260-B6260-003 MTS Replace RoofTop Unit_ADDENDUM 2.pdf

Office of Facilities Planning and Support Services 8333 Little River Turnpike, Suite 312 Annandale, Virginia 22003

Addendum #2

To All Bidders

Reference: 260-B6260-003

Title: NVCC MTS Replace Roof Top Unit

Dated: October 23, 2026

Bid Due: November 2, 2026

Bidders are reminded that all questions should be submitted no less than 6 days prior to the bid due date.

Note: A signed acknowledgement of this Addendum #2 must be received at the location indicated on the IFB either prior to the bid due date and hour or attached to your bid. Signature on this addendum does not substitute for your signature on the original bid document. The original bid document must be signed.

Sincerely, Merlin Espinal

Merlin A. Espinal Contracts Officer Phone 703-425-5689

Name of Firm

Signature

Addendum #2, Attachment

Reference: 260-B6260-003

Title: NVCC MTS Replace Roof Top Unit

Dated: October 23, 2026

Bid Due: November 2, 2026

The Following items represent changes, modifications and/or clarifications to the Contract Documents for this project.

This Addendum shall become a part of the Contract Documents, and all bidders shall include its provisions in their proposals. Receipt of this Addendum shall be acknowledged on the Bid Form where designated.

This Addendum consists of the following:

• (5) drawing sheets including:

o ME-002: Note added to identify controls contact.

o ME-101: Sheet notes modified to adjust TAB scope.

o ME-201: Sheet notes modified to adjust TAB scope.

o ME-301: Sheet notes modified to adjust TAB scope.

o ME-801: Note added to identify controls contact.

• (3) pages of memo describing additional Testing and Balancing scope to establish baseline operating performance of the existing RTU-1 system prior to demolition and equipment replacement.

MICHAEL L.

HATHORNE

Lic. No. 0402066441

10.23.2026

Multiple zone

RTU1

System name and number RTU1

Condition analyzed (impacts Ez, Vdz, Vpz and Vps) Heating

All zones are included in the VRP calculation Yes

Zone Name and Number

Occupancy Category

Zone Floor Area Are you using default value for zone population?

Zone Population

Zone Air Distribution

Effectiveness

Zone Outdoor Airflow

Zone Discharge

Airflow

Zone Primary Airflow

Zone Secondary Recirculation

Fraction Zone Primary Air

Fraction

Az Pz Ez Voz Vdz Vpz Er Ep (sq ft) (people) (cfm) (cfm) (cfm)

01-060 281 OPEN SPACE / CORRIDORS Corridors 700 Yes 0.00 0.80 52.50 1,100 330 0.50 0.30 01-070 281 TRAINING SUITE Classrooms (age 9 plus) 531 No 5.00 0.80 142.15 676 203 0.50 0.30 01-070 278 CORRIDOR Corridors 180 Yes 0.00 0.80 13.50 75 23 0.50 0.30 01-070 208 CORRIDOR Corridors 212 Yes 0.00 0.80 15.90 100 30 0.50 0.30 01-050 213-MENS RESTROOM 146 Yes 0.00 0.80 0.00 75 23 0.50 0.30 01-030 214-WOMENS RESTROOM 151 Yes 0.00 0.80 0.00 75 23 0.50 0.30 01-050 203-SECURITY ADMIN Office space 106 No 1.00 0.80 14.20 100 30 0.50 0.30 01-090 204-SKILL SOURCE Office space 842 No 12.00 0.80 138.15 1,350 405 0.50 0.30 01-080 206-WORKFORCE Office space 473 No 7.00 0.80 79.23 1,100 330 0.50 0.30 01-070 209-STORAGE CLOSET Storage rooms 60 Yes 0.00 0.80 9.00 50 15 0.50 0.30 01-110 215,218-SYSTEMIC SOLUTIONS Office space 450 No 5.00 0.80 65.00 500 150 0.50 0.30 01-110 216-STORAGE CLOSET Storage rooms 33 Yes 0.00 0.80 4.95 50 15 0.50 0.30 01-100 217-OFFICE Office space 126 No 1.00 0.80 15.70 200 60 0.50 0.30 01-050, 110 219 CORRIDOR Corridors 856 Yes 0.00 0.80 64.20 250 75 0.50 0.30 01-110 221-ROBOTIC STORAGE Storage rooms 277 Yes 0.00 0.80 41.55 150 45 0.50 0.30 01-100 222-ROBOTIC CLASSROOM Classrooms (age 9 plus) 535 No 18.00 0.80 305.25 1,200 360 0.50 0.30 01-010 229-CLASSROOM Classrooms (age 9 plus) 543 No 28.00 0.80 431.45 1,500 450 0.50 0.30 01-020 230-CLASSROOM Classrooms (age 9 plus) 543 No 25.00 0.80 393.95 1,500 450 0.50 0.30 01-030 231-CLASSROOM Classrooms (age 9 plus) 612 No 28.00 0.80 441.80 1,500 450 0.50 0.30 01-040 232-CLASSROOM Classrooms (age 9 plus) 614 No 28.00 0.80 442.10 1,600 480 0.50 0.30 01-050 234-STUDENT LOUNGE Break rooms (general) 403 Yes 10.08 0.80 93.19 1,200 360 0.50 0.30 01-090 282 WORK COPY Office space 63 No 1.00 0.80 10.98 250 75 0.50 0.30

System area As (sq ft) 8,456 Net occupiable floor area served by the ventilation system

System population Ps (people) 151.00

Sum of zone population sum of Pz (people) 169.07 ∑Pz

Occupant diversity D 0.89 Ps / ∑Pz

Uncorrected outdoor air intake Vou (cfm) 2,054.19 D ∑ (Rp Pz) + ∑(Ra Az)

System primary airflow (at condition analyzed) Vps (cfm) 4,380

Average outdoor air fraction Xs 0.46 Vou / Vps

Which method from ASHRAE 62.1 is being used to determine system ventilation efficiency (Ev)? Appendix A

Ventilation efficiency Ev 0.79 Ventilation efficiency from critical zone

Outdoor air intake flow (required by 62.1) Vot (cfm) 2,600 Vou / Ev

Outdoor air intake flow provided (measured or design) (cfm) 3,100

Multiple zone

RTU1 (DEMAND CONTROL VENTILATION MINIMUM)

Show simple view

System name and number RTU1

Condition analyzed (impacts Ez, Vdz, Vpz and Vps) Heating

All zones are included in the VRP calculation Yes

Zone Name and Number

Occupancy Category

Zone Floor Area Are you using default value for zone population?

Zone Population

Zone Air Distribution

Effectiveness

Zone Outdoor Airflow

Zone Discharge

Airflow

Zone Primary Airflow

Zone Secondary Recirculation

Fraction Zone Primary Air

Fraction

Az Pz Ez Voz Vdz Vpz Er Ep (sq ft) (people) (cfm) (cfm) (cfm)

01-060 281 OPEN SPACE / CORRIDORS **** Corridors 700 Yes 0.00 0.80 52.50 1,100 330 0.50 0.30 01-070 281 TRAINING SUITE Classrooms (age 9 plus) 531 No 0.00 0.80 79.65 676 203 0.50 0.30 01-070 278 CORRIDOR Corridors 180 Yes 0.00 0.80 13.50 75 23 0.50 0.30 01-070 208 CORRIDOR Corridors 212 Yes 0.00 0.80 15.90 100 30 0.50 0.30 01-050 213-MENS RESTROOM 146 Yes 0.00 0.80 0.00 75 23 0.50 0.30 01-030 214-WOMENS RESTROOM 151 Yes 0.00 0.80 0.00 75 23 0.50 0.30 01-050 203-SECURITY ADMIN Office space 106 No 0.00 0.80 7.95 100 30 0.50 0.30 01-090 204-SKILL SOURCE Office space 842 No 0.00 0.80 63.15 1,350 405 0.50 0.30 01-080 206-WORKFORCE Office space 473 No 0.00 0.80 35.48 1,100 330 0.50 0.30 01-070 209-STORAGE CLOSET Storage rooms 60 Yes 0.00 0.80 9.00 50 15 0.50 0.30 01-110 215,218-SYSTEMIC SOLUTIONS Office space 450 No 0.00 0.80 33.75 500 150 0.50 0.30 01-110 216-STORAGE CLOSET Storage rooms 33 Yes 0.00 0.80 4.95 50 15 0.50 0.30 01-100 217-OFFICE Office space 126 No 0.00 0.80 9.45 200 60 0.50 0.30 01-050, 110 219 CORRIDOR *** Corridors 856 Yes 0.00 0.80 64.20 250 75 0.50 0.30 01-110 221-ROBOTIC STORAGE Storage rooms 277 Yes 0.00 0.80 41.55 150 45 0.50 0.30 01-100 222-ROBOTIC CLASSROOM Classrooms (age 9 plus) 535 No 0.00 0.80 80.25 1,200 360 0.50 0.30 01-010 229-CLASSROOM Classrooms (age 9 plus) 543 No 0.00 0.80 81.45 1,500 450 0.50 0.30 01-020 230-CLASSROOM Classrooms (age 9 plus) 543 No 0.00 0.80 81.45 1,500 450 0.50 0.30 01-030 231-CLASSROOM Classrooms (age 9 plus) 612 No 0.00 0.80 91.80 1,500 450 0.50 0.30 01-040 232-CLASSROOM Classrooms (age 9 plus) 614 No 0.00 0.80 92.10 1,600 480 0.50 0.30 01-050 234-STUDENT LOUNGE Break rooms (general) 403 No 0.00 0.80 30.23 1,200 360 0.50 0.30 01-090 282 WORK COPY Office space 63 No 0.00 0.80 4.73 250 75 0.50 0.30

