NNM17615413E_Questions_and_Answers_35,_42,_50_thru_69.pdf

NNM17615413E Question and Answers 35, 42, 50-69

35. Regarding the Natural Gas / Liquid Petroleum Gas Distribution specification 335115, paragraph 3.10-

B states the normal operating pressure for the system is 50 psi. Are we to assume this is the operating pressure of the future Liquid Petroleum service also?

35A. The stated gas pressure is expected to be the normal operating pressure for all gaseous fuels which may be supplied. Maximum gas pressure may exceed 50 psi at times, but shall remain less than

60 psi.

42. The specifications require 1 ½” exterior HDPE gas piping. The smallest size made is 2”. Therefore 2” will be installed.

42A. 2” exterior HDPE gas piping is acceptable for use in lieu of 1 ½” piping.

50. Who is furnishing the gas regulators and meters? What is the incoming natural gas pressure?

50A. The contractor is to provide meters and regulators. See revised spec 335115 3.10.B

51. Is both control valves on the condensing boiler furnished by the control contractor?

51A. It is the Prime Contractor’s responsibility to coordinate purchase responsibilities between trades.

52. We will need to get back in the buildings to measure the coils that are to be replaced – what will be the security?

52A. The only organized site visit for this project was on June 13, 2017.

53. Building 4203 shows removing the heating water pumps. Is this piping to be capped off?

53A. Remove drawings FAC-BY-4203-A0, FAC-BY-4203-ED1, FAC-BY-4203-MD1, FAC-BY-4203-UCS1, FAC-

BY-4203-UCS2 from the contract documents. See previous answer

54. The drawings show removal of the condensate pump receiver and the steam PRV in the mechanical rooms. Are there any vents or relief valve piping going through the roof that will require roof repair after pipe removal?

54A. Bid per plans and specs

54. Can you please clarify the “300# point load roof”? Are they asking for 300# to be hung anywhere in addition to the 10# collateral? If so, how many places?

54A. This load listing is from Table 1607.1 in the 2012 IBC. It is a reference in Table 1607.1, Item 26 and it states that “All roof surfaces subject to maintenance workers’” and it is a 300# concentrated load, not a point load. The roof structure must be capable of supporting a 300# concentrated load. Per 1607.4, when not specifically identified, the concentrated load shall be assumed to be uniformly distributed over an area of 2-1/2 feet by 2-1/2 feet and shall be located as to produce the maximum load effects in the structural members.

55. The drawings show IBC 2012, but only a 90 MPH wind speed. We are going to make it 120 per code.

55A. This is acceptable.

56. The drawings show 5 psf ground snow. IBC says it has to be 10 psf minimum. We are going to quote

10 per code.

56A. Per 2012 IBC Figure 1608.2 the ground snow load should be 10psf.

57. The specs show the roof to be standing seam, however the LS-36 panel that is specified is a thru-fastened roof panel. Please advise on which panel is required.

57A. Provide roof panel in accordance with the specifications.

58. During the site visit, discrepencies were discovered between the drawings and existing equipment.

Are proposals to be based on drawings alone or the discovered discrepencies?

58A. The site visit was intended to help the contractors prepare their bids and develop specific questions.

59. Confirm that bids can be hand delivered to the location of the bid opening.

59A. Yes, bids may be hand delivered to the bid opening site specified in the solicitation.

60. What manufactures are acceptable for the boilers? It is not stated on the schedules nor is it stated in the specifications.

60A. Any manufacturer that meets the requirements in the specifications for high mass, high efficiency boilers and the requirements set forth in the drawings is acceptable.

61. Are Boiler Power Off (BPO) switches required at all boiler room exits or just where they are shown on the Mechanical/Electrical drawings?

61A. Yes, Boiler Power Off Switches are required at all boiler room exits. These are emergency shutoffs and shall be provided as occupants leave the room.

62. Reference Specification Section 235216 – Condensing Boilers, paragraph 2.6 – Venting Kits:

Stainless steel materials are specified. We are accustomed to seeing PVC materials used for these applications. Please confirm the requirement for stainless steel venting kits.

62A. Provide stainless steel as specified.

63. Reference Building 4760, drawing M2, Room 111/112, Note 7: Steam coil is shown to be demolished in this room and Note 7 states to replace with hydronic coil per schedule. We do not find a hydronic coil scheduled for this location. We suspect a similar situation in Room 118. Please clarify.

63A. See revised Drawings. A revised schedule has been provided which has the coil scheduled.

64. Reference Building 4765A, drawing M3, Detail 8: The control diagram indicates the presence of a motorized damper. Please confirm.

64A. This is correct, a motorized damper is used in conjunction with Louver L-1. This will work in tandem with the exhaust fan.

65. Reference Building 4707, drawing M2: Note 3 states to provide new electric steam humidifier but drawing M1 does not have a schedule for humidifiers

65A. See revised Drawings. The Schedule for the humidifiers has been provided.

66. Reference Building 4707, drawing M2: Note 4 states to connect existing chilled water to new dehumidification unit but schedule on M1 for dehumidification unit does not give chilled water coil requirements. Please provide specifications for the dehumidifier unit. Also, please provide dehumidifier sequence of operation which is not shown on Detail 3/M11.

66A. There is no chilled water connected to this unit, chilled water is provided to the associated air handling unit. The sequence of operation as noted, calls for the unit to be reconnected and provided with the same controls that are currently configured to work in conjunction with the associated air handling unit.

67. Reference Building 4707, drawings M1 & M11: Drawing M1 General Notes state commissioning for humidifiers 4707-HUM0011 & 4707-HUM0012 but there is no schedule for these humidifiers. Also, drawing M11 shows control sequence for same humidifiers. Please provide a schedule for these humidifiers.

67A. The schedule of humidifiers has been added to the drawing 4707 M1.

68. Reference Building 4707, drawing M1: Dehumidifier schedule shows 1,125 CFM for the reactivation blower section but shows 396 CFM for the reactivation heating section and 371 CFM for the reactivation air conditions. Please advise which CFM is correct for the reactivation section for this unit. Also, please provide chilled water coil conditions and requirements for the dehumidification unit.

68A. The reactivation heating and blower CFM’s are to be the same, and the reactivation air conditions are now scheduled with the same CFM-396. This unit does not have chilled water connections, the chilled water connections are to the associated air handling unit.

69. Will submittals submitted electronically be acceptable?

69A. Yes. NASA plans to use a web based system to process and track submittals electronically in this project.