Bryant 581A/B - Manual (Page 4)

4
FEATURES/BENEFITS (cont)
INDOOR-AIR QUALITY (IAQ) BEGINS WITH BRYANT ROOF-
TOPS — Sloped condensate pans minimize biological growth in
rooftop units in accordance with ASHRAE (American Society of
Heating, Refrigeration and Air Conditioning Engineers)
Standard 62. Two-inch filters with optional dirty filter indicator
switch provide for greater particle reduction in the return air.
The face-split evaporator coils improve the dehumidification
capability of standard units, maximize building humidity control.
Optional proportional reacting CO
2
sensor is available with the
EconoMi$er IV outdoor air damper option/accessory to aid the
IAQ benefits.
PERFECT HUMIDITY™ ADAPTIVE DEHUMIDIFICATION
SYSTEM (581B036-150 only) — Bryant’s Perfect Humidity
adaptive dehumidification system is an all-inclusive factory-
installed option that can be ordered with any 581B rooftop unit
to meet the demand for providing a flexible and high performing
solution to accommodate all of these design related issues.
This system expands the envelope of operation of 581B rooftop
products to provide unprecedented flexibility to meet year-round
comfort conditions. The Perfect Humidity adaptive dehumidifica-
tion system has the industry’s only dual dehumidification mode
setting. The Perfect Humidity system includes two new modes
of operation. The 581B rooftop coupled with the Perfect Humid-
ity system is capable of operating in normal design cooling
mode, subcooling mode, and hot gas reheat mode. Normal
Design Cooling mode is when the unit will operate under its nor-
mal sequence of operation by cycling compressors to maintain
comfort conditions. Subcooling mode will operate to satisfy part
load type conditions when the space requires combined sensi-
ble and a higher proportion of latent load control. Hot Gas
Reheat mode will operate when outdoor temperatures diminish
and the need for latent capacity is required for sole humidity
control. Hot Gas Reheat mode will provide neutral air for maxi-
mum dehumidification operation.
EXCLUSIVE HOT GAS REHEAT DEHUMIDIFICATION PACK-
AGE (581A181-300) — The hot gas reheat dehumidification
package is a result of recent advances by Bryant in controlling
comfort levels. This factory-installed option significantly
improves the dehumidification capability of the rooftop unit and
helps control humidity levels in the building.
This option provides increased dehumidification by cooling the
hot liquid refrigerant leaving the condenser coil. The hot gas
reheat package consists of a subcooling coil located on the
leaving-air side of the evaporator coil. The location of this coil in
the indoor airstream enhances the latent capacity of the units
by as much as 40%. Many buildings suffer from humidity dam-
age or poor indoor air quality due to humid conditions. The
improved latent capacity provided by the hot gas reheat option
reduces the building’s humidity, eliminating potential property
damage and making the space more comfortable.
The hot gas reheat option is the ideal IAQ option for hot and
humid regions. The operation of the hot gas reheat package
can be controlled by a field-installed, wall mounted humidistat
or Thermidistat™ device. The circuit activates only when
needed (using the accessory humidistat) as opposed to some
dehumidification systems that operate continuously. The humi-
distat can be set for any humidity level between 20% and 80%
relative humidity. The Thermidistat device can be set for any
humidity level between 50% and 90% relative humidity.