Bryant 581A/B manual 143

GUIDE SPECIFICATIONS — 580F036-151 AND 581B036-150 (cont)

23.Return Air Enthalpy Sensor (EconoMi$er IV or EconoMi$er2):

The return air enthalpy sensor shall be used with the EconoMi$er IV or EconoMi$er2 device. When used in conjunction with an outdoor air enthalpy sensor, the EconoMi$er IV or EconoMi$er2 device will pro- vide differential enthalpy control.

24.Return Air Temperature Sensor (EconoMi$er IV or EconoMi$er2):

The return air temperature sensor shall be used with the EconoMi$er IV or EconoMi$er2 device. When used in conjunction with the standard outdoor air tem- perature sensor, the EconoMi$er IV or EconoMi$er2 device will provide differential temperature control.

25.Indoor Air Quality (CO2) Sensor (EconoMi$er2):

a.Shall have the ability to provide demand ventila- tion indoor air quality (IAQ) control through the EconoMi$er2 with an IAQ sensor.

b.The IAQ sensor shall be available in duct mount, wall mount, and wall mount with LED display. The set point shall have adjustment capability.

c.Requires EconoMi$er2 control option.

26.Indoor Air Quality (CO2) Room Sensor (EconoMi$er IV):

Sensor shall have the ability to provide demand ven- tilation control through the EconoMi$er IV. The IAQ sensor shall be wall mounted with an LED display in parts per million. The set point shall have adjustment capability.

27. Return Air CO2 Sensor (EconoMi$er IV):

Sensor shall have the ability to provide demand ven- tilation control through the EconoMi$er IV. The IAQ sensor shall be duct mounted. The set point shall have adjustment capability.

28.Gas Heat options (sizes 004-006):

a.Single-stage gas heat shall be provided in lieu of two-stage heat.

b.NOx reduction shall be provided to reduce nitrous oxide emissions to meet the California Air Quality Management NOx requirement of 40 nanograms/ joule or less.

c.Primary tubes on low NOx units shall be 409 stainless steel. Other components shall be alumi- nized steel.

29.Ultraviolet Germicidal Lamps:

Ultraviolet germicidal lamps are designed to elimi- nate odor causing mold and fungus that may develop in the wet area of the evaporator section of the unit. The high output, low temperature germicidal lamps are field installed in the evaporator section of the unit, aimed at the evaporator coil and condensate pan. The short wavelength ultraviolet light inhibits and kills mold, fungus and microbial growth. The lamps have an output rating at 45F in 400 fpm airflow of 120 microwatts/cm2 at 1 meter.

30.Perfect Humidity™ Adaptive Dehumidification Sys- tem (581B only):

a.The Perfect Humidity dehumidification system shall be factory-installed in the rooftop units, and shall provide greater dehumidification of the occu- pied space by two modes of dehumidification operations beside its normal design cooling mode:

1)Subcooling mode further subcools the hot liq- uid refrigerant leaving the condenser coil when

both temperature and humidity in the space are not satisfied.

2)Hot gas reheat mode shall mix a portion of the hot gas from the discharge of the compressor with the hot liquid refrigerant leaving the con- denser coil to create a two-phase heat transfer in the system, resulting in a neutral leaving-air temperature when only humidity in the space is not satisfied.

b.The system shall consist of a subcooling/reheat dehumidification coil located downstream of the standard evaporator coil. This dehumidification coil is a two-row coil with the exception of the 036 unit, which has a one-row coil.

c.The system shall include crankcase heater(s) for the scroll compressor(s).

d.The system shall include a low outdoor air tem- perature switch to lock out both subcooling and hot gas reheat mode when the outdoor-air tem- perature is below 40 F.

e.The system shall include a Motormaster® low ambient control to ensure the normal design cool- ing mode capable of down to 0° F low ambient operation.

f.The system shall include a low-pressure switch on the suction line to ensure low pressure start- up of hot gas reheat mode at lower outdoor tem- perature condition.

g.The system operation may be controlled by a field-installed, wall-mounted humidistat. The dehumidification circuit will then operate only when needed. Field connections for the humidis- tat are made in the low-voltage compartment of the unit control box. The sensor can be set for any level between 55% and 80% relative humidity.

h.The system shall include a thermostatic expan- sion valve (TXV) to ensure a positive superheat condition and a balance of pressure drop.

i.For units with two compressors (sizes 090-150), depending on the conditions required to maintain the space set points, one or both compressors can operate in subcooling mode, one compressor could operate in subcooling mode while the other operates in hot gas reheat mode, or one or both compressors can operate in hot gas reheat mode.

31.Humidistat:

Field-installed, wall-mounted humidistat is used to control activation of the dehumidification package. The humidistat can be set for humidity levels between 20% and 80% relative humidity.

32. Hinged Panel Option:

Hinged panel option provides hinged access panels for the filter, compressor, evaporator fan, and control box areas. Filter hinged panels permit tool-less entry for changing filters. Each hinged panel is perma- nently attached to the rooftop unit.

33. Louvered Hail Guard:

The hail guard shall protect the entire outdoor coil surface from direct or indirect (from adjacent sur- faces) hail damage. Hail guard shall have a pressure drop of 2%.

580F036-151 AND 581B036-150

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