Attachment 8 - Drawings Part 3 of 3 - Manchester - 608-315.pdf

UPS

LS

CM

MM

NET

1QTY:VFD 1QTY:ECM

T/C

CSCS

T/H

CSCS

T/H/C

CSCSCS

A

POS

O

POS

C

POS

O/C

POS

O/C

POS

O/C

POS

O/C

POS

CT-A

CT-B

T/H/C

CSCSCS

M

A

POS

M

O/C

POS

O/C

POS

O/C

POS

O/C

POS

1QTY:

A F

M S

M

CT-A

O/C

POS

O/C

POS

1QTY:

A F

M S

CT-A

O/C

POS

O/C

POS

ST/ST

E-HTG

SP-RES

SPD-C

VCI

VCO

SW

H

CO2

T

SMD

RS

SPM

CO

MS

NO2

OCC

DWP

OS

PC

H ACCH-1

NET

BAT-L UPS BATTERY LOW ALARM

DEVICE LEGEND - MISCELLANEOUS

MOTOR START/STOPST/ST

GENERAL RELAY (ON/OFF)GR

ELECTRICAL LIGHT SENSORLS

CM FIRE ALARM CONTROL MODULE

CM FIRE ALARM MONITOR MODULE

STS STATUS

CT-A

CT-B

CURRENT TRANSDUCER (ANALOG)

CURRENT TRANSDUCER (BINARY)

ASSEMBLY LEGEND

AO

BO

BI

ST/ST

ALM

SPD-C SPD-C

ST/ST

AO

BO

T-RM CO2-RM T-RM H-RM

T-RM CO2-RM

AI

V-CLG AO

POS-A

AI

V-ISO V-ISO V-ISO

POS-O POS-C POS-OCBI BI

BI

BI

BO BO BO

AIR COOLED CHILLER

AI

BI

BI

BO

AI

VARIABLE FREQUENCY DRIVE

ELECTRONICALLY

COMMUTATED MOTOR

COMBINATION ROOM SENSOR

NOTE: SENSOR TYPE IS INDICATED IN LETTER

DESIGNATION

"T" = TEMPERATURE

"H" = HUMIDITY

"C" = CARBON DIOXIDE (CO2)

DAMPER AND VALVE POSITION INDICATION

ANALOG

BINARY

LETTER DESIGNATION INDICATES POSITION TYPE

"A" = ANALOG

"O" = OPEN

"C" = CLOSED

"O/C" = OPEN AND CLOSED

POS-OC

BI

BI

POS-A AI

D-OA

AO

NOTE: ASSEMBLIES ARE EXISTING DEVICES FROM THE LEGEND THAT ARE GROUPED INTO THE ITEMS BELOW AND SHOWN EITHER ON THE GROUP, ON A STATUS BAR OR LETTER DESIGNATION. WHEN SHOWN THE POINTS WILL BE INDICATED IN THE POINT LIST ON THE DRAWING. IF THE ASSEMBLY HAS A QUANTITY “QTY: #”, THE “#” NUMBER NEXT TO IT INDICATES A MULTIPLIER FOR ALL POINTS FOR THAT GROUP. EX: “VFD QTY: 4”. THIS MEANS THERE ARE 4 VFD’S, NOT ONE. ALSO THAT MEANS THERE ARE 4 OF EACH POINT TYPE SHOWN FOR THAT ASSEMBLY.

CT-A

AI

BI

AI

POS-OC

D-SISO

BI

A-SA

BO

SUPPLY/RETURN/EXHAUST FAN

BDD

NOTE: QUANTITY NUMBER

IS A MULTIPLIER FOR ALL

POINTS SHOWN

STATUS BAR STATUS BAR

NOTE: QUANTITY

NUMBER IS A

MULTIPLIER FOR

ALL POINTS

SHOWN

NOTE: QUANTITY

NUMBER IS A

MULTIPLIER FOR

ALL POINTS

SHOWN

BI

BO

BO

BI

SYMBOL TYPE DESIGNATION SERVICE

ALM ALARMBI

E-HTG ELECTRIC SCR HEAT CONTROL

SPD-C MOTOR SPEED CONTROL

SP-RES SETPOINT RESET

FH-SS FUME HOOD SASH SENSOR

VCI VARIABLE COMMAND INPUT

AO

AO

AO

AI

VCO VARIABLE COMMAND OUTPUT

SW SWITCH

AI

AO

BI

DEVICE LEGEND - ROOM / SPACE SENSORS

H-RM

H-OA

HUMIDITY ROOM / SPACE

HUMIDITY OUTSIDE AIR

CO2-RM CARBON DIOXIDE (CO2) ROOM / SPACE

T-RM

T-OA

T-SLB

ROOM / SPACE TEMPERATURE

OUTSIDE AIR TEMPERATURE

SLAB TEMPERATURE

SD-RM SMOKE DETECTOR ROOM / SPACE

RS-M

RS-W

RS-ALM

REFRIGERANT SENSOR MONITOR (PPM)

REFRIGERANT SENSOR - LOW WARNING

REFRIGERANT SENSOR - HIGH ALARM

SPM

CO CARBON MONOXIDE

MS

NO2

OCC

MOISTURE SENSOR

NITROGEN DIOXIDE

OCCUPANCY SENSOR

DWP-RM DEW POINT TEMPERATURE

SPACE PRESSURE MONITOR

OS OXYGEN SENSOR

PC PARTICLE COUNTER

AI

AI

AI

AI

AI

AI

BI

AI

AI

AI

AI

BI

AI

SYMBOL TYPE DESIGNATION SERVICE

STATUS BAR

ST/ST

AO

ALM

BO

SP-RES

BI

AI AI AI AI

AI AI

H-RM

SNOW SENSOR SWITCHS-SSBI

Project Number

Building Number

Drawing Number

Project Title

Location

Issue Date Checked Drawn

Drawing Title

Approved:

VA FORM 08 - 6231

A

Office of Construction and Facilities Management

U.S. Department of Veterans Affairs

B

C

D

E

F

A

B

C

D

E

F

21 4 5 6 7 8 9 10

Phase

ARCHITECT STAMPCONSULTANT

321 4 5 6 7 8 9 10

129 South St, 2nd floor Boston, MA 02210

T: 617.772.0260 F: 617.772.0261 www.e4harchitecture.com

FINAL FOR

CONSTRUCTION

FULLY SPRINKLERED

STRUCTURAL MEP / FP

Simpson Gumpertz & Heger 480 Totten Pond Road Waltham, MA 02451

T: 781.907.9000 sgh.com

BR+A

10 Guest Street, 4th FLR Boston, MA 02135

T: 617.254.0016 brplusa.com

CIVIL

Meridian Associates, Inc.

