1080 Marina Village Parkway, Suite 501 Alameda, CA (510) Fax (510) HVAC DESIGN INTENT

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1 Taylor Engineering 1080 Marina Village Parkway, Suite 501 Alameda, CA (510) Fax (510) LLC HVAC DESIGN INTENT PART 1 - GENERAL 1.1 Overview A. The project consists of a 3-story office building, totaling approximately 52,000 square feet, located in the City of East Palo Alto, California. The building includes an 8,000 square foot library on the first floor, and different county tenants on various occupancy schedules on the other floors. B. There have been small interior retrofits typically done without considerations for the HVAC (heating, ventilating and air conditioning) system and zoning. C. The chiller and boiler were replaced in Previous HVAC upgrades were done in The chiller and boilers will remain as installed. The County requests only the existing AHU, the zone equipment and zone distribution to be part of the retrofit. D. The County wishes to upgrade the HVAC system and address occupant comfort issues. The County requests the HVAC Building Automation System be replaced with a Niagara AX compatible system and the lighting controls be monitored with the new BMS (building management system). E. The building shall remain occupied during the HVAC upgrade. 1.2 Design Criteria A. Design Temperatures and Humidity: Heating Cooling Outside air drybulb temperature F F Outside air coincident wetbulb temperature F Inside air drybulb temperature Interior offices 70 F 73 F Exterior offices 70 F 75 F Other (toilets, corridors, etc) 70 F 75 F Electrical rooms, switchgear F B. Internal Loads: 1. Diversity factors: Loads to each zone or area shall be based on the densities listed in each section below. Central fan systems airflow is sized based on the total coincident load multiplied by a diversity factor. 2. Densities: Based on conditioned (net) square feet.

2 Page 2 3. Occupancy Heat Gain: Occupancy shall be based on the densities listed in the table below or the number of workstations or assembly chairs indicated on furniture plans where available. The density data in the table below will be used where no furniture information is available. People Occupancy Lighting Equipment Sensible Latent (W/ft 2 ) (W/ft 2 ) Density (Btu/hr (Btu/hr (ft 2 /person) per per person) person) Breakroom Conference room Copy Room Corridor/Storage Library Reading Rooms Library Stacks Lobby Office <= 250 ft HSA Office <= 250 ft Office > 250 ft HSA Office > 250 ft Toilet C. Envelope Loads: 1. Heat transfer conductances of the building envelope are provided in the table below. These heat transfer conductances have framing factors built in. Envelope Component U-factor (Btu/hrft 2 - F Walls (assumed no insulation) 0.43 Roof 0.21 Ceiling for 3 rd floor spaces (insulation on ceiling tiles) Window Shading Coefficients: Glass Type U value* SC Single Coated Single Coated with venetian blinds** *The U-values include frame effects. **Spaces behind the curtain wall system on the north end of the building are assumed to have venetian blinds on their east and west facing walls. The south facing offices served by VAV-1-8 were also considered with venetian blinds closed at times of direct solar radiation. These offices have full height glazing. Other spaces assume no blinds. D. Noise Criteria: Space Type Grille/Diffuser NC Conference room 25-30

3 Page 3 Space Type Grille/Diffuser NC Copy Room 40 Corridor 40 Delivery-Shipping/Receiving 40 Kitchen 40 Library Reading Rooms 35 Library Stacks 35 Lobby/Lounge 40 Office Toilet 40 E. Outside Air Ventilation Rates: Outside air requirements of each space will be in accordance with Title 24 ventilation standards. 1.3 Air Systems A. Conditioned Air System Description 1. Variable Air Volume Systems Description a. The building is served by an existing central built-up variable air volume air handler (AHU-1) located on the roof. The unit includes a supply fan, chilled water and hot water coils. This unit does not have a return or relief fan. b. The existing unit is to be refurbished and the work should include: (1) Replace the supply fan 50 hp motor with a premium efficiency motor (2) Replace the existing supply fan variable frequency drive (VFD) (3) Replace the fan bearings (4) Replace the fan and motor drives and belts (5) Replace the fan scroll access door gasket (6) Dynamic balance the fan (7) Adjust and tune the existing spring isolators (8) Remove the filters on the outside air intake (9) Replace the existing outside air louver with a new airflow measuring stationary louver type Ruskin AML3 or equal (10) Replace the outside air damper (11) Service, clean, lubricate and adjust the linkage of the return air damper (12) Replace the filter frames and filters (13) Replace the doors and seal existing holes and cracks (14) Replace the chilled water coils (15) Remove the hot water coils, all heating to be done by terminal 2- row reheat coils (16) Replace the condensate drain pans (17) Replace the coils support 2. Secondary HVAC System a. There are currently 55 existing VAV (variable air volume) boxes with pneumatic controls. 8 of these boxes have reheat coils. These VAV boxes with reheat coil serve the Council Chambers, the Community

