Attach 6 - Questions and Answers.pdf

QUESTIONS

B530 Replace & Repair Air Cooled Chillers

Goodfellow AFB, TX August 5th, 2021

1. The existing concrete pads will not be long enough to accommodate the length of the two new chillers. Will the Contractor be required to design and build new chiller pad extensions to accommodate the new chillers? New chillers will be placed where existing chillers are now, a new pad will not be needed.

2. If the Contractor is required to design the new chiller pad extensions, will the design need to be performed, signed, and sealed by a licensed professional engineer? New chillers will be placed where existing chillers are now, a new pad will not be needed.

3. If the Contractor is required to provide design for new chiller pad extensions will the Contractor be required to submit design drawings and/or specifications for review and approval? New chillers will be placed where existing chillers are now, a new pad will not be needed.

4. Will the Government confirm that the existing temporary chiller will remain on site and operational throughout the duration of this project? Yes, until the contractor takes it down to replace the 250 ton chiller.

5. The RFP scope of work indicates a requirement for three (3) new transfer switches to be mounted on the exterior side of the north mechanical room wall. Did the Government intend for these to be disconnect switches in lieu of transfer switches? No

6. If deemed adequate will the Contractor be allowed to reuse the existing chiller circuits from existing switchgear to the existing chillers, or is the Contractor required to remove and replace these circuits from existing chiller back to the existing switchgear? Yes

7. The RFP indicates that the Contractor is required to remove, retain, and re-install EMCS control wiring and materials for communication from chillers to 17 CES EMCS monitoring office. Will it be acceptable to simply disconnect this wiring from the existing chillers and reconnect to new chillers? Yes

8. RFP states “Contractor shall install two (2) 600 Amp 3-pole transfer switches on the North outside wall of the mechanical room. Contractor shall install one (1) 400 Amp 3-pole transfer switch on the North outside wall of the mechanical room.” Can example of what is being requested be provided? Did the Government intend to these to be “disconnect” switches in lieu of “transfer” switches, or are these supposed to be new ATS’s being fed from emergency power? If these are being fed from emergency power please indicate where source is located so that appropriate quantities can be determined. These are not automatic transfer switches (ATS). These are to be manual transfer switches and not disconnects. They are to be installed for resilience purposes so that if one of the chillers goes down a portable unit can be tied in.

9. The existing 275T Trane Air Cooled Chilled has an electrical service for each of the refrigerant circuits. Is the reason for the RFP requirement of (1) 600 Amp 3-pole transfer switch & (1) 400 amp 3-pole transfer switch to accommodate a new 275T multi-point power replacement chiller (one switch for each refrigerant circuit)? There are (3) 600 Amp 3-pole transfer switches. Two (2) 600 Amp 3-pole transfer switches to feed the 275T Trane Air Cooled Chiller and one (1) 600 Amp 3-pole transfer switch to feed the 250T Trane Air Cooled Chiller.

10. Is the reason for the RFP requirement of (1) 600 amp 3-pole transfer switch to accommodate a new single-point power 250T chiller? See answer on question #9.

11. There is a J-Box inside the mechanical room. Are J-Boxes allowed? Yes, as long as they meet NEC requirements.

12. If existing circuit breakers are appropriately sized, can they be re-used? Yes

13. Regarding chiller selection and options: Is anything other than 1-year parts & labor warranty required (i.e. is a 5-year compressor parts & labor required or different) Trane provides a standard 1 year warranty on compressor.

14. Regarding chiller selection and options: Are Hailguards required? Yes.

15. Regarding chiller selection and options: Is a chiller BACNet interface card required? Yes.

16. Regarding chiller selection and options: Are service isolation valves required on the chiller?

Chilled water isolation valves are required.

17. Regarding chiller selection and options: Are there any special factory testing options required?

Chiller must have the factory start up required by TRANE.

18. The current Trane 275 Ton Air-Cooled chiller has two separate electrical circuits powering each refrigerant circuit. The only Trane chiller model that has this option is a RTAC model. The Trane RTAF & ACRB models are not available with a dual power option. Please clarify that the RTAC chiller model is acceptable or if other requirement. Existing chillers are RTAC.

