Specifications

12
Natatorium DesigN maNual
At the moment NP series units are offered starting at
18 HP but all Seresco units can be provided with the
dry cooler heat rejection option.
Seresco’s innovative heat rejection design makes the
Protocol Series equally efficient as DX systems on
summer design days and five to seven-percent more
efficient throughout the rest of the year. The innovative
design uses an active refrigeration head pressure
monitor/control that ensures the lowest possible
condensing pressures to boost system performance.
The Protocol NP Series delivers better overall
performance and eliminates all issues associated with
large refrigerant charges.
Other benefits of the Protocol Series are:
• Fully modulating, total variable reheat provides
the ultimate indoor air comfort by providing
unprecedented stability in pool space temperature
and relative humidity levels.
• Factory-charged and sealed refrigeration system
means no on-site field charge refrigeration work or
EPA-certified installation technicians are required.
• Small factory sealed refrigerant charges totally
eliminate all issues of refrigerant and oil migration
associated with all traditional DX systems.
• Significant reduction of system refrigerant charges
protect building owners from costly service bills in the
event of a refrigerant leak.
• Package or split system and indoor or outdoor
configurations are available with no distance limits
between the unit and the AC heat exchanger.
• Glycol is 95-percent less expensive than refrigerants,
thus any recharging service costs are significantly
reduced in materials and labor.
• No copper piping between the unit and remote
condenser eliminates temptation of material theft.
Chilled Water with Reheat Air
Handler: Seresco’s NW-Series
These units are generally only found on applications
that have abundant chilled water year round The
dehumidification process of these systems is essentially the
same as with compressorized systems. The chilled water
coil is used in the same manner as the evaporator coil.
The chilled water supply temperature must be low enough
to cool the air below its dew point at the chilled water coil
and condense moisture out of the air. Reheat is required
for most of the year. Systems that cannot use captured
condenser heat for reheating air require the operation of a
heating coil while the chilled water coil is in use. If reclaimed
heat is not available for reheat, this approach may not
comply with local energy codes. This approach is not
recommended if chilled water is not available year round.
Note: Seresco’s NW series offer all the same
performance, configurations and options of the
compressorized NE and NP series units but uses chilled
water coils for dehumidification and cooling.
Outdoor Air Ventilation Systems:
Seresco’s NV Series
While technically a ventilation unit, because only outdoor
ventilation air is used, this approach to dehumidification
is considered in areas with suitable climates that are dry
and/or cool outdoors year round. These systems can
be a very basic, from a single pass of outdoor air that
is introduced at one end of the space and exhausted
at the other to a more sophisticated system that has
variable outdoor air and heat recovery. The single pass
system is rare due to the prohibitive operating costs.
A more typical approach is that of the Seresco NV series
style ventilation unit. These units modulate outdoor
ventilation air as needed for humidity control. Modulation
of the outdoor air is essential to help keep the space
conditions comfortable and minimize the operating costs.
The units are rarely configured withoutheat recovery. The
units are generally in 100% outdoor air modes for milder
weather. It is important to note that the space conditions
may not be maintained in summer as the outdoor air
may not be cool or dry enough. It is important to model
warm weather operation to understand what the space
conditions might be at those times.
The outdoor ventilation style units have several attractive
features if your facility is located in a suitable geographic
area. They have a lower first cost than a refrigerant
based approach and are also considerably simpler units
operationally. With heat recovery between the exhaust
air and outdoor air streams and controls that properly
sequence the outdoor air, this can be a very attractive
means to ventilate a natatorium.
While Seresco can incorporate any style of heat
recovery in our units, we have decided to standardize on
the glycol-run around loop. The glycol run around loop is
very compact and available in several capacity ranges.
Seresco’s 6 row deep coil set dramatically outperforms
other competitor models. As a result Seresco’s NV
series units are compact, lightweight and deliver
outstanding perormance compared to systems using
other forms of heat recovery.
There is a misconception that because these systems
provide more outdoor air than a refrigeration based unit
that the spaces as a result will have better air quality.
This is not correct. The airside design requirements are
the same for a natatorium regardless of which solution is
chosen. Supply air CFM, minimum outdoor air CFM and