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| 60.10 | Electrical System |
| 60.15 | Instrumentation and Control System |
| 60.20 | Potable Water System (W1) |
| 60.25 | Non-Potable Water System (W2) |
| 60.30 | Non-Potable Water System (W3) |
| 60.33 | Fire Protection System (FW) |
| 60.35 | Emergency Generator |
| 60.40 | Diesel Fuel System |
| 60.45 | HVAC |
| 60.50 | Hoists and Cranes |
| 60.55 | Communication System |
| 60.60 | Compressed Air System |
| 60.65 | Sump Pumps |
Electric power for the treatment plant is supplied from the Clark County Public Utilities (CCPU) Shipyard Substation located just north of SR-14 and approximately 1/2 mile west of the plant site. An existing radial 12.5/7.2 kV overhead line brings power to a point just outside the plant property line. An underground tap from the overhead line then connects to the pad mounted transformer supplied by the utility.
The reliability of the utility service is expected to be high because of the relatively short distance between the substation and plant site. The 12.5/7.2 kV line can be switched on the north side of SR-14 to different utility substations in emergency situations.
The plant power distribution system is designed to operate at 480Y/277 volts. The double-ended, distribution system is designed to operate with any one major plant feeder or motor control center out of service.
There are 14 motor control centers (MCCs).
MCC-01 and MCC-02 are located on the main level of the influent pump station. MCC-01 and MCC-02 control equipment associated with influent pumping, screening removal and grit classification. The fronts of MCC-01 and MCC-02 are shown in Figures 10.01 and 10.02, respectively.
MCC-03 and MCC-04 are located on the main level of the influent pump station. MCC-03 and MCC-04 control equipment associated with grit removal, headworks aeration, primary scum and sludge collection, and primary scum and sludge pumping. The fronts of MCC-03 and MCC-04 are shown in Figures 10.03 and 10.04, respectively.
MCC-05 and MCC-06 are located in the Aeration Blower Room of the Aeration Complex. MCC-05 and MCC-06 control equipment associated with process aeration, W2 pumping and polymer mixing. The fronts of MCC-05 and MCC-06 are shown in Figures 30.01 and 30.02, respectively.
MCC-07 and MCC-08 are located in the Electrical Distribution Room of the Aeration Complex. MCC-07 and MCC-08 control equipment associated with the Administration Building, the Chemical Building the Maintenance Building, aeration mixing, and mixed liquor recirculation. The fronts of the MCC-07 and MCC-08 are shown in Figures 30.03 and 30.04, respectively.
MCC-09 and MCC-12 are located in the Phase 1 and Phase 2 RAS Pump Stations. MCC-09 and MCC-12 control equipment associated with RAS and WAS pumping, and operation of the secondary clarifiers. The front of MCC-09 is shown in Figure 55.01.
MCC-10, MCC-11, MCC-13 and MCC-14 are located in the Effluent Treatment Complex. MCC-10 and MCC-11 control equipment associated with Phase 1 disinfection and W3 pumping. MCC-13 and MCC-14 control equipment associated with Phase 2 disinfection and effluent pumping. The fronts of MCC-10 and MCC-11 are shown in Figures 35.04 and 35.05, respectively.
Standby generating capacity is available to adequately supply the essential influent pumping, primary treatment, and effluent disinfection loads. Refer to Sections 6035, Emergency Generator, and 6040, Diesel Fuel System, of this manual for descriptions of these systems.
The following devices are located on engine control panel EGP-13010:
The fuel tank full light will come on when the fuel tank is full to alert the supplier to stop filling.
The emergency transfer switch gear provides local control logic (timers and relays) to switch from the utility power source to the emergency generator power source should the utility source fail. It will also re-transfer when the utility source is back to normal.
When the tank is filling, as sensed by fuel oil tank level transmitter, the fuel oil tank full light will blink once every 30 seconds for 1 second. This is done to test the lamp. When the tank is full, the light will come on continuously.
