B1080_Q&A's.pdf

14 March 2018

Questions and Answers (VNVP 181605 – Repair Chiller, Cooling Tower, & Controls, B1080)

1. Are there any photo restrictions?

Answer:

There are no photo restrictions at the project site for the purpose of bidding preparation.

2. Does the project require temporary HVAC service equipment to maintain the building business normal during the construction?

Answer:

Yes. During the construction, the HVAC service to the building shall not be interrupted.

Temporary HVAC equipment shall be required for chilled water or hot heating water (depending on the season).

3. Does the facility have to stay in service, or can the system be taken completely down while work is being completed?

See the answer to question 2.

4. Is the requirement to repair the CMU blocks in the wall in addition to painting?

Yes. Repairing the loose bricks and other defects in the wall, are included in the project.

The work includes internal wall as well.

5. Where/how will the condensation line be run down from the roof?

As shown in Plumbing Drawing, P-101. If a better route is suggested by the contractor, it may be considered.

6. Is the intent for the roof to be replaced or repaired?

Replaced. See sheet A-101.

7. Will the loose panels (Transit panels) on the walls above the roof have to tie-in to the existing wall and will they require replacement? A detail of the roof will be required.

Answer:

Yes, re-securing the panels will be required to allow installation of new flashing.

Replacing transite panels is not in the scope of work. New roof flashing should be installed behind the existing panels and extend a minimum of 8 inches above the new roof. Please note these existing transite panels do contain asbestos. This response should provide sufficient information to perform the work, therefore a detail of the roof is not provided.

8. Will an Arc Flash Study have to be done?

No.

9. Will Arc Flash Labels be required?

Yes, general arc flash stickers are required.

10. Where do electrical feeders for the panels in the mechanical room come/start from?

The electrical panels are fed from MDP-1 and MDP-2, which are in Room 4A3, about 600 feet away (see attached floor plan).

11. Question about solicitation time frame.

The project period of performance is 130 calendar days; 60 days for the project labor and 70 days material lead times. If the material lead times are extensive through no fault of the contractor, the period of performance can be extended. Documentation from the material manufacturer will be required to show proof of extensive lead times, before period of performance extensions will be authorized.

12. Is there process for getting contractors on base?

Yes, once a contractor is awarded, the AF Form 151 is used to issue contractors passes.

AF Form 151 was included in the original solicitation posting.

13. Are there any fees involved for the badging process?

14. Are passes run through a Security System for any potential violations?

Security Forces runs all AF Form 151 individual pass requestor information through a screening process. Security Forces determines if persons can access the base.

15. Is a complete electrical overhaul of the mechanical room required?

Yes. New and relocated electrical equipment shall have new wiring. However, the equipment that are in use but not fed through the current power panel shall not be touched; they are not in the current scope.

16. Will all required wiring need to be brought back to the breaker/feeder panel that would be supplying the newly installed equipment?

Yes, new branch wiring is required from the load to its panel.

17. Will all utilities have to be demo’d back to the source/back to pipeline?

Gas Pipe: Cut and replace the corroded gas pipe to the point near the wall (Roughly 20 feet in length; weld, pressure test and paint).

Electrical: Demo in according to the SOW. See also response to #16.

Sanitary Sewer: New sanitary sewer line as shown in drawings.

Service Water: Demo to the Back-Flow Preventer Union in the Mech. Room.

18. Will wiring need to be in GRC?

If an existing circuit uses GRC, the new replacement circuit must use GRC as well. EMT may be used for other new circuits if permitted by the NEC.

19. Will saw cutting and trenching be required or can drain lines be ran sanitary in the trench?

(Contractor is assuming they will have to saw cut for the sanitary line.)

Answer:

Yes saw cutting and trenching is required. See sheet C-101. Drain lines cannot be ran in the existing trench.

