Solicitation Attachment - B466 Mechanical RFIs.pdf

B466 Mechanical RFI Responses

• Sheet M005, detail 2: The hot water piping diagram shows a 2-way modulating control valve for min flow control for the boiler. It’s location between the pumps and the boiler will not work. It will need to be located on the other side of the pumps.

Also, there needs to be a flow meter for the control system to know how to modulate that valve to maintain min flow to the boiler. That flow meter needs to be in the supply line between the boiler and the bypass valve. Can you please confirm if this will be acceptable.

o DWG Response: In building 464, the heat pump boiler is only serving one piece of equipment (AHU-5) the 2-way modulating control valve is not required. Minimum flow to the boiler will be achieved upon a call for heat from AHU-5 and the associated 3-way modulating control valve before the heating coil. Please refer to the attached document showing the updated hot water piping diagram.

• Sheet M106, detail 1: The B466 mechanical room renovation plan does not show an emergency stop switch for boiler shut down by the door. Is one required?

o DWG Response: Yes, an emergency stop switch for the boiler shut down is required. Please locate it adjacent to the door.

• Sheet M106, detail 1: There is no sequence of operation for the boiler and pump in

B466. Can that be provided?

o DWG Response: Please see the attached document for the sequence of operation.

• Sheet M007, detail 2: For AHU-5, there is no sequence of operation or list of control points necessary to complete that sequence of operation. Can that be provided?

o DWG Response: Please see the attached document for the sequence of operation.

• Sheet M007, detail 3: For AHU-1,2,3, and, 4, there is no sequence of operation or list of control points necessary to complete that sequence of operation. Can that be provided?

o DWG Response: Please see the attached document for the sequence of operation.

• Sheet M105, detail 1: It is unclear if the chilled water valves need to be 3-way or 2-way valves. Can you please clarify this?

o DWG Response: The chilled water valves are required to be 3-way valves to maintain the functionality of the existing chilled water loop.

T

M

OUTSIDE

AIR

FILTER

MIXING

BOX T

P P

T T

C FAN

F T P

P P

T T

T

T

P

P

M

UNIT

CONTROLLER

AHU

SUPPLY

BAS

LOCATE 2/3RDS DOWN

THE SUPPLY DUCT

VFD

T

P

F

C

S

M

M

TEMPERATURE SENSOR

PRESSURE SENSOR

HIGH STATIC FLOW SWITCH

CURRENT SWITCH

SMOKE DETECTOR

MOTORIZED ACTUATOR

3-WAY CONTROL VALVE

LEGEND

BUILDING AUTOMATION SYSTEM

VARIABLE FREQUENCY DRIVE

BAS

VFD

COOLING

COIL

R E

T U

R N

A

IR

M

AHU-1, AHU-2, AHU-3 & AHU-4 SEQUENCE OF OPERATION:

OCCUPIED MODE (VAV):

IN OCCUPIED MODE, SUPPLY FAN SHALL BE ENABLED TO RUN THROUGH THE VARIABLE FREQUENCY DRIVE (VFD) AND SHALL RUN CONTINUOUSLY AND THE OUTSIDE AIR CONTROL DAMPER SHALL MODULATE TO MAINTAIN SCHEDULED OUTSIDE AIR VOLUME.

COOLING COIL SUPPLY AIR TEMPERATURE CONTROL:

THE CHILLED WATER VALVE WILL MODULATE OPEN AND CLOSED TO THE CHILLED WATER COIL AS REQUIRED TO MAINTAIN THE CURRENT SUPPLY AIR TEMPERATURE SETPOINT. IN MANUAL MODE, THE SUPPLY AIR SETPOINT WILL REMAIN AT THE STARTUP/MANUAL SETPOINT. IN AUTOMATIC MODE, THE SUPPLY AIR TEMPERATURE SETPOINT WILL BE RESET LINEARLY BETWEEN 55°F (ADJ.) AND 60°F (ADJ.) BASED ON THE HIGHEST COOLING SIGNAL FROM THE ASSOCIATED VAV BOXES. IF THE COOLING SIGNAL IS HIGH, THEN THE SUPPLY AIR TEMPERATURE SETPOINT WILL BE RESET TOWARD THE MINIMUM. IF THE COOLING SIGNAL IS LOW, THEN THE SUPPLY AIR TEMPERATURE SETPOINT WILL BE RESET TOWARD THE MAXIMUM.