The programmable logic controller and supervisory control system (PLC/SCADA) is composed of three SCADA computers and five PLC's with distributed remote input and output (I/O).
The PLC's consist of central processing units (CPUs), I/O modules, and appropriate communication modules, cables, power supplies, and components. The PLC's will perform all the process control functions necessary to control the plant processes as outlined in the computer control sections of this manual.
The SCADA computers run a Windows based process control software package. The SCADA provides graphic displays of the plant processes, alarm handling routines, real time and historical trending of process variables, report generation and data acquisition.
The SCADA computer monitors (CRTs) are the operators' primary windows to view and make changes to the process. The operators can adjust timer values, change controller set points and modes, and start and stop selected sequences and equipment through the SCADA CRT.
The three SCADA computers at the Marine Park Water Reclamation Facility communicate to the PLC's via a direct link to the data highway or over a fiber optic network. One of the SCADA computers acts as an active display server for the Westside SCADA computer. The SCADA computers also communicate directly to each other over an ethernet local area network (LAN). The SCADA at the Westside Treatment Plant communicates with the PLC over a network link to the active display server. The information on the data highway is available to all SCADA computers.
Three standard types of handswitch configurations are used to control the equipment:
Exceptions to these configurations are described in the Computer Control sections for the equipment items.
W1 water is provided at the following locations:
W1 is obtained from the Vancouver Water Department via an 8-inch water main that enters the plant from the southwest corner of the plant site. The connection to this 8-inch service is made below the plant access drive.
The W1 service is split to provide an 8-inch fire protection service (see Section 6035) and a 6-inch potable water service. The potable water service flows through a 6-inch compound water meter in a vault located in the island to the east of the plant access drive before being distributed in the plant. The water meter is provided with a bypass to allow potable water service to be continued while maintenance is being performed on the meter. All maintenance on the meter will be conducted by the City of Vancouver Water Department.
W2 water is non-potable water that comes to the plant as potable water and is passed through an air gap device to the non-potable water system. This air gap ensures that no potential existing for cross-contamination of the potable water system from the processes or applications where W2 water is used. W2 water is provided for the following functions/processes:
The W2 Tank and the three W2 Pumps are located in the Aeration Blower Room of the Aeration Complex. The W2 Water Tank provides an air gap between the W1 and W2 water systems.
The W2 primary elements, associated equipment and instrument number are listed in Table 60.25.b.1.60.20 Potable Water System (W1)
60.25 Non-Potable Water System (W2)
60.25.a Overview
60.25.b Primary Elements
|
| Primary Element | Location | Element No.
| Level control valve | W2 water tank | LCV-11050
| Low level switch | W2 water tank | LSL-11060
| Pressure indicators | Each W2 pump suction and discharge | n/a
| High pressure switch | W2 pumps discharge header | PSH-11070
| Pump sequencing flow sensor | W2 pump discharge header | FI/FS-11070
| Pressure indicator | W2 pump discharge header | PI-11070
| Pressure element and transmitter | W2 pump discharge header | PT-11070
| | ||
Control of the W2 water system is normally automatic. For automatic or manual operation, open the manual feed valve on the W1 line to allow water to flow into the W2 tank. A hydraulically operated level control valve will automatically open and close to maintain the desired level in the W2 Tank.
Place the three W2 pump HOA switches (HS-11041, HS-11042, HS-11043) on local panel 11040 to AUTO. Set the MAIN SELECT switch to 1 or 2.
In automatic, the pumps are sequenced on system demand flow. The lead pump operates between 0 and 20 percent of the system's rated capacity (250 gpm at 90 psig discharge pressure). As demand exceeds 20 percent, the main 1 pump activates and the lead pump deactivates. As demand exceeds 40 percent, the lead pump is reactivated and operates in conjunction with the main 1 pump to provide 60 percent of the total demand. As the demand exceeds 60 percent, the main 2 pump is activated and the lead pump is deactivated. Main pumps 1 and 2 handle flows up to 80 percent of the total demand. As the demand exceeds 80 percent, the lead pump is reactivated. The three pumps operating together provide 100 percent of the system demand. As demand decreases, the pumps shut down in reverse sequence.
