697DCK-23-R-00419 Amendment 0001.pdf

697DCK-23-R-00419

Barrow FSS HVAC Upgrades Project

RFO Questions & Answers

1) Question: Are there any painting or coatings required on the exterior sch 40 steel gas piping?

Answer: No painting or coatings required for above ground exterior natural gas piping.

Coating would be required for underground steel pipe, but there is no underground natural gas piping in scope.

2) Question: Would pex tubing be acceptable instead of PVC for the condensate piping?

Answer: Yes. PEX tubing is acceptable.

3) Question: Detail 4, M601 states to slope condensate piping. Does this piping all need to be sloped even though it is downstream of a condensate pipe?

Answer: Detail is standard, in some applications pipe sloping may be necessary to ensure proper function of drain. If lift from condensate pump is sufficient to drain water to existing sanitary waste drain, the piping does not need to be sloped.

4) Question: P101 2nd floor shows the ¾” drain from the AC unit routed down near the bathroom but does not note where this is discharging. Is the intent to add a condensate receiver in the wall and tie into the drain from LAV-1? Or route through the floor along with the drain from the 1st floor AC unit and discharge in the Funnel fitting in the mech room?

Answer: Intent was to discharge drain in the existing sanitary waste drain from LAV-1.

Drain may be routed elsewhere.

5) Question: Mech plan level 1, note 9 states to install new spring return, failsafe damper actuator. Is this an on/off or a modulating actuator? If modulating, what type of control signal is being used (i.e., 2-10V DC or 4-20ma)? Also, what is the voltage of the actuator (24VAC, 120V, or 240V)?

Answer: Per sheet M002, VENTILATION AND EXHAUST Para. 3: Damper actuator is on/off, 24V.

6) Question: AC units are specified to be provided with wired controllers. We do not see any specified locations for the controllers on the drawings. Please specify locations, if required, or if locations are to be determined by the contractor?

Answer: Controller locations to be field coordinated with FAA resident engineer.

7) Question: NEC 210.63 requires a service receptacle within 25 feet of the air conditioning equipment. Is there an existing receptable that meets this requirement, or, if not, is the contractor required to provide one?

Answer: There is no existing receptable that meets the requirements of NEC 210.63 on the exterior of the building within 25 feet of AC-1A and AC-2A. Contractor to provide service receptable.

RFO Questions & Answers

8) Question: The scope of work 1.03 B 2 states to relocate the humidifier in operations area to serve electronics equipment room. However, the drawings do not reflect any work regarding this humidifier. Please clarify.

Answer: Disregard comment. This is left over from an earlier iteration of the scope.

9) Question: D101 shows removal of the furnace duct mounted humidifier. Is there any associated piping or humidifier generator that also needs to be removed? Any piping that needs to be capped?

Answer: Per scope of work on Sheet M001, intent is to replace the existing duct mounted humidifier with a like-for-like product, or value-added improvement.

10) Question: Scope of work 1.09 A states that work is to be completed within 30 days of the issuance of the Notice to Proceed. Depending on timing of the contract award, limited notice to proceed and notice to proceed, 30 days may not be practical for getting all materials onsite and completing all work. Is the Notice to Proceed a date that can be scheduled and arranged so the contractor has up to a full 30 days onsite to complete work?

Answer: The 30 days from Notice to Proceed is for the onsite work only. The submittal process must be complete, all materials ordered, and all material lead times taken into consideration in the planning stages prior to issuance of Notice to Proceed. The Notice to Proceed is issued after confirmation of material delivery dates, including materials with long lead times. In addition, the 30-days for onsite work is only an estimate and is negotiable based on the contractor’s final approved schedule.

11) Question: Scope of work 3.1 B states to sequence pump replacement. We do not see any work related to pumps on this project. Please clarify.

Answer: Disregard. This is an error and not applicable to this project.

12) Question: Scope of work 3.04 D calls for precharged refrigerant tubing with quick connect fittings. This does not seem appropriate for these AC units. Please confirm that we can use compatible linesets, cut to length and flared connections at indoor units and outdoor condensers.

Answer: Compatible linesets with flared connections are acceptable.

13) Question: Detail 2, M601 states to reuse existing 14x14 opening in roof. Figure 19 in the photo package shows what appears to be an approximate 6” round penetration. Is this 14x14 framed opening the same location as the photo or somewhere else?

Answer: This appears to be a mistake in detail 2, M601. The site survey did not perform any destructive testing and did not access the roof, so the nature of the roof penetration should be considered an unknown and will need to be evaluated in the field. Figure 19 is an

RFO Questions & Answers accurate view of the vent from below the ceiling. Our site survey report notes a 3” diameter plumbing vent enclosed in a 6” sheet metal vent with interstitial close cell foam insulation at ceiling level’. It is unclear if the foam insulation extends to the roof level.