AHU DEHUMIDIFICATION MODE:

IF THE UNIT RETURN DUCT HUMIDISTAT MEASURES OVERALL RETURN AIR AT OR ABOVE 60% RH (ADJU.), THE AHU SHALL ENTER DEHUMIDIFICATION MODE. IN THIS MODE, AIRFLOW SHALL INCREASE TO FULL SUPPLY AIR VOLUME AS LISTED ON SCHEDULE, AND SHALL DELIVER 55°F (ADJ) SUPPLY AIR THE SAME AS IN COOLING MODE. RE-HEAT SHALL OCCUR AT THE TERMINAL UNITS AS NECESSARY TO PREVENT OVERCOOLING. ONCE RETURN DUCT SENSOR MEASURE REACHES 50%RH (ADJ), THE UNIT SHALL RETURN TO NORMAL OCCUPIED MODE.

ECONOMIZER CONTROL (DRY BULB CONTROL):

WHEN THE OUTSIDE AIR TEMPERATURE (GLOBAL POINT) IS LESS THAN 55°F (ADJ.) AND THERE IS A REQUEST FOR COOLING, ECONOMIZER MODE WILL BE ENABLED. DURING ECONOMIZER MODE THE SPACE COOLING SIGNAL WILL MODULATE THE DAMPERS AS REQUIRED TO SATISFY THE CURRENT COOLING SETPOINT. IF THE OUTSIDE AIR DAMPER IS OPEN 100%, AND THE SETPOINT CANNOT BE MET, THEN ADDITIONAL COOLING CONTROL WILL BE ENABLED AS SPECIFIED IN THE “COMPRESSOR CONTROL” SECTION. AS THE MIXED AIR TEMPERATURE VARIES WITHIN THE RANGE OF 55° F TO 45° F, THE OUTSIDE AIR DAMPER WILL MODULATE CLOSED AS REQUIRED TO PREVENT EXCESSIVELY COLD SUPPLY AIR.

ALARMS:

THE FOLLOWING SOFTWARE ALARMS WILL BE GENERATED AND DISPLAYED AT THE OPERATOR’S WORKSTATION:

· SPACE TOO WARM (3°F GREATER THAN COOLING SETPOINT)

· SPACE TOO COLD (3°F LESS THAN HEATING SETPOINT)

· NONFUNCTIONAL SPACE TEMP SENSOR ALARM (GREATER THAN 120°F OR LESS THAN 40°F)

· HIGH SUPPLY AIR TEMP (GREATER THAN 180°F)

· LOW SUPPLY AIR TEMP (LESS THAN 45°F)

· BAD SUPPLY TEMP SENSOR ALARM (GREATER THAN 180°F OR LESS THAN -20°F)

· HIGH MIXED AIR TEMP (GREATER THAN 85°F, ADJ.)

· LOW MIXED AIR TEMP (LESS THAN 45°F, ADJ.)

· BAD MIXED AIR TEMP SENSOR ALARM (GREATER THAN 180°F OR LESS THAN -20°F)

· BAD RETURN AIR TEMP SENSOR ALARM (GREATER THAN 180°F OR LESS THAN -20°F)

· SUPPLY FAN ALARM (COMMAND WITH NO STATUS)

· FILTER ALARM (WHEN RUNTIME EXCEEDS 3000 HOURS, (ADJ.))

· FILTER ALARM (WHEN FILTER DIFFERENTIAL IS GREATER THAN 1”WC., MANUALLY ADJUSTABLE)

SAFETIES:

THE FOLLOWING SAFETIES WILL BE MONITORED AS A STATUS INPUT AND WILL BE DISPLAYED AT THE OPERATOR’S WORKSTATION:

· FIRE ALARM/SMOKE DETECTOR: ON A SIGNAL FROM ANY SMOKE DETECTOR ASSOCIATED WITH THE UNIT THE SUPPLY FAN WILL BE DE-

ENERGIZED VIA THE FACP RELAY MODULE

(HARDWIRED INTERLOCK).

· EMERGENCY STOP SWITCH: AN EMERGENCY STOP SWITCH (ESS) WILL, WHEN ACTIVATED LOCALLY, STOP THE SUPPLY FAN. THE STOP

SWITCH WILL REQUIRE MANUAL RESET.