To operate the pumps manually place the number of pumps in service required to meet the system demand by turning the HOA switches (HS-11041, HS-11042, HS-11043) on local panel 11040 to HAND. Place the remaining pump(s) out of service by turning the HOA switch(es) to OFF.
The following devices are provided:
The level in the tank is controlled automatically by the hydraulically operated level control valve.
The W2 water system control panel is a package system. The following devices are located on panel LP-11040 (see Figure 60.03):
The following devices are located at the pump discharge header:
The pumps are run manually by placing the HOA switch in the HAND position. Local alarm conditions are reset by pushing the RESET button.
The pumps are controlled automatically by placing the HOA switch in the AUTO position. The W2 control panel then sequences the pumps based on system flow demand.
See Figure 60.04, W2 Water System P&ID.
Loop Function: Monitor alarm and status of the W2 system equipment and flow conditions:
The W2 pump design specifications are as follows:
| Liquid pumped: | Potable water |
| Pumping temperature: | 40 to 60°F |
| Suction head: | 2 to 4 feet head |
| Rated capacity: | 250 gpm at 90 psig discharge pressure |
| Pump Speed: | 3,450 rpm maximum |
| Motor: | Constant speed, see Table 60.25.e.1 for horsepower ratings. |
|
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Table 60.25.f.1 provides a troubleshooting guide for the W2 Non-Potable Water System.
|
| Problem | Corrective Action
| Low system pressure as indicated by low pressure alarm |
|
| ||||||||
W3 water is chlorinated plant secondary effluent. It is supplied by the non-potable water pumps at the Effluent Treatment Complex. W3 water is used for the following functions/processes (see Figure 60.06):
The W3 pumping system consists of a wet well and three vertical turbine pumps. The W3 pump arrangement consists of two larger capacity pumps and one smaller capacity pump. Each pump is provided with a pilot-operated pressure relief valve that will discharge water flow back to the wet well as pressures (and corresponding demand) exceed the design range. This control valve protects the pumps from operating at or near shut-off head and will protect the distribution system from high pressures and water hammer.
The W3 distribution system is provided with a strainer to remove particulates present in the plant effluent. This strainer has an automatic backwash system that will initiate the backwash cycle when differential pressure across the strainer element exceeds a preset limit.
Biological regrowth in the W3 wet well and distribution system is controlled by the addition of a sodium hypochlorite solution. The hypochlorite solution is added to the W3 wet well on a continuous basis; with the dose of sodium hypochlorite pacing the W3 flow as measured by a propeller flow meter (FE/FIT-16311). To provide adequate disinfection, the hypochlorite solution feed system should be set-up initially to maintain a free chlorine residual of 2.0 ppm at a median flow condition (i.e., one large pump operating with no recirculation). This should equate to a sodium hypochlorite feed rate of approximately 12 gph. Disinfection points are provided throughout the distribution system for periodic shock application and flushing of the system. During system flushing, the initial flush of water in the remote areas of the system should be checked for residual chlorine to ensure that the wet well dose of hypochlorite is adequate. If the residual chlorine concentration is above about 1.0 ppm in all locations checked, then the dose to the wet well should be decreased. If no detectable residual is found, then the hypochlorite dose should be increased or system flushing done more frequently. See also Section 45 for a discussion of the sodium hypochlorite delivery system.
To accommodate future W3 demands associated with plant expansion, the wet well and portions of the distribution mains have been sized for increased pumping capacity. To provide this increased capacity, the Phase I W3 pumps must be replaced in future phases of expansion to meet the W3 demands projected for that expansion. Similarly, the W3 strainer, flow meter, and pump control valves will have to be replaced or modified as the capacities for each of these pieces of equipment are exceeded.