19. The reference to “Lead/Lag” control capability is done through the existing EMCS system. Please clarify that this will remain in effect and is not a selectable Chiller option. Yes.

20. Are the two (2) existing Belimo control valves to be re-used or are new control valves required?

Yes if working properly.

21. Is the existing CHW sequence to remain or are any modifications needed? Need clarification for this RFI.

22. Can the Contractor re-use existing piping and conduit to chillers to the greatest extent possible?

Yes.

23. The POP is listed as 90 calendar days. The current lead time for these chillers is approximately

14-16 weeks. Will the Government adjust the POP accordingly or provide a separate NTPs with separate construction duration once equipment arrives? The government has changed the period of Performance to 180 days to account for lead time.

24. Please confirm the requirements for onsite Quality Control Manager and Site Safety Officer and confirm that this person is expected to not perform any other work. The Quality Control Manager and Site Safety Officer can hold multiple roles as long as they are able to perform their duties as a Quality Control Manager or Site Safety Officer.

25. Can the QC Manager and SSHO be the same person? Yes, QC Manager and SSHO can be the same person.

26. Per 1.5 of the SOW, the period of performance is 90 days. It will take approximately ___ weeks to procure the equipment. Will this time be incorporated into the performance period? See question 23.

27. The Technical Exhibit of the Controls Diagram is blurry and unclear to read some of the items, can a better copy be uploaded to replace the current version? There is nothing but a start stop in place for the Controls diagram. It is a single cube relay, two wire connection.

28. Is a copy of the current Chiller Drawings to include associated pipes, fittings and devices be uploaded for viewing? No there are no Chiller Drawings that can be uploaded for viewing at this time.

29. Are the replacement chillers and associated equipment expected to fit on the current concrete pads in place or can we add concrete as required per manufacturers specs if needed? Trane chillers will be used, so they should fit the pad.

30. Will the temporary unit (chiller) being used now be in the same place as it is in now during the performance of this project? Yes.

31. In 1.2 of the SOW it states, “Contractor shall install one (1) 400 Amp 3-pole transfer switch on the North outside wall of the mechanical room.” During the site visit we were unable to see if this was present due to multiple enclosures which may or may not house the switch to tell currently in place and to be replaced or a new installation requirement, as well if the power is available or needed to be installed/routed? Transfer switches are new installation, power will be used from existing power to chillers and routed.

32. In 1.2, 1.4c of the SOW it states, “Contractor shall remove, retain, and re-install EMCS (Energy Management Control System) control wiring and materials for communication from chillers to 17 CES EMCS (Civil Engineer Squadron Energy Management Control System) monitoring office.” Is this to reinstall/re-use the same wiring and materials or to replace? Yes.

33. In 1.2 of the SOW it states “Government will salvage parts from chillers. Subsequent to Government salvage, Contractor shall take custody of both removed chillers, VFD’s, piping, and valves to include any oil and refrigerant, plus all other equipment and materials resulting from the demolition.” Understanding that it is the Contractor’s responsibility to store the NEW equipment, will the Government offer a place to store the removed equipment, and is the Government picking up the old equipment? See1.13.1 Contractor Parking & Storage:

34. 1.5.1 of the SOW states “Working hours for the Contractor will normally be between the hours of 7:30 a.m. and 4:30 p.m. excluding Saturdays, Sundays, Federal Holidays, AETC Family Days.” Is there the ability to work outside of these hours to minimize the effect on the use of the building for normal operations due to scheduled outages with prior approval from the Contracting Office? See section 1.5.1, submit to base contracting you justification for approval by the contracting officer.

35. In 1.16.4b of the SOW it states, “The Contractor, then will be issued a temporary Defense Biometric Identification System (DBIDS) pass or AF Form 75A through the expiration date on the BAL request.” Is this an incurred fee to the contractor similar to RAPIDGate and if so, what is the additional cost? No additional costs are required other than the standard administrative costs typical to access military installations.

36. Will commissioning be required?

See 3.4 CONTRACTOR PROVIDED MATERIALS SECTION E

37. What if any Bonding is required?

Bonding is not required.

38. Do we need a project schedule with our bid submission? See 1.5.1.

39. Do we need to submit a certificate of insurance with our bid submission? This is not required.

40. Is there a requirement for a dedicated Quality Control and/or Site Safety Officer? No, daily reports still have to be submitted.