H S

H HUMIDITY SENSOR

T awesterbeck Text Box

AHU-1, AHU-2, AHU-3 & AHU-4 SEQUENCE OF OPERATION

T

M

OUTSIDE

AIR

FILTER

MIXING

BOX T

P P

LL

T T

C FAN

S F T P

P P

T T

T

T

P

P

M

UNIT

CONTROLLER

AHU

SUPPLY

BAS

LOCATE 2/3RDS DOWN

THE SUPPLY DUCT

VFD

T

P

F

C

S

M

LL

M

TEMPERATURE SENSOR

PRESSURE SENSOR

HIGH STATIC FLOW SWITCH

CURRENT SWITCH

SMOKE DETECTOR

MOTORIZED ACTUATOR

LOW LIMIT

3-WAY CONTROL VALVE

LEGEND

FAN CONTROL (GENERAL):

THE SUPPLY FAN SHALL BE CONTROLLED THROUGH A HAND-OFF-AUTO (H-O-A) SWITCH INTEGRAL WITH THE VARIABLE FREQUENCY DRIVE (VFD). WHEN THE SWITCH IS IN THE "AUTO" POSITION, THE SUPPLY FAN SHALL BE STARTED AND STOPPED AND FAN SPEED SHALL BE CONTROLLED THROUGH THE BUILDING AUTOMATION SYSTEM (BAS). WHEN THE SWITCH IS IN THE "HAND" POSITION, THE SUPPLY FAN SHALL RUN AND THE FAN SPEED SHALL BE CONTROLLED THROUGH A MANUAL SPEED ADJUSTMENT INTEGRAL TO THE VFD. WHEN THE SWITCH IS IN THE "OFF" POSITION, THE SUPPLY FAN AND DRIVE SHALL REMAIN OFF. WHEN THE STARTING CIRCUIT IS ACTIVATED BY THE BAS OR BY PLACING THE SELECTOR SWITCH IN "HAND" POSITION, THE VFD SHALL START UNLOADED AND SHALL RAMP UP TO SPEED AS

PROGRAMMED INTO THE VFD'S SAFETY CIRCUIT.

WHEN AHU-5 IS INDEXED TO RUN MODE BY THE BAS, THE FAN SHALL START AND THE OA DAMPER SHALL OPEN AND SHALL RUN 24/7. THE UNIT CONTROLLER SHALL MAINTAIN A UNIT DISCHARGE AIR TEMPERATURE AT 55° F IN COOLING MODE BY MODULATING THE COOLING VALVE. UPON A CALL FOR HEAT THE HEATING VALVE SHALL OPEN AND SHALL MAINTAIN A DISCHARGE AIR TEMPERATURE OF 65°F.

SUPPLY DUCT STATIC PRESSURE CONTROL:

THE SUPPLY FAN VFD SHALL BE MODULATED TO MAINTAIN THE SUPPLY DUCT STATIC PRESSURE SETPOINT AS SENSED BY DUCT STATIC PRESSURE SENSOR LOCATED DOWNSTREAM IN THE SUPPLY MAIN. UPON STARTUP, THE VFD SHALL BE IN THE "UNLOADED" POSITION.

THE VFD SPEED SHALL BE ADJUSTED THROUGH A CONTROL LOOP IN RESPONSE TO THE DUCT STATIC PRESSURE SETPOINT. AS THE DUCT STATIC PRESSURE RISES ABOVE SETPOINT, THE FAN SPEED SHALL BE REDUCED THROUGH THE VFD SPEED SIGNAL CONTROLLER DOWN TO THE PROGRAMMED MINIMUM SPEED (ADJ.). AS THE STATIC PRESSURE DECREASES BELOW THE ACTIVE SETPOINT, THE FAN SPEED SHALL BE INCREASED. DUCT STATIC PRESSURE SETPOINT SHALL RESET BETWEEN AN ADJUSTABLE MINIMUM AND MAXIMUM SETPOINT. RESET OF STATIC PRESSURE SETPOINT SHALL BE BASED UPON AIRFLOW DEMANDS FROM AHU-1, AHU-2, AHU0-3, & AHU-4. IF THE FAN SPEED IS AT 100 PERCENT AND THE SUPPLY DUCT STATIC PRESSURE IS STILL BELOW SETPOINT, THE DISCHARGE AIR TEMPERATURE RESET CONTROL LOOP SHALL BE OVERRIDDEN TO DECREASE THE ACTIVE DISCHARGE AIR TEMPERATURE SETPOINT

UNTIL THE STATIC PRESSURE SETPOINT IS SATISFIED.

ECONOMIZER CONTROL:

WHEN THE OUTSIDE AIR TEMPERATURE (GLOBAL POINT) IS LESS THAN 55°F (ADJ.) AND THERE IS A REQUEST FOR COOLING, ECONOMIZER MODE WILL BE ENABLED. DURING ECONOMIZER MODE THE SPACE COOLING SIGNAL WILL MODULATE THE DAMPERS AS REQUIRED TO SATISFY THE CURRENT COOLING SETPOINT. IF THE OUTSIDE AIR DAMPER IS OPEN 100%, AND THE SETPOINT CANNOT BE MET, THEN ADDITIONAL COOLING CONTROL WILL BE ENABLED. AS THE MIXED AIR TEMPERATURE VARIES WITHIN THE RANGE OF 55° F TO 45° F, THE OUTSIDE AIR DAMPER WILL MODULATE CLOSED AS REQUIRED TO PREVENT EXCESSIVELY COLD SUPPLY AIR.