System area As (sq ft) 8,456 Net occupiable floor area served by the ventilation system

System population Ps (people) 151.00

Sum of zone population sum of Pz (people) 0.00 ∑Pz

Occupant diversity D 0.00 Ps / ∑Pz

Uncorrected outdoor air intake Vou (cfm) 714.42 D ∑ (Rp Pz) + ∑(Ra Az)

System primary airflow (at condition analyzed) Vps (cfm) 4,380

Average outdoor air fraction Xs 0.16 Vou / Vps

Which method from ASHRAE 62.1 is being used to determine system ventilation efficiency (Ev)? Appendix A

Ventilation efficiency Ev 0.67 Ventilation efficiency from critical zone

Outdoor air intake flow (required by 62.1) Vot (cfm) 1,066 Vou / Ev

Outdoor air intake flow provided (measured or design) (cfm) 1,100

ROOFTOP AIR CONDITIONING UNIT SCHEDULE

DESIGNATION

MANUFACTURER

MODEL

NUMBER

LOCATION /

SERVICE

NOMINAL

COOLING

CAPACITY

(TON)

REFRIGERANT

SUPPLY

AIR

CFM

OUTSIDE

AIR CFM

OUTSIDE AIR DATA SUPPLY FAN EXHAUST FAN COOLING COIL ELECTRIC HEATING COIL ELECTRICAL DATA

GEN.

POWER

(Y/N)

VFD

(Y/N)

OPER.

WEIGHT

(LB)

NOTES

SUMMER WINTER

C

FM ES

P

(IN

W G

R

PM

BR

AK

E H

P

M O

TO

R

H P

ES

P

Q

TY

M O

TO

R

H P

FL

A

/ M O

C (E

AC

H

EAT LAT CAPACITY

EA

T

(º F)

LA

T

(º F)

C

AP

AC

IT

Y (K

W

C O

N

TR

O L

VO

LT

AG

E/

PH

AS

E

M C

A/ M

O P

U N

IT

FL

A

D B

(º F)

W B

(º F)

D B

(º F)

D B

(º F)

W B

(º F)

D B

(º F)

W B

(º F)

TO

TA

L (M

BH

SE

N

SI

BL

E (M

BH

RTU-1 CARRIER 50K ROOF / SECOND FLOOR EAST 40 R-454B 13,000 3,100 93.0 74.8 11.7 13,000 2.10 980 13.4 15 0.11 4 1 3.1 80.0 67.0 56.5 55.4 469 329 70.0 87.5 72.0 SCR 460 / 3 131 / 150 86.6 N Y 5,680 ALL

GENERAL NOTES:

A) PROVIDE DOWNFLOW SUPPLY / UPFLOW RETURN AIRFLOW CONFIGURATION WITH POWER EXHAUST FAN.

B) PROVIDE UNIT WITH 0-100% ENTHALPY ECONOMIZER.

C) PROVIDE 4" MERV 13 FILTERS.

D) PROVIDE STAINLESS STEEL DRIP PAN AND COOLING COIL CASING.

E) PROVIDE HINGED AND LATCHED ACCESS DOORS THAT DO NOT REQUIRE TOOLS FOR ACCESS.

F) COMMUNICATION INTERFACE SHALL BE BACNET.

G) EQUIPMENT SHALL MEET OR EXCEED MINIMUM EFFICIENCY REQUIREMENTS OF IEER 13.2 (ASHRAE 90.1-2022).

H) PROVIDE NEMA 3R DISCONNECT SWITCH MOUNTED ON UNISTRUT FRAMING, INSTALLED INDEPENDENTLY OF THE AHU CABINET AND ROOF CURB.

I) PROVIDE UNIT-MOUNTED WEATHERPROOF GFCI 120V DUPLEX CONVENIENCE RECEPTACLE.

J) PROVIDE CURB ADAPTER.

K) OPERATING WEIGHT REPRESENTS RTU ONLY AND DOES NOT INCLUDE CURB ADAPTER.

L) MAXIMUM COMBINED WEIGHT OF ROOFTOP UNIT AND CURB ADAPTER SHALL NOT EXCEED 6,800 LB. WHERE THE COMBINED INSTALLED WEIGHT EXCEEDS THIS LIMIT, THE CONTRACTOR SHALL PROVIDE STRUCTURAL ANALYSIS AND DESIGN, AND SHALL FURNISH AND INSTALL ALL REQUIRED SUPPLEMENTAL STRUCTURAL REINFORCEMENT TO SAFELY SUPPORT THE IMPOSED LOADS.

M) PROVIDE UNIT EXHAUST FAN WITH MULTI-STAGE POWER EXHAUST WITH BUILDING PRESSURE CONTROL.

N) PROVIDE FACTORY FURNISHED RETURN AIR HUMIDITY SENSOR TO FACILITATE COOLING-ONLY DEHUMIDIFICATION MODE. COOLING-ONLY DEHUMIDIFICATION MODE SHALL BE IMPLEMENTED USING THE UNIT MANUFACTURER'S NATIVE CONTROLLER LOGIC.

O) PROVIDE ECONOMIZER FAULT DETECTION AND DIAGNOSTIC SYSTEM (FDDS) AS STANDARD FEATURE.

P) MINIMUM SYSTEM OUTSIDE AIRFLOW WITH ALL TERMINAL UNITS IN DEMAND CONTROL VENTILATION MODE SHALL BE 1,100 CFM AS CALCULATED IN MECHANICAL VENTILATION CALCULATIONS, DEMAND CONTROL VENTILATION - ASHRAE 62.1 TABLE BELOW.

Q) CONTROLS SHALL BE PROVIDED BY CHESAPEAKE CONTROLS. POINT OF CONTACT IS JOHN CRANE, JOHNCRANE@CHESAPEAKECONTROLS.COM, 757-717-5172.

WSP USA Buildings Inc wsp.com

1300 N 17TH ST, SUITE 1000

ARLINGTON VA, 22209

(202) 362-2800

NO. REVISION DATE

SCALE:

DWN. BY:

VCCS PROJECT NO.:

WSP PROJECT NO.:

CKD. BY:

OWNER NAME:

PROJECT TITLE:

TITLE

WRITTEN DIMENSIONS ON THESE DRAWINGS SHALL TAKE PRECEDENCE OVER

SCALED DIMENSIONS. THESE DRAWING SHALL BE COPIED FROM THE ORIGINAL

BLUEPRINTS AND ARE APPROXIMATELY TO SCALE. IT IS THE CONTRACTORS

RESPONSIBILITY TO VERIFY AND BE RESPONSIBLE FOR ALL DIMENSIONS AND

CONDITIONS ON THE PROJECT AND SHALL NOTIFY THE ENGINEER OF ANY

VARIATIONS FROM THE DIMENSIONS AND CONDITIONS SHOWN ON THESE

DRAWINGS.

N.T.S.

MEP Engineer:

PROJECT CODE:

Commissioning Agent:

10030 WINDY HOLLOW RD

GREAT FALLS, VA 22066

703.731.1509

US0027294.0531

260-B6260-003

MT MLH

VCCS - NORTHERN

VIRGINIA COMMUNITY

COLLEGE

MTS REPLACE ROOF

TOP UNIT

SCHEDULES AND

CALCULATIONS

ME-002

PROJECT ADDRESS:

10500 BATTLEVIEW PKWY

MANASSAS, VIRGINIA 20109

260-B6260-003

MECHANICAL VENTILATION CALCULATIONS - ASHRAE 62.1

1.

NOTES:

ZONE POPULATION IS BASED ON THE LARGEST OF THE DESIGN OCCUPANCY AND THE OCCUPANCY

CALCULATED USING DESIGNATED IMC / ASHRAE DEFAULT OCCUPANCY RATE UNLESS OTHERWISE

NOTED.

DEMAND CONTROL VENTILATION CALCULATIONS - ASHRAE 62.1

1 ISSUE FOR BID 09/04/2026

2 ADDENDUM #2 10/23/2026

MICHAEL L.

