SECTION HVAC TABLE OF CONTENTS PART 1 - SYSTEM DESCRIPTION / OUTLINE SPECIFICATIONS FILED SUB BID PROJECT OVERVIEW...

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1 SECTION TABLE OF CONTENTS SECTION PART 1 - SYSTEM DESCRIPTION / OUTLINE SPECIFICATIONS FILED SUB BID PROJECT OVERVIEW DESIGN CRITERIA CODE ISSUES EQUIPMENT SYSTEM DESCRIPTIONS AND OPTIONS i

2 SECTION PART 1 - SYSTEM DESCRIPTION / OUTLINE SPECIFICATIONS 1.00 FILED SUB BID A. Bidding procedures shall be in accordance with latest edition of Massachusetts General Laws, Chapter 149, Section 44, including provisions for pre-qualification; and Chapter 30, Section 39M. Time and place for submission of sub-bids is given in Advertisement for Bids. Sub-bids for work under this Section shall be for complete work of this Section and shall be filed in a sealed envelope with Awarding Authority, at time and place specified in Advertisement for Bids. The following shall appear on the face of the envelope: NEW DOUGLAS ELEMENTARY SCHOOL [NAME OF BIDDER] SUB-BID FOR SECTION , HEATING, VENTILATING AND AIR CONDITIONING B. Every sub-bid submitted for work under this Section shall be on forms furnished by awarding authority, as required by Section 44 of Mass. General Laws, and specified in Advertisement for Bids. C. Sub-bids filed with the Awarding Authority shall be as accompanied by bid deposits in form of a bid bond, or cash, or a certified check on, or a treasurer's or cashier's check issued by, a responsible bank or trust company, payable to in compliance with Chapter 149, Section 44 B. Amount of bid deposit shall be 5 percent of value of bid. D. Additional Requirements: 1. Sub-bidder's attention is directed to Massachusetts G.L. Chapter H, as amended, which provides in part as follows:

3 a. Each sub-bidder shall list in Paragraph E of the "Form for Sub-bids" the name and bid price of each person, firm or corporation performing each class of work or part thereof for which the Section of the Specifications for that sub trade requires such listing, provided that, in the absence of a contrary provision in the Specifications, any sub-bidder may, without listing any bid price, list his own name or part thereof and perform that work with persons on his own payroll, if such sub-bidders, after sub-bid openings, shows to the satisfaction of the Awarding Authority that he does customarily perform such class of work with persons on his own payroll and is qualified to do so. This Section of the Specifications requires that the following classes of work shall be listed in Paragraph E under the conditions indicated herein. Classes of Work Reference Specification Paragraphs (1) Water Treatment (2) Insulation (3) Sheet Metal Work (4) Automatic Temperature Controls (5) Balancing (independent company) PROJECT OVERVIEW A. This project includes the construction of a 90,000 square foot new elementary school located in Douglas, Massachusetts. B. The building will consist of a new central boiler and chiller plant (option). This plant will serve optional induction units or variable air volume terminal units, energy recovery ventilation units and roof top air handling units. C. The work under this Section shall include the furnishings of all materials, labor, equipment and supplies and the performance of all operations to provide complete working systems, in general, to include the following items: 1. Piping and Fittings (all systems and types) 2. Pipe Hangers and Supports 3. Identification 4. Sleeves, Firestopping 5. Pipe Expansion Joints, Guides and Anchors 6. Valves and Accessories (all types)

4 7. Expansion Tanks 8. Air Separators 9. Freeze Protection 10. Pressure Gauges, Thermometers, Strainers, Accessories 11. Electric Motors and Starters 12. Pumps (Water systems) 13. Convectors 14. Fin-Tube Radiation 15. Oil Fired Boiler/Burner Units 16. Oil Storage Tank 17. Chemical Treatment Systems 18. Air Cooled Chiller 19. Air Cooled Condenser and Condensing Section 20. Factory Tests 21. Vibration Isolation 22. Ductwork 23. Sound Attenuation Equipment 24. Diffusers, Registers and Grilles 25. Fans 26. Coils 27. Air Filters 28. Air Handling Units 29. Induction Units (TBD) 30. Variable Air Volume Boxes (TBD) 31. Unit Heaters (all types) 32. Cabinet Unit Heaters (all types) 33. Electric Baseboard Heaters 34. Energy Recovery Units 35. Insulation