500 Cummings Center, Suite 5950 Beverly, MA 01915

T: 978.299.0447 meridianassoc.com

K J o b s \1

.N

G \B

A S

\2

B

A S

D

IA

G R

A M

S

C U

R R

E N

T

B A

S M

A S

T E

R D

IA

G

R A

M S

.r v t

/1 /2

:0

:1

A

M

MH7-0.2

CONTROLS LEGEND DESIGN SPECIALTY

CARE BUILDING

718 Smyth Rd, Manchester, NH 03104

608-315

12/20/2023Revisions: Date:

CONSTUCT SPECIALTY

CARE BUILDING

CONSTRUCT SPECIALTY

CARE BUILDING

4QTY:

NET

4QTY:VFD

CT-ACT-A

A F

M S

A F

M S

CT-A

A F

M S

CT-A

A F

M S

4 QTY:

CT-A

A F

M S

CT-A

A F

M S

CT-ACT-A

A F

M S

A F

M S

NET

4QTY:VFD

M

A

POS

M

M

M

O

POS

UPS

T T

T P

P

PP

P

P

P P P

T

T

T

H

HH

M

O

POS

A F

M S

T

H

T

ST/ST

PHCP

CT-A

P

M

O/C

POS

O/C

POS

O/C

POS

O/C

POS

M

AHU BOUNDARY

SUPPLY AIR

RETURN AIR

A F

T E

R F

IL

T

E R

P R

E -F

IL

T

E R

C O

O L

IN

G C

O

IL

NAC

BACNET IP

ETHERNET

CHWS

CHWR

CONTROL

PANEL

F

IN

A L F

IL

T

E R

TO RELIEF

OUTSIDE AIR

A-RA

BDD

P-RALL

D-RISO T-RA H-RA

SD-RA

D-OA

P-DP-A P-DP-A

T-MA T-PHT

V-CLG

T-LTD P-DALL

T-CC

A-SA

BDD

P-DAHL

P-DP-A

BAT-L

AFS

H-HL

D-ISO

H-DA T-RA

P-SAHL

SD-SA

P-RFSP

D-RLF

D-RA

P-DASP

T-OA

H-OA

A-OA

H

S T

E A

M C

O N

D E

N S

A T

E

S T

E A

M S

U P

P L Y

T-SW

V-HUMT-HWR

V-PH

HWS

HWR

P R

E H

E A

T C

O

IL

GLOBAL POINTS

KEY NOTES

STATIC PRESSURE SENSOR AS SHOWN ON HVAC DUCTWORK SHEET MH1-0.1. SENSOR

SHALL BE HARDWIRED TO AHU CONTROLLER. SHARED POINT OVER THE

NETWORK SHALL NOT BE ALLOWED.

THESE DEVICES SHOULD BE MOUNTED IN A SERVICABLE LOCATION ON A NORTH WALL

OUT OF DIRECT SUNLIGHT AND AWAY FROM ANY EXHAUST VENTS.

P-RAHL

D-ISO

V-ISO

D-RLF

TO PENTHOUSE

Project Number

Building Number

Drawing Number

Project Title

Location

Issue Date Checked Drawn

Drawing Title

Approved:

VA FORM 08 - 6231

A

Office of Construction and Facilities Management

U.S. Department of Veterans Affairs

B

C

D

E

F

A

B

C

D

E

F

21 4 5 6 7 8 9 10

Phase

ARCHITECT STAMPCONSULTANT

321 4 5 6 7 8 9 10

129 South St, 2nd floor Boston, MA 02210

T: 617.772.0260 F: 617.772.0261 www.e4harchitecture.com

FINAL FOR

CONSTRUCTION

FULLY SPRINKLERED

STRUCTURAL MEP / FP

Simpson Gumpertz & Heger 480 Totten Pond Road Waltham, MA 02451

T: 781.907.9000 sgh.com

BR+A

10 Guest Street, 4th FLR Boston, MA 02135

T: 617.254.0016 brplusa.com

CIVIL

Meridian Associates, Inc.

500 Cummings Center, Suite 5950 Beverly, MA 01915

T: 978.299.0447 meridianassoc.com

K J o b s \1

.N

G \B

A S

\2

B

A S

D

IA

G R

A M

S

C U

R R

E N

T

B A

S M

A S

T E

R D

IA

G

R A

M S

.r v t

/1 /2

:0

:2

A

M

MH7-0.3

MIXED AIR AHU DIAGRAM &

POINTS LIST

DESIGN SPECIALTY

CARE BUILDING

718 Smyth Rd, Manchester, NH 03104

608-315

12/20/2023

Air Handling Unit - Mixed Air Fan Array Hot Water Preheat, Cooling with Humidification Control Points List

EQUIPMENT TYPE DESIGNATION SERVICE ALM_LO ALM_HI

ALM_OFF /

NORMAL COMMENTS

VFD-RF AO SPD-C MOTOR SPEED CONTROL

VFD-RF AO SPD-C MOTOR SPEED CONTROL

VFD-RF AO SPD-C MOTOR SPEED CONTROL

AO V-CLG COOLING COIL VALVE

AO V-HUM HUMIDIFIER VALVE

AO V-PH PREHEAT COIL VALVE

BI AFS DUCTWORK AIR FLOW SWITCH X HARDWIRE INTERLOCK

VFD SF BI ALM ALARM X

VFD SF BI ALM ALARM X

VFD SF BI ALM ALARM X

VFD SF BI ALM ALARM X

VFD-RF BI ALM ALARM X

VFD-RF BI ALM ALARM X

VFD-RF BI ALM ALARM X

VFD-RF BI ALM ALARM X

BI BAT-L UPS BATTERY LOW ALARM X

BI P-DAHL DISCHARGE AIR / HIGH PRESSURE LIMIT X UNIT STATIC SAFETY - HARDWIRE INTERLOCK

BI P-DALL DISCHARGE AIR / LOW PRESSURE LIMIT X UNIT STATIC SAFETY - HARDWIRE INTERLOCK

BI P-RAHL RETURN AIR / HIGH PRESSURE LIMIT X DUCTWORK STATIC SAFETY - HARDWIRE INTERLOCK

BI P-RALL RETURN AIR / LOW LIMIT X DUCTWORK STATIC SAFETY - HARDWIRE INTERLOCK

BI P-SAHL SUPPLY AIR / HIGH PRESSURE LIMIT X X DUCTWORK STATIC SAFETY - HARDWIRE INTERLOCK

BI POS-O DAMPER POSITION - OPEN SUPPLY D-ISO

BI POS-O DAMPER POSITION - OPEN RETURN FAN ISOLATION

BI POS-OC DAMPER POSITION - OPEN & CLOSED RETURN FAN ISOLATION

BI POS-OC DAMPER POSITION - OPEN & CLOSED

BI SD-RA RETURN AIR SMOKE DETECTOR X HARDWIRE INTERLOCK

BI SD-SA SUPPLY AIR SMOKE DETECTOR X HARDWIRE INTERLOCK

BI T-LTD LOW TEMPERATURE X HARDWIRE INTERLOCK

BO D-ISO ISOLATION DAMPER UNIT SUPPLY ISOLATION

BO D-ISO ISOLATION DAMPER

BO D-RISO RETURN FAN ISOLATION DAMPER

PHCP BO ST/ST MOTOR START/STOP

VFD SF BO ST/ST MOTOR START/STOP

VFD SF BO ST/ST MOTOR START/STOP

VFD SF BO ST/ST MOTOR START/STOP

VFD SF BO ST/ST MOTOR START/STOP

VFD-RF BO ST/ST MOTOR START/STOP

VFD-RF BO ST/ST MOTOR START/STOP

VFD-RF BO ST/ST MOTOR START/STOP

VFD-RF BO ST/ST MOTOR START/STOP

BO V-ISO ISOLATION VALVE - OPEN / CLOSE HUMDIFIER PREHEAT JACKET ISOLATION VALVE

Air Handling Unit - Mixed Air Fan Array Hot Water Preheat, Cooling with Humidification Control Points List

