260-B6260-003 MTS Replace RoofTop Unit_ADDENDUM 1.pdf

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

Addendum #1

To All Bidders

Reference: 260-B6260-003

Title: NVCC MTS Replace Roof Top Unit

Dated: October 22, 2026

Bid Due: November 2, 2026

1) Please see the Attachment for Answers to Pre-bid Questions.

2) Please see the Attachment for the Pre-bid Sign-In Sheet.

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 #1 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 #1, Attachment

Reference: 260-B6260-003

Title: NVCC MTS Replace Roof Top Unit

Dated: October 22, 2026

Bid Due: November 2, 2026

The Following Pre-Bid Questions are answered:

1. Question 1. Specification Section 23 7416, page 10, paragraph 3.02 B:

If cleaning of ductwork is in scope, is it just ductwork from rooftop unit to each VAV?

Or all ducts including from rooftop unit to each VAV and from the VAVs to each air device?

Response 1:

All ducts and air devices currently served by RTU-1 require cleaning. Specification section 23 01 30 HVAC Air Distribution System Cleaning is attached.

2. Question 2. Specification Section 23 7416, page 10, paragraph 3.02 B:

Can you please clarify if duct cleaning of existing to remain ductwork is in scope? The specifications document says “Do not operate any fans for any purpose, temporary or permanent until: Ductwork is clean”. All ductwork that is existing to remain would not be in a clean state given system usage over the years and subsequent debris accumulation.

Response 2:

Existing duct cleaning is in scope. Refer to Response 1 above.

3. Question 3. Drawing Sheet: ME-801, Controls and Details:

In the “Existing Controls System and Vendor” note: “The building is controlled by a Tridium Niagara BAC control system by Honeywell. The controls contractor is Chesapeake Controls Inc.” Who is the customers point of contact at Chesapeake Controls Inc.? Please provide an email and phone number.

“The undersigned agrees that it will use as the subcontractor for Work under Section 230900 ‘Instrumentation and Control for HVAC’ and for related Work shown on the drawings, Chesapeake Controls, a subcontractor selected by the Owner." Again, Who is the customers point of contact at Chesapeake Controls Inc.? Please provide an email and phone number.

Response 3:

The controls shall be provided by Chesapeake Controls. The point of contact is John Crane. His email address is johncrane@chesapeakecontrols.com and his phone number is 757-717-5172.

4. Question 4. Specification Section 20, page 13:

It was mentioned during the pre-bid conference that an additional site visit could be held for subcontractor participation. Will NVCC please confirm if another visit will be scheduled?

Response 4:

There will be a one-time follow-up walkthrough of the building/project site on Tuesday, October 27th, at 10:00

AM.

mailto:johncrane@chesapeakecontrols.com

DEB #260-B6260-003 NVCC MTS Replace Roof Top Unit 22 October 2026 HVAC Air Distribution System Cleaning 230130-1

SECTION 230130 - HVAC AIR DISTRIBUTION SYSTEM CLEANING

PART 1 – GENERAL

1.1 WORK INCLUDED

A. The work of this Section shall include, but is not limited to the following:

1. Duct Cleaning

1.2 RELATED DOCUMENTS

A. Section 23 05 00 – HVAC General Provisions

1.3 REFERENCE STANDARDS

A. The latest editions of specifications standards, tests or recommended methods of trade, industry or governmental organizations apply to work in this Section where cited below:

1. IMC – International Mechanical Code

2. NADCA – National Air Duct Cleaners Association:

a. ACR, The NADCA Standard for Assessment, Cleaning and Restoration of HVAC Systems.

3. Local Codes

B. Above-referenced standards may be superseded by notes and details on the Drawings and in any specification.

C. Where two or more references conflict, the most stringent, as determined by Engineer, shall take precedence.

1.4 QUALITY ASSURANCE

A. HVAC System Cleaning Contractor Qualifications: Perform duct-cleaning work under the supervision of a National Air Duct Cleaners Association Air Systems Cleaning Specialist (NADCA ASCS) experienced in commercial HVAC system cleaning of similar scope and complexity.

1.5 SUBMITTALS

A. Submit the following for review:

1. Duct-Cleaning Work Plan: Submit a work plan identifying duct systems and HVAC components to be cleaned, proposed cleaning methods and equipment, locations of temporary access openings, provisions for protecting occupied areas and HVAC components, and methods for verifying cleanliness.

2. Closeout Documentation: Submit written confirmation that specified ductwork and HVAC components were cleaned and verified in accordance with ACR, The NADCA Standard. Include photographs taken before and after cleaning and identify damage or deficiencies observed during the work.

DEB #260-B6260-003 NVCC MTS Replace Roof Top Unit 22 October 2026 HVAC Air Distribution System Cleaning 230130-2

PART 2 – PRODUCTS

NOT USED

PART 3 – EXECUTION

3.1 DUCT CLEANING

A. General:

1. Perform duct cleaning in accordance with ACR, The NADCA Standard for Assessment, Cleaning and Restoration of HVAC Systems, and the requirements of this Section.

B. Extent of Cleaning:

1. Clean all new ductwork and the entire existing supply and return duct system associated with the rooftop unit being replaced, including all supply diffusers, return grilles, and registers served by the unit. Cleaning of ductwork associated with other HVAC systems is not required unless contaminants resulting from the Work have migrated into those systems.

C. Before beginning cleaning, inspect the portions of the duct system included in the Work and document visible debris, damage, or conditions that could interfere with cleaning.

Notify Engineer of conditions requiring repair or cleaning beyond the specified limits before proceeding.

D. Isolate the work area and protect occupied spaces, air-handling equipment, coils, terminal devices, sensors, dampers, and other components from dislodged debris. Do not permit contaminants removed from one portion of the system to migrate or redeposit in another portion of the system or occupied building areas.

E. Clean ductwork using source-removal methods. Maintain the portion of the system being cleaned under continuous negative pressure using vacuum-collection equipment.

Mechanically agitate duct surfaces as required to dislodge non-adhered dust, debris, and construction contaminants. Collect and remove dislodged material from the building.

F. Do not use cleaning methods or equipment that damage ductwork, duct liner, insulation, coatings, seals, dampers, sensors, or other HVAC components. Repair damage resulting from cleaning at no additional cost to Owner.

G. Provide temporary service openings where required to perform and verify cleaning.

Locate, construct, and close service openings in accordance with ACR, The NADCA Standard. Restore duct construction, pressure classification, sealing, insulation, vapor barriers, and fire-resistance-rated assemblies after completion of cleaning.

H. After cleaning, visually inspect accessible internal surfaces of ductwork and affected HVAC components. Surfaces shall be visibly clean, with no visible accumulation of non-adhered dust, debris, or construction contaminants. Repeat cleaning where the specified level of cleanliness has not been achieved.

I. Remove temporary protection and restore dampers, sensors, and other devices to their intended operating positions. Submit closeout documentation specified in Part 1.

END OF SECTION