SENSORS:

A DRY CONTACT FROM THE VFD CONTROLLER SHALL PROVIDE SUPPLY FAN STATUS FOR UNIT SUPPLY FAN. AN ALARM SHALL BE INITIATED WHENEVER THE FAN COMMAND AND STATUS DO NOT MATCH. A FAULT CONTACT SHALL BE INPUT TO THE CONTROLLER TO INDICATE AN INTERNAL PROBLEM WITH THE SUPPLY FAN VFD. A DUCT TEMPERATURE SENSOR DOWNSTREAM OF THE COOLING COIL

SECTION SHALL MONITOR SUPPLY AIR TEMPERATURE FROM THE UNIT.

ALARMS:

THE FOLLOWING SOFTWARE ALARMS WILL BE GENERATED AND DISPLAYED AT THE OPERATOR’S WORKSTATION:

· SPACE TOO WARM (3°F GREATER THAN COOLING SETPOINT)

· SPACE TOO COLD (3°F LESS THAN HEATING SETPOINT)

· NONFUNCTIONAL SPACE TEMP SENSOR ALARM (GREATER THAN 120°F OR LESS THAN 40°F)

· LOW SUPPLY AIR TEMP (LESS THAN 45°F)

· BAD SUPPLY TEMP SENSOR ALARM (GREATER THAN 180°F OR LESS THAN -20°F)

· SUPPLY FAN ALARM (COMMAND WITH NO STATUS)

· FILTER ALARM (WHEN RUNTIME EXCEEDS 3000 HOURS, (ADJ.))

· FILTER ALARM (WHEN FILTER DIFFERENTIAL IS GREATER THAN 1”WC., MANUALLY ADJUSTABLE)

SAFETIES:

THE FOLLOWING SAFETIES WILL BE MONITORED AS A STATUS INPUT AND WILL BE DISPLAYED AT THE OPERATOR’S WORKSTATION:

· FIRE ALARM/SMOKE DETECTOR: ON A SIGNAL FROM ANY SMOKE DETECTOR ASSOCIATED WITH THE UNIT THE SUPPLY FAN WILL BE DE-

ENERGIZED VIA THE FACP RELAY MODULE

(HARDWIRED INTERLOCK).

· EMERGENCY STOP SWITCH: AN EMERGENCY STOP SWITCH (ESS) WILL, WHEN ACTIVATED LOCALLY, STOP THE SUPPLY FAN. THE STOP

SWITCH WILL REQUIRE MANUAL RESET.

BUILDING AUTOMATION SYSTEM

VARIABLE FREQUENCY DRIVE

BAS

VFD

HEATING

COIL

COOLING

COIL

awesterbeck

AHU-5 SEQUENCE OF OPERATION

HEAT PUMP BOILER

NOTES:

1. PROVIDE UNIONS AND ISOLATION VALVES

ON ALL CONNECTIONS TO EQUIPMENT.

AHU-5

BUFFER

TANK

BT-1

T

T

DIFFERENTIAL

PRESSURE

SENSOR

HWP-1

HWP-2

CHEMICAL

FEED POT

EXPANSION

TANK

ET-1

T

T

DP

FLOW

METER

FROM SYSTEM

TO SYSTEM

M muyak Rectangle muyak Rectangle awesterbeck Text Box

B464 UPDATED HOT WATER PIPING DIAGRAM

muyak Snapshot muyak Rectangle muyak Snapshot muyak Rectangle muyak Line muyak Line

BOILER B466

NOTES:

1. PROVIDE UNIONS AND ISOLATION VALVES

ON ALL CONNECTIONS TO EQUIPMENT.

AHU-5

T

T

DIFFERENTIAL

PRESSURE

SENSOR

B466 HPW-1

CHEMICAL

FEED POT

EXPANSION

TANK

T

DP

FLOW

METER

FROM SYSTEM

TO SYSTEM

M

MODULATING MIN FLOW

BYPASS PRESSURE INDEPENDENT

CONTROL VALVE LOCATED IN

MECHANICAL ROOM

awesterbeck

B466 HOT WATER PIPING DIAGRAM