EQUIPMENT TYPE DESIGNATION SERVICE ALM_LO ALM_HI

ALM_OFF /

NORMAL COMMENTS

AI A-OA OUTSIDE AIR FLOW

RF AI A-RA RETURN AIR FLOW

RF AI A-RA RETURN AIR FLOW

RF AI A-RA RETURN AIR FLOW

RF AI A-RA RETURN AIR FLOW

SF AI A-SA SUPPLY AIR FLOW

SF AI A-SA SUPPLY AIR FLOW

SF AI A-SA SUPPLY AIR FLOW

SF AI A-SA SUPPLY AIR FLOW

PHCP AI CT-A CURRENT TRANSDUCER (ANALOG)

RF AI CT-A CURRENT TRANSDUCER (ANALOG)

RF AI CT-A CURRENT TRANSDUCER (ANALOG)

RF AI CT-A CURRENT TRANSDUCER (ANALOG)

RF AI CT-A CURRENT TRANSDUCER (ANALOG)

SF AI CT-A CURRENT TRANSDUCER (ANALOG)

SF AI CT-A CURRENT TRANSDUCER (ANALOG)

SF AI CT-A CURRENT TRANSDUCER (ANALOG)

SF AI CT-A CURRENT TRANSDUCER (ANALOG)

AI H-DA DISCHARGE AIR HUMIDITY X

AI H-HL HUMIDITY HIGH LIMIT X HARDWIRE INTERLOCK

AI H-OA OUTSIDE AIR HUMIDITY

AI H-RA RETURN AIR HUMIDITY X X

AI P-DASP DISCHARGE / STATIC PRESSURE X X

AI P-DP-A DIFFERENTIAL PRESSURE - ANALOG X FINAL FILTER

AI P-DP-A DIFFERENTIAL PRESSURE - ANALOG X AFTER FILTER

AI P-DP-A DIFFERENTIAL PRESSURE - ANALOG X PRE-FILTER

AI P-RFSP RELIEF AIR / STATIC PRESSURE X X

AI POS-A DAMPER POSITION - ANALOG MINIMUM OA DAMPER

AI T-CC COOLING COIL LEAVING AIR TEMPERATURE

AI T-HWR HOT WATER RETURN TEMPERATURE

AI T-MA MIXED AIR TEMPERATURE

AI T-OA OUTSIDE AIR TEMPERATURE

AI T-PHT PREHEAT COIL LEAVING AIR TEMPERATURE

AI T-RA RETURN AIR TEMPERATURE

AI T-RA RETURN AIR TEMPERATURE

AO D-OA OUTSIDE AIR DAMPER

AO D-RA RETURN AIR DAMPER

AO D-RLF RELIEF AIR DAMPER

AO D-RLF RELIEF AIR DAMPER PENTHOUSE MECHANICAL VENTILATION

VFD SF AO SPD-C MOTOR SPEED CONTROL

VFD SF AO SPD-C MOTOR SPEED CONTROL

VFD SF AO SPD-C MOTOR SPEED CONTROL

VFD SF AO SPD-C MOTOR SPEED CONTROL

VFD-RF AO SPD-C MOTOR SPEED CONTROL

Revisions: Date:

CONSTUCT SPECIALTY

CARE BUILDING

1. Air Handling Unit: Mixed Air Fan Array Hot Water Preheat, Cooling with Humidification A. General

1. Programs and sequences indicated or implied herein shall be provided.

2. Provide all I/O points indicated on the control diagram and as required to accomplish the sequence of operation.

3. All wire terminals, devices, gauges and wires shall be identified within the panels.

4. Dampers and safeties shall be hard wire interlocked such that they will operate per the sequence below in either auto, hand or off on the VFD/MMC.

5. All points shall be able to integrate to all trends, totalizations, etc., as applicable.

6. All alarms as indicated on the diagrams in the sequence of operation shall be generated to the appropriate server/workstations.

7. If the unit is served by Generator power, the BAS Contractor shall confirm all sequences on normal power, generator power and transition startups so all restarts occur automatically without user intervention.

B. Start/Stop

1. The unit normally operates continuously with remote capability for start/stop/scheduling functions.

2. The H.O.A. switch shall be kept in the “auto” position. “Hand” and “Off” positions shall be utilized for maintenance purposes.

When the air handling unit is off, the outside damper, relief damper, supply unit isolation damper and the return isolation damper shall be closed with the return damper being open. The cooling and humidification valves shall be closed. The preheat valve shall control as indicated below

3. When the unit receives a start command, the following shall occur simultaneously: a “Fan Speed Release Delay Timer” of 60 seconds (adj.) shall start; the minimum outside damper and relief damper shall open to its minimum position with return damper tracking in opposite action; the supply and return isolation dampers shall open; the supply and return fans shall start at minimum speed.

4. Upon confirmation the supply and return fans are running; the fan speed release delay timer ending; the unit isolation damper end switches are open; then the supply and return fans respectively shall modulate as indicated below for control.

5. When the unit is running, the relief damper shall open to X% as determined by the balancer to a supply CFM of 600 to the mechanical room.

6. Fan Failure and Restart Modes

a. Individual Fan Failure

1. If after a 60 second delay (adj.) upon startup or during normal operation a single fan fails, that individual fan shall be shut down and an alarm shall be generated. The fan shall be locked out in software and flagged on the graphic screen.

2. The remaining fans shall modulate to maintain static pressure control but shall monitor the individual motor amperage to make sure the fans do not increase into the motor service factor as listed on the motor nameplate.

b. Complete Supply or Return Fan Failure

1. If after a 60 second delay (adj.) upon startup or during normal operation all of the supply or return fans fail, the entire unit shall be shut down and an alarm shall be generated. The valves and dampers shall drive to the position indicated above for the unit being off. The fan shall be locked out in software and flagged on the graphic screen.

c. Individual Fan Restart Mode

1. When a fan is down for maintenance mode or failed and is ready to be restarted there shall be an individual fan restarted button on the graphic screen to start the fan without shutting down the rest of the unit.

2. Once the restart button is selected, the fan/VFD shall be restarted at minimum speed. Once the fan has proven status, its speed shall be ramped up over a 10-minute (adj.) duration. This shall be done utilizing a low select between the static pressure control loop and the ramp which will reduce the operating fans in response to the system static pressure increase. When all operating fans are at the same control signal, the ramp shall be terminated and all fans shall operate in unison. The 10 minute duration will be tested and adjusted based on system dynamics.

d. Fan Maintenance Mode

1. When a fan needs to be shut down for service, a Maintenance mode shall be activated on a fan by fan basis from the graphic screen. When activated the selected fan shall be slowly ramped down over a 10 minutes (adj.)

duration, allowing the static pressure control loop to increase the remaining operable fans without causing hunting. Once the fan selected for maintenance is at 0% speed signal, the fan shall be shutdown. The 10 minute duration will be tested and adjusted based on system dynamics.