20. Where is MDP2 located? (Source for the power for the MCC that gets replaced.)

It’s located in the first-floor electrical room (Room # 4A3) near the exterior service transformers, (south part of the building, roughly 600 feet long conduit and original conduit to be used).

21. When is the last day for RFI’s?

Please see amendment 2; 6 March, 2018 @ 10 a.m. CST.

22. Who does the Air Force Base use for utilities (work)?

PAE (the base Civil Engineering Contractor).

23. Is an abatement required? An Asbestos Report was provided, but is abatement required?

No abatement is required per the current statement of work. Any unforeseen hazardous materials encountered will be handled on a case by case basis. Please note the potential for unforeseen hazardous materials does exist. For example, see response to question 7 about re-securing transite panels which do contain asbestos.

24. About Control drawings, Tran UCC Box backnet, tridpin and tie-in to EMCS – who will be responsible for tie into EMCS?

Answer:

The responsibilities in Automatic Control side of the project are little complicated.

Following is a clarification:

− The network VLAN port opening shall be provided by Government to the Comm.

Box in Room 3B5 of the B1080 Building, (middle part of the building, on the 2nd floor).

− The network cable from the Comm. Box to the Mechanical Room, as well as the Ethernet connector drop near the controller, shall be provided by CE Department via 82CS/SCOI Office on the Base.

− The conduit for the Comm. Cable shall be the General Contractor’s responsibility.

There is an existing conduit, (see the picture below), which is recommended to be used. In the Mechanical Room, connecting conduit from the entrance of the existing conduit to the enclosure for the Ethernet drop, (including the enclosure for the drop), shall be the Contractor’s responsibility. Also, the possible connection conduit, (from the penetration point in the second floor ceiling of B1080 to the first office that has a connection box for the cable), which is about 15 to 30 feet long, shall be Contractor’s responsibility if applicable.

(Existing Conduit from Mech. Room to Building)

− The contractor is responsible for the DDC part of the work, which must be done by a control expert. A lap-top computer, which is used for control system tune-up and which is loaded with software of the chiller controller program and the system controller program, as well as associated back-up CD’s, shall be provided by the contractor. The lap-top and software shall be part of the submittal, and eventually be passed to the Maintenance Group of the Base.

− The GUI update at the front end of the EMCS system is the responsibility of the contractor and must be done by the OEM or an expert in EMCS. The control expert shall provide necessary software support from the controller side to help the front end software worker for the signal communication between the two.

25. Specifications call for a Trane UC 600 BACNET controller to be tied in to EMCS front end – will a chiller equipped with BACNET interface in conjunction with NIAGARA N4 JACE be an acceptable alternate?

Answer:

The network communication protocol at controller level, (between Chiller and the System Controller, and between the System Controller to EMCS frontend), shall all be ASHRAE Bacnet. Niagara-type of protocol is not acceptable. (Refer to Drawings).

26. Inlet pumps with inlet suction diffuser or a Y strainer (page 16 of 27, detail 1) – do we need both components required?

Suction diffuser is required; Y-Strainer is optional.

27. What is the existing EMCS frontend? Who will perform the integration to the frontend?

− Existing EMCS frontend is a Honeywell system. See answers for Question No. 25.

− The functions at EMCS side shall be the HVAC status monitoring and Emergency Shut-Down (ESD).

− Contractor must use OEM or a specialist who is specialized in the existing EMCS to integrate the EMCS frontend part. The control expert shall provide software support from the controller side.

28. Drawing MD-101 Key Note 1 calls for the demolition of the existing chiller, including all controls. Does the Air Force Base want to keep the existing removed controls or is the contractor to dispose of them?

Answer:

The original System Controller, (Honeywell System), shall be returned back to the Base (Maintenance Group) for security and reuse purpose. The chiller, pumps, cooling towers, and old electrical panels, etc., shall be disposed of by the Contractor.

29. Drawing M-102 shows new controls conduit roof penetration from new electrical disconnect panel and single roof penetration. Will control cables have their own conduit separate from the power conduit and enclosures?