The W3 pumping system is sized to provide design flows with one large pump out of service. For additional system reliability, the redundant pump can also be used when unexpectedly high W3 demands are encountered. The W3 strainer is provided with bypass/isolation capabilities for maintenance purposes.
W3 Wet Well
| Length | 18 ft
| Width | 8 ft
| Depth | 14 ft
|
| W3 Demand
| Minimum | 500 gpm
| Maximum | 1,440 gpm
|
| W3 Pumps
| Number | 3 (1 large, 1 small, 1 large redundant)
| Type | Vertical Turbine
| Power Requirement | Large: 75 hp
| Small: 60 hp
| Capacity | Large: 880 gpm @ 231 ft TDH
| Small: 680 gpm @ 231 ft TDH
|
| W3 Flowmeter
| Type | Propeller Flowmeter
| Capacity | 2,250 gpm
| Size | 12 inch
| Number of Units | 1
|
| W3 Strainer
| Type | Automatic Backwash Strainer
| Number of Units | 1
| Capacity | 1,500 gpm @ 150 psig test pressure
| |
Primary elements, associated equipment, and element numbers are listed in Table 60.30.e.1.
|
| Primary Element | Location | Element No.
| High pressure switch | Each pump discharge | PSH-16301, PSH-16302, PSH-16303
| Differential pressure switches | Across W3 strainer | PDS-16341, PDS-16342
| Flow meter | W3 discharge header | FIT-16311
| Pressure element and transmitter | W3 discharge header | PT-16311
| Pressure indicators | Strainer suction and discharge line | PI-16311, PI-16312
| | ||
The following devices are located at the MCC:
The following controls are located on the package control panel provided with the strainer (see Figure 60.05):
In the AUTO mode, the strainer starts the backwash cycle when the differential pressure across the filter element exceeds a preset limit. The strainer starts the backwash arm and opens the backwash drain valve. In the HAND mode, the backwash is started using the SS pushbuttons.
Loop Function: The purpose of this control loop is to sequence the W3 pumps to maintain flow and pressure in the W3 distribution system. It is also used to monitor alarms and the status of W3 system equipment and flow conditions.
When in REMOTE, the W3 pumps are started and stopped based on pressure and flow in the W3 distribution system as measured just downstream of the strainer. Set points for sequencing pump operation are listed in Table 60.30.g.1.
|
| Initial Conditions | Sequence Point | Action
| Small pump running | Header pressure > 85 psi | None
| Small pump running | Header pressure < 85 psi | Start large pump, stop small pump
| Large pump running | Header pressure > 85 psi | None
| Large pump running | Header pressure < 85 psi | Start small pump
| Small and large pump running | Header pressure > 105 psi and system flow | < 800 gpm for a time delay of 15 min Stop small pump
| Large pump running | Header pressure > 105 psi and system flow | < 600 gpm for a time delay of 15 min Stop large pump, Start small pump
| Any condition | Header pressure < 75 psi | PAL-16311 low pressure alarm
| | ||
The 15 minute time delay when stopping the pumps on low system flow and high system pressure will prevent pump cycling caused by fluctuating demands and will reduce excessive pump motor starts. With only the small pump operating or when between sequencing points, as the demand in the W3 system drops and, correspondingly, the system pressure rises above the set point of the pressure control valves at the discharge of the W3 pumps (115 psig), W3 water will be recirculated back to the wet well. This will allow the W3 pumps to remain safely on their operating curves.
The large pumps are automatically alternated (when both are in REMOTE mode) to equalize pump run time. A pump discharge failure alarm is actuated when a pump run command is not confirmed by the pump discharge pressure switch closing after a set time delay.