HATHORNE

A

B

C

D

11 12 13 14 15 16 17 18

WSP USA Buildings Inc wsp.com

1300 N 17TH ST, SUITE 1000

ARLINGTON VA, 22209

(202) 362-2800

SHEET NOTES GENERAL NOTES

NO. REVISION DATE

SCALE:

DWN. BY:

VCCS PROJECT NO.:

WSP PROJECT NO.:

CKD. BY:

OWNER NAME:

PROJECT TITLE:

TITLE

WRITTEN DIMENSIONS ON THESE DRAWINGS SHALL TAKE PRECEDENCE OVER

SCALED DIMENSIONS. THESE DRAWING SHALL BE COPIED FROM THE ORIGINAL

BLUEPRINTS AND ARE APPROXIMATELY TO SCALE. IT IS THE CONTRACTORS

RESPONSIBILITY TO VERIFY AND BE RESPONSIBLE FOR ALL DIMENSIONS AND

CONDITIONS ON THE PROJECT AND SHALL NOTIFY THE ENGINEER OF ANY

VARIATIONS FROM THE DIMENSIONS AND CONDITIONS SHOWN ON THESE

DRAWINGS.

MEP Engineer:

PROJECT CODE:

Commissioning Agent:

10030 WINDY HOLLOW RD

GREAT FALLS, VA 22066

703.731.1509

3/32" = 1'-0"

US0027294.0531

260-B6260-003

MT MLH

VCCS - NORTHERN

VIRGINIA COMMUNITY

COLLEGE

MTS REPLACE ROOF

TOP UNIT

OVERALL PLAN

ME-101

PROJECT ADDRESS:

10500 BATTLEVIEW PKWY

MANASSAS, VIRGINIA 20109

260-B6260-003

3/32" = 1'-0"

OVERALL PLAN

A.

B.

C.

D.

E.

THE NEW ROOFTOP EQUIPMENT MAY BE MOUNTED ON THE EXISTING ROOF CURB

OR CURB ADAPTER, IF COMPATIBLE. OTHERWISE, DEMOLISH CURB ADAPTER AND

PROVIDE NEW CURB ADAPTER DESIGNED FOR PROPOSED NEW EQUIPMENT.

COORDINATE INSTALLATION TIMING WITH THE OWNER.

COORDINATE THE OWNER'S REQUIREMENTS FOR POSITIONING OF THE MAIN CAB

AND PROTECTION OF THE OWNER'S GROUNDS.

CONTRACTOR IS RESPONSIBLE FOR ALL PERMITS FOR CRANE RIGGING, ROAD

CLOSURES, ELECTRICAL WORK, AND THE REPLACEMENT OF EQUIPMENT.

CONTRACTOR SHALL NOT VOID ANY ROOF WARRANTIES. ROOFING SERVICE

COMPANY SHALL INSPECT THE ROOF PRIOR TO AND AFTER CONSTRUCTION FOR

DAMAGES CAUSED BY THE PROJECT. ROOFING WILL BE REPAIRED / RESTORED

AT CONTRACTOR'S EXPENSE.

F. REFER TO THE TABLE ON SHEET ME-301 FOR THE LIST OF SPACES SERVED BY

THE EXISTING RTU AND THE CORRESPONDING DESIGN AIRFLOW QUANTITIES.

THE INFORMATION PRESENTED IN THE SHEET ME-301 TABLE IS BASED ON 2015

CONSTRUCTION DOCUMENTS AND IT IS PROVIDED FOR REFERENCE ONLY.

G. PROVIDE TESTING, MEASUREMENT, DOCUMENTATION, AND REPORTING OF THE

EXISTING RTU-1 AIR DISTRIBUTION SYSTEM SERVING THE SECOND-FLOOR EAST

AREA PRIOR TO ANY DEMOLITION ACTIVITIES, INCLUDING ALL SPACES INDICATED

ON SHEET ME-301. REFER TO PRE-CONSTRUCTION AIRFLOW MEASUREMENT

SCOPE DOCUMENT INCLUDED IN PROJECT MANUAL.

H. BALANCE ASSOCIATED SYSTEM ACCORDING TO PRE-CONSTRUCTION

AIRFLOWS AS INDICATED IN NOTE G.

I. CONTRACTOR SHALL PROVIDE A MINIMUM 7-DAY NOTICE TO THE CxA AND A/E

PRIOR TO THE RTU START-UP AND FUNCTIONAL TESTING.

N

J. BEFORE CxA SITE VISIT, ALL PRE-FUNCTIONAL CHECKLISTS, START-UP

REPORTS, AND BAS INTEGRATION MUST BE VERIFIED BY THE

CONTRACTOR AS 'COMPLETE'. ANY RE-TESTING REQUIRED DUE TO

INCOMPLETE INSTALLATION WILL BE AT THE CONTRACTOR'S EXPENSE.

K. CONTRACTOR MUST PROVIDE WALKWAY PADS OR PLYWOOD

PROTECTION FROM THE ROOF HATCH OR ROOF ACCESS TO THE UNIT

TO PREVENT DAMAGE TO THE EXISTING MEMBRANE DURING THE

"TURNKEY" INSTALLATION.

L. COORDINATE NOISY WORK OR CRANE LIFTS A WEEK IN ADVANCE TO

AVOID DISRUPTING CLASSES

08' 4'

SCALE: 3/32" = 1' - 0"

GRAPHIC SCALE

8' 16' 32'24'

1 ISSUE FOR BID 09/04/2026

2 ADDENDUM #2 10/23/2026

MICHAEL L.

HATHORNE

A

B

C

D

11 12 13 14 15 16 17 18

(X)RTU

(E)RTU

(E)RTU

(E)RD

(E)RD

(E) L2E Sec 2/ 38,40,42

(X) RTU-1

S

S

(E)ROOF HATCH

A

B

C

D

11 12 13 14 15 16 17 18

RTU

2 3

(E)RTU

(E)RTU

2 4

(E)RD (E)RD

1 1/4" D

S

S

(E) L2E Sec 2/ 38,40,42

RTU-1

5 GFCI

WP (E)

(E)ROOF HATCH

(E)

(E)

WSP USA Buildings Inc wsp.com

1300 N 17TH ST, SUITE 1000

ARLINGTON VA, 22209

(202) 362-2800

NO. REVISION DATE

SCALE:

DWN. BY:

VCCS PROJECT NO.:

WSP PROJECT NO.:

CKD. BY:

OWNER NAME:

PROJECT TITLE:

TITLE

WRITTEN DIMENSIONS ON THESE DRAWINGS SHALL TAKE PRECEDENCE OVER

SCALED DIMENSIONS. THESE DRAWING SHALL BE COPIED FROM THE ORIGINAL

BLUEPRINTS AND ARE APPROXIMATELY TO SCALE. IT IS THE CONTRACTORS

RESPONSIBILITY TO VERIFY AND BE RESPONSIBLE FOR ALL DIMENSIONS AND

CONDITIONS ON THE PROJECT AND SHALL NOTIFY THE ENGINEER OF ANY

VARIATIONS FROM THE DIMENSIONS AND CONDITIONS SHOWN ON THESE

DRAWINGS.

MEP Engineer:

GENERAL NOTES

KEYNOTES

PROJECT CODE:

Commissioning Agent:

10030 WINDY HOLLOW RD

GREAT FALLS, VA 22066

703.731.1509

1/8" = 1'-0"

US0027294.0531

260-B6260-003

MT MLH

VCCS - NORTHERN

VIRGINIA COMMUNITY

COLLEGE

MTS REPLACE ROOF

TOP UNIT

ROOF PLANS

ME-201

PROJECT ADDRESS:

10500 BATTLEVIEW PKWY

MANASSAS, VIRGINIA 20109

260-B6260-003

1 REMOVE EXISTING RTU AND ASSOCIATED ACCESSORIES. EXISTING SMOKE

DETECTOR TO REMAIN.

2 PROVIDE NEW ROOF TOP UNIT RTU-1 AS SCHEDULED. PROVIDE NEW ADAPTER

CURB TO ACCOMMODATE NEW RTU-1. THE NEW UNIT AND CURB ADAPTER WILL

SIT ON AN EXISTING CURB WITH GASKETING AND SHALL BE INSTALLED PER

MANUFACTURER'S RECOMMENDATIONS.

3 THIS UNIT SERVES THE SECOND FLOOR EAST SPACES.

4 ROUTE PIPING DOWN TO ROOF AND DISCHARGE AT ROOF DRAIN. PROVIDE ROOF

PIPING SUPPORT PER SPECIFICATION 232113.

5 EXISTING VERTICAL SUPPLY AND RETURN AIR DUCTWORK AND SMOKE

DETECTORS SHOWN FOR REFERENCE ONLY. FIELD VERIFY EXACT DUCTWORK

LOCATION AND ADJUST CURB ADAPTER REQUIREMENTS AS NEEDED.

6 PROVIDE NEW EPDM PRESSURE-SENSITIVE MOLDED WALKWAY PADS AS SHOWN.

7 REFER TO ROOM 200-J ELECTRICAL FOR PANEL L2E ON SHEET ME-301.

1/8" = 1'-0"

ROOF DEMOLITION PLAN - EAST

1/8" = 1'-0"

ROOF NEW WORK PLAN - EAST

1 A.

B.

C.

D.

E.

F.

G.

H.

I.

J.

K.

L.

THE NEW ROOFTOP EQUIPMENT MAY BE MOUNTED ON THE EXISTING ROOF

CURB OR CURB ADAPTER, IF COMPATIBLE. OTHERWISE, DEMOLISH CURB

ADAPTER AND PROVIDE NEW CURB ADAPTER DESIGNED FOR PROPOSED NEW

EQUIPMENT.