Yes.

30. Will controls conduit up to roof be permitted to be install in a small water tight junction box on the disconnect support structure? Typically, the insulation rating of control cables require they be installed in their own conduit – separate from high voltage.

31. Drawing M-501, Detail 1, End Suction Pump Detail, shows an inline flow switch which appears to be of the paddle wheel type typically used to prove chilled water flow. Typically, we see installation of a differential pressure switch using ¼” copper lines originating from tees in the pressure gauge supply and return lines, with ball valves for isolation and service to prove pump run function. This type of pump status proof is far more easily maintained, more reliable and easier to service. Please confirm the type of pump proofing required, inline flow switch or differential pressure type.

Answer:

The detail is a generic standard detail, not necessarily 100% to be used. The flow switch and pressure differential switch for proof of flow and pump running status are shown in the P&ID Drawing, (M-601).

32. There is a manifold wide differential pressure switch shown on M-601, but this is not the same as the flow switches shown on the pump detail. The intent seems to be to use a single differential pressure switch across the manifold to energize R3 in the HVAC control panel to provide for proof of a pump running, both the high and low flow pumps to be proved via the one switch.

Please confirm if this is the case. Also, are the flow switches shown on the detail actually needed?

Answer:

− See the answer for above Question (#31). Your understanding for the manifold differential pressure switch is correct.

− The flow switch shown in Detail is a generic standard. For this project, we only need one (1) flow switch for the pump system; we do not need one for each-and-every pump.

33. Drawing M-601 does not show a temperature element (sensor) on the leaving side of the chiller;

however, it does show TE-103, Supply water temperature. Is a leaving chiller temperature sensor required in case of malfunction of three way diverting valves V1 and/or V2?

Answer:

− The intention of the design is to use TE-103 to represent the chiller leaving water temperature.

− The boiler has more leaving temperature sensors for consideration of mixing control, which demands more reliability.

− As for malfunction of diverting valves V1/V2, it has been considered in the inter-lock of the control algorithm, (hardware as well as software). In another word, if V1 & V2 had any malfunction, the chiller, (and the boiler as well), should not be able to start at the first place.

34. Drawing M-601 does not show a safety flow switch directly in the chiller or boiler loops. Are they needed?

Answer:

− Safety flow switch(s) for chiller and boiler, if there is any need from OEM side, it (they) should be self-contained in the equipment package.

− If no flow switch in the equipment package, and that becomes an explicit requirement for the equipment to operate safely by OEM, flow switch FL-101 shall be used for that purpose through associate relay. In another word, both chiller and boiler, as well as pumps, shall share the same one flow switch to direct their action, if the equipment (Boiler or Chiller) demands the flow signal but the equipment itself is not self-contained with the said switch.

− If more dry contacts needed by any or more of the equipment for flow switch signal, properly selected relay that is associated with FL-101 should be able to provide the function.

35. Specifications 23 09 00 indicate control system shall be compatible to Niagara System. Is this control system required to be tied back to the Niagara N-4 (FIPS 140-2 compliant) Server for remote monitoring or is this a standalone control system?

Answer:

− No. All Niagara System type of language was supposed to have been cleaned out from specifications. If there is any residual of such language left in the specifications, it is purely by accident. All communication protocols at Controller level shall be ASHRAE BACNET. See Question No. 25.

− Please use drawing as much as possible, which spells out the requirement for BACNET. If there is any conflict between the Drawings and the Specs, the Drawings take precedence.

36. If new controller is required to be tied into the Niagara Server, who is responsible for the IT network connections local to the controller?

No Niagara type of controller. See above question, (No. 35).

37. Immersion thermostat, 2 pole, to prevent operator error by switching to summer mode when water temperature is above safe limit, say 110 F, but check chiller guide.

Answer:

Not sure understanding the question. If it says that the Chiller Installation and Maintenance Guide requires a water temperature switch in the chiller control circuit, please follow OEM Guidance in installation. If there is any alternation to the current engineering design, please mark up for final as-built documentation.

38. Is a BACnet comm card required in the chiller for communications back to controller and/or server?

Answer:

This question should go to the chiller manufacturer. HVAC manufacturers shall provide BACNET communication option.

39. Is a BACnet comm card required in the boiler for communications back to controller and/or server?

Answer:

Boiler is the existing equipment and will be used as is. The status of the boiler and its control shall be through the system controller. Its status will be passed to EMCS by that controller.

40. Is the entire roof to be replaced as a part of this project?

Yes. Replaced. See answer to question 6.

41. Will the Air Force provide detail drawings on how the roof flashes to existing hanger?

See question 7 for additional information.

42. Because the project includes installation of an air-cooled chiller, is a condensate drain pipe from the new roof down the wall to the storm drain required?

The condensate drain is piped to sanitary sewer. Refer Plumbing Drawing, (P-101).

43. Is any temporary chilled water required during this project while the chiller/ tower/ pumps are being replaced?

See Answer to Question No. 2 above.

44. Is any temporary power required during this project while the electrical MCC equipment is being replaced?

45. Some masonry is cracked and separated. Is the contractor required to repair the cracks and separated blocks as part of this project?

46. Is arc flask testing and a report required for this project?

Arc flash testing and a report are not required. See also the answer to Question No. 9.

47. Do all plans and specs for chiller components meet the 100MPH wind speed, jet wash requirements? (The question was written in concern for the new chiller and that it would likely need to be manufactured to withstand 100MPH winds (and/or aircraft jet wash from the engines) without the Condenser Cooling Fans and other chiller components being affected by the high velocities.)

There are no jet wash requirements because this area is not part of the active airfield.

48. To what extent does the Air Force expect the Contractor to prep the walls of the building (both interior and exterior) as the paint is completely peeling off the interior and exterior walls?

See specification section 09 90 00.

49. Is sand blasting the walls of the building allowed given the building’s location near aircraft?

50. Is sand blasting required or just pressure spraying of the interior and exterior walls?

51. Can a scaled drawing be provided showing the locations of MDP-1 & MDP-2 that feed the existing electrical panels and which are to feed the new electrical panels?

Answer:

Yes. An as-built plan is attached. MDP-1 and MDO-2 are in Room 4A3 of the 1st floor, (south side of the hanger in the middle, see attached plan).

52. Does the superintendent have to be an employee of the Prime Contractor?

Answer:

Please see FAR 52.236-6 -- Superintendence by the Contractor.

53. Is this project Tax Exempt?

Answer:

Please FAR 52.229-3 -- Federal, State, and Local Taxes.

54. Will any of the work performed be in Confined Spaces? If so, do these spaces require a permit or retrieval team?

Answer:

No.

55. Should drawings or specs contradict each other, which should supersede?

Answer:

The general rule of precedence order for conflict among project document are: (from top to bottom)

(1) Law, government regulation, Court order, etc.

(2) Clarification letter (such like this one), change order, etc.

(3) Drawing and Drawing Notes

(4) Technical Specifications

(5) Industrial Standards

(6) Industrial general practice

56. Is contractor responsible for locating and marking existing utilities?

Not beyond the current working scope. All new installation shall be properly marked.

57. Is contractor responsible for tie-in from sanitary sewer to sanity sewer main line?

Answer:

Yes, see CU-101 key note 2.

58. Is there an existing sanitary sewer that serves the Equipment room, and if so does it need to be capped?

Yes, see P-101 key note 4.

59. What is to be done with the Equipment being removed? (i.e. Chiller, Cooling Tower etc.)

See answer for Question No. 28.

60. A portion of 10th Avenue will need to be shut down to install the new sewer line across it. Are there any issues with shutting down a small portion of 10th Avenue for a minimum of 3 to 4 days?

Answer:

No issues.

61. Can excavated soil be reused for backfill?

Answer:

Yes

62. Are the new panels (MCC and G) to be connected to the existing feeders serving the existing?

What size breaker feeds the exiting MCC? What size breaker feeds panel G currently?

Answer:

Reuse the existing feeder conduits, but pull new cables. Refer to attached riser diagram and answer to Question No. 20 for additional info.

63. Is there a panel schedule and branch breaker size for the existing panel G to be matched?

Refer to attached riser diagram and answers to Questions No. 20 and 62 for additional info.

64. Will the new MCC really be motor control center or just a distribution panel with fuses?

The MCC will be a bona fide motor control center. A real one, (see drawings).

65. Will the new pumps need combination motor starters or VFD’s?

See Drawing M-600’s

66. How are the new pumps going to be controlled?

See Drawing M-600’s

67. Due to inclement weather, contracting rescheduled the pre-bid site visit and RFI submission deadline. However, contracting did not extend the final bid submission deadline. With only three business days between RFI submission and final bid submission, contractors will not have adequate time to make adjustments and submit an accurate bid. Will the contracting office extend the final bid submission deadline?

Answer:

Yes, Amendment 5 extends the proposal deadline to 23 March 2018 at 1:00 p.m. Central Time

68. Will contractors have access to restroom facilities in Building 1080?

No. See specification Section 01 50 00 paragraph 3.2.D.

69. Will we be provided either a storage area or a place to put our metal, weatherproof storage container? If so, where will that be?

Answer:

Yes, see specification section 01 50 00 paragraph 3.4.C. This location will be determined after project award. Short term storage outside or inside of the Machine Room can be worked out with the Building Management personnel.

70. Will we be required to abate any asbestos, lead, or other dangerous materials as part of the project? If so, where are these dangerous materials located and what quantities should we use for cost estimate development purposes?

See response to question 23.

71. All of the existing vertical "exterior wall" panels on Building B1080 that the new roof from the mechanical/electrical room will tie into appear to be loose. We ask that a detailed be provided that clearly shows how the new roof is to tie into the existing vertical "exterior wall" panels on Building B1080.

See response to question 7.

72. The existing masonry/CMU in the mechanical/electrical room has numerous cracks in it. We assume that we are tuck point and repair the existing cracks. We ask that a quantity be provided for the amount of tuck pointing and repair that must be completed so that all bids are operating off of the same quantity as opposed to each contractor guessing as to the amount of tuck pointing and repair that must be accomplished for the existing masonry/CMU.

Answer:

For bidding purposes, assume 200 linear feet of tuck pointing and repair of existing cracks.

73. The existing paint inside and outside the mechanical/electrical room is in poor condition. We assume that for bid purposes we are to sandblast away the existing paint and underlying primer (if any) and then re-prime all interior and exterior walls, and then repaint all interior and exterior walls. Are we correct?

See responses to questions 48, 49, & 50

74. Please provide a specification for the required interior and exterior wall primer, and a specification a color for the required interior and exterior wall paint.

See responses to questions 48, 49, & 50

75. Please provide a specification and verify the number of required new light fixtures inside the mechanical/electrical room.

Answer:

Refer Drawing E-101. The ten Finelite fixtures (or approved equal) specified to meet the lighting requirements.

76. Section 3.1.2.1 Subfactor A to the Solicitation requires a discussion on "Risk Management" as part of our Technical Proposal. The term "Risk Management" has wide variations in terms of its meaning. Please provide clarity on what aspects of Risk Management the Government is looking for in regard to Risk Management.

Answer:

There are many approaches to project risk management planning, but essentially the risk management plan identifies risks and outlines mitigation actions for those risks. The list of risks is not meant to be exhaustive nor are there any particular risks that must be addressed; instead, the contractor is to identify and address those risks that it finds to be most relevant by its assessment of the nature and complexity of the project. As an example, however, the contractor could identify critical equipment that, if delayed, could significantly delay project completion. The plan would then provide a mitigating solution that would either help prevent the risk from happening or limit the impact if it does occur, for example, working on another section of the project while awaiting the delivery of the delayed equipment.

