RFP 5845871 Amendment 0003.pdf

(SEE ITEM 13)

B518 Replace Chillers Project: RFIs Received 4 March 2021

A. Is there a way to get these Chillers out and the new ones in, in one piece or do we need these broken down for each new and demo?

Removal and installation of new equipment is part of the contractor’s means and methods.

B. How close to the building can we get for the Temp Chillers?

Previous temporary chillers have been staged directly outside the mechanical room’s exterior double doors.

C. What is the access for the rigger get the crane as close to the building?

A base map will be provided for use in planning access routes and crane location(s).

D. Can we get a map of the base to know where bldg 518 is located? The map provided does not show it.

See above response. (Base Map Attached).

E. Can we get some pictures for the existing conditions, specifically in mechanical room?

No.

F. Can we get as build architectural drawings for mechanical room?

Architectural record drawings will be provided. (Attached).

Scope of the project stated that the current system uses two chillers and two roof mounted cooling towers, is adding a new cooling tower required, as it is not mentioned in the scope.

No; an additional cooling tower is not required.

Section 01 33 10.05 20 in the specifications called for design submittal, 1.3 called for design requirements? Is design required for this project?

Refer to RFP Part 2, Section 01 33 10.05 20 Design Submittal Procedures. As indicated in subparagraph “i” of section 1.3, Contractors are encouraged to prepare design drawings more like shop drawings to minimize construction submittals. However, at minimum, the Contractor’s design should include:

Basis of Design narrative; shop drawings indicating new equipment, electrical connections, piping layouts, equipment schedules and control sequences; specifications and any supporting calculations.

A cooling load analysis/calculation is not required as new chiller sizes were provided in the RFP.

Would a 227 ton Chiller be acceptable in lieu of the 300 ton they are asking for in option #2?

Assume 300 ton capacity for bidding purposes.

G. Per section D303001 in Attachment A of the RFP, “Provide oil-free, magnetic bearing, semi-hermetic centrifugal compressors with heat recovery capability.“

1. Do the existing chillers have heat recovery capability?

No.

2. What is the goal of the heat recovery capability?

See response to #5 below.

3. What hydronic loop are we trying to heat with the heat recovery chiller?

See response to #5 below.

4. What temperature needs to be maintained in the heat recovery loop?

See response to #5 below.

5. After reviewing the RFP chiller requirements with chiller manufacturers there is not an option for heat recovery on an oil-free chiller. Please confirm if heat recovery is required as indicated in the RFP. If so, then the chiller will not be oil-free.

Heat recovery is not required. Oil-free magnetic bearings are required.

H. Please advise if the Cx agent needs to be a 3rd party agent?

Refer to the RFP, Part 2, Project Description.

I. Please advise if the Navy will be providing the Cx Agent or will the Contractor?

Refer to the RFP, Part 2, Project Description.

J. In the base bid it mentions that the cooling towers were replaced in 2019 and are therefore not a part of the scope. Bid option #1 indicates that chiller CH-1 is to be replaced. Is there an associated cooling tower that also needs to be replaced?

No. The system operates with (2) chillers and (2) cooling towers. The 3rd chiller is for redundancy and possible expansion of the chilled water plant in the future.

K. The RFP mentions that building 518 is a secure building and that escorts are required. Does this include the mechanical spaces where the chillers and pumps are located?

Yes.

L. Please advise if the chilled water system should have an air separator?

Yes.

M. Please advise if mechanical as built drawings are available. If so please distribute.

Mechanical record drawings were provided in Part 6 of the RFP.

N. For option #2, would it be preferred that permanent chilled water supply and return connections are installed outside for future use?

No.

O. Option #2 indicates to provide a temporary chiller with a total capacity not to exceed 300 tons. What is the minimum capacity required of the temporary chiller? 300 tons nominal capacity?

Assume 300 ton capacity for bidding purposes.

P. Please advise if a refrigerant monitoring station is available. If not, is one required to be installed?

There is an existing refrigeration alarm in the mechanical room.

Q. Does the current chilled water and condenser water loops contain glycol? If yes, is there a contingency plan to deal with the disposal of this material should the building existing isolation valves not function properly?

No; glycol is not used in the hydronic systems at B518.

R. Is there an existing refrigerant monitoring system in the mechanical room? If yes, please provide information on the existing unit.

There is an existing refrigeration alarm in the mechanical room. Specific information regarding the unit is not available at this time.

S. Will this project require recommissioning and will the DOD Cybersecurity Requirements be needed when we retrofit the new units to the existing control system?

The existing DDC system meets current DOD Cybersecurity requirements. Alterations to the existing system.