COORDINATE INSTALLATION TIMING WITH THE OWNER.

COORDINATE THE OWNER'S REQUIREMENTS FOR POSITIONING OF THE MAIN

CAB AND PROTECTION OF THE OWNER'S GROUNDS.

CONTRACTOR IS RESPONSIBLE FOR ALL PERMITS FOR CRANE RIGGING, ROAD

CLOSURES, ELECTRICAL WORK, AND THE REPLACEMENT OF EQUIPMENT.

CONTRACTOR SHALL NOT VOID ANY ROOF WARRANTIES. ROOFING SERVICE

COMPANY SHALL INSPECT THE ROOF PRIOR TO AND AFTER CONSTRUCTION

FOR DAMAGES CAUSED BY THE PROJECT. ROOFING WILL BE REPAIRED /

RESTORED AT CONTRACTOR'S EXPENSE.

REFER TO THE TABLE ON SHEET ME-301 FOR THE LIST OF SPACES SERVED BY

THE EXISTING RTU AND THE CORRESPONDING DESIGN AIRFLOW QUANTITIES.

THE INFORMATION PRESENTED IN THE SHEET ME-301 TABLE IS BASED ON 2015

CONSTRUCTION DOCUMENTS AND IT IS PROVIDED FOR REFERENCE ONLY.

PROVIDE TESTING, MEASUREMENT, DOCUMENTATION, AND REPORTING OF THE

EXISTING RTU-1 AIR DISTRIBUTION SYSTEM SERVING THE SECOND-FLOOR

EAST AREA PRIOR TO ANY DEMOLITION ACTIVITIES, INCLUDING ALL SPACES

INDICATED ON SHEET ME-301. REFER TO PRE-CONSTRUCTION AIRFLOW

MEASUREMENT SCOPE DOCUMENT INCLUDED IN PROJECT MANUAL.

BALANCE ASSOCIATED SYSTEM ACCORDING TO PRE-CONSTRUCTION

AIRFLOWS AS INDICATED IN NOTE G.

CONTRACTOR SHALL PROVIDE A MINIMUM 7-DAY NOTICE TO THE CxA AND A/E

PRIOR TO THE RTU START-UP AND FUNCTIONAL TESTING.

BEFORE CxA SITE VISIT, ALL PRE-FUNCTIONAL CHECKLISTS, START-UP

REPORTS, AND BAS INTEGRATION MUST BE VERIFIED BY THE CONTRACTOR AS

'COMPLETE'. ANY RE-TESTING REQUIRED DUE TO INCOMPLETE INSTALLATION

WILL BE AT THE CONTRACTOR'S EXPENSE.

CONTRACTOR MUST PROVIDE WALKWAY PADS OR PLYWOOD PROTECTION

FROM THE ROOF HATCH OR ROOF ACCESS TO THE UNIT TO PREVENT DAMAGE

TO THE EXISTING MEMBRANE DURING THE "TURNKEY" INSTALLATION.

COORDINATE NOISY WORK OR CRANE LIFTS A WEEK IN ADVANCE TO AVOID

DISRUPTING CLASSES.

GFCI

WP (E)

N

N 08' 4'

SCALE: 1/8" = 1' - 0"

GRAPHIC SCALE

8' 16' 24'

08' 4'

SCALE: 1/8" = 1' - 0"

GRAPHIC SCALE

8' 16' 24'

(E)

(E)

1 ISSUE FOR BID 09/04/2026

2 ADDENDUM #2 10/23/2026

MICHAEL L.

HATHORNE

4'- 0"

4'-0"

4'- 0"

4'- 0"

4'- 0"3'-0"

4'- 0"

4'- 0"

4'-0"4'-0"

4'-0" 4'-0" 4'- 0"

4'- 0"

'-0

'-0

'-0

'-0

30'-0" 30'-0"

60'-0"

3'- 6"

3'- 5"

3'- 6"

3'- 6"

4'- 3"

3'- 5"

4'- 6"

7'- 6"

6'-0" 6'-0"

4'-0"5'-0"

1'-9"4'-0"

4'- 0"

4'- 0"

4'-0"

3' MIN.

" M

IN

5'-0" MIN

1'-8"

17'-6"

'-0

'-0

10'-0"

'-0

10'-0"9'-6"

27'-6"

27'-0"

'-0

27'-0"27'-0" 81'-0"

'-0

WZPE24

WZPE24

WZPE24

WZPE24

1 2 3 4 6 75

8 9 10 11 13 1412

15 16 17 18 20 2119

22 23 24 25 27 2826

1 2 3 4 5 6 7

8 9

15 16

22 23

10 11 12

17 18 19

24 25 26

13 14

20 21

27 28

1 2 3 4 6 75

8 9

15 16

22 23

A1 A2

10 11 13 1412

17 18 20 2119

24 25 27 2826

A1 A2 A1 A2

6 7 8 9 10

16 17 18 19 20

26 1

A1 A2

A1 A2

A1 A2

DN

DN

A

B

C

D

161514131211

B

A

MICRO

REQUIRED CLEAR

FLOOR AREA

*******REMEMBER---YOU NEED TO FIGURE OUT HOW MANY

STAIR TREADS YOU NEED FOR YOUR SLAB TO SLAB

HEIGHT--THIS IS INTENDED AS A HELPFUL PLACEHODER

AND STARTING POINTONLY!!*************

*******REMEMBER---YOU NEED TO FIGURE OUT HOW MANY

RACKS YOU HAVE, WHAT SIZE THEY ARE, WHAT HVAC

UNIT IS NEEDED, WHAT SIZE IT IS (ANDALL CLEARANCES ALSO)--THIS IS INTENDED AS A HELPFUL PLACEHODER AND STARTING POINTONLY!!*************

SHOULD BE ADJACENT TO ROOM(S)

REQUIRING AV EQUIPMENT. SIZE MAY VARY.

SHOULD BE ADJACENT TO DIVISIBLE OR

RECONFGURABLE CONFERENCE ROOM(S). ALSO

CONSIDER THE LENGTH OF THE RUN YOU'LL NEED TO

MAKE WITH YOUR DUCT TO THE BUILDING CORE, AND

THE FACT THAT ALONG THAT RUN, THE CEILING MAY

WELL HAVE TO BE FAIRLY LOW. SIZE MAY VARY,

CONTACT YOUR MEP ENGINEER FOR SIZING AND

CLEARANCES FOR EQUIPMENT.

WATCH PROPORTIONS--A ROOM THAT'S

NOT WIDE ENOUGH TO ACCOMODATE 6'6"

WIDE TABLES AND CHAIRS ON DOLLIES IS

USELESS. SHOULD HAVE A DOUBLE DOOR.

THIS BLOCK WAS CREATED DIRECTLY FROM KNOLL'S

"OPEN PLAN #1902", WHICH IS DIVIDENDS HORIZON

THIS BLOCK WAS CREATED DIRECTLY FROM KNOLL'S

"OPEN PLAN #405", WHICH IS AN ANTENNA WORKSPACE

OPEN FLOOR AREA

WE DON'T HAVE DEFINITE DESIGNS FOR WHAT THESE

LOOK LIKE, BUT THIS IS A GOOD STARTING POINT.

WE DON'T HAVE DEFINITE DESIGNS FOR WHAT THESE

LOOK LIKE, BUT THIS IS A GOOD STARTING POINT, BASED

ON A RECORDING SETUP THAT WE DID FOR

HEARST-ARGYLE DC.