C. Airflow Control

1. Setpoints

a. Supply Air Static Pressure = 1.5”w.c. (adj.)

b. Return fan flow matching setpoint = -500 CFM

c. Relief Air Minimum Static Pressure = 0.1”w.c. (adj.)

2. Upon start-up of the supply fans and return fans, the BAS panel receives a static pressure signal for the supply fan system.

The speed of the supply fans shall slowly ramp to increase system static pressure to maintain setpoint at the duct mounted static pressure sensor. The BAS Contractor shall work with the Testing and Balancing Contractor to confirm final static pressure setpoints for air system(s).

3. The return fan shall track the supply fan less the offset given above.

4. The outside air dampers and relief air damper shall modulate in unison with the return damper modulating in opposite action to provide a minimum outside air flow setpoint as indicated on AHU schedules (adjustable). The outside air dampers shall modulate open to maintain the outdoor air minimum ventilation setpoint, 6,000 cfm (adj.).

5. At no point shall the ductwork upstream of the relief air damper be negatively pressurized. The relief damper control shall only be overridden by slowly closing down the damper if the relief air pressure starts to fall below the minimum pressure setpoint.

6. Airflow Verification:

a. The BAS Contractor shall totalize the downstream air terminal units associated with the AHU by fan system and display on the unit graphics as follows:

b. The supply and return/exhaust fan airflow stations at the AHU totals shall be displayed by the fans.

c. Next to the fan total flow, the associated downstream air terminal unit flow totals will be displayed.

d. If the AHU serves more than a single floor or building, a sub graphic screen will be provided giving the air terminal unit totals on a floor by floor basis.

e. The secondary graphic screen will be launched from the air terminal unit total on the AHU screen.

D. Temperature Control

1. Setpoints:

a. Heating/Cooling: Discharge Air Temperature of 52 DegF (adj.)

1. Discharge Air Temperature Setpoint Deadband = +/- 0.75 DegF

b. Dehumidification: Discharge Air Dewpoint of 53 DegF (adj.) (calculated by discharge air temperature and humidity sensors)

c. Differential Enthalpy with Fixed Dry Bulb High Limit Lockout: Fixed Dry Bulb Setpoint = 75 DegF.

1. Fixed Dry Bulb Differential = 2 DegF (adj.)

2. The discharge temperature sensor shall control the cooling and heating coil control valves, the outside air, return air and relief air dampers in sequence to maintain the discharge air temperature setpoint. At no time shall the cooling and heating control valves be open at the same time during normal operation.

3. The outside air, return and relief air dampers will also be controlled via enthalpy calculation and outdoor air dry bulb temperature.

4. Economizer Mode

a. If the outdoor air enthalpy is less than the return air enthalpy and the outside air temperature is less than the fixed dry bulb setpoint minus the differential, then the unit will be in economizer control.

b. On a rise in discharge air temperature above setpoint the outside and relief air dampers will modulate to 100% open with the return air damper modulating in opposite action. On a further rise in temperature, the cooling coil control valve will be modulated open. On a drop in discharge temperature, the reverse sequence shall occur.

c. A mixed air low limit sequence shall operate to prevent nuisance tripping of the low limit temperature thermostats by reducing the outside air intake and increasing the return. Once the AHU is maintaining stable airflow and discharge temperature control, the mixed air low limit override shall release the damper to minimum ventilation control.

5. Mechanical Only Cooling

a. If the outside air enthalpy is greater than the return air enthalpy or the outside air temperature is greater that the outside air lockout temperature, then the economized mode will be locked out and the outside, return and relief air dampers shall control for minimum outside airflow.

b. On a rise in discharge air temperature above setpoint the cooling coil control valve will be modulated open. On a drop in discharge air temperature, the reverse sequence shall occur.

c. At an outside air temperature of 48 DegF (adj.) or lower, the cooling coil valve shall be shut. The cooling coil control valve shall remain closed when the air cooled chillers are not operating.

6. Dehumidification

a. When the discharge air dewpoint (calculated by the temperature and humidity sensors) rises above the discharge air dewpoint setpoint, then the cooling coil control valve will modulate open. On a drop in discharge air dewpoint temperature the reverse shall occur.

7. Heating

a. On a drop in discharge air temperature below setpoint the heating coil control valve will be modulated open to maintain setpoint. On a rise in discharge air temperature, the reverse shall occur.

b. When the AHU is off, the outside air temperature is below 35 DegF (adj.) and the preheat coil leaving air temperature falls below 50 DegF (adj.), the heating coil control valve will be modulated open to maintain the preheat coil leaving air setpoint of 50 DegF (adj.).

8. Cold Weather Startup:

a. When the outside air temperature is below 40 DegF and the unit start command is initiated, the position of the preheat hot water coil control valve will be checked. If the valve is open to maintain the preheat leaving air temperature and the coil hot water return temperature is equal to or greater than the discharge air temperature setpoint, then the unit will be released to start. If the preheat hot water coil valve is closed, then the preheat hot water coil control valve will be modulated open until the coil return hot water temperature is equal to or greater than the discharge air temperature setpoint, then the unit will be released to start.

b. During cold weather startup of the air handling unit, a mixed air low limit sequence shall operate to prevent nuisance tripping of the low limit temperature thermostats by reducing the outside air intake and increasing the return. Once the AHU is maintaining stable airflow and discharge temperature control, the mixed air low limit override shall release the damper to minimum ventilation control.

E. Humidification

1. Setpoints:

a. Return Humidity: 30% RH (adj.)

b. Discharge Humidity Reset Range: 40% RH to 65% RH

c. Discharge Humidity Setpoint Maximum: 80% (adj.)

d. Hardwired High Limit Analog Safety: 85% RH

e. Humidifier Lockout Setpoint: Outside Air Dewpoint of 44 DegF (adj.)

f. Humidifier Lockout Differential: 2 DegF Dewpoint.

2. The BAS Contractor shall provide a supply humidity sensor, differential pressure switch for proof of airflow, a modulating humidity high limit safety and interlock these safeties with the humidifier to prevent over humidifying.

When there is no airflow, the safety shall shutdown humidification by hardwire interlock along with disabling the humidity control loop. When the humidity high limit senses that the discharge air humidity exceeds the setpoint as set on the device, the control signal shall be scaled back proportionally. The device JCI HL-69158NP shall be provided.

3. The return air humidity shall reset the discharge air humidity setpoint via proportional plus integral (PI) loop. The return humidity setpoint and the supply humidity reset range shall be as listed above. At no time shall the supply humidity setpoint rise above the maximum setpoint as listed above.

a. On a drop in discharge humidity below the discharge humidity setpoint, the humidifier valve shall modulate open. On a rise in discharge humidity, the reverse shall occur.

b. On a drop in return humidity below the room/return humidity setpoint, the discharge humidity setpoint shall be slowly increase from the minimum reset range to maximum reset range setpoint. On a rise in return humidity, the reverse shall occur.

4. On a call for humidification the isolation valve will open. When the discharge air humidity control loop has dropped to zero percent command the isolation valve shall shut after a 4 hour, (adj.) delay.