Table 60.30.h.1 provides a troubleshooting guide for the W3 Non-Potable Water System.
|
| Problem | Corrective Action
| Low system pressure is indicated by the low pressure alarm |
|
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Fire protection at the plant site is provided from a separate fire water system (FW). FW is non-potable water that comes to the plant as potable water and is passed through a double check valve assembly to the fire water distribution system. The FW distribution system is fed by two separate 8-inch mains from the City of Vancouver Water Department. One connection is located to the south of the Effluent Treatment Complex (coordinates N110034.64, E1457790.50); the second is adjacent to the main plant potable water service located to the east of the main plant entrance drive.
Site fire protection is provided by fire hydrants located throughout the plant site. Individual building and/or area fire protection is provided by fire sprinkler systems. Areas not subject to freezing conditions utilize wet pipe systems, whereas areas that have the potential to freeze are provided with dry pipe systems. In wet pipe systems the entire sprinkler system is filled with pressurized water that sprays out when the sprinkler head is activated. Dry pipe systems are filled with compressed air that is automatically purged when the sprinkler heads are activated before the water sprays out.
Those areas not provided with fire sprinkler systems are equipped with portable, dry chemical fire extinguishers. These fire extinguishers are designed for use on A, B, and C class fires.
The fire sprinkler systems are designed in accordance with the Uniform Building Code (UBC) Standard 38-1 and National Fire Protection Association (NFPA) Standard 13. Table 60.33.b.1. lists the areas that have fire sprinkler systems, the types of systems, and the design criteria for the areas. Each area listed is provided with a separate standpipe. This standpipe is designed in accordance with the requirements of the standards listed above, and include a fire sprinkler control valve, a fire department connection, and, in the case of the dry pipe systems, an air compressor. All sprinkler heads are designed to activate at 165 °F with the exception of the fuel storage room which has 140 °F sprinkler heads.
[Table]
The type and installation of fire hydrants on the plant site are in accordance with the City of Vancouver Water Department's Standard Plan No. W-5.
All double check valves are installed in below grade concrete vaults to protect them from freezing and physical damage. The type and installation of the double check valves are in accordance with the City of Vancouver Water Department's Standard Plan No. W-12.
Each standpipe location will be provided with a local annunciator (an electrically-operated alarm bell) located on the outside of the building directly above the fire department connection. In addition, all alarm signals will be annunciated at the fire alarm control panel.
Each standpipe will be provided with the following primary control devices:
The fire sprinkler systems are designed to operate automatically without operator or fire department intervention. Maintenance of the system should consist of an annual flow test of each sprinkler system that will be witnessed by the fire department. Maintenance of individual components in the system should be done in accordance with the manufacturers' recommendations.
Use and operation of the fire hydrants should be limited to fire department personnel. Maintenance of the fire hydrants should be done in accordance with the manufacturers' recommendations.
Each double check valve assembly consists of a double check valve between two OS&Y isolation gate valves, a bypass-type detector meter, and a fire department pumper truck connection downstream of the check valves. The assembly operates automatically and requires no operation. The detector meter registers any flow through the double check valve assembly.
The double check valve assembly must be tested annually by someone certified in the State of Washington's Cross Connection Program, and these results must be submitted to the City of Vancouver Water Department. Maintenance should be done in strict accordance with the manufacturer's written instructions.
| Area Served | Sprinkled Area (ft2) | Occupancy | Hazard Classification | Sprinkler System Type
|
| Influent Pump Station Pump Room 01-001 | Influent Pump Station Motor Room 01-101 | Screenings Area 02-201 | Screenings/Grit Handling Hopper Room 03-201 | Screenings/Grit Handling Truck Room 03-101 | Gallery (Aerated Grit Chambers Pump Room) 04-001 | Gallery 01-002 and 02-001 | Headworks Blower Room 05-101 | Gallery 07-001 and 08-001 | Scum Skimmer Room 08-201 (Unheated) | Fuel Storage Room 13-102 | Chemical Storage Building | | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Standby generating capacity is available to adequately supply the essential influent pumping, primary treatment, and effluent disinfection loads. The generator will begin operation during a power outage and continue running until preferred power has been restored. Emergency power will be provided to all the essential equipment to assure continuous operation and required effluent quality of the plant's critical treatment processes based on a priority system.