T F

A

B

C

D

11 12 13 14 15 16 17

(E) L2E Sec 1

(E) L2E Sec 2

(E) P2E Sec 1

(E) P2E Sec 2

(E) P2E Sec 3

206 - WORKFORCE

SUITE

205 - WORK/COPY

203 -

SECURITY/ADMIN

OFFICE

213 - MENS

RESTROOM

214 - WOMENS

RESTROOM

217 - OFFICE218 - WORK/COPY

215 - SYSTEMIC

SOLUTION SUITE

216 - STORAGE

CLOSET

222 - ROBOTIC

CLASSROOM

221 - ROBOTICS

STORAGE 220 - STUDY NOOK

230 - TRAINING

CLASSROOM

231 - TRAINING

CLASSROOM

232 - TRAINING

CLASSROOM

234 - STUDENT

LOUNGE

200-J - EXISTING

ELECTRICAL

210 - NETWORK

CLOSET

209 - STORAGE

CLOSET

211 - CORRIDOR 219 - CORRIDOR

208 - CORRIDOR

204 - SKILL SOURCE

SUITE

200 - ATRIUM

281 - TRAINING SUITE

233 - STUDY NOOK

223 - ROBOTIC

CLASSROOM

229 - WORKFORCE

CLASSROOM

278 - CORRIDOR

TABLE 1.1 - LIST OF ROOMS AND CORRESPONDING AIRFLOWS SERVED BY EXISTING RTU

VAV

DESIGNATION

ROOM

NUMBER ROOM NAME

OUTLET AIRFLOW DATA

TOTAL CFM NUMBER OF SUPPLY

AIR DIFFUSERS COMMENT

VAV 200 ATRIUM 1100 3 3x375 CFM DIFFUSERS AT ATRIUM WALL

VAV

203 SECURITY ADMIN 100 1 1X100 CFM DIFFUSER

211 CORRIDOR 100 1 1X100 CFM DIFFUSER BY ATRIUM

213 MENS RESTROOM 75 1 1X75 CFM DIFFUSER AT DOOR

234 STUDENT LOUNGE 1200 4 4X300 CFM DIFFUSERS

VAV 204, 205 SKILL SOURCE 1350 6

3X250 CFM DIFFUSERS AT WINDOWS

3X200 CFM DIFFUSERS CENTER OF ROOM

218 WORK/COPY 250 1 1X250 CFM DIFFUSER AT WINDOWS

VAV 206 WORKFORCE 1100 4 4X275 CFM DIFFUSERS AT WINDOWS

VAV

208 CORRIDOR 100 1 1X100 CFM DIFFUSER

209 STORAGE CLOSET 50 1 1X50 CFM DIFFUSER

273 CORRIDOR 75 1 1X75 CFM DIFFUSER

281 TRAINING SUITE 675 3 3X225 CFM DIFFUSERS

VAV

215 SYSTEMIC SOLUTIONS 250 2 2X250 CFM DIFFUSERS BY CORRIDORS

216 STORAGE CLOSET 50 1 1X50 CFM DIFFUSER

219 CORRIDOR 250 1 1X150 CFM DIFFUSER AT ROOM 231 DOOR

220 STUDY NOOK 200 1 1X200 CFM DIFFUSER IN CORRIDOR

221 ROBOTIC STORAGE 150 1 1X150 CFM DIFFUSER

VAV

217 OFFICE 200 1 1X200 CFM DIFFUSER

222 ROBOTIC CLASSROOM 1200 4 4X300 CFM DIFFUSERS

VAV 229 CLASSROOM 1500 4 4X375 CFM DIFFUSERS

VAV 230 CLASSROOM 1500 4 4X375 CFM DIFFUSERS

VAV

214 WOMENS RESTROOM 75 1 1X75 CFM DIFFUSER AT DOOR

231 CLASSROOM 1500 4 4X375 CFM DIFFUSERS

VAV 232 CLASSROOM 1600 4 4X400 CFM DIFFUSERS

GENERAL:

A. THE INFORMATION PRESENTED IN THIS TABLE WAS DERIVED FROM THE EXISTING CONSTRUCTION DOCUMENTS DATED JULY 6, 2015 AND IS PROVIDED FOR REFERENCE PURPOSES ONLY. FIELD VERIFICATION OF ALL EXISTING CONDITIONS IS REQUIRED PRIOR TO CONSTRUCTION.

B. RETURN AIR GRILLES ASSOCIATED WITH THE SPACES IDENTIFIED IN THIS TABLE ARE CONNECTED TO THE EXISTING RETURN AIR PLENUM SYSTEM. AS PART OF A PLENUM RETURN CONFIGURATION, THESE RETURN AIR DEVICES ARE NOT INDIVIDUALLY BALANCED AND NO RETURN

AIRFLOW QUANTITIES ARE ASSOCIATED WITH THE GRILLES.

C. REFER TO EXISTING BUILDING AUTOMATION SYSTEM FOR VAV BOX DESIGNATION.

WSP USA Buildings Inc wsp.com

1300 N 17TH ST, SUITE 1000

ARLINGTON VA, 22209

(202) 362-2800

NO. REVISION DATE

SCALE:

DWN. BY:

VCCS PROJECT NO.:

WSP PROJECT NO.:

CKD. BY:

OWNER NAME:

PROJECT TITLE:

TITLE

WRITTEN DIMENSIONS ON THESE DRAWINGS SHALL TAKE PRECEDENCE OVER

SCALED DIMENSIONS. THESE DRAWING SHALL BE COPIED FROM THE ORIGINAL

BLUEPRINTS AND ARE APPROXIMATELY TO SCALE. IT IS THE CONTRACTORS

RESPONSIBILITY TO VERIFY AND BE RESPONSIBLE FOR ALL DIMENSIONS AND

CONDITIONS ON THE PROJECT AND SHALL NOTIFY THE ENGINEER OF ANY

VARIATIONS FROM THE DIMENSIONS AND CONDITIONS SHOWN ON THESE

DRAWINGS.

MEP Engineer:

GENERAL NOTES

KEYNOTES

PROJECT CODE:

Commissioning Agent:

10030 WINDY HOLLOW RD

GREAT FALLS, VA 22066

703.731.1509

As indicated

US0027294.0531

260-B6260-003

MT MLH

VCCS - NORTHERN

VIRGINIA COMMUNITY

COLLEGE

MTS REPLACE ROOF

TOP UNIT

PARTIAL FLOOR

PLANS

ME-301

PROJECT ADDRESS:

10500 BATTLEVIEW PKWY

MANASSAS, VIRGINIA 20109

260-B6260-003

A.

B.

C.

REFER TO THE TABLE ON SHEET ME-301 FOR THE LIST OF SPACES

SERVED BY THE EXISTING RTU AND THE CORRESPONDING DESIGN

AIRFLOW QUANTITIES. THE INFORMATION PRESENTED IN THE

SHEET ME-301 TABLE IS BASED ON 2015 CONSTRUCTION

DOCUMENTS AND IT IS PROVIDED FOR REFERENCE ONLY.

PROVIDE TESTING, MEASUREMENT, DOCUMENTATION, AND

REPORTING OF THE EXISTING RTU-1 AIR DISTRIBUTION SYSTEM

SERVING THE SECOND-FLOOR EAST AREA PRIOR TO ANY

DEMOLITION ACTIVITIES, INCLUDING ALL SPACES INDICATED ON

SHEET ME-301. REFER TO PRE-CONSTRUCTION AIRFLOW

MEASUREMENT SCOPE DOCUMENT INCLUDED IN PROJECT

MANUAL.

BALANCE ASSOCIATED SYSTEM ACCORDING TO PRE-

CONSTRUCTION AIRFLOWS AS INDICATED IN NOTE B.

1/8" = 1'-0"

SECOND FLOOR NEW WORK PLAN

N

1 PROVIDE A SPARE FUSE CABINET IN THE ELECTRICAL CLOSET. PROVIDE 1

COMPLETE SET OF FUSES FOR EACH TYPE OF FUSES USED FOR THIS PROJECT.

08' 4'

SCALE: 1/8" = 1' - 0"

GRAPHIC SCALE

8' 16' 24'

1 ISSUE FOR BID 09/04/2026

2 ADDENDUM #2 10/23/2026

MICHAEL L.

HATHORNE

SEQUENCE OF OPERATIONS

ROOFTOP AIR CONDITIONING UNIT WITH ELECTRIC HEAT

BUILDING AUTOMATION SYSTEM INTERFACE:

THE BUILDING AUTOMATION SYSTEM (BAS) SHALL SEND THE CONTROLLER OCCUPIED BYPASS,

MORNING WARM-UP / PRE-COOL, OCCUPIED / UNOCCUPIED AND HEAT / COOL MODES.

IF A BAS IS NOT PRESENT, OR COMMUNICATION IS LOST WITH THE BAS THE CONTROLLER SHALL

OPERATE USING DEFAULT MODES AND SETPOINTS.

THE BAS SHALL ALSO SEND THE CONTROLLER A DUCT STATIC PRESSURE SETPOINT, DISCHARGE AIR

TEMPERATURE SETPOINT, AND VENTILATION AIRFLOW SETPOINT, EACH CALCULATED BY

OPTIMIZATION ROUTINES IN THE BAS.

EXISTING BAS PROGRAMMING SHALL BE UPDATED TO ACCOMMODATE NEW EQUIPMENT WITH

CONTROLS POINTS AND GRAPHICS.

OCCUPIED MODE:

DURING OCCUPIED PERIODS, THE SUPPLY FAN SHALL RUN CONTINUOUSLY AND THE OUTSIDE AIR DAMPER SHALL OPEN TO MAINTAIN THE CURRENT AIRFLOW SETPOINT. THE UNIT CONTROLLER SHALL CONTROL THE SUPPLY FAN SPEED TO MAINTAIN THE CURRENT DUCT STATIC PRESSURE SETPOINT (ADJ.).THE DX COOLING AND ELECTRIC HEAT SHALL STAGE TO MAINTAIN THE CURRENT DISCHARGE

AIR TEMPERATURE SETPOINT. IF ECONOMIZING IS ENABLED THE OUTSIDE AIR DAMPER SHALL

MODULATE TO MAINTAIN THE CURRENT DISCHARGE AIR TEMPERATURE SETPOINT.

UNOCCUPIED MODE (VERIFY SEQUENCES ACCEPTABLE WITH EXISTING PROGRAMMING):

WHEN THE SPACE TEMPERATURE IS BELOW THE UNOCCUPIED HEATING SETPOINT OF 55.0 DEG. F (ADJ.) THE SUPPLY FAN SHALL START, THE OUTSIDE AIR DAMPER SHALL REMAIN CLOSED AND THE

ELECTRIC HEAT SHALL BE ENABLED. WHEN THE SPACE TEMPERATURE RISES ABOVE THE

UNOCCUPIED HEATING SETPOINT OF 55.0 DEG. F (ADJ.) PLUS THE UNOCCUPIED DIFFERENTIAL OF 4.0

DEG. F (ADJ.) THE SUPPLY FAN SHALL STOP AND THE ELECTRIC HEAT SHALL BE DISABLED.