5. The humidification control shall not operate during dehumidification mode of operation as indicated in the cooling portion of the temperature control sequence. Whenever humidification is required the steam isolation valve shall be open. The humidifier control valve shall be closed when the outside air dewpoint rises above the outside air lockout setpoint. Whenever the outside air dewpoint is above the lockout setpoint for longer than 24 hours (adj.), the steam isolation valve shall be closed. When the outside air dewpoint falls below the outside air dewpoint setpoint minus the lockout differential, the humidifier shall be enabled for operation.

F. Filters

1. There shall be an analog differential pressure sensor for each individual filter bank within the AHU.

2. An alarm shall be generated when the pressure across the filter bank rises above the dirty filter setpoint as indicated on the AHU filter schedules (adj.).

G. Safety Interlocks

1. The high discharge static pressure safety located on the discharge of the supply fan in the unit housing shall be set as scheduled for 1.0”w.c. above the total pressure rating of the supply fan as indicated on the AHU schedule.

The high suction static pressure safety located on the suction side of the supply fan in the unit housing shall be set as scheduled for 1.0”w.c. above the total pressure rating of the supply fan as indicated on the AHU schedule. The high discharge static pressure safety located in the discharge ductwork outside of the unit shall be set as scheduled for duct pressure class. If any of the safeties pressure setting is exceeded the safety will trip and via hardwire interlock to the supply fans VFD's so the fans shall shutdown and the unit isolation dampers shall close.

This safety shall operate in either hand or auto on the VFD's and shall be reset manually. If the supply fan is shutdown by safety the return fan shall also be shutdown.

2. The high discharge static pressure safety located on the discharge of the return fan in the unit housing shall be set as scheduled for 1”w.c. above the total pressure rating of the return fan as indicated on the AHU schedule. The high suction static pressure safety located on the suction side of the return fan in the unit housing shall be set as scheduled for 1”w.c. above the total pressure rating of the return fan as indicated on the AHU schedules. The high suction static pressure safety located in the return ductwork outside of the unit shall be set as scheduled for duct pressure class. If any of the safeties pressure setting is exceeded the safety will trip and via hardwire interlock to the return fans VFD's so the fans shall shutdown and the unit isolation dampers shall close. This safety shall operate in either hand or auto on the VFD's and shall be reset manually. If the return fan is shutdown by safety the supply fan shall also be shutdown.

3. When smoke is detected by the supply or return duct smoke detectors, the supply and return fans shall shut "off", the supply smoke isolation damper shall close and an alarm shall be generated. Supply and return fans shall restart and unit isolation dampers shall open when the fire alarm circuit is reset.

4. Provide a series of low temperature thermostats (freeze stats) on the inlet face of the cooling coil which will stop the unit and send an alarm if the freeze stat temperature falls below 38 DegF (adj.). The preheat coil control valve shall modulate to maintain 50 DegF at the Preheat coil sensor.

H. Energy Conservation Measures

1. Discharge Air Temperature Reset

a. Setpoints

1. Maximum Discharge Air Temperature Setpoint = 60 DegF (adj.)

2. Reset Routine Temperature Increments = 0.5 DegF (adj.)

3. Step and Wait Frequency = 15 minutes (adj.)

b. The discharge air temperature reset routine shall provide a reset from the above mentioned discharge air temperature setpoint up to the Maximum Discharge Air Temperature Setpoint for all associated AHU’s. The routine shall adjust the temperature by the Reset Routine Temperature Increments if all of the below mentioned criteria has been achieved. The calculation for change shall occur at the above mentioned Step and Wait Frequency. If any one of the criteria is not met then the reset routine shall decrease the discharge air temperature setpoint in the reverse fashion to and not below the discharge air temperature setpoint as noted in the Temperature Control section.

c. Only the VAV boxes served by the individual unit(s) shall be monitored for the basis of each AHU’s calculations. The setpoint will be adjusted up or down as follows:

1. The discharge air dewpoint shall not exceed the dehumidification setpoint.

2. The discharge air temperature will be increased when all VAV box cooling commands are less than

85% open for a 30 minute (adj.) duration with a differential of 2%.

3. The discharge air temperature will be decreased when any one zone VAV box cooling command is more than 95% for a 30 minute (adj.) duration with a differential of 2%.

4. The BAS shall accumulate a list of zones that are always greater than a 95% cooling command and produce a weekly report listing these zones and the number of instances these zones were in that state. This will allow the staff to investigate the zone and determine if airflow is choked or unsustainable loads have been placed in the zone.

5. If any VAV box cooling command reaches 100% for a 90 min (adj.) duration, an alarm shall be generated.

d. Maintenance Mode

1. The reset routine shall have the ability to provide a maintenance function on an individual VAV box level. The operator shall have the ability to flag zones as “Removed from Reset”. This function will then disable that individual controller from the reset routine until such time as the operator enables it again. The default shall be all controllers enabled.

2. The BAS contractor shall develop a report group that the Owner can run to indicate by AHU, which VAV boxes have been removed from the reset routine. The report will be grouped by AHU, by floor with the controller address and room number. This report will run on a weekly basis.

2. Static Pressure Reset

a. Setpoints

1. Reset Routine Static Pressure Increments = 0.1”w.c. (adj.)

2. Step and Wait Frequency = 15 minutes (adj.)

b. Supply VAV Box

1. The supply VAV box damper position for all boxes serviced by this AHU shall be monitored at the above mentioned step and wait frequency to determine the ability to automatically reset the supply static pressure setpoint for optimization. If all VAV box damper positions are less than 85% (adj.), the supply static pressure setpoint shall be reduced by the above mentioned pressure increments. If any one VAV box damper position is greater than 95% (adj.), the box will be deemed unsatisfied and the supply static pressure setpoint shall be increased by the above mentioned pressure increments. At no time should any boxes reach 100% open during the reset routine. If a box reaches 100% open for a 90 minute (adj.) duration an alarm shall be generated.

2. The BAS shall accumulate a list of zones that are unsatisfied and produce a weekly report will be grouped by AHU, by floor with the controller address and room number along with the number of instances these zones were unsatisfied and driving the reset logic. This will allow the staff to investigate the zone and determine the potential issue.

c. Maintenance Mode

1. The reset routine shall have the ability to provide a maintenance function on an individual VAV box level. The operator shall have the ability to flag zones as “Removed from Reset”. This function will then disable that individual controller from the reset routine until such time as the operator enables it again. The default shall be all controllers enabled.

2. The BAS contractor shall develop a report group that the Owner can run to indicate by AHU, which VAV boxes have been removed from the reset routine. The report will be grouped by AHU, by floor with the controller address and room number. This report will run on a weekly basis.

3. Optimal Start/Stop

a. Regardless if the unit is determined to run continuously, in the event that a schedule is implemented the unit shall be programmed to provide an Optimal Start/Stop routine which shall automatically ramp the building temperatures for the Optimal Start and Stop times to conserve energy while maintaining space temperature setpoints. Where applicable this strategy shall include but not be limited to incorporating terminal unit override for zones specifically associated to this AHU to help implement this routine.