The emergency generator sets are located in the Emergency Generator Room in the Aeration Complex (see Figure 60.02). The Emergency Power System consists of two 480-volt, 3-phase, 750 kW diesel engine driven generator, emergency transfer switchgear, and fuel storage facilities. See Section 6010 for a description of the plant electrical power distribution systems and Section 6040 for a description of the Diesel Fuel System.
The Engine Generators were purchased as a package. Please refer to the manufacturer's O&M manual for details on its operation and maintenance. The following devices are located on engine control panel EGP-13010:
Refer to Section 6040 of this manual for a detailed description of the diesel fuel system. The following devices are located on engine control panel EGP-13010:
The fuel tank full light will come on when the fuel tank is full to alert the supplier to stop filling.
The emergency transfer switch gear provides local control logic (timers and relays) to switch from the utility power source to the emergency generator power source should the utility source fail. It will also re-transfer when the utility source is back to normal.
The Emergency Engine Generator design criteria are as follows:
| Number of units | 1 |
| Phase 2 | 2 (1 new, 1 existing) |
| Type | Diesel |
| Peak Output Capacity | 750 kW @ 1,800 rpm |
| Cooling System | Air-cooled Radiator |
| Fuel Oil Tank Capacity | 660 Gallons |
| Fuel Consumption | 53 gph @ Full Load |
The normal power distribution system is set up with Clark County Public Utilities (CCPU) supply as the preferred source. The double-ended, distribution system is designed to operate with any one major plant feeder or motor control center out of service.
The PLC controls the re-start of equipment when switching from utility power to the emergency generator source. There are three different re-start sequences, depending on which plant power source has failed. The first sequence will occur if power is lost to both main buses A and B, which is determined to have happened if both circuit breakers ACB-152 and ACB-252 have opened and no voltage is sensed on the buses by VT-12203 and VT-12206. Equipment with ON/OFF handswitches will re-start immediately when the emergency generator comes on line if the equipment's handswitch is in the ON position. This equipment includes the following:
All equipment with HAND/OFF/REMOTE or HAND/OFF/AUTO handswitches and START/STOP pushbuttons will not re-start if they are running in HAND mode before the switch to emergency power.
Equipment with HAND/OFF/AUTO handswitches that are running in the AUTO mode before the switch to emergency power will re-start as required by local control. This equipment includes the following:
Equipment with HAND/OFF/REMOTE handswitches that are running in the REMOTE mode before the switch to emergency power will be allowed to re-start by the PLC in the following sequence:
Twenty seconds after the transfer switch has switched to emergency power, the following equipment will be allowed to re-start as required:
After thirty seconds:
After forty seconds:
After fifty seconds:
After sixty seconds:
The following equipment will not be allowed to re-start by the PLC in the REMOTE mode:
The second sequence will occur if power is lost only on bus A, which is determined to have happened if circuit breaker ACB-152 has opened and no voltage is sensed on the bus by VT-12203. The second re-start sequence is identical to the re-start of the first sequence with the following differences. Equipment powered from bus B will continue to operate without interruption. Equipment on bus A that was running as a LEAD piece of equipment will become the LAG or standby equipment and will be allowed to re-start after the re-start time delay has elapsed and as the process demand requires. The only equipment items not allowed to re-start on bus A are aeration blowers B-11022 and B-11024. The following equipment is powered from bus A:
The third sequence will occur if power is lost only on bus B, which is determined to have happened if circuit breaker ACB-252 has opened and no voltage is sensed on the bus by VT-12206. The third re-start sequence is identical to the second re-start sequence except it applies to equipment on bus B. The only equipment items not allowed to re-start on bus B are aeration blowers B-11021 and B-11023. The following equipment is powered from bus B:
If the tie-breaker circuit breaker ACB-352 is closed, such that the power feed to the plant is coming from a single bus A or B, and power is lost to the plant, the first re-start sequence will be performed.