5 36. Chimneys, Stacks, and Flues 37. Roof Curbs 38. Operating and maintenance instructions and manuals 39. Coordination drawings 40. Shop drawings 1.02 DESIGN CRITERIA 41. Cleaning, Testing, Adjusting & Balancing of All Ducted and Piped Systems and Equipment 42. Record (as-built) Drawings 43. Control Systems 44. Seismic Restraints 45. Training of Ownerʼs Personnel on Equipment, Systems, and Controls A. Outdoor Design Conditions 1. For load calculations (ASHRAE 1% - Table 1A): Summer: 87 0 F dry bulb; 71 0 F wet bulb Winter: 4 0 F 2. For condensing units/air cooled chillers and freeze protection: Summer: 95 0 F dry bulb; F wet bulb (ASHRAE 0.4% worst month Table 4A) Winter: 0 0 F (ASHRAE Annual Min. Extreme Table 1A) B. Indoor Design Conditions 1. Offices and occupied areas: Occupied cooling: 75 0 F (maximum 60% relative humidity) Unoccupied cooling: no unoccupied cooling Occupied heating: 70 0 F (no humidification) Unoccupied heating: 55 0 F (no humidification) 2. Mechanical/Electrical rooms: F maximum (no humidity control) 60 0 F minimum (no humidity control)

6 3. Elevator machine rooms: 90 0 F maximum (no humidity control) (or shafts for MRL* elevators) 60 0 F minimum (no humidity control) * MRL = Machine-Room-Less C. Occupancy and Outdoor Air 1. Offices: 7 people/1000 sf at 20 cfm/person 2. Corridors: 0.1 cfm/sf 3. Conference rooms: 50 people/1000 sf at 20 cfm/person 4. Cafeteria: 70 people/1000 sf at 15 cfm/person 5. Auditoriums: 150 people/1000 sf at 15 cfm/person 6. Classrooms: 50 people/1000 sf at 15 cfm/person D. Electrical Load Density 1.03 CODE ISSUES 1. Lighting: 1.3 watts/sf maximum 2. Power: 2 watts/sf A. A fail open (normally closed) smoke damper will be provided for the elevator shaft vents. This damper will open on loss of power, rise in temperature to 90 o F, or a signal from the fire alarm system. B. The 100% outdoor air units will require energy recovery, as it will be larger than 5,000 cfm EQUIPMENT A. Boilers shall be oil fired cast iron sectional type (up to 88% efficient) as manufactured by Buderus or equal. Oil for heating system to be stored in a 10,000 gallon capacity double wall fiberglass tank below grade and shall include tank leak detection monitoring. B. Hot water shall be base mounted with variable frequency drives. All pumps shall be similar in construction to Bell & Gossett. C. Cooling Option 1 (VAV) Variable air volume packaged units for all areas of the school. Units include direct expansion (DX) cooling. Classrooms, offices and other spaces which are cooled shall have variable air volume boxes serving the spaces

7 D. Cooling Option 2 (Induction) The air cooled chiller shall be roof or grade mounted. The chiller will be provided with an integral variable frequency drive. It shall be similar in construction to Trane, York or McQuay. Induction units shall be 4 pipe ceiling mounted units and shall be linear Chilled beam arrangement. The induction units shall be as manufactured by Trox or equal. Energy recovery units shall be roof mounted. Each will contain hot water heating and DX cooling coils, enthalpy wheel, supply and exhaust fans, and filters. It shall be similar in construction to Greenheck 1.05 SYSTEM DESCRIPTIONS AND OPTIONS A. Central Plant Options: 1. Boiler Plant Option a. Provide complete hot water heating system including, but not limited to: boilers, combustion air, flue system, fuel piping, pumps, DDC controls, air separator, expansion tank, valving, piping, insulation, fittings, expansion provisions, drains vents, chemical treatment and make-up water. All motors shall be premium efficiency. b. The central hot water plant will be located in the ground floor boiler room. c. Provide two (2) 1800 MBH output boilers set to supply F hot water with F return water temperature. Provide for temperature reset down to F supply, based on outdoor air temperature. d. Provide two (2) hot water pumps. Provide spring isolated hangers for pumps. A maximum of one pump will be running at any one time, and one pump as a standby, to provide redundancy in the event of a pump failure. Provide a variable frequency drive (with harmonic filters) for each pump motor with remote differential pressure speed control. Provide bypass for minimum pump flow. e. Hot water pipe distribution will be provided by 4 hot water mains. Total hot water flow will be approximately 250 gpm. 2. Chiller Plant (Option 2) a. Provide complete chilled water cooling system including, but not limited to: an air cooled chiller, pumps, DDC controls, air separator, expansion tank, valving, piping, insulation, fittings, drains vents, expansion provisions, chemical treatment and makeup water. All motors shall be premium efficiency

