H21.REV

PACKAGED ROOF-TOP UNITS

NOTE: FINAL COPY: MAY, 1987.

Part 1 -	GENERAL

1)	WORK INCLUDED

A.	Work in this Section includes the providing of labor, materials, equipment and services necessary for a complete and safe installation in accordance with the contract documents and all applicable codes and authorities having jurisdiction for packaged roof-top air conditioning units

2)	RELATED WORK AND REQUIREMENTS

A.	Requirements of GENERAL CONDITIONS, DIVISION NO.1 and Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK apply to all work in this Section

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE ONLY SECTIONS DIRECTLY AFFECTING WORK OF THIS SECTION

B.	Related work in the following Sections:

1.	SHEET METAL WORK.

2.	AIR HANDLING SYSTEM EQUIPMENT.

3.	MOTORS.

4.	MOTOR CONTROLLERS.

5.	AUTOMATIC CONTROL SYSTEMS.

6.	VIBRATION ISOLATION.

7.	BALANCING AIR AND WATER SYSTEMS.

8.	-----.

3)	REFERENCE STANDARDS

A.	Published Specifications' standards, tests or recommended methods of trade, industry or governmental organizations apply to work in this Section

B.	Comply with all applicable national, state and local codes and refer to Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK for additional Reference Standards

4)	QUALITY ASSURANCE

A.	Conform to AMCA Bulletins regarding construction and testing. Fans shall bear the AMCA Certified Rating Seal

B.	Refer to Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK for other Quality Assurance requirements. The complete unit shall be guaranteed for one (1) year and the compressors and furnace heat exchangers shall be guaranteed for five (5) years

NOTE: INCLUDE AS APPLICABLE FOR THIS PORJECT. OBTAIN OCTAVE BAND ANALYSIS FROM MANUFACTURER OF EQUIPMENT AND INSERT IN FOLLOWING SCHEDULE OR IN SCHEDULE ON DRAWINGS

C.	Acoustical criteria.

1.	The follwing are maximum permissible sound power levels by octave bands for air handling units and fans, when installed as indicated on drawings

DB

a.	Fan No. Component Octave Bands 1 2 3 4

b.	Refer to schedule on drawings.

DB

5)	SUBMITTALS

A.	Submit the following shop drawings to Architect and/or Engineer

1.	Manufacturer's descriptive literature, installation instructions, operating instructions, maintenance and repair data

NOTE: INCLUDE ONLY REFERENCES DIRECTLY AFFECTING WORK OF THIS SECTION

2.	Performance data.

3.	Dimensions and weights.

4.	Test reports.

5.	Wiring and control diagrams.

6.	Fan curves with and without inlet vanes.

Part 2 -	PRODUCTS

1)	BASE BID MANUFACTURERS

A.	Roof-top air conditioning units: Trane Co., McQuay Div., McQuay-Perfex Inc. and Mammoth Div. of Lear Siegler, Inc

2)	FACTORY FABRICATED UNITS

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. DELETE ITEMS NOT REQUIRED IN THIS PROJECT

A.	Unit shall be complete with compressors, air-cooled condenser, direct expansion cooling coils, chilled water cooling coils, hot water heating coils, steam heating coils, gas-fired furnace, supply fan, return/exhaust fan, power exhaust fan, modulating dampers, filters, controls and insulated casing

B.	Units shall be rated in accordance with ARI Standard 360.

C.	Complete factory assembled units, piped and wired. Operated and tested at factory for three hours minimum, dehydrated and charged with refrigerant R-22 and lubricant oil. Ship fully assembled

ZONE

D.	Single zone.

NOTE: MULTI-ZONE UNITS NOT USED IN CALIFORNIA.

E.	Multi-zone units with zone dampers, hot and cold deck damper arrangement sectionalized for multiple zones air distribution. Construction shall be as specified for automatic dampers. Refer to Section AUTOMATIC CONTROL SYSTEMS

F.	Double duct units.

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT.

ZONE

VAR VOL

G.	Variable volume and/or constant volume as scheduled

H.	Face and by-pass dampers at cooling coils and at heat recovery coils

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. CHECK MANUFACTURER FOR CORRECT MODEL DESIGNATION WITH THE FEATURES SPECIFIED FOR THIS PROJECT

VAR VOL

I.	Provide units similar to Trane Series -------.

J.	Construction: Cold rolled steel cabinets reinforced and braced with angles, and access sections with hinged door with quick opening handles. For insulation, provide minimum 1 inch thick, coated fiberglass board NFPA-90 approved, 1.0 lb. density.