The Diesel Fuel System consists of two 660-gallon Fuel Tanks, a Fuel Filling Station and necessary piping. The fuel tanks are located in separate rooms in the Generator Room of the Aeration Complex. The Fuel Filling Station is west of the Generator Room near the electrical transformer.
The fuel tank full light will come on when the fuel tank is full to alert the supplier to stop filling.
When the tank is filling, as sensed by the fuel oil tank level transmitter, the fuel oil tank full light will blink for 1 second once every 30 seconds. This is done to test the lamp. When the tank is full, the light will come on continuously.
In the event of a diesel fuel spill, the operator's first priority concern is the safety of people. Second priority is the environment, and third is property. For small spills, absorption with shop floor absorbent is the fast, inexpensive, and readily available method. It minimizes the surface area of the spilled diesel fuel, thus reducing the amount of vapor released and makes the diesel fuel easy to remove and dispose of. For larger spills, follow the procedures outlined in Section 80 of this manual.
The HVAC systems for the Vancouver Marine Park Water Reclamation Facility are described below. The intent of this section of the operations manual is to provide the basic design concepts for the systems as well as a general operating description. The systems are described by building.
The HVAC systems were designed to meet the following standards: Uniform Building Code, Uniform Mechanical Code, Washington State Energy Code, the National Fire Code, and Recommended Standards for Sewage Works. Special attention is focused on National Fire Protection Association (NFPA) 820, Recommended Practice for Fire Protection in Wastewater Treatment Plants. Also, the HVAC design should generally comply with the applicable standards and recommended practices of the following trade organizations:
The HVAC system is intended to perform the following functions:
Outdoor design conditions are as follows:60.40 Diesel Fuel System
60.40.a Overview
60.40.b Local Status and Control
60.40.b.1 Fuel Oil Tank
60.40.c PLC/SCS Functions
60.40.c.1 Fuel Oil Tank
60.45 HVAC
60.45.a HVAC Standards
60.45.b Functions of the HVAC System
60.45.c HVAC Design Data
60.45.c.1 Outdoor
| Summer: | 88° F DB, 67° F WB, 0.5 percent design point
96.6° F, median annual high (estimated) 107° F, record high (estimated) 23° F, daily range (estimated) 300 cooling degree days/year |
| Winter: | 22° F, 0.6 percent design point
14° F, median annual low -3° F, record low (estimated) 4,667 heating degree days/year, 65° F base 3,385 heating degree days/year, 60° F base 1,333 heating degree days/year, 50° F base 708 heating degree days/year, 45° F base |
Indoor design conditions vary, depending on the occupancies of the areas served. Table 60.45.c.1. lists the indoor design conditions as well as the code required ventilation rates. Note that some areas with low heat gains may not reach the maximum design temperature listed.
Table 60.45.c.1 lists the ventilation rates for spaces as required by NFPA 820. These rates are expressed in air changes per hour (AC/hr). This corresponds to the flow rate of fresh, outdoor air that must be supplied to the spaces continuously. The code also requires that all mechanically ventilated spaces should be served by both supply and exhaust fans.
Design Temp Design Temp (Outdoor Air) Vent. Rate Emergency Power
| Influent Pump Station | Wet Well | Pump Room | Motor Room | Screening Area | Screening Area | Screening/Grit Handling | Hopper Area | Truck Area | Aerated Grit Chambers | Grit Tanks | Tank Vents Above Grit Tanks | Grit Pump Gallery | Blower Room | Blower Room | Air Treatment System | Air Treatment System | Primary Clarifiers | Sludge Pump Gallery | Clarifier | Scum Skimmer Room | Satellite Operation Ctr | Polymer Room | Office/Laboratory | Aeration Blower Room | Blower Room | Generator Room | Generator Room | Combustion Air Electrical Distribution | Distribution Room | Distribution Yard | RAS Pump Station | Pump Room | MCC Room | | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||