Project Number

Building Number

Drawing Number

Project Title

Location

Issue Date Checked Drawn

Drawing Title

Approved:

VA FORM 08 - 6231

A

Office of Construction and Facilities Management

U.S. Department of Veterans Affairs

B

C

D

E

F

A

B

C

D

E

F

21 4 5 6 7 8 9 10

Phase

ARCHITECT STAMPCONSULTANT

321 4 5 6 7 8 9 10

129 South St, 2nd floor Boston, MA 02210

T: 617.772.0260 F: 617.772.0261 www.e4harchitecture.com

FINAL FOR

CONSTRUCTION

FULLY SPRINKLERED

STRUCTURAL MEP / FP

Simpson Gumpertz & Heger 480 Totten Pond Road Waltham, MA 02451

T: 781.907.9000 sgh.com

BR+A

10 Guest Street, 4th FLR Boston, MA 02135

T: 617.254.0016 brplusa.com

CIVIL

Meridian Associates, Inc.

500 Cummings Center, Suite 5950 Beverly, MA 01915

T: 978.299.0447 meridianassoc.com

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MH7-0.4

MIXED AIR AHU SEQUENCE OF

OPERATION

DESIGN SPECIALTY

CARE BUILDING

718 Smyth Rd, Manchester, NH 03104

608-315

12/20/2023Revisions: Date:

CONSTUCT SPECIALTY

CARE BUILDING

M

FE

T

T

M

FE

T

T

KEY NOTES:

UAC FOR ALL CONTROL POINTS

SHOWN ON DIAGRAM

PRICE REHEAT COIL LEACING AIR

TEMPERATURE SENSOR AS

DEDUCT ALTERNATE FOR ALL

VAV BOXES

AIR FLOW

SUPPLY

UAC

V-RH

HWS

HWR

D-VAV

FE-SA

T-RM

T-RHT

RHC

1. Terminal Unit: Supply VAV/CV with Reheat A. General

1. Programs and sequences indicated or implied herein shall be provided.

2. Provide all I/O points indicated on the control diagram and as required to accomplish the sequence of operation.

3. Control panel shall be labeled to identify power source. All wire terminals, devices, gauges and wires shall be identified within the panels.

4. All points shall be able to integrate to all trends, totalizations, etc., as applicable.

5. All alarms as indicated on the diagrams in the sequence of operation shall be generated to the appropriate server/workstations.

B. Air Flow Control

1. The supply air terminal box shall be variable or constant flow as indicated on the individual terminal box schedules.

2. For rooms with positive or neutral room pressure, the associated return/exhaust VAV box shall track the supply VAV box. For rooms with negative room pressure, the supply VAV box shall track the associated return/exhaust VAV box.

3. If the terminal box schedules do not have specific Maximum Heating CFM listed, then the Maximum Heating CFM setpoint shall be 50% of the Maximum Cooling CFM Setpoint.

C. Temperature Control

1. The occupied/unoccupied temperature control modes shall be enabled by manual command or time of day schedule, as coordinated with the Owner. For public spaces the BAS Contractor shall coordinate with the Owner the hours for occupancy with initial default being 7am to 7pm.

2. Setpoints: The BAS Contractor shall coordinate the Room Temperature Setpoints with the Owner prior to the start of any programming. The coordinated setpoints shall be included in the room schedules as part of the BAS submittals. The default setpoints shall be as follows.

a. Occupied: Cooling = 75 DegF (adj.); Heating = 70 DegF (adj.)

b. Unoccupied: Cooling = 85 DegF (adj.); Heating = 62 DegF (adj.)

c. Maximum Heating Discharge Air Temperature Setpoint = Active Room Heating Setpoint + 15

DegF Heating Differential Setpoint. Not applicable if deduct alternate is accepted.

3. Occupied Mode:

a. Cooling: If the room temperature rises above the occupied room cooling temperature setpoint the supply VAV box damper shall modulate open from its minimum cooling CFM setpoint to its maximum cooling CFM setpoint as scheduled to maintain the room temperature. On a drop in room temperature the reverse shall occur. While in deadband the supply VAV box shall be at minimum cooling CFM setpoint. For CV boxes no CFM setpoint change shall occur.

b. Heating: If the room temperature falls below the occupied room heating temperature setpoint the reheat coil valve shall modulate open to maintain the room temperature without exceeding the Maximum Discharge Air Temperature Setpoint. On a continued drop in room temperature the supply VAV box damper shall modulate open from its minimum heating CFM setpoint to its maximum heating CFM setpoint to maintain room temperature. On a rise in room temperature the reverse shall occur. While in deadband the reheat coil valve shall be closed and the supply VAV box damper shall be at its minimum heating CFM setpoint.

4. Unoccupied Mode:

a. Cooling: If the room temperature rises above the unoccupied room cooling temperature setpoint the supply VAV box damper shall modulate open from its minimum cooling CFM setpoint to its maximum cooling CFM setpoint as scheduled to maintain the room temperature. On a drop in room temperature the reverse shall occur. While in deadband the supply VAV box shall be at its unoccupied CFM setpoint. For CV boxes no CFM setpoint change shall occur.

b. Heating: If the room temperature falls below the unoccupied room heating temperature setpoint the reheat coil valve shall modulate open to maintain the room temperature without exceeding the Maximum Discharge Air Temperature Setpoint. On a continued drop in room temperature the supply VAV box damper shall modulate open from its minimum heating CFM setpoint to its maximum heating CFM setpoint to maintain room temperature. On a rise in room temperature the reverse shall occur. While in deadband the reheat coil valve shall be closed and the supply VAV box damper shall be at its unoccupied CFM setpoint.

D. Safety Interlocks

1. If any VAV box damper is 100% open and is 10% (adj.) below CFM setpoint for 30 min (adj.) an alarm shall be generated at Facilities.

1. Terminal Unit: Supply VAV/CV with Reheat & Radiant Panel A. General

1. Programs and sequences indicated or implied herein shall be provided.

2. Provide all I/O points indicated on the control diagram and as required to accomplish the sequence of operation.

3. Control panel shall be labeled to identify power source. All wire terminals, devices, gauges and wires shall be identified within the panels.

4. All points shall be able to integrate to all trends, totalizations, etc., as applicable.

5. All alarms as indicated on the diagrams in the sequence of operation shall be generated to the appropriate server/workstations.

B. Air Flow Control

1. The supply air terminal boxes shall be variable or constant flow as indicated on the individual terminal box schedules.

2. If the terminal box schedules do not have specific Maximum Heating CFM listed, then the Maximum Heating CFM setpoint shall be 50% of the Maximum Cooling CFM Setpoint.

C. Temperature Control

1. The occupied/unoccupied temperature control modes shall be enabled by manual command or time of day schedule, as coordinated with the Owner. For public spaces the BAS Contractor shall coordinate with the Owner the hours for occupancy with initial default being 7am to 7pm.

2. Radiant Panel: When the outside air temperature drops below 42 DegF (adj.), the radiant panel valve shall be enabled for heating as indicated below. When the outside air temperature rises above 45 DegF (adj.) the radiant panel valve shall close.

3. Setpoints: The BAS Contractor shall coordinate the Room Temperature Setpoints with the Owner prior to the start of any programming. The coordinated setpoints shall be included in the room schedules as part of the BAS submittals. The default setpoints shall be as follows.

a. Occupied: Cooling = 75 DegF (adj.); Heating = 70 DegF (adj.)

b. Unoccupied: Cooling = 85 DegF (adj.); Heating = 62 DegF (adj.)

c. Maximum Heating Discharge Air Temperature Setpoint = Active Room Heating Setpoint + 15 DegF

Heating Differential Setpoint. Not applicable if deduct alternate is accepted.