WHEN THE SPACE TEMPERATURE IS ABOVE THE UNOCCUPIED COOLING SETPOINT OF 85.0 DEG. F (ADJ.) THE SUPPLY FAN SHALL START, THE OUTSIDE AIR DAMPER SHALL OPEN IF ECONOMIZING IS

ENABLED AND REMAIN CLOSED IF ECONOMIZING IS DISABLED AND THE DX COOLING SHALL BE

ENABLED. WHEN THE SPACE TEMPERATURE FALLS BELOW THE UNOCCUPIED COOLING SETPOINT OF

85.0 DEG. F (ADJ.) MINUS THE UNOCCUPIED DIFFERENTIAL OF 4.0 DEG. F (ADJ.) THE SUPPLY FAN SHALL STOP, THE DX COOLING SHALL BE DISABLED AND THE OUTSIDE AIR DAMPER SHALL CLOSE.

OPTIMAL START:

THE BAS SHALL MONITOR THE SCHEDULED OCCUPIED TIME, OCCUPIED SPACE SETPOINTS AND SPACE

TEMPERATURE TO CALCULATE WHEN THE OPTIMAL START OCCURS.

MORNING WARM-UP MODE (VERIFY SEQUENCES ACCEPTABLE WITH EXISTING PROGRAMMING):

DURING OPTIMAL START, IF THE AVERAGE SPACE TEMPERATURE IS BELOW THE OCCUPIED HEATING

SETPOINT A MORNING WARM-UP MODE SHALL BE ACTIVATED.

WHEN MORNING WARM-UP IS INITIATED, THE UNIT SHALL ENABLE THE HEATING AND SUPPLY FAN. THE

OUTSIDE AIR DAMPER SHALL REMAIN CLOSED.

WHEN THE AVERAGE SPACE TEMPERATURE REACHES THE OCCUPIED HEATING SETPOINT (ADJ.), THE

UNIT SHALL TRANSITION TO THE OCCUPIED MODE.

PRE-COOL MODE:

DURING OPTIMAL START, IF THE AVERAGE SPACE TEMPERATURE IS ABOVE THE OCCUPIED COOLING SETPOINT, PRE-COOL MODE SHALL BE ACTIVATED. WHEN PRE-COOL IS INITIATED, THE UNIT SHALL ENABLE THE FAN AND COOLING OR ECONOMIZER. THE OUTSIDE AIR DAMPER SHALL REMAIN CLOSED, UNLESS ECONOMIZING. WHEN THE AVERAGE SPACE TEMPERATURE REACHES OCCUPIED COOLING

SETPOINT (ADJ.), THE UNIT SHALL TRANSITION TO THE OCCUPIED MODE.

OPTIMAL STOP:

THE BAS SHALL MONITOR THE SCHEDULED UNOCCUPIED TIME, OCCUPIED SETPOINTS AND SPACE TEMPERATURE TO CALCULATE WHEN THE OPTIMAL STOP OCCURS. WHEN THE OPTIMAL STOP MODE IS ACTIVE THE UNIT CONTROLLER SHALL MAINTAIN THE SPACE TEMPERATURE USING AN ADJUSTED SPACE TEMPERATURE SETPOINT BASED ON THE CURRENT MODE OF OPERATION. IN COOLING MODE, THE ACTIVE SPACE TEMPERATURE SETPOINT SHALL BE EQUAL TO THE OCCUPIED COOLING SETPOINT

PLUS THE SPACE TEMPERATURE OFFSET. IN HEATING MODE, THE ACTIVE SPACE TEMPERATURE

SETPOINT SHALL BE EQUAL TO THE OCCUPIED HEATING SETPOINT MINUS THE SPACE TEMPERATURE OFFSET. UPON EXPIRATION OF THE OPTIMAL STOP PERIOD OR TRANSITION TO UNOCCUPIED MODE, THE UNIT SHALL REVERT TO NORMAL UNOCCUPIED CONTROL SEQUENCES. SETPOINT OFFSET SHALL

BE ADJUSTABLE BUT SHALL NOT BE REDUCED BELOW 2 DEG F.

OCCUPIED BYPASS:

THE BAS SHALL MONITOR THE STATUS OF THE “ON”AND “CANCEL”BUTTONS OF THE SPACE

TEMPERATURE SENSORS. WHEN AN OCCUPIED BYPASS REQUEST IS RECEIVED FROM A SPACE

SENSOR, THE UNIT SHALL TRANSITION FROM ITS CURRENT OCCUPANCY MODE TO OCCUPIED BYPASS

MODE AND THE UNIT SHALL MAINTAIN THE SPACE TEMPERATURE TO THE OCCUPIED SETPOINTS

(ADJ.).

COOLING MODE:

THE UNIT CONTROLLER SHALL USE THE DISCHARGE AIR TEMPERATURE SENSOR AND DISCHARGE AIR

TEMPERATURE COOLING SETPOINT TO DETERMINE WHEN TO INITIATE REQUESTS FOR COOLING.

DISCHARGE AIR SETPOINT SHALL BE MAINTAINED BY MODULATING THE ECONOMIZER OR STAGING

THE DX COOLING AS REQUIRED TO MAINTAIN THE DISCHARGE AIR SETPOINT.

COOLING-ONLY DEHUMIDIFICATION MODE:

THE UNIT SHALL BE CAPABLE OF OPERATING IN A COOLING-ONLY DEHUMIDIFICATION MODE WHEN A DEHUMIDIFICATION DEMAND IS PRESENT. A DEHUMIDIFICATION DEMAND SHALL BE GENERATED WHEN THE RETURN AIR RELATIVE HUMIDITY EXCEEDS THE DEHUMIDIFICATION SETPOINT OF 55% RH (ADJ.). WHEN A DEHUMIDIFICATION DEMAND IS PRESENT, THE UNIT CONTROLLER SHALL OVERRIDE THE NORMAL COOLING CONTROL SEQUENCE AND STAGE DX COOLING TO MAINTAIN A COOLING COIL TEMPERATURE SETPOINT OF 50°F (ADJ.), REGARDLESS OF THE

DISCHARGE AIR TEMPERATURE COOLING SETPOINT.

DURING COOLING-ONLY DEHUMIDIFICATION MODE:

THE SUPPLY FAN SHALL OPERATE.

THE OUTDOOR AIR DAMPER SHALL OPERATE AT THE MINIMUM OUTDOOR AIR POSITION.

ECONOMIZER OPERATION SHALL BE DISABLED.

DX COOLING SHALL BE STAGED AS REQUIRED TO MAINTAIN THE DEHUMIDIFICATION COOLING CONTROL

SEQUENCE SETPOINT.

ELECTRIC HEAT AND DISCHARGE AIR TEMPERATURE REHEAT SHALL BE DISABLED.

COOLING-ONLY DEHUMIDIFICATION MODE SHALL TERMINATE WHEN THE RETURN AIR RELATIVE HUMIDITY FALLS BELOW THE DEHUMIDIFICATION SETPOINT MINUS A 5% RH DIFFERENTIAL (ADJ.), AT WHICH TIME THE UNIT SHALL

RESUME NORMAL OCCUPIED COOLING OPERATION.

DURING COOLING-ONLY DEHUMIDIFICATION MODE, VAV TERMINAL UNITS SHALL BE PERMITTED TO REHEAT AS REQUIRED TO MAINTAIN SPACE TEMPERATURE SETPOINTS IN ACCORDANCE WITH THE TERMINAL UNIT CONTROL

SEQUENCES.

HEATING MODE:

WHEN DISCHARGE AIR TEMPERATURE FALLS BELOW THE SUPPLY DISCHARGE SETPOINT TEMPERATURE (53 DEGREES F. ADJUSTABLE), THE HEATING COIL SHALL ENERGIZE AND MODULATE TO MAINTAIN

DISCHARGE SETPOINT TEMPERATURE.

IF FOUR (4) OR MORE VAV BOXES ARE UNABLE TO REACH ZONE SETPOINT IN HEATING MODE, THE LEAVING AIR TEMPERATURE FROM THE RTU SHALL BE RESET TO 65 DEGREES (ADJ.) TO SATISFY SPACE TEMPERATURE.

ECONOMIZER:

THE ECONOMIZER SHALL BE ENABLED WHEN THE OUTDOOR AIR ENTHALPY IS AT LEAST 3.0 BTU/LB LESS THAN THE

RETURN AIR ENTHALPY.

WHEN ENABLED, THE OUTDOOR AIR AND RETURN AIR DAMPERS SHALL MODULATE TO MAINTAIN THE DISCHARGE AIR TEMPERATURE SETPOINT BETWEEN THE MINIMUM OUTDOOR AIR POSITION AND 100% OUTDOOR AIR.

