HVAC Guide Specifications
Packaged Rooftop Air-To-Air Heat Pump —Constant Volume Application
SIZERANGE:
2 TO 10 TONS, NOMINAL (COOLING)
34,800 TO 114,000 BTUH, NOMINAL(HEATING)
4 TO 50 kW NOMINAL (ELECTRICHEATING)
BRYANT MODEL NUMBER:
549B
549C
PART 1 — GENERAL
1.01 SYSTEM DESCRIPTION
Outdoor rooftop mounted, electrically controlled air-to-airheat pump unit utilizing a scroll compressor for coolingduty and electric resistance coils for heating duty. Unitshall discharge supply air vertically or horizontally asshown on contract drawings.
1.02 QUALITY ASSURANCE
A. Unit shall be rated in accordance with ARI Standards 210/240 or 360 and 270. Designed in accordance with ULStandard 1995. Units shall be Energy Star qualified.
B. Unit shall be designed to conform to ASHRAE 15, latestrevision.
C. Unit shall be UL-tested and certified in accordance withANSI Z21.47 Standards and UL-listed and certified underCanadian standards as a total package for safetyrequirements.
D. Roof curb shall be designed to conform to NRCAStandards.
E. Insulation and adhesive shall meet NFPA 90A requirementsfor flame spread and smoke generation.
F. Unit casing shall be capable of withstanding 500-hour saltspray exposure per ASTM B117 (scribed specimen).
G. Unit shall be designed in accordance withISO 9001:2000, and shall be manufactured in a facilityregistered to ISO 9001:2000.
H. Each unit shall be subjected to a completely automatedrun testing on the assembly line. A factory-supplied printoutindicating tested pressures, amperages, data, andinspectors; providing certification of the unit status at thetime of manufacture shall be provided upon request.
1.03 DELIVERY, STORAGE, AND HANDLING
Unit shall be stored and handled per manufacturer’srecommendations.
PART 2 — PRODUCTS
2.01 EQUIPMENT (STANDARD)
A. General:
Factory assembled, single-piece heat pump unit.Contained within the unit enclosure shall be all factorywiring, piping, controls, refrigerant charge (R-22), andspecial features required prior to field start-up.
B. Unit Cabinet:
1. Unit cabinet shall be constructed of galvanized steel,and shall be bonderized and coated with a prepaintedbaked enamel finish on all externallyexposed surfaces.
2. Evaporator fan compartment interior cabinet surfacesshall be insulated with a minimum 1/2-in. thick,1 lb density, flexible fiberglass insulation, neoprenecoated on the air side. Aluminum foil-facedfiberglass insulation shall be used in the gas heatcompartment.
3. Cabinet panels shall be easily removable forservicing.
4. Holes shall be provided in the base rails for riggingshackles to facilitate maneuvering and overheadrigging.
5. Unit shall have a factory-installed, sloped condensatedrain pan made of a non-corrosive material, providinga minimum 3/4-in.-14 NPT connection withboth vertical and horizontal drains, and shall complywith ASHRAE Standard 62.
6. Unit shall have a factory-installed filter access panelto provide filter access with tool-less removal.
7. Unit shall have standard thru-the-bottom power connectioncapability (accessory kit is required).
C. Fans:
1. Indoor Fan:
a. Fan shall be direct or belt driven as shown on theequipment drawings. Belt drive shall include anadjustable-pitch motor pulley.
b. Fan wheel shall be double-inlet type withforward-curved blades.
c. Bearings shall be sealed, permanently lubricatedball-bearing type for longer life and lowermaintenance.
2. Indoor fan shall be made from steel with a corrosion-resistantfinish and shall be dynamically balanced.
3. Outdoor fan shall be of the direct-driven (with totallyenclosed motors) propeller type and shall dischargeair vertically.
4. Outdoor fan shall have aluminum blades riveted tocorrosion-resistant steel spiders and shall be dynamicallybalanced.
D. Compressor(s):
1. Fully hermetic type, internally protected scroll-type.
2. Factory mounted on rubber grommets and internallyspring mounted for vibration isolation.
3. On dual electrically and mechanically independentcircuits (090-120).
E. Coils:
1. Standard indoor and outdoor coils shall have copperor aluminum plate fins mechanically bonded toseamless internally grooved copper tubes with alljoints brazed.
2.Testing:
a. Indoor and outdoor coils shall be qualified to UL1995 burst test at 2,200 psi.
b. Indoor and outdoor coils shall be leak tested to150 psig and pressure tested to 400 psig.
3. Coils:
a. Copper-fin coils shall be constructed of copperfins mechanically bonded to copper tubes andcopper tube sheets. Galvanized steel tube sheetsshall not be acceptable. A polymer strip shall preventcoil assembly from contacting the sheetmetal coil pan to minimize potential for galvaniccorrosion between coil and pan. All copper constructionshall provide protection in moderatecoastal environments.
b. E-Coated aluminum-fin coils shall have a flexibleepoxy polymer coating uniformly applied to all coilsurface areas without material bridging betweenfins. Coating process shall ensure complete coilencapsulation. Color shall be high gloss blackwith gloss — 60 deg of 65 to 90% per ASTMD523-89. Uniform dry film thickness from 0.8 to1.2 mil on all surface areas including fin edges.Superior hardness characteristics of 2H perASTM D3363-92A and cross-hatch adhesion of4B-5B per ASTM D3359-93. Impact resistanceshall be up to 160 in.-lb (ASTM D2794-93).Humidity and water immersion resistance shall beup to minimum 1000 and 250 hours respectively(ASTM D2247-92 and ASTM D870-92). Corrosiondurability shall be confirmed through testingto be no less than 1000 hours salt spray perASTM B117-90. Coil construction shall be aluminumfins mechanically bonded to copper tubes.
c. E-Coated copper-fin coils shall have a flexibleepoxy polymer coating uniformly applied to all coilsurface areas without material bridging betweenfins. Coating process shall ensure complete coilencapsulation. Color shall be high gloss blackwith gloss — 60 deg of 65 to 90% per ASTMD523-89. Uniform dry film thickness from 0.8 to1.2 mil on all surface areas including fin edges.Superior hardness characteristics of 2H perASTM D3363-92A and cross-hatch adhesion of4B-5B per ASTM D3359-93. Impact resistanceshall be up to 160 in.-lb (ASTM D2794-93).Humidity and water immersion resistance shall beup to minimum 1000 and 250 hours respectively(ASTM D2247-92 and ASTM D870-92). Corrosiondurability shall be confirmed through testingto be no less than 1000 hours salt spray perASTM B117-90. Coil construction shall be copperfins mechanically bonded to copper tubes withcopper tube sheets. Galvanized steel tube sheetsshall not be acceptable. A polymer strip shall preventcoil assembly from contacting sheet metalcoil pan to maintain coating integrity and minimizecorrosion potential between coil and pan.
d. Optional pre-coated aluminum-fin coils shall havea durable epoxy-phenolic coating to provide protectionin mildly corrosive coastal environments.Coating shall be applied to the aluminum fin stockprior to the fin stamping process to create an inertbarrier between the aluminum fin and coppertube. Epoxy-phenolic barrier shall minimum galvanicaction between dissimilar metals.
F. Heating Section:
1. May be equipped with field-installed electric resistanceheater(s) of the characteristics shown in theequipment schedule.
2. Heater elements shall be open wire, adequately supportedand insulated with ceramic bushings.
G. Refrigerant Components:
Refrigerant circuit components shall include:
1. Fixed orifice metering system (fixed orifice device).
2. Refrigerant filter drier.
3. Reversing valve.
4. Service gage connections on suction, discharge, andliquid lines.
H. Filter Section:
1. Standard filter section shall consist of factory-installed,low velocity, throwaway 2-in. thick fiberglassfilters of commercially available sizes.
2. Filter face velocity shall not exceed 320 fpm at nominalairflows.
3. Filter section should use only one size filter.
4. Filters shall be accessible through an access panelwith “no-tool” removal.
I. Controls and Safeties:
1. Unit Controls:
Unit shall be complete with self-contained low-voltagecontrol circuit protected by a fuse on the 24-vtransformer side (090-120 units have a resettablecircuit breaker).
2. Safeties:
a. Unit shall incorporate a solid-state compressorprotector which provides anti-cycle reset capabilityat the space thermostat, should any of the followingstandard safety devices trip and shut offcompressor.
1) Compressor overtemperature, overcurrent.
2) Loss-of-charge/low-pressure switch.
3) Freeze-protection thermostat, evaporator coil.
4) High-pressure switch.
5) Automatic reset motor thermal overloadprotector.
The lockout protection shall be easily disconnectedat the control board, if necessary.
b. Heating section shall be provided with the followingminimum protections:
1) High-temperature limit switches.
2) Overcurrent protection.
c. Unit shall incorporate an outdoor coil defrost systemto prevent excessive frost accumulation duringheating duty, and shall be controlled asfollows:
1) Defrost shall be initiated on the basis of timeand coil temperature.
2) A 30/50/90-minute timer shall activate defrostcycle only if the coil temperature is low enoughto indicate a heavy frost condition.
3) Defrost cycle shall terminate when defrostthermostats are satisfied and shall have a positivetermination time of 10 minutes.
J. Operating Characteristics:
1. Unit shall be capable of starting and running at 125 Fambient outdoor temperature, meeting maximumload criteria of ARI Standard 210/240 or 360 at+ 10% voltage.
2. Compressor with standard controls shall be capableof operation down to 25 F (in cooling mode) ambientoutdoor temperature.
3. Compressor with standard controls shall be capableof operation down to –20 F (in heating mode) ambientoutdoor temperature.
4. Unit shall be capable of simultaneous heating dutyand defrost cycle operation when using accessoryelectric heaters.
K. Electrical Requirements:
All unit power wiring shall enter unit cabinet at a singlefactory-predrilled location.
L. Motors:
1. Compressor motors shall be cooled by refrigerantgas passing through motor windings and shall haveline break thermal and current overload protection.
2. Indoor-fan motor shall have permanently lubricatedbearings and inherent automatic-reset thermal overloadprotection.
3. Totally enclosed outdoor-fan motor shall have permanentlylubricated bearings, and inherent automaticresetthermal overload protection.
M. Special Features:
Certain features are not applicable when the featuresdesignated * are specified. For assistance in amendingthe specifications, contact your local Bryant Sales Office.
1. Roof Curbs (Horizontal and Vertical):
a. Formed galvanized steel with wood nailer stripand shall be capable of supporting entire unitweight.
b. Permits installation and securing of ductwork tocurb prior to mounting unit on the curb.
* 2. Integrated Economizers:
a. Integrated integral modulating type capable ofsimultaneous economizer and compressor operation.During economizer operation, up to twocompressors on sizes 090-120 will operate.
b. Available as a factory-installed option in verticalsupply/return configuration only. (Available as afield-installed accessory for dedicated horizontaland/or vertical supply return configurations.)
c. Includes all hardware and controls to providecooling with outdoor air.
d. Equipped with low-leakage dampers, not toexceed 2% leakage at 1 in. wg pressuredifferential.
e. Capable of introducing up to 100% outdoor air.
f. EconoMi$erIV and EconoMi$er2 shall beequipped with a barometric relief damper capableof relieving up to 100% return air.
g. Designed to close damper(s) during loss-of-powersituations with spring return built intomotor.
h. Dry bulb outdoor-air temperature sensor shall beprovided as standard. Outdoor air sensor setpoint is adjustable and shall range from 40 to100 F. For the EconoMi$erIV, the return air sensor,indoor enthalpy sensor, and outdoor enthalpysensor shall be provided as field-installed accessoriesto provide enthalpy control, differentialenthalpy control, and differential dry bulb temperaturecontrol. For the EconoMi$er2, the enthalpy,differential temperature (adjustable), and differentialenthalpy control shall be provided as field-installedaccessories.
i. The EconoMi$erIV and EconoMi$er2 shall have agear-driven parallel blade design.
j. EconoMi$erIV microprocessor control shall providecontrol of internal building pressure throughits accessory power exhaust function. Factory setat 100%, with a range of 0% to 100%.
k. EconoMi$er2 shall be capable of control from a4 to 20 mA signal through optional 4 to 20 mAdesign without microprocessor control (requiredfor third party control interface).
l. EconoMi$erIV Microprocessor Occupied MinimumDamper Position Setting maintains the minimumairflow into the building during occupiedperiod providing design ventilation rate for fulloccupancy (damper position during heating). Aremote potentiometer may be used to overridethe set point.
m. EconoMi$erIV Microprocessor Unoccupied MinimumDamper Position Setting — TheEconoMi$erIV damper shall be completely closedwhen the unit is in the occupied mode.
n. EconoMi$erIV Microprocessor IAQ/DCV MaximumDamper Position Setting — Setting the maximumposition of the damper prevents theintroduction of large amounts of hot or cold airinto the space. This position is intended to satisfythe base minimum ventilation rate.
o. EconoMi$erIV Microprocessor IAQ/DCV controlmodulates the outdoor-air damper to provideventilation based on the optional 2 to 10 vdc CO2sensor input.
p. Compressor lockout sensor (opens at 35 F,closes at 50 F).
q. Actuator shall be direct coupled to economizergear, eliminating linkage arms and rods.
r. Control LEDs:
1) When the outdoor-air damper is capable ofproviding free cooling, the “Free Cool” LEDshall illuminate.
2) The IAQ LED indicates when the module is onthe DCV mode.
3) The EXH LED indicates when the exhaust fancontact is closed.
s. Remote Minimum Position Control — A field-installedaccessory remote potentiometer shallallow the outdoor-air damper to be opened orclosed beyond the minimum position in the occupiedmode for modified ventilation.
3. Manual Outdoor-Air Damper:
Manual damper package shall consist of damper,birdscreen, and rainhood which can be presetto admit up to 50% outdoor air for year roundventilation.
* 4. 100% Two-Position Damper:
a. Two-position damper package shall include singleblade damper and motor. Admits up to 100%outdoor air.
b. Damper shall close upon indoor (evaporator) fanshutoff.
c. Designed to close damper during loss of powersituations.
d. Equipped with 15% barometric relief damper.
* 5. 25% Two-Position Damper:
a. Two-position damper package shall include singleblade damper and motor. Admits up to 25%outdoor air.
b. Damper shall close upon indoor fan shutoff.
* 6. Head Pressure Control Package:
Control package shall consist of solid-state controland condenser-coil temperature sensor to maintaincondensing temperature between 90 F and 110 F atoutdoor ambient temperatures down to –20 F bycondenser-fan speed modulation or condenser-fancycling and wind baffles.
7. Electric Resistance Heaters:
a. Open wire nichrome elements with all necessarysafety operating controls.
b. UL listed and indicated on basic unit informationplate.
c. Available in multiples to match heatingrequirements.
d. Single point kits available for each heater whenrequired.
* 8. Electronic Programmable Thermostat:
Unit shall be capable of using deluxe full-featuredelectronic thermostat. Thermostat shall use built-incompressor cycle delay control for both heating andcooling duty. Thermostat shall be capable of workingwith third party direct digital controls.
* 9. Thermostat and Subbase:
Thermostat shall provide staged cooling and heatingautomatic (or manual) changeover, fan control, andindicator light.
* 10. Outdoor Coil Hail Guard Assembly:
Hail guard shall protect against damage from hailand flying debris.
11. Unit-Mounted, Non-Fused Disconnect Switch:
Switch shall be factory-installed, internally mounted.NEC and UL approved non-fused switch shall provideunit power shutoff. Switch shall be accessiblefrom outside the unit and shall provide power offlockout capability.
12. Convenience Outlet:
Switch shall be factory-installed and internallymounted with easily accessible 115-v female receptacle.Switch shall include 15 amp GFI receptaclewith independent fuse protection. Voltage required tooperate convenience outlet shall be provided by afactory-installed step-down transformer. Switch shallbe accessible from outside the unit.
NOTE: Convenience outlet shall be designed forshort duration electrical maintenance loads, and foruse with long term electrical supply.
13. Outdoor Coil Grille:
The grille protects the outdoor coil from damage bylarge objects without increasing unit clearances.
14. Compressor Cycle Delay:
Unit shall be prevented from restarting for minimumof 5 minutes after shutdown.
15. Thru-the-Bottom Utility Connectors:
Kit shall provide connectors to permit electrical connectionsto be brought to the unit through thebasepan.
16. Fan/Filter Status Switch:
Switch shall provide status of indoor (evaporator) fan(ON/OFF) or filter (CLEAN/DIRTY). Status shall bedisplayed over communication bus when used withdirect digital controls or with an indicator light at thethermostat.
17. Power Exhaust Accessory for EconoMi$erIV orEconoMi$er2:
Power exhaust shall be used in conjunction withEconoMi$erIV or EconoMi$er2 to provide systemexhaust of up to 100% of return air (vertical only).The power exhaust is a field-installed accessory(separate vertical and horizontal design).
NOTE: Horizontal power exhaust is intended tomount in return ductwork.
As the outdoor-air damper opens and closes, bothpropeller fans are energized and de-energizedthrough the EconoMi$erIV controller. The set point isfactory set at 100% of outdoor-air, and is adjustable0 to 100% to meet specific job requirements. Availablein 208/230-1-60 v or 460-3-60 v. An LED lighton the controller indicates when the power exhaustis operating.For the EconoMi$er2, the power exhaust shall becontrolled by the third party controls.
18. Outdoor Air Enthalpy Sensor (EconoMi$erIV orEconoMi$er2):
The outdoor air enthalpy sensor shall be used withthe EconoMi$erIV or EconoMi$er2 device to providesingle enthalpy control. When used in conjunctionwith a return air enthalpy sensor, the controller willprovide differential enthalpy control. The sensorallows the con-troller to determine if outside air issuitable for free cooling.
19. Return Air Enthalpy Sensor (EconoMi$erIV orEconoMi$er2):
The return air enthalpy sensor shall be used with theEconoMi$erIV or EconoMi$er2 device. When usedin conjunction with an outdoor air enthalpy sensor,the EconoMi$erIV or EconoMi$er2 device will providedifferential enthalpy control.
20. Return Air Temperature Sensor (EconoMi$erIV orEconoMi$er2):
The return air temperature sensor shall be used withthe EconoMi$erIV or EconoMi$er2 device. Whenused in conjunction with the standard outdoor airtemperature sensor, the EconoMi$erIV orEconoMi$er2 device will provide differential temperaturecontrol.
21. Outdoor Air/Return Air Temperature Sensor (adjustable)(EconoMi$er2):
Optional sensor uses a third party control to controloutdoor air damper and compressor operation.
22. Indoor Air Quality (CO2) Sensor (EconoMi$er2):
a. Shall have the ability to provide demand ventilationindoor air quality (IAQ) control through theEconoMi$er2 with an IAQ sensor.
b. The IAQ sensor shall be available in duct mount,wall mount, and wall mount with LED display. Theset point shall have adjustment capability.
23. Indoor Air Quality (CO2) Room Sensor(EconoMi$erIV):
Sensor shall have the ability to provide demand ventilationcontrol through the EconoMi$erIV. The IAQsensor shall be wall mounted with an LED display inparts per million. The set point shall have adjustmentcapability.
24. Return Air CO2 Sensor (EconoMi$erIV):
Sensor shall have the ability to provide demandventilation control through the EconoMi$erIV. TheIAQ sensor shall be duct mounted. The set pointshall have adjustment capability.
25. Ultra-Violet Germicidal Lamps: