Attachment 13 - Addendum 2.pdf

Addendum No. 2 FAA Hangar 08 & 09 Mechanical Upgrades

SIR/RFO DTFAAC-17-R-00023 August 16, 2017

Work Order 2014-014040

Attachment 12

Addendum No. 2 forms a part of the Contract Documents and modifies the original bid documents. Items in this

Addendum take precedence over the original documents. Addendum No. 2 consists of the following:

1. Requests for Substitution(s) will be considered only after the contract is awarded. Proposals should be based upon the Contract Documents.

2. QUESTION: Are the chillers redundant?

ANSWER: Assuming this refers to the temporary chillers, they are not redundant. Both chillers will be required to operate simultaneously.

3. QUESTION: What is the turnaround time for submittals?

ANSWER: Reference Specification Section 01.30.00, item 3.078.H.

4. QUESTION: Do the fill systems contain glycol?

ANSWER: The system does not contain glycol. The contractor will have to provide freeze protection of the temporary chillers and exterior piping (i.e. heat trace temp chiller bundles, keep water circulating in or heat trace the temp piping risers, etc.).

5. QUESTION: The solicitation makes reference to four new AHUs and replacement of one existing AHU with a new unit located in a first floor mechanical room. The question refers to the AHU units…Are these for the HVAC building unit, or would they be used to provide air condition to the aircraft while at the hangar?

ANSWER: The units only serve the building HVAC.

6. QUESTION: Is the roofer defined?

ANSWER: Reference Specification Section 07.54.00, item 1.04.C. for roofer qualifications, and item 2.01 for roofing membrane manufacturer.

7. QUESTION: There is no Riser Diagram in the plans or Fixed Schedule. Please advise.

ANSWER: Correct. There is no Riser Diagram or Fixed Schedule.

8. QUESTION: Please confirm how many copies (hard and electronic) are required for each volume of this proposal. The Solicitation, Offer, and Award for states 1 original and 1 copy. However, Section L references electronic copies of the proposal.

ANSWER: Only 1 copy is necessary. The original hard copy or an electronic copy of the proposal may be submitted.

9. QUESTION: Work hours and outages.

Addendum No. 2 FAA Hangar 08 & 09 Mechanical Upgrades

SIR/RFO DTFAAC-17-R-00023 August 16, 2017

Work Order 2014-014040

Attachment 12

ANSWER: Reference Specification Section 01.10.00, items 1.03 and 1.05.D. for time restrictions.

10. QUESTION: Please provide a part number for the 400A breaker for power to the temp chillers.

ANSWER: The breaker/switchgear information is included in the Addendum #2 drawings. The drawing

E2.10 has been updated and drawing E2.11 has been added.

11. QUESTION: Please provide clarification on where the cable can be routed for the temp chillers. In addition, does it need to be buried at the exterior? In conduit inside the building?

ANSWER: “At contractor’s option, route the temporary chiller power cables on the ground or in conduit(s) in accordance with applicable code requirements. Cut a hole in the exterior wall of the electrical room using a hole saw for routing of cables. Electrical room exterior wall consists of a porcelain metal exterior panel and 8-inch concrete blocks on the interior. Seal opening weather tight while temporary cables are in use. Following removal of the temporary cables, cover opening with galvanized sheet metal plate attached with a minimum of four sheet stainless steel metal screws, sealed weather tight on the exterior, and fill hole in interior concrete blocks with expansive foam insulation.”

12. QUESTION: Does the temp chiller water piping require insulation? If so, what type and size.

ANSWER: It is required. Please reference specification 230719, Paragraphs 3.12 thru 3.15 for insulation and jacketing requirements. Please note in 3.15 exposed piping requires a jacket of Stainless Steel, while concealed requires PVC.