IF THE OUTDOOR AIR DAMPER REACHES 100% OPEN AND THE DISCHARGE AIR TEMPERATURE REMAINS ABOVE

SETPOINT, MECHANICAL COOLING SHALL BE ENABLED AS REQUIRED.

WHEN THE OUTDOOR AIR ENTHALPY IS GREATER THAN OR EQUAL TO THE RETURN AIR ENTHALPY OR OUTDOOR AIR DRY BULB TEMPERATURE EXCEEDS 75°F", THE ECONOMIZER SHALL BE DISABLED AND THE OUTDOOR AIR DAMPER

SHALL RETURN TO THE MINIMUM OUTDOOR AIR POSITION.

THE ECONOMIZER SHALL BE DISABLED WHEN THE OUTDOOR AIR TEMPERATURE IS BELOW 38°F (ADJ.) OR ABOVE

75°F OUTSIDE AIR TEMPERATURE.

THE EXHAUST FAN SHALL MODULATE AS NECESSARY TO MAINTAIN BUILDING PRESSURE DURING ECONOMIZER

OPERATION.

SUPPLY FAN:

THE SUPPLY FAN SHALL BE ENABLED WHILE IN THE OCCUPIED MODE AND CYCLED ON DURING THE

UNOCCUPIED MODE.

THE SUPPLY FAN SHALL MODULATE MAINTAINING THE DUCT STATIC PRESSURE TO SETPOINT AT THE SENSOR

LOCATED 2/3 DOWNSTREAM. LOCATION SHALL BE COORDINATED WITH ENGINEEER.

ON SYSTEM STARTUP, THE SUPPLY FAN'S SPEED SHALL BE SLOWLY INCREASED TO THE INITIAL DUCT STATIC

PRESSURE SETPOINT (1.2" ADJ.).

IF THE SWITCH DOES NOT OPEN WITHIN 40 SECONDS AFTER A REQUEST FOR FAN OPERATION, A FAN FAILURE ALARM SHALL BE ANNUNCIATED AT THE BAS, THE UNIT SHALL STOP, REQUIRING A MANUAL RESET.

DEMAND CONTROL VENTILATION (DCV):

DURING OCCUPIED MODE, THE BAS SHALL CALCULATE A VENTILATION AIRFLOW SETPOINT BASED ON ZONE CO ₂ SENSOR MEASUREMENTS. THE BAS SHALL RESET THE VENTILATION AIRFLOW SETPOINT BETWEEN THE MINIMUM VENTILATION AIRFLOW AND THE DESIGN VENTILATION AIRFLOW BASED ON THE HIGHEST ZONE CO ₂ LEVEL RELATIVE TO ITS SETPOINT. THE UNIT CONTROLLER SHALL MODULATE THE OUTDOOR AIR DAMPER TO MAINTAIN THE CURRENT VENTILATION AIRFLOW SETPOINT PROVIDED BY THE BAS. THE MINIMUM OUTDOOR AIR POSITION SHALL CORRESPOND TO THE MINIMUM VENTILATION AIRFLOW SETPOINT AS DETERMINED DURING TESTING AND

BALANCING.

DURING PERIODS OF LOW OCCUPANCY, AS INDICATED BY ZONE CO₂ LEVELS BELOW SETPOINT, THE VENTILATION

AIRFLOW SETPOINT SHALL BE REDUCED TO THE MINIMUM VENTILATION AIRFLOW.

DURING PERIODS OF HIGH OCCUPANCY, AS INDICATED BY ZONE CO₂ LEVELS APPROACHING OR EXCEEDING SETPOINT, THE VENTILATION AIRFLOW SETPOINT SHALL INCREASE UP TO THE DESIGN VENTILATION AIRFLOW AS

REQUIRED TO MAINTAIN INDOOR AIR QUALITY.

DEMAND CONTROL VENTILATION SHALL BE ACTIVE ONLY DURING OCCUPIED MODES AND SHALL BE DISABLED DURING UNOCCUPIED OPERATION, AT WHICH TIME THE OUTDOOR AIR DAMPER SHALL REMAIN CLOSED UNLESS

REQUIRED FOR ECONOMIZER OPERATION.

DEMAND CONTROL VENTILATION OPERATION SHALL BE COORDINATED WITH ECONOMIZER CONTROL. WHEN ECONOMIZING IS ENABLED, THE OUTDOOR AIR DAMPER MAY EXCEED THE VENTILATION AIRFLOW SETPOINT AS

REQUIRED TO SATISFY THE DISCHARGE AIR TEMPERATURE SETPOINT.

BUILDING PRESSURE CONTROL:

A DIFFERENTIAL PRESSURE TRANSDUCER SHALL ACTIVELY MONITOR THE DIFFERENCE IN PRESSURE BETWEEN THE BUILDING (INDOORS) AND OUTDOORS. IF THE BUILDING PRESSURE INCREASES ABOVE THE DIFFERENTIAL PRESSURE SETPOINT, THE UNIT CONTROLLER SHALL TURN ON THE EXHAUST FAN AND VARY THE SPEED OF THE EXHAUST FAN. IF MODULATING THE EXHAUST FAN IS NOT SUFFICIENT TO CORRECT THE BUILDING PRESSURE TO SETPOINT, THEN THE SYSTEM WILL MODULATE THE EXHAUST FAN

DAMPER. IF THE BUILDING PRESSURE DECREASES BELOW THE DIFFERENTIAL PRESSURE

SETPOINT, THE CONTROLLER SHALL DEACTIVATE THE EXHAUST FAN AND CLOSE THE EXHAUST DAMPER.

EXHAUST FAN STATUS:

A DIFFERENTIAL PRESSURE SWITCH SHALL MONITOR THE DIFFERENTIAL PRESSURE ACROSS THE FAN. IF THE SWITCH IS DETECTED TO BE OPEN FOR 40 CONSECUTIVE SECONDS AFTER A REQUEST FOR EXHAUST FAN OPERATION A FAN FAILURE ALARM SHALL BE ANNUNCIATED AT THE BAS AND THE EXHAUST FAN

SHALL STOP. A MANUAL RESET SHALL BE REQUIRED.

FILTER STATUS:

A DIFFERENTIAL PRESSURE SWITCH SHALL MONITOR THE DIFFERENTIAL PRESSURE ACROSS THE FILTER WHEN THE FAN IS RUNNING. IF THE SWITCH CLOSES FOR 2 MINUTES AFTER A REQUEST FOR FAN

OPERATION A DIRTY FILTER ALARM SHALL BE ANNUNCIATED AT THE BAS.

SNOW DAY OVERRIDE:

PROVIDE A SNOW DAY BUTTON ON THE FRONT END GRAPHIC THAT PLACES ALL SYSTEMS IN THE BUILDING IN

UNOCCUPIED MODE.

ROOFTOP UNIT - SYSTEM POINTS LIST

CONTROLLER: MFR POINT TYPE ALARMS

SYSTEM POINT DESCRIPTION

G R

AP

H

IC

H

AR

D W

AR

E

IN

PU

T

H

AR

D W

AR

E

O U

TP

U

T

SO

FT

W

AR

E

PO

IN

T

H

AR

D W

AR

E

IN

TE

R

LO

C K

W

IR

EL

ES

S

N

ET

W O

R K

D

EF

AU

LT

V

AL

U E

H

IG

H A

N

AL

O G

L

IM

IT

LO

W

A N

AL

O

G L

IM

IT

BI

N

AR

Y

LA

TC

H D

IA

G

N O

ST

IC

SE

N

SO

R

F

AI

L

C O

M M

U N

IC

AT

IO

N

F

AI

L

DIAGNOSTICS NOTES

BUILDING STATIC PRESSURE LOCAL X AI X X X

DISCHARGE AIR TEMPERATURE X AI X X X

DUCT STATIC PRESSURE LOCAL X AI X X X

OUTDOOR AIR RELATIVE HUMIDITY LOCAL X AI X

OUTDOOR AIR TEMPERATURE LOCAL X AI

OUTSIDE AIR CFM LOCAL AI

RETURN AIR HUMIDITY LOCAL X AI X

RETURN AIR TEMPERATURE LOCAL X AI

DIRTY FILTER ALARM OPEN X BI X

EXHAUST FAN STATUS OPEN X BI

SUPPLY FAN STATUS OPEN X BI X X

EXHAUST AIR DAMPER COMMAND X AO

OUTDOOR AIR DAMPER COMMAND X AO

RETURN AIR DAMPER COMMAND X AO X

SUPPLY FAN SPEED COMMAND X AO

COMPRESSOR 1 COMMAND X BO

COMPRESSOR 2 COMMAND X BO

COMPRESSOR 3 COMMAND X BO

COMPRESSOR 4 COMMAND X BO

COMPRESSOR 5 COMMAND X BO

EXHAUST FAN START STOP COMMAND X BO

HEATING OUTPUT COMMAND X AO

ENTHALPY SENSOR X X

OCCUPANCY X

OCCUPIED COOLING SETPOINT X 74.0 deg. F OCCUPIED HEATING SETPOINT X 70.0 deg. F OCCUPIED STANDBY COOLING SETPOINT X 80.0 deg. F OCCUPIED STANDBY HEATING SETPOINT X 65.0 deg. F UNOCCUPIED COOLING SETPOINT X 85.0 deg. F UNOCCUPIED HEATING SETPOINT X 60.0 deg. F