4. Occupied Mode:

a. Cooling: If the room temperature rises above the occupied room cooling temperature setpoint the supply VAV box damper shall modulate open from its minimum cooling CFM setpoint to its maximum cooling CFM setpoint as scheduled to maintain the room temperature. On a drop in room temperature the reverse shall occur. While in deadband the supply VAV box shall be at minimum cooling CFM setpoint. For CV boxes no CFM setpoint change shall occur.

b. Heating: If the room temperature falls below the occupied room heating temperature setpoint the radiant panel valve shall open and the reheat coil valve shall modulate open to maintain the room temperature without exceeding the Maximum Discharge Air Temperature Setpoint. On a continued drop in room temperature the supply VAV box damper shall modulate open from its minimum heating CFM setpoint to its maximum heating CFM setpoint to maintain room temperature. On a rise in room temperature the reverse shall occur. While in deadband the radiant panel and reheat coil valves shall be closed and the supply VAV box damper shall be at its minimum heating CFM setpoint.

5. Unoccupied Mode:

a. Cooling: If the room temperature rises above the unoccupied room cooling temperature setpoint the supply VAV box damper shall modulate open from its minimum cooling CFM setpoint to its maximum cooling CFM setpoint as scheduled to maintain the room temperature. On a drop in room temperature the reverse shall occur. While in deadband the supply VAV box shall be at its unoccupied CFM setpoint. For CV boxes no CFM setpoint change shall occur.

b. Heating: If the room temperature falls below the unoccupied room heating temperature setpoint the radiant panel valve shall open and the reheat coil valve shall modulate open to maintain the room temperature without exceeding the Maximum Discharge Air Temperature Setpoint. On a continued drop in room temperature the supply VAV box damper shall modulate open from its minimum heating CFM setpoint to its maximum heating CFM setpoint to maintain room temperature. On a rise in room temperature the reverse shall occur. While in deadband the radiant panel and reheat coil valves shall be closed and the supply VAV box damper shall be at its unoccupied CFM setpoint.

D. Safety Interlocks

1. If any VAV box damper is 100% open and is 10% (adj.) below CFM setpoint for 30 min (adj.) an alarm shall be generated at Facilities.

KEY NOTES:

UAC FOR ALL CONTROL POINTS

SHOWN ON DIAGRAM

PRICE REHEAT COIL LEACING AIR

TEMPERATURE SENSOR AS

DEDUCT ALTERNATE FOR ALL

VAV BOXESAIR FLOW

SUPPLY

UAC

V-RH

HWS

HWR

D-VAV

FE-SA

T-RM

T-RHT

RADIANT

PANEL

V-RDP

RHC

HWSHWR

Project Number

Building Number

Drawing Number

Project Title

Location

Issue Date Checked Drawn

Drawing Title

Approved:

VA FORM 08 - 6231

A

Office of Construction and Facilities Management

U.S. Department of Veterans Affairs

B

C

D

E

F

A

B

C

D

E

F

21 4 5 6 7 8 9 10

Phase

ARCHITECT STAMPCONSULTANT

321 4 5 6 7 8 9 10

129 South St, 2nd floor Boston, MA 02210

T: 617.772.0260 F: 617.772.0261 www.e4harchitecture.com

FINAL FOR

CONSTRUCTION

FULLY SPRINKLERED

STRUCTURAL MEP / FP

Simpson Gumpertz & Heger 480 Totten Pond Road Waltham, MA 02451

T: 781.907.9000 sgh.com

BR+A

10 Guest Street, 4th FLR Boston, MA 02135

T: 617.254.0016 brplusa.com

CIVIL

Meridian Associates, Inc.

500 Cummings Center, Suite 5950 Beverly, MA 01915

T: 978.299.0447 meridianassoc.com

K J o b s \1

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MH7-0.5

TERMINAL UNIT DETAILS, POINTS

LISTS & SEQUENCE OF

OPERATIONS

DESIGN SPECIALTY

CARE BUILDING

718 Smyth Rd, Manchester, NH 03104

608-315

12/20/2023

1 Terminal Unit - VAV/CV with Reheat

Terminal Unit - VAV/CV with Reheat Control Points List

EQUIPMENT TYPE DESIGNATION SERVICE ALM_LO ALM_HI

ALM_OFF /

NORMAL COMMENTS

AI FE-SA SUPPLY AIR FLOW ELEMENT

AI T-RHT REHEAT COIL LEAVING AIR

TEMPERATURE

X X SEE KEY NOTE 2

AI T-RM ROOM/SPACE

TEMPERATURE

X X

AO D-VAV VAV DAMPER

AO V-RH REHEAT COIL VALVE

Terminal Unit - Supply VAV/CV with Reheat & Radiant Panel Control Points List

EQUIPMENT TYPE DESIGNATION SERVICE ALM_LO ALM_HI

ALM_OFF /

NORMAL COMMENTS

AI FE-SA SUPPLY AIR FLOW ELEMENT

AI T-RHT REHEAT COIL LEAVING AIR TEMPERATURE X X SEE KEY NOTE 2

AI T-RM ROOM/SPACE TEMPERATURE X X

AO D-VAV VAV DAMPER SUPPLY AIR

AO V-RH REHEAT COIL VALVE

BO V-RDP RADIANT PANEL VALVE - OPEN / CLOSE

Terminal Unit - Supply VAV/CV with Reheat & Radiant Panel

Revisions: Date:

CONSTUCT SPECIALTY

CARE BUILDING

M

P

O

POS

NET

1QTY:VFD

1 QTY:

CT-A

D-EISO

EXHAUST AIR

P-EALL

NOTE:

VFD FOR BALANCING

PURPOSES ONLY

EF

1. Constant Volume Exhaust Fan with VFD for Balancing A. General

1. Programs and sequences indicated or implied herein shall be provided.

2. Provide all I/O points indicated on the control diagram and as required to accomplish the sequence of operation.

3. All wire terminals, devices, gauges and wires shall be identified within the panels.

4. Dampers and end switches shall be interlocked such that they will operate per the sequence below in either auto, hand or off on the VFD/MCC.

5. All points shall be able to integrate to all trends, totalizations, etc., as applicable.

6. All alarms as indicated on the diagrams in the sequence of operation shall be generated to the appropriate server/workstations.

B. Start/Stop

1. The exhaust fan normally operates continuously with remotely capability for start/stop/scheduling functions. The H.O.A. switch shall be kept in the “auto” position. “Hand” and “Off” positions shall be utilized for maintenance purposes. When the exhaust fans are off, the intake isolation damper shall be closed.

2. When the fan receives a start command, the intake isolation damper shall open. When the end switch proves open via hardwire interlock, the exhaust fan shall start at minimum speed.

3. Upon confirmation the exhaust fan is running; the exhaust fan shall modulate as indicated below for control.

4. If at any point the exhaust fan fails by indication of current or VFD alarm, the fan shall be deactivated, its isolation damper shall be closed, an alarm will be generated and the unit will be locked out in software. Current shall be given a minimum of a 60 second delay (adj.) at startup.

