Mechanical Pre-Bid Design Narrative

Mechanical Pre-Bid Design Narrative

DB-526FLIGHTLINE FIRE STATION

MECHANICAL PRE-BID DESIGN NARRATIVE

NOTE: At this time, RFIs remain unanswered by the Government. The information provided herein is based solely on the RFP requirements at this time. These documents are subject to change once written responses to RFIs are received from the Government. For Contractor bid docs only not for distribution to Government.

  1. Codes and References
  • ASHRAE Standard 62.1 “Ventilation for Acceptable Indoor Air Quality” (2016)
  • ASHRAE Standard 90.1 “Energy Standard for Buildings Except Low Rise Residential Buildings” (2013)
  • The International Mechanical Code (2015)
  • NFPA Standard 90A “Standard for Installation for Air Conditioning and Ventilating Systems”
  • SMACNA HVAC Duct Construction Standards
  • UFC 1-200-02 High Performance and Sustainable Building Requirements (1 DEC 2016)
  • UFC 4-010-01 DoD Minimum Antiterrorism Standards for Buildings
  • UFC 4-730-01 Fire Stations
  • Authority Having Jurisdiction
  1. HVAC Design Conditions
  2. Summer

Ambient:93.4F DB / 76.2FWB

  1. Winter

Ambient:28.3F

  1. HVAC Overview
  • The project requirement is to design and construct a 27,841 ft^2Flightline Fire Station & 700 ft^2 tire storage building. The proposed design shall achieve 30% energy savings below ASHRAE 90.1 baseline in accordance with UFC1-200-02 & Epact 2005.
  • The HVAC requirements for the Structural Bay (Apparatus Bay) shall be ventilated in the summer to maintain max of 10 degree difference between the room and outside temperatures utilizing propeller wall mounted exhaust fans with roof mounted intakes. The Apparatus Bay shall be negatively pressurized relative to adjacent occupied spaces utilizing a dedicated make up air unit with an energy recovery ventilator and shall distribute air downward to assist in pushing the diesel exhaust fumes out of the Apparatus Bay doors when open. A vehicle exhaust removal system shall be provided to eliminate 100% of vehicle exhaust emissions in accordance with the preferred method of (FAVERS) utilizing a direct vent system that evacuates vehicle exhaust directly to the outside in accordance with UFC 4-730-01. Gas fired infrared heaters shall be provided to heat the Apparatus Bay.
  • The occupied area of the Flightline Fire Station shall be condition with an air cooled chiller coupled with a variable air volume central station air handling unit with an air-to-air total energy recovery ventilator system. The heating system shall be by a gas fired condensing boiler. Each zone will be controlled by a VAV air terminal unit with hot water reheat. The chilled water pumps shall be variable speed base mounted end suction sized for 100% of the total system capacity and shall operate in parallel in a lead-lag arrangement for the primary & secondary pumping systems. The hot water pump shall be variable speed inline pump. The kitchen will be served by a gas fired tempered roof mounted direct make-up air unit and roof mounted exhaust system equipped with grease trap.
  • Communication room shall be conditioned to 78 deg F by a dedicated unit to allow for 24/7 operation.
  • Mechanical & Electrical rooms shall be ventilated in summer to maintain a maximum of 10 degrees difference between the room and outside temperatures with exhaust fans and intake louvers with low leakage dampers.
  1. HVAC System

Structural Bay (Apparatus Bay):

  • Tempered packaged 6520 CFM make-up air unit rated for outdoor with energy recovery ventilation of 7250 CFM Exhaust.
  • (6) 6270 CFM Propeller exhaust fan
  • (2) 72”x72” 18,820 CFM gravity roof mounted intake.
  • Belt drive direct vented vehicle exhaust fan, stainless steel ductwork directly to the outdoor with exhaust stack.
  • (12 – 40’L) 125 MBH gas fired infrared heaters.

Logistics 092:

  • 1 Ton Mini Split

IT/COMM 139:

  • 2 Ton Mini Split

COMM 138:

  • 2 Ton Mini Split

ELEC 137:

  • 220 CFM Exhaust fan with intake & low leakage damper.

MECH 137:

  • 1100 CFM Exhaust fan with intake & low leakage damper.

Occupied Space:

  • 17,500 CFM variable air volume central station air handling unit.
  • Dedicated DOAS system 4,000 CFM outdoor air & 3,500 CFM exhaust ducted to and from spaces.
  • (30) VAV boxes with hot water reheat.
  • 50T air cooled chiller.
  • 120 GPM (2) primary/ (2) secondary variable end suction base mounted chilled water pumps lead-lag configuration.
  • 300 MBH input gas fired condensing boiler.
  • 29 GPM variable inline hot water pump.
  • Gas fired tempered roof mounted direct kitchen make-up air unit and roof mounted kitchen exhaust fan.

Tire storage:

  • 360 CFM exhaust fan with intake and low leakage damper. 2KW electric unit heater.
  • 740 CFM exhaust fan with intake and low leakage damper. 3KW electric unit heater.
  1. Load Calculations
  2. We are using Carrier’s Hourly Analysis Program Version 5.0 to evaluate the HVAC system.
  1. HVAC Control System

DDC control with Energy Management and Control System interface in accordance with Eglin AFB DDC standards.

Mechanical Pre-Bid Design Narrative1

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