41. Per SOW, the contractor is to Demo/install 2 new VFD’s. Please confirm the existing motors/pumps are not to be replaced with the VFD’s? See 1.2 PROJECT DESCRIPTION.

42. Please advise whom the EMCS is currently managed by? Is it proprietary? Contractor must remove and installed EMCS equipment and wiring.

43. Please confirm if the expectation on LEAD/Lag is to be done through the chiller controls or through the EMCS? Through chiller controls.

44. Please confirm if the government is planning on salvaging the refrigerant in either machine or is it to be disposed of off site per EPA? See 1.2 PRODUCT DESCRIPTION.

45. Please confirm if “in” factory witness performance testing is required? This is extremely expensive and not cost effective. If it is, how many Representatives will attend and at who’s cost.

This is not common. See 3.4 CONTRACTOR PROVIDED MATERIALS SECTION E

46. What is the projected magnitude of this project? Need clarification on this question. What do they mean by this and why do they need to know the magnitude outside of what is stated in the SOW?

47. With the change in SOW to replace both chillers. Will the Government accept any other chiller manufacturer? Daikin, Carrier, York? See Chiller Approval Memo

48. There is a lot of damage on the existing pipe coverings/insulation. Does the Government want to reinsulate all the pipes on this project? Yes.

49. There is no existing heat trace on the pipes, will the Government want to upgrade and install heat trace to protect the pipe in cold weather? There is heat trace, contractor need to ensure it is operational.

50. The existing 2 control valves, are probably isolation valves for when each chiller is not running to not let water flow thru while its off for efficiency, can they be reused? Yes if they are operational.

51. Install 2 new 600 amp transfer switches on north outside wall of mechanical room. Does this mean a transfer switch, wiring, and tie it into standby power or install disconnects into power feeding existing chillers? Install transfer switches into power feeding existing chillers. This will require some new wiring and rewiring of existing power feeding the existing chillers.

52. Install 1 new 400 amp transfer switch on north side of mechanical room.

Does this mean install wire, transfer switch, and tie into backup power, or install new disconnect, wiring, and tie into existing electrical bank? Install new transfer switch, wiring, and tie into existing electrical bank.

53. What is the minimum circuit ampacity and maximum overcurrent protection of both chillers? Are these 480vac? Pictures of “Both” existing chiller data tags from Bldg. 530 – 480V are attached.

54. What is the HP of the drives? Will they be provided by others?

Both pumps are 20 HP 480V. No, these are awarded contractor provided as part of the contract as stated -“Contractor proposed to provide and install”

55. Contractor proposed to install two (2) 600 Amp 3-pole transfer switches on the North outside wall of the mechanical room.

Questions – A. Are these automatic or manual?

B. What type of enclosure?

C. Are these to protect the new chillers?

D. What is the distance from the emergency source?

E. What is the distance from the commercial source?

F. Are these 480vac?

G. Is there control monitoring for these?

H. Who will be responsible for that?

ANSWERS –

A. Manual B. Must be exterior rated C. Not for protection- Intended as a connection point for a portable chiller when needed.

D, E & F. No, these are to allow addition of a portable chiller as needed to support the facility when the chiller is not operational. This is not in any way related to emergency generation of power at this facility The commercial power is accessible outside the facility, on the exterior mechanical room wall reflective of the requirement stated- “ Contractor proposed to install two (2) 600 Amp 3-pole transfer switches on the North outside wall of the mechanical room” This is not an emergency power application. Intended as a connection point for a portable chiller for circuit (1) – (200 Ton section) of the 275 Ton West chiller, and (1) for the 250 Ton East chiller ***both connected to 600 Amp 480V main distribution Breakers*** G&H. No external controls – GAFB personnel will manual change over when applicable

56. Contractor proposed to install one (1)400 Amp 3-pole transfer switch on the North outside wall of the mechanical room?

Questions – ALL ARE THE SAME AS IN SECTION 3 ABOVE – But, in regard to the “400 AMP transfer switch” which will be installed on Circuit 2 of the 275 West chiller. (75Ton)

ANSWERS -

There is no need for contractor to install “400 AMP transfer switch” This has been removed from the updated Statement of Work.