C. Airflow Control

1. Upon start-up of the exhaust fan, the BAS shall ramp the fan to a fixed speed signal as determined by the Testing and Balancing contractor. The fan is constant volume utilizing the VFD as a balancing device.

D. Safety Interlocks

1. The high suction static pressure safety located on the suction side of the exhaust fan in the unit housing shall be set as scheduled for duct pressure class. If the safeties pressure setting is exceeded the safety will trip and via hardwire interlock to the exhaust fans VFD's so the fan shall shutdown and the isolation dampers shall close. This safety shall operate in either hand or auto on the VFD's and shall be reset manually.

Project Number

Building Number

Drawing Number

Project Title

Location

Issue Date Checked Drawn

Drawing Title

Approved:

VA FORM 08 - 6231

A

Office of Construction and Facilities Management

U.S. Department of Veterans Affairs

B

C

D

E

F

A

B

C

D

E

F

21 4 5 6 7 8 9 10

Phase

ARCHITECT STAMPCONSULTANT

321 4 5 6 7 8 9 10

129 South St, 2nd floor Boston, MA 02210

T: 617.772.0260 F: 617.772.0261 www.e4harchitecture.com

FINAL FOR

CONSTRUCTION

FULLY SPRINKLERED

STRUCTURAL MEP / FP

Simpson Gumpertz & Heger 480 Totten Pond Road Waltham, MA 02451

T: 781.907.9000 sgh.com

BR+A

10 Guest Street, 4th FLR Boston, MA 02135

T: 617.254.0016 brplusa.com

CIVIL

Meridian Associates, Inc.

500 Cummings Center, Suite 5950 Beverly, MA 01915

T: 978.299.0447 meridianassoc.com

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MH7-0.6

EXHAUST FAN DIAGRAMS, POINTS

LIST & SEQUENCE OF OPERATION

DESIGN SPECIALTY

CARE BUILDING

718 Smyth Rd, Manchester, NH 03104

608-315

12/20/2023

Constant Volume Exhaust Fan with VFD for Balancing

Constant Volume Exhaust Fan with VFD for Balancing Control Points List

EQUIPMENT TYPE DESIGNATION SERVICE ALM_LO ALM_HI

ALM_OFF /

NORMAL COMMENTS

EF AI CT-A CURRENT TRANSDUCER (ANALOG) X

VFD EF AO SPD-C MOTOR SPEED CONTROL

VFD EF BI ALM ALARM X

BI P-EALL EXHAUST AIR / LOW PRESSURE LIMIT X DUCTWORK STATIC SAFETY - HARDWIRE

INTERLOCK

BI POS-O DAMPER POSITION - OPEN D-EISO - HARDWIRE INTERLOCK

BO D-EISO EXHAUST FAN ISOLATION DAMPER

VFD EF BO ST/ST MOTOR START/STOP

Revisions: Date:

CONSTUCT SPECIALTY

CARE BUILDING

T

T

T

T

A

POS

A

POS

HWP-2

CT-A

HWP-1

CT-A

NET

1QTY:VFD

NET

1QTY:VFD

M

T

T

T

SW

SW

P

A

POS

A

POS

P

P P

UPS

M

O/C

POS

O/C

POS

O/C

POS

O/C

POS

O/C

POS

O/C

POS

O/C

POS

O/C

POS

P-DP-A

T-HWS

T-HWR

T-HWS

HWS

HWR

HWS

HWR

HWS

HWR

H W

S

HWS

HWS

V-STM

V-STM

MPS

1/3

2/3

V-DP

HEX-2

HEX-1

T-HWR

T-HWS T-HWHL

T-HWHL

FC

FC

GR

SW

GR

SW

HEX-1 HWHL LOCKOUT

HEX-2 HWHL LOCKOUT

P-SP

V-STM

V-STM

MPS

1/3

2/3

FC

FC

HPS

P-SP P-SP

STEAM PRV

(PRV-1A/1B)

NAC

BACNET IP

ETHERNET

CONTROL

PANEL

BAT-L

P-SP

FM-STM

STEAM METER

LOCATED IN

BASEMENT

CLEAN STEAM

GENERATOR (CSG-1)

ALM

ALM

ALM

ALM

VALVE SUPPLIED

WITH EQUIPMENT

1. Steam to Hot Water HEX A. General

1. Programs and sequences indicated or implied herein shall be provided.

2. Provide all I/O points indicated on the control diagram and as required to accomplish the sequence of operation.

3. All wire terminals, devices, gauges and wires shall be identified within the panels.

4. All points shall be able to integrate to all trends, totalizations, etc., as applicable.

5. All alarms as indicated on the diagrams in the sequence of operation shall be generated to the appropriate server/workstations.

B. Start/Stop

1. There shall be a software Enable/Disable point for the system. No operation can take place unless the system is enabled.

2. The Hot Water System shall operate year round. The heat exchangers shall be manually selected for steam supply and water side service.

3. If the primary pump fails to start within 30 seconds (adj.), the standby pump shall be started and an alarm shall be generated.

4. The pumps shall be programmed for primary/standby operation. The runtime for each pump shall be totalized by the BAS system. The primary pump shall be selected as the pump with the least amount of runtime. The primary pump shall also be alternated monthly to maintain equal runtime.

C. Pressure Control

1. Setpoint

a. System Differential Pressure: 15 psi (adj.)

2. Upon confirmation of pump status, the primary pump shall ramp to maintain system differential pressure.

3. The BAS Contractor shall allot sufficient time to work with the Testing and Balancing Contractor for determining the optimal final system differential pressure setpoint during balancing.

4. If the VFD is at minimum speed and the pressure continues to rise the differential pressure control valve shall modulate open.

5. The pumps are sized that one can handle the load so running 2 at the same time for capacity is not needed.

6. Upon failure of the D.P. sensor feedback to the DDC panel, the bypass valve and/or pump(s) speed shall remain in the last known state. An alarm shall be generated at the BMS.

D. Temperature Control

1. Setpoint

a. Hot Water Supply Temperature: 180 DegF (adj.)

2. On a drop in hot water supply temperature below setpoint the 1/3 2/3 lead steam heat exchanger valves shall modulate in a staged fashion to maintain the hot water supply temperature setpoint. On a rise in temperature the reverse shall occur.

3. Both the 1/3’s and 2/3’s valves have position feedback. Any time the valve position feedback is more that 15% from the valve command for more than 30 seconds an alarm shall be generated.

4. In the event the hot water temperature leaving the heat exchanger exceeds 200 DegF (adj.) the system shall be shutdown and an alarm shall be generated. It shall only restart after being reset by an operator from the BAS.

5. In the event the lead heat exchanger fails, the lag heat exchanger shall be started. The lead heat exchanger shall be alternated monthly.

E. Heat Exchanger Switchover

1. The primary heat exchanger shall be rotated based on runtime monthly on the first Tuesday of the month at 9am. The user can also set the lead heat exchanger

2. When the heat exchangers switch the isolation valve on the lag heat exchanger shall open

3. The steam valves for the lag heat exchanger shall begin to control

4. The other steam valves ramp closed over 5 minutes

5. The isolation valve is closed and the switchover is complete.

F. Safety Interlocks

1. Provide a Hot Water High Temperature Limit (HWHTL) device on the leaving side of the heat exchanger as shown.