77. There is an existing ladder leading to the roof of the mechanical/electrical room. Please clarify whether this ladder is to be replaced or left in place. If left in place, provide a specification for the metal sealer and paint and a paint color for painting the ladder.

See specification 09 90 00

78. For schedule development purposes, what is the assumed date that we should use for when temporary heating must transition to temporary cooling and then back to temporary heating?

Answer:

As a rule of thumb, Heating Season is generally from December through March; Cooling Season from May through October. April and November are transit months, and could be either or both. However, temporary equipment for both heating and cooling is not recommended during transit seasons or even for the construction period. Properly timing of the project is required.

79. Will ARC flash studies be required for new electrical equipment?

Detailed arc flash studies for new electrical equipment are not required. However, state any manufacturers’ arc flash info on equipment labels. See also the answer to Question No. 46.

80. Will ARC flash labels be required for new electrical equipment?

General arc flash stickers are required. See also the answer to Question No. 46.

81. Will the bid due date be extended to allow time for RFIs to be answered?

See responses to question 67.

82. Will it be acceptable to place the temporary air-cooled chiller directly behind the mechanical room?

Answer:

Details of area allocation for temporary storage and temp-equipment shall be worked out with the building management in construction stage of the project. Nonetheless, the proposed location seems good for the temp-equipment.

83. Does the contracting office have a preferred location for the temporary air-cooled chiller?

See Answer to Question 82.

84. Will it be acceptable to block the entrance of Building 1080 during crane lifts and excavation for new sanitary sewer lines once the proper paperwork has been filed and approved?

Yes, but one exit on the west side of the building must remain open at all times.

85. Note #3 on drawing C-101 states that the contractor should assume that the area to be excavated will be free of underground utility interference. In the same note it states that the contractor shall be responsible for and shall repair all underground utility systems damaged in the course of work at the contractor's expense. Which is it?

See specification section 01 11 00 paragraph 1.8.

86. Would it be acceptable to pour back concrete in road saw cut trench rather than asphalt?

No, patch must be asphalt.

87. Who maintains the building management systems (BMS) for the base? Who is the point of contact for DDC controls integration?

Answer:

PAE maintains Energy Management Control System (EMCS) for the base, which may be close to BMS. For questions regarding DDC system design itself, contact the Design Engineer Shawn Lee via Contracting Office. For EMCS frontend work, contact PAE via Contracting Office.

88. A-101 Shows in Detail 2 adding a beam (note 12) into an existing steel frame and it is to be a W6 x 16 W Beam; however, the size of a W6 x 16 does not match the sizes shown in Detail 6 views on A-101. The W6 x 16 beam is 6.28” in height but the detail shows the height to be 5 ½” of which there is none this size in the new steel books. For a width, the W6 x 16 is 4.030” and the details shows 8” or 7 ¼”. What is the existing beam size on the project and is it still available?

Answer:

The beam referenced in key note 12 should be a W6x15. The depth in detail 6 should be 6 inches not 5.5 inches. Detail 6 is for the built-up steel plate supports on the edge of the existing frame.

89. M-501 shows in Detail 6 a chiller supporting frame that in no way matches what is shown on sheet A-101. Is this another frame from somewhere else? What detail is correct and to be used on this project?

Answer:

For roofing and building structure construction, as well as supporting beams, follow A-

101. For Mechanical Equipment installation, follow M-501.

90. Does the existing paint on block walls and metal frames contain lead?

Answers:

91. Please confirm that existing structure is adequate for weight of new construction.

Answers:

Confirmed based on the mechanical equipment specified. If different equipment is submitted and approved. The engineer of record must re-confirm this prior to equipment installation.

(End of Questions and Responses)