8 b. The chiller with integral VFD (with harmonic filters) shall be set to supply 57 0 F chilled water (30% glycol) with a 7 0 F temperature rise to the induction units. Provide one 80-ton chiller which is roof or grade mounted. c. Provide two (2) chilled water pumps each sized for the flow of the chiller. The pumps shall be located in the ground floor boiler room. A maximum of one pump will be running at any one time, and one pump as a standby, to provide redundancy in the event of a pump failure. Provide a variable frequency drive (with harmonic filters) for each pump motor with remote differential pressure speed control. Provide flow sensor for the chiller with bypass for minimum chiller flow. d. Chilled water pipe distribution will be provided by 4 chilled water mains. Total chilled water flow rate will be approximately 200 gpm. e. Provide water treatment system, with blow down valve, conductivity sensor, make-up water flow meter, and coupon rack. Provide a make up water connection from the city water supply with back flow preventer. B. Building Systems 1. Option 1 The system for the classrooms shall consist of a variable air volume air conditioning system. The classrooms shall receive cooling air from roof mounted packaged air conditioning units. Variable Air Volume terminal units shall control the amount of cool air to each classroom. The VAV terminals shall also include hot water heating coils. The perimeter of the classrooms shall include fin tube radiation. Each room shall have individual temperature controls. 2. Option 2 - The systems serving the Classroom areas of the building will be four pipe induction units. The hot water and chilled water will be supplied by the central plants. Ventilation for these spaces will be supplied by roof mounted Energy Recovery Units. The Classrooms will each have two ceiling mounted induction units. Each classroom shall have individual temperature controls. 3. The Gymnasium will be served by a rooftop air handling unit. This unit shall provide heating and Ventilation only. Gymnasium ventilation will be controlled with CO2 controls. No cooling for the Gymnasium. 4. The school administration area shall be heated, cooled and ventilated by packaged variable air volume roof top mounted unit with DX cooling. 5. The cafeteria will be heated cooled and ventilated by one roof top air handling unit. The kitchen shall be served by a make up air unit. Ventilation will be controlled with CO2 controls

9 6. The Library will be heated, cooled and ventilated by a roof mounted air handling units. 7. Toilet exhaust will be provided by 2 pressure class galvanized duct sealed to leakage class 12 ductwork from each toilet room and janitorʼs closets. 8. Provide separate roof mounted exhaust fans to serve the kitchen exhaust hood and the dishwasher exhaust. The grease hood shall have minimum 16 gauge welded grease black steel ductwork (stainless steel where exposed). The duct shall be covered with 2-layers of fire rated insulation between the kitchen and the fan. The dishwasher shall have welded 16 gauge stainless steel ductwork. The fans shall operate via local switches with interlocks to the make-up air terminal units. C. Miscellaneous Exhaust Systems 1. Provide exhaust systems for the following systems: a. Trash and Recycle b. Mechanical Room Ventilation c. Electric Room Ventilation D. Automatic Temperature Controls 1. Provide a complete DDC controls system for the building complex. System will include a complete operating station, web-server, programming and graphics. 2. Provide all DDC field panels and interlocking wiring to integrate all system components. All panels will be stand-alone and fully programmable. 3. Provide adjustable high / low alarms for all sensors