B533 RFI Responses.pdf

B533 Cooling Tower Replacement RFIs:

1. The SOW notes the condenser water is to have a chemical free water treatment. The water for the condenser is a closed-loop system in which normal water treatment inhibitors, etc. would typically be used. Often, a chemical free water treatment would be used in the Spray water system. Please confirm where the government would like the Chemical Free Water Treatment.

The closed loop system does not need water treatment. The water that is continuously circulated and sprayed over the closed loop coils does need the chemical-free treatment to keep the water in good condition.

2. We would like to build a temporary timber frame platform to assist in the demolition and rigging of the cooling towers. This platform would rest partially on the riprap between the cooling tower platform and the adjacent parking area. Is the riprap between the cooling tower platform and the adjacent parking area covering any underground utility lines, water pipes, or anything else that would preclude construction of the platform?

Record Drawings do not indicate any underground utilities under the riprap.

3. The SOW states that we can reuse the existing condenser water piping, equipment pads and electrical conduit runs to the greatest extent possible. It doesn't mention the existing I-beam frame mounted to the cooling tower platform, on which the cooling tower is bolted. Are we permitted to reuse the existing I-beam frame or would the government prefer that the frame be new along with the rest of the cooling tower materials?

Provide new steel framing as required for installation of the new tower.

4. The Scope of Work suggests that all existing electrical conduit and piping from the building to the exterior evaporative cooling towers is to be reused. If existing conduit or piping requires replacement (due to existing condition or code requirements) please clarify how this would be reimbursed by the Government.

In the event that existing conduit or piping is determined to be unsuitable a Contract Modification may be considered according to the applicable Contract FAR Clauses.

5. Will it be allowable to reuse existing electrical conduit and circuits if it is determined they are adequately sized to support the new equipment?

Yes.

6. Considering current lead-time for electrical and mechanical equipment, would the Government consider increasing the period of performance from 270-days to 365?

7. The required performance period as stated in the SOW is 270 calendar days. Initial delivery lead time for the 400 ton cooling tower after submittal approval is 365 calendar days. Accordingly, request that the performance period be extended by a minimum of 300 calendar days.

RFI #6 will increase the Contract to 365 days. If the approved design includes equipment requiring lead times that will further affect the CCD, a no-cost modification will be considered.

8. Please verify that re-balancing of the chilled-water distribution system is only required for primary and total secondary flow and that no terminal equipment in the building is to be rebalanced.

Confirmed.

9. Please verify that the ASHRAE 90.1-2013 standard applies only to new equipment identified in the Scope of

Work and excludes all modifications associated with existing equipment or systems as necessary to satisfy building energy performance standards.

10. Please provide as-built drawings showing the current installation of the recently installed 250-ton chiller.

Drawings will be provided post-award.

11. Is there any hazardous material abatement under this contract? Has a hazardous material survey been conducted and is the report available?

Hazardous material is not known to be located at B533 or the cooling tower platform.

12. SOW mentions new “condenser pump”. CP-1 is noted to be replaced only and is noted as 1350-gpm which is presumed to be the pump feeding the new 250-ton chiller. Per the most recent as-built drawings provided, CP-1 is the condenser water pump that serves the 130-ton chiller rated at 390 gpm. Please confirm which condenser pump is scheduled to be replaced.

The condenser pump servicing the 130T chiller rater for 390 gpm is to be replaced.

13. Please confirm if the new cooling towers are required to be stainless steel construction. SOW mentions

“protective coatings”.

New CECC basins must be stainless steel. Protective coatings apply to the tower coils.

14. MCC-1 for CECC (see PDF Labeled MCC1 circuit schedule) includes 5 circuits: Fan, 2 Spray pumps and 2 sump heaters.

Modifications to the MCC will require Arc Flash compliance per Code once opened. Does the current MCC1 comply with current OSHA standards for Arc Flash protection?

• Unknown. Equipment is original to the building that was completed in 1993.

Should the obsoleted circuits be capped in the field at the concrete floor interface?

• Yes.

Are the existing buckets for the obsoleted circuits to be removed and disposed of?

• Yes.

15. The current CECC 1 through 4 are not grounded to the building ground grid. Is the new unit to be grounded to the 4/0 buried wire (ref. B533 cooling tower wiring)?

16. Can existing electrical disconnects be reused where possible for the NEMA 3r disconnect (ref. PDF Electrical Disconnect)?

17. The 2016 retro-commissioning report noted that the refrigeration monitoring panel should be installed after this upgrade. Are we to include this option and upgrade of the BMS and commissioning? And, will the Government furnish the panel?

No.

18. The 2016 retro-commissioning report indicates that the triple duty valves do not hold and are not adjustable (ref.

triple duty PDF). This valve condition will require the entire system to be drained and remain inoperable until system valves are replaced and the system is rebalanced. Please verify operating condition of the existing valves and system outage requirements (allowable periods and durations) in the event they require replacement.

Replacement of the valves is not included in the scope of work. In the event that existing valves are determined to be unsuitable a Contract Modification may be considered according to the applicable Contract FAR Clauses.

19. During the 35%-50% design development process we would like to expedite release of major equipment due to the current long lead times. Please confirm if this is acceptable to the Government.

20. The SOW states that the cooling tower system must be configured for "economizer operation when the outdoor temperature is below 45 degrees." Please clarify what extent the economizer mode must operate and what the cooling load is during the heating season. With the current information, it is unknown if a partial or full waterside economizer is possible without specific operating conditions. In order to achieve the different economizer modes, a plate frame heat exchanger, additional piping, and motorized control valves will need to be installed. The chilled water and condenser water system controls will need to be upgraded as well. Please confirm that this is the direction you wish to proceed.

Cooling load required during heating season is currently unknown. However, for bidding purposes assume that 10-15% of overall capacity is required. It is not the intent of the project to provide additional heat exchangers.

21. Reference SOW D3040, 2nd paragraph states “Provide complete Testing and Balancing (TAB) and commissioning of all new equipment and the chilled water system throughout the building”. SOW D3070 states “Provide complete t wo season Testing and Balancing (TAB) of all new HVAC equipment.” The scope of this RFP was reduced to eliminate the TAB to the existing chilled water terminal equipment, please clarify the intent of D3040 related to the TAB of “chilled water system throughout the building.”

TAB is only required for equipment installed as part of this contract.

22. The following includes a work scope narrative and a plan of equipment