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. COORDINATE FINISH OF EXPOSED UNITS WITH ARCHITECT. IT MAY BE POSSIBLE TO OBTAIN THE PROPER COLOR FROM THE MANUFACTURER. IF NOT, ARRANGE WITH ARCHITECT TO SPECIFY FINISH PAINTING OF THE UNITS

1.	Standard factory finish, galvanized and painted. Submit color options, if any, for approval to Architect and/or Engineer

2.	Completely weatherproof joints sealed to prevent leakage and tops crowned or sloped to drain. Allow no pockets to retain water. Gasketed access panels with quick opening handles and brass or stainless steel hinge

3.	Insulated drain pans under cooling coils and fan. For unit base, provide one piece welded assembly, 14 gauge formed bearing members, base installed to curb complete with sealing gasketing, curb overhang and lifting lugs for use as unit tiedown points

K.	Fans shall be AMCA Certificed in accordance with ARI Standard 360. Fan capacities shall be minimum as noted

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT.

1.	Fans with variable inlet vanes on supply and return/exhaust fans. Fan performance characteristics shall be manufacturer's published catalog rating data of fan with variable inlet vanes

NOTE: COORDINATE WITH ELECTRICAL DEPARTMENT.

a.	Motors shall be high efficiency type.

2.	Wheels shall be formed steel or extruded aluminum. Fans shall be forward or backward curved or air foil blades as noted and shall be factory balanced, statically and dynamically. Multiple wheels shall be mounted on a common shaft

3.	Multiple V-belt drives shall be matched with cast iron pulleys and provide removable belt guards for exposed drives. Motor pulley shall be variable pitch diameter. Companion sheaves shall maintain belts parallel. Refer to Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK

4.	Bearings shall be ball, roller or taper pressure type lubricating fittings with pressure relief fittings extended to accessible locations. Lubricating fittings shall be similar to Alemite and pressure relief fittings shall be similar to Keystone. Life rating shall be minimum 200,000 hous per AFBMA Standard L-50, at maximum catalog rating

5.	Fans shall be capable of accommodating static pressure variations of plus or minus 10 percent

FAN

6.	Fan performance shall be based on sea level conditions

7.	Fan performance shall be based on -----ft. altitude conditions

FAN

8.	Prime coat fan wheels and housing at factory, inside and outside. Prime coating on aluminum parts is not required

9.	Power fan shall exhaust a minimum of (75) (100) percent of supply air.

10.	Return fan shall be centrifugal type, belt-driven, multiple or single wheel and similar to supply fan specified above. Smaller units may use propeller fan

L.	Coils:

COILS

1.	Coils as specified in Section AIR HANDLING SYSTEM EQUIPMENT

2.	Extended surface type coils with tubes of copper minimum thickness 0.020 inch. and plate or helical fins of copper or aluminum. Fins shall be flat or conformed; helical fins shall be solder dipped and minimum thickness shall be 0.008 inch. Maximum face length shall be 12 feet per section

ROW

a.	Minimum rows and fins, as scheduled.

b.	Minimum rows and fins as required to maintain scheduled conditions

NOTE: EDIT AS REQUIRED.

ROW

c.	Maximum fins shall be of 14 per inch. Minimum rows shall be (4 for direct expansion) (6 for chilled water)

d.	Circuiting shall be as required. Coil shall be certified by ARI current Standards. Coils shall be pressure and leak tested at the factory. Mount coil section in galvanized steel casing designed for bolting to other sections or ductwork. Headers shall be totally enclosed

COILS

COIL

3.	Water heating coils shall be designed for 200 psig and 220 degrees F, similar to Trane Type W

4.	Steam Heating Coils: design for 100 psig and 400 degrees F, single row, single tube coils with supply and return headers at opposite ends

5.	Steam Heating Coils: design for 100 psig and 400 deg F. Double tube coils with internal 3/8 inch OD steam distributing tube shall provide uniform distribution over face of coils and headers shall be arranged as follows

HEAD

a.	Steam and return connection on same end or on opposite end

b.	Double steam connection, open at each end and either one or two return connections

c.	Double pass with the single steam connecton and return at either end

HEAD

d.	Coils similar to Trane Type NS.