4 Page 4 room and the perimeter spaces of the Human Services Agency on the third floor. b. All the existing VAV boxes shall be replaced with new VAV reheat boxes. See the attached new zoning diagram. Taylor Engineering conducted a detailed load calculation to verify proper zoning as well as adequate equipment cooling and heating capacities. Total number of existing VAV boxes to be replaced 55 Number of added VAV boxes 22 Total number of new VAV boxes 77 Table 1. Number of Existing and New VAV Boxes c. All the existing Moduline diffusers shall be replaced with new ceiling diffusers. d. The existing perimeter heating units associated ducts and grilles shall be removed. As a price alternate, leave all the existing perimeter heating units and associated abandoned in place. 3. Split System a. The existing split systems serving the Council Chambers, the community room, the police department and the server closet on the 3 rd floor are to remain in place. They shall be monitored through the main BMS system. B. Relief Air 1. The current building relief air system relies on passive relief through the two stairwells located on the east and west sides of the building. At each floor two openings with fire dampers connect the ceiling plenums to each stairwell. A barometric relief vent with back draft damper sits at the top of both stairwells. Based on the new airflows from the load calculations and the pressure drop calculations, the following measures shall be implemented: a. The fire dampers at the relief grilles to the building stairwell shall be permanently closed, insulated and sealed. The other existing fire dampers are to be left in place. b. The relief dampers at the top of the stairwells shall be removed, structurally covered and re-roofed. As an alternate, the dampers shall be permanently closed and sealed. c. A new relief fan shall be added at the roof with a backdraft damper. The relief fan shall be connected to the 3 rd floor return air plenum. Provide electrical service and controls to the new fan. d. Provide two new fire smoke dampers on the second and third floor as shown on the zone sketches. Provide new electrical service and controls. Both dampers will be 60 x18 type Ruskin FSD-36 or equal. C. Exhaust Air System Description 1. Toilet Exhaust a. The existing toilet exhaust system is to remain in place, but will be integrated with the BMS for control and monitoring. 2. Office Exhaust (EF-2 and EF-3)

5 Page Water Systems a. The existing exhaust fans are currently not operated. Existing system shall be removed, structurally covered and reroofed. As an alternate the system should be left in place. A. Chilled Water System Description 1. Chiller and Pumping System Description a. The existing 155-ton semi-hermetic screw chiller (CH-1) is served by a constant volume 300 gpm pump (CHP-1). The chiller and chiller pump are to remain in place. b. Add insulation to the chilled water pump. B. Hot Water System Description 1. Pumping systems description a. The existing non condensing gas fired boiler (B-1) boiler is currently served by a constant speed pump to a constant volume system. The boiler and hot water pump are to remain in place. b. Existing piping to the perimeter heating units shall be re-used to connect the new reheat coils to the hot water loop. c. Add insulation to the hot water pump. 1.5 Energy Saving Measures A. Energy Savings Measures Description 1. The new DDC controls with supply air temperature and static pressure resets will allow to provide tighter room temperature control and lower energy consumption. The VAV boxes will have full shut down capability allowing the system to have isolation zones. 2. The new controlled relief system will provide enhanced economizer operation. 1.6 Controls A. Control System Description 1. All existing controls down to the zone level shall be replaced with new DDC controls. 2. AHU-1 a. The air handler shall have a new set of temperature, pressure sensors and outdoor airflow measuring station (part of the outside air louver see section 1.3A.1.b(9) above). The unit shall have new outdoor air dampers. b. Replace the existing supply fan VFD. 3. VAV boxes a. The pneumatic zones shall be replaced with full DDC controls and all new variable air volume boxes with 2-row hot water reheat coils. b. Isolation zones shall be provided to allow spaces to run outside of normal occupied hours. 4. Chiller: The chilled water supply temperature setpoint will be reset to maintain AHU-1 discharge air temperature at setpoint. The existing chilled water 3-way valve shall be removed. The cooling tower existing Robertshaw controls shall be replaced with new DDC controls.

6 Page 6 5. Boiler: The hot water pump will remain constant volume. The reheat valves will be 2-way control valves. 6. Lighting: A gateway to the lighting controls shall be provided to monitor the lighting operation. B. Programming Description 1. A fully new energy efficient and title-24 compliant controls system will be provided. PART 2 - PRODUCTS 2.1 Equipment Schedule A. For Existing Equipment see attached schedule. B. New Equipment: Plan Mark Device/ Service Size Quant ity Location Electrical Remarks V HP (E) AHU- 1 RF-1 VAVxxx SDxxx CDxxx Air Handler Relief fan VAV Boxes Unducted smoke damper OA Control Damper 45,000 cfm 2x 19,000 cfm 60x Penthouse HP 2 Roof x 5 HP 77 All Floors nd and 3 rd floor Provide new motor and VFD type ABB or equal Type COOK 490- ACEB or equal. Provide VFD Type Price SDV with 2- row reheat coil or equal Type Ruskin FSD-36 or equal 72x96 1 Penthouse Type Ruskin CD Controls A. Manufacturer 1. New DDC controls system shall be compatible with Niagara AX and shall be network connected to the County s central server. No front end computer is required at the building site. B. User interface 1. All the graphics are to be on the County server located at the Youth Services Center Central Plant. Licenses must be open to Vicon.

7 Page 7 C. Controls shall be web accessible D. Trending 1. The trends will be stored on the County s server. PART 3 - EXECUTION 3.1 Controls A. Schedules Description 1. Schedules will need to be coordinated with the different tenants of the building. 3.2 Commissioning A. By Taylor Engineering