
doors/windows/skylights and other openings, exposed structural
surfaces, insulation, ventilation, vapor barriers, ductwork,
and mechanical space requirements are critical aspects
in the design and engineering of each residential/commercial
project that must be addressed in the design and planning
stages of the project
III. Dew Point Temperature
As
you cool air, it cannot hold the same amount of moisture.
At some
point, that air will become saturated and moisture
will begin to condense out of the air onto any adjacent
surface. When it condenses, at that point it is called “Dew
Point Temperature”. For example, take a cold can
of pop outside and sit it down on a 90 Degree Day. What
happens? It begins to sweat, or in our terms it has reached
its “Dew Point Temperature”. The Design Objective
for pool enclosures is to ensure that no surface within
the pool enclosure or within the structural members reaches “Dew
Point” and causes moisture to condense.
IV. Designing a Clean, Healthy, Stable Environment – IT
ALL STARTS WITH GOOD DESIGN
The design
objective for designing mechanical air handling systems
for pool is to ensure that no surface within the
pool enclosure or within the structural members of the
building will reach “Dew Point” and cause moisture
to condense. The DRY-AIR Dehumidifier helps to accomplish
this objective by reducing the relative humidity in the
pool enclosure and therefore, effectively reducing the
Dew Point Temperature. Air distribution also plays a key
role in preventing surfaces from reaching DEW POINT TEMPERATURE.
There are surfaces, in particular glass surfaces such as
windows, door walls and skylights that will reach Dew Point
Temperature even with reduced humidity levels affected
by the dehumidifier. For these surfaces, the objective
is to completely blanket the area with warm dry air supplied
by the dehumidifier, thereby increasing the surface temperature
to a point above the temperature at which moisture will
condense.
EPS,
Inc. forms a “partnership” with each
client. As we interface with architects, engineers,
building and mechanical firms, we provide the
necessary services to include Design Guidelines,
project engineering for the air delivery system,
and technical competency in high humidity envelopes
that focuses on and addresses all of these issues.
Each
DRY-AIR Dehumidification system is sized and
built to exceed all ASHRAE requirements and ensures
maximizing energy and cost savings. You have
a complete resource for assistance in the building
planning and design stages, engineering of the
system for your application, and a Risk Free
-- 100% Money Back Guaranty/Warranty on all DRY-AIR
products.
V.
Designing& Engineering The Dehumidification
System For The Pool Room
To properly design a system, the following information
is utilized to engineer your system:
Commercial, Residential, School, Medical Facility
Size of room in square feet
Size of pool(s) in square feet
Size of Spa in square feet
Design Conditions: Air Temperature to be maintained
Pool Temperature to be maintained
Spa Temperature to be maintained
Type of Construction: 2x4, 2x6, concrete block, steel
framed, manufactured enclosure, etc.
The amount of glass (windows, skylights, doorwalls)
within the structure
Sensible Calculations (heat loss/heat gain)
Will a pool cover be used?
If this is an existing facility or retrofit please complete
the
Pool
Room environments should be designed and maintained
as a separate environment from the rest of
the commercial or residential structure. Because pool
rooms operate at a much high integrity level than non-pool
related environments, certain precautions should be
taken at the planning and designing stages. Humidity
and chlorine can cause serious problems for areas (i.e.
commercial -- work-out/fitness areas with equipment,
residential – living areas) that are not related
to pool room and are not protected by dehumidification,
vapor barriers, etc.
Indoor
pools are treated much the same way you would treat
your home.
Pool rooms require year round conditioning to prevent
condensation, mold, mildew, rot, warping and an overall
deterioration of the structure. With new construction,
the type of building materials used, the amount and
type of glass, insulation, heat gain/heat loss, windows,
pool covers, will be taken into consideration when
designing the system. The air delivery system will
also play a critical role in the overall protection,
operation and energy costs associated with indoor pools.
The complete environmental control package is a SEPARATE
system from office or home systems.
EPS is the home of DRY-AIR & VERI-DRY. We provide Design, Engineering, Consulting and Manufacturing for Residential and Commercial Indoor Swimming Pool Applications.