COIL

CHILL

6.	Chilled water coils designed for 200 psig and 200 degrees F, similar to Trane Type W

7.	Refrigerant coils, serpentine type, with brass or copper header arranged to prevent trapping of oil and to distribute liquid refrigerant to all circuits. Joints silver soldered or brazed for refrigerant R-12 or R-22. Include factory assembled multi-circuit distributor, one circuit per compressor, and expansion valves. Coils shall be similar to Trane Type F

CHILL

NOTE: INCLUDE IF APPLICABLE; NOT REQUIRED IF HOT WATER OR STEAM COILS ARE INCLUDED

M.	Gas furnace shall be completely assembled and wired gas fired heating system integral within unit, UL and CSA approved specifically for outdoor applications, and mounted downstream from refrigerant cooling coils. Gas supply shall be through side or bottom of unit. Furnace shall be as follows

1.	Furnance shall be factory pressure and leak tested heat exchanger of tubular two pass design, 16 gauge stainless steel primary heat exchanger surface and 18 gauge secondary heat exchanger surfaces

2.	Industrial type burner with air proving switch and ceramic cone burner assembly

3.	Combustion blower with centrifugal type fan and fan motor with built-in thermal overload

4.	Electronic flame gas safety controls shall prove combustion air prior to ignition sequence. Controls shall be two stage with sixty second delay between first and second stage gas valves, continuous electronic flame supervision and proof of air-flow switch

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT; NOT REQUIRED IF CHILLED WATER COOLING IS USED

N.	Refrigeration System:

1.	Compressors: Provide serviceable semi-hermetic type, direct driven, 1750 rpm with the following

a.	Capacity unloaders.

b.	Unloaded starting.

c.	Vibration isolators.

d.	Suction strainer.

e.	Crankcase oil level sight glass and oil charging valve

f.	Forced feed lubrication with reversible rotating oil pump

g.	Magnets in oil circuit.

h.	Ring valves.

i.	Backseating suction and discharge service valves

j.	Suction line accumulator to prevent compressor slugging

2.	Air cooled condensers shall be complete with direct driven propeller type fans, permanently lubricated ball bearings, built-in thermal overload protection, safety guard. Seamless copper tubes and aluminum fins extended surface coils sub-cooling circuit, accumulator and low ambient temperature control

O.	Filters:

FILT

1.	Refer to Section AIR HANDLING SYSTEM EQUIPMENT.

2.	Provide UL Class II bag filters with 40 percent minimum efficiency per ASHRAE Standard 52-76

FILT

3.	Filters shall be mounted in galvanized steel frames with stainless steel clips and latching hardware

P.	Economizer Dampers shall be factory installed with actuators, low leak construction with side seals fully modulating type located in outside air, return air and exhaust air systems. Maximum leakage 6 cfm per sq ft at 1 inch pressure drop across damper

Q.	Controls and control panel shall be as follows:

NOTE: COORDINATE WITH ELECTRICAL DEPARTMENT AND AUTOMATIC CONTROL SEQUENCE

1.	Electrical wiring and controls shall be in conformance with the latest codes and the authorities having jurisdiction. Wiring shall be color coded and/or numbered for easy identification. Unit control panel shall include integral power disconnect, circuit breaker type overload protection, starters and relays. Unit shall be factory wired and run tested prior to shipment

NOTE: COORDINATE ALL OF THE FOLLOWING ITEMS WITH THE OVERALL SYSTEM OPERATION AS SPECIFIED IN SECTION "AUTOMATIC CONTROL SYSTEMS" AND EDIT ACCORDINGLY

2.	Automatic temperature controls for overall operation of builidng systems will be provided under Section AUTOMATIC CONTROL SYSTEMS

3.	Internal controls required for operation of economizer system and condensing unit operation, upon receiving starting signal from external control interface. Refer to Section "AUTOMATIC CONTROL SYSTEMS" for sequence of operation

4.	Additional relays, internal wiring, additional components and terminals to make external control sequences compatible with internal control sequence

5.	Electronic control circuit with discharge sensor to start compressors and load and unload compressors with capacity changes

6.	Time delays and hot gas by-pass to prevent short cycling compressor between load stages for VAV units

7.	Install actuators furnished under Section AUTOMATIC CONTROL SYSTEMS for inlet vanes on supply and return/exhaust fans

8.	Control to prevent compressor short cycling resulting due to a rapid change in load conditions and to prevent compressor re-start within five minutes after shutdown