OCCUPIED BYPASS TIMER X 2.0 HRS

ECONOMIZER MINIMUM POSITION X

HEATING MODE SETPOINT X

COOLING MODE SETPOINT X

SUPPLY AIR PRESSURE SETPOINT X

SETPOINT OFFSET X

COMPRESSOR ENABLE X AUTO

HEAT / COOL MODE X COOL

FAN MODE COMMAND X ON

APPLICATION MODE X AUTO

OUTSIDE AIR DAMPER MINIMUM POSITION X 10%

EFFECTIVE OCCUPANCY X X

EFFECTIVE HEAT / COOL MODE X X

EFFECTIVE SPACE TEMPERATURE X X

EFFECTIVE SPACE SETPOINT X

LOCAL SETPOINT X

HEAT OUTPUT X X

COOL OUTPUT X X

ALARM X X

SUPPLY AIR HEATING/COOLING SETPOINT X

MAINTENANCE REQUIRED X 600 HRS

BAS COMMUNICATION STATE X X

FILTER RUNTIME HOURS X

COMPRESSOR LOCKOUT STATUS X

TIME OVERRIDE STATUS X

GENERAL NOTES

3.0 deg. F

H L

BI

OPEN

FILT STS

H L

BI

OPEN

SF STS

AI

DA PRESS

DA TEMP

AI DI

SD

INTERLOCK TO

STOP UNIT

SA

RA

OA

EA

H L

BI

OPEN

EF STS AO

RA ACT

D-2

EA ACT

AO

D-1 CONFIGURABLE AHU

S/S BO

AI

HUMID

AI

TEMP

RA

TEMP/HUMIDITY

DI

SD

INTERLOCK TO

STOP UNIT

DX

C

AI

HUMID

AI

TEMP

OA TEMP/HUMIDITY

AOSPD

SF VFD

SF S/S AO

AO

TRAQ OA VCM

AO

TRAQ ACT

D-3

BUILDING PRESSURE SENSOR

BLD PRESS

OA PRESS SPACE PRESS

L H

AI

H

C

SCR

C.O. C.O.

DRAIN LINE SHALL BE

AT LEAST THE SAME

SIZE AS THE NIPPLE

ON THE DRAIN PAN.

DRAIN PAN

CONDENSATE TRAP

WITH SUFFICIENT TRAP

SEAL TO OFFSET

PRESSURE AT DRAIN

PAN

PITCH DOWN

TOWARD DRAIN,

MIN. 1/8" PER ft.

ROOF

DRAIN

C.O. @ EVERY

CHANGE IN DIRECTION

GREATER THAN 45°

AND AT MAX. OF 25

FEET INTERVALS

E.

S.

P.

O

F

FA

N

T.S.P. OF FAN PLUS

1" WATER

CURB ADAPTER

VIBRATION

ISOLATION

GASKETING

EXISTING CURB

ROOFING

MATERIALS

SCREWS SIZED AND

SPACED PER

MANUFACTURERS

RECOMMENDATIONS

WSP USA Buildings Inc wsp.com

1300 N 17TH ST, SUITE 1000

ARLINGTON VA, 22209

(202) 362-2800

NO. REVISION DATE

SCALE:

DWN. BY:

VCCS PROJECT NO.:

WSP PROJECT NO.:

CKD. BY:

OWNER NAME:

PROJECT TITLE:

TITLE

WRITTEN DIMENSIONS ON THESE DRAWINGS SHALL TAKE PRECEDENCE OVER

SCALED DIMENSIONS. THESE DRAWING SHALL BE COPIED FROM THE ORIGINAL

BLUEPRINTS AND ARE APPROXIMATELY TO SCALE. IT IS THE CONTRACTORS

RESPONSIBILITY TO VERIFY AND BE RESPONSIBLE FOR ALL DIMENSIONS AND

CONDITIONS ON THE PROJECT AND SHALL NOTIFY THE ENGINEER OF ANY

VARIATIONS FROM THE DIMENSIONS AND CONDITIONS SHOWN ON THESE

DRAWINGS.

N.T.S.

MEP Engineer:

PROJECT CODE:

Commissioning Agent:

10030 WINDY HOLLOW RD

GREAT FALLS, VA 22066

703.731.1509

US0027294.0531

260-B6260-003

MT MLH

VCCS - NORTHERN

VIRGINIA COMMUNITY

COLLEGE

MTS REPLACE ROOF

TOP UNIT

CONTROLS AND

DETAILS

ME-801

PROJECT ADDRESS:

10500 BATTLEVIEW PKWY

MANASSAS, VIRGINIA 20109

260-B6260-003

12" = 1'-0"1 AHU SEQUENCE

N.T.S.

ROOFTOP UNIT SYSTEM POINTS LIST

N.T.S.

ROOFTOP UNIT CONTROLS DIAGRAM

3N.T.S.

CONDENSATE DRAIN DETAIL

EXISTING CONTROLS SYSTEM AND VENDOR

THE BUILDING IS CONTROLLED BY A TRIDIUM NIAGARA BAC CONTROL SYSTEM BY HONEYWELL.

THE CONTROLS CONTRACTOR IS CHESAPEAKE CONTROLS INC.

POINT OF CONTACT IS JOHN CRANE, JOHNCRANE@CHESAPEAKECONTROLS.COM, 757-717-5172.

N.T.S.

CURB ADAPTER INSTALLATION DETAIL

1 ISSUE FOR BID 09/04/2026

2 ADDENDUM #2 10/23/2026

MICHAEL L.

HATHORNE

WSP

1300 North 17th Street, Suite 1000 Arlington, VA 22209 1

Memo

Subject: MTS Replace Rooftop Unit – Pre-Construction Airflow Measurement Scope

Purpose: Establish baseline operating performance of the existing RTU-1 system prior to demolition and equipment replacement.

I. Scope Overview

Provide testing, measurement, documentation, and reporting of the existing RTU-1 air distribution system serving the second-floor east area prior to any demolition activities. The intent is to document current operating conditions so the replacement RTU and associated controls can be adjusted to match existing space airflow distribution.

All measurements shall be taken with the associated systems, terminal units, and air outlets operating at full capacity in the applicable operating mode.

All work shall be in accordance with the Associated Air Balance Council or National Environmental

Balancing Bureau Standards.

II. Existing System Testing Requirements

A. Rooftop Unit Measurements

1. Measure and document:

• RTU supply fan airflow (CFM)

• Outside airflow

• Return airflow

• Fan operating status and speed

• Supply air temperature

• Return air temperature

• Supply duct static pressure

• Building automation system operating mode at time of testing

B. VAV Terminal Unit Measurements

1. For every VAV terminal unit served by RTU-1:

• VAV identification/tag number

• Space(s) served

• Current airflow setpoint

• Actual primary airflow

• Maximum cooling airflow setting

MTS Replace Rooftop Unit – Pre-Construction Airflow Measurement Scope 2

• Minimum airflow setting

• Heating airflow setting (if applicable)

• Damper position during testing

• Electric reheat operational status (if applicable)

• Electric heater stage operation and amperage verification (if applicable)

C. Air Outlet Measurements

1. Measure and document airflow at each diffuser, and balanceable register or grille served by RTU-1:

• Device designation/location

• Airflow (CFM)

• Supply, return, or exhaust classification

• Observed deficiencies or inoperative devices

III. Operating Conditions During Testing

A. Testing shall be performed:

▪ During normal occupied building operation.

▪ With the RTU operating under stable conditions.

▪ With the BAS controlling the system normally.

▪ During periods coordinated with Owner operations.

B. The contractor shall note:

▪ Outdoor air temperature.

▪ Building occupancy conditions.

▪ Any unusual operating conditions.

▪ Any overridden controls or equipment issues.

IV. Reporting Requirements

A. Provide a written report containing:

▪ Executive summary.

▪ RTU airflow measurements.

▪ VAV airflow data table.

▪ Air terminal airflow data table.

▪ Electric heater verification results.

▪ BAS screenshots or trend data supporting measured conditions (if available).

▪ Identification of deficiencies, failed components, or airflow discrepancies.

▪ Recommendations for issues that may affect final balancing.

B. Report shall be submitted to the following parties prior to demolition:

▪ Owner

▪ Engineer of Record

MTS Replace Rooftop Unit – Pre-Construction Airflow Measurement Scope 3

▪ Commissioning Agent

V. Deficiency Notification

A. Immediately notify the Owner and Engineer of:

▪ Inoperative VAV boxes.

▪ Failed actuators.

▪ Failed airflow sensors.

▪ Non-functioning electric reheat coils.

▪ Airflows that cannot be maintained within existing BAS setpoints.

▪ Any condition that may prevent balancing the replacement system to existing performance.

VI. Post-Construction Verification

A. Following installation of the new RTU:

▪ Balance the replacement system to the documented pre-construction airflow values.

▪ Re-verify VAV minimum and maximum airflow settings.

▪ Verify electric heater operation.

▪ Submit final TAB report demonstrating conformance with documented baseline conditions.