9.	Head pressure control to control condenser fan and maintain head pressure control down to -20 deg F. outside air temperature

10.	Remote control and monitoring panel for each unit to contain system operating switch, fan operating pilot light, fan malfunction pilot light, cooling malfunction pilot light and dirty filter pilot light

3)	ROOF CURB

A.	Roof curb shall be galvanized steel construction with wood nailer strips, base plate and 1 1/2 inch thick, 1 1/2 lb density, UL listed, fire retardent insulation

NOTE: DELETE THE FOLLOWING FOR FLAT ROOFS OR WHERE STRUCTURAL CURBS WITH LEVEL TOPS ARE PROVIDED

1.	For top level of pitched construction, determine pitch from field conditions

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS: USE OPTION 2 ONLY IF SPRING BASE IS USED

BASE

2.	Match unit base. Gaskets shall be between unit and curb

3.	Match isolating base.

BASE

4.	Installation shall be weatherproof and bases shall be similar to Stiles Corp., Model No. SC-2AP

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. USE THE FOLLOWING IF REQUIRED BY THE ACOUSTICAL CONSULTANT'S RECOMMENDATION. COORDINATE WITH SECTION CONTROL

4)	ISOLATION BASES

BASE

A.	For isolation bases, refer to Section VIBRATION ISOLATION.

B.	Factory fabricated spring isolation bases shall fit on top of roof curb and match underside of roof top unit. Provide special extension extrusions, if required, to match curb and/or equipment base

BASE

C.	Base shall be extruded aluminum construction with heliarc welded corners and one piece, where possible, with as few joints as possible if multiple sections are required. will Provide splicing kit for joining multiple sections

NOTE: SPECIFY GREATER DEFLECTION IF REQUIRED.

D.	Vibration isolation: Cadmium plated freestanding springs with horizontal stiffeners for wind and seismic forces and minimum 1 inch static deflection. For snubbers, provide neoprene pads at corners with 1/4 inch minimum clearance

E.	Provide continuous neoprene wind and water seals. Seal between base and curb and between base and bottom of unit

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. USE THE FOLLOWING ONLY IF REQUIRED FOR CRITICAL INSTALLLATIONS. COORDINATE WITH DETAILS ON THE DRAWINGS

F.	Hold down hardware shall be galvanized 6 x 19 plow steel wire hoisting rope. Provide galvanized U bolt clips in accordance with Federal Specification, FF-C-450, Type I, Class 1 and eyebolts, devices, etc., as required

G.	Isolation base shall be similar to Mason Type CMA.

Part 3 -	EXECUTION

1)	INSTALLATION

A.	Air conditioners: Where units are shipped in sections, reassemble factory fabricated components in field, at no additional cost.Install units in accordance with manufacturer's instructions

NOTE: COORDINATE WITH ARCHITECT AND STRUCTURAL ENGINEER. EDIT TO SUIT PROJECT REQUIREMENTS

NOTE: COORDINATE WITH SECTION VIBRATION ISOLATION.

B.	Unit Mounting Bases: Mount on isolating base specified in Section VIBRATION ISOLATION or as specified above. Provide hold down method using two (2) restraints on each of two long sides and cable loop at each restraint point, as specified in Section VIBRATION ISOLATION

C.	Piping Connections:

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. COORDINATE SECTION NUMBER AND NAME WITH PLUMBING DEPARTMENT

1.	Refer to Section "GAS SYSTEMS" for gas piping.

2.	Refer to Section "PIPING" for condensate drain piping

2)	TESTING, ADJUSTING AND START-UP

A.	Start-up work shall be performed by service personnel employed by manufacturer

B.	Test and adjust completed air handling units to insure proper operation as follows

1.	Perform a complete and thorough start-up of the refrigeration cycle and check that all drives are aligned, set screws are tightened and seated. Outside air dampers are fully closed and return damper fully open when system is off

2.	Operate economizer cycle through its extremes using unit controls to check calibration and proper damper operation

3.	Do not operate fans for any purpose, temporary or permanent, until ductwork is clean, filters are in place, bearings lubricated and fans have been operated under observation

C.	Provide operational tests to demonstrate proper operation and adequate capacity at completion of balancing and adjusting

D.	Supply and install sheaves as necessary for final air balancing

E.	Coordinate operational tests with Section AUTOMATIC CONTROL SYSTEMS and Section BALANCING AIR AND WATER SYSTEMS

F.	Submit report certifying above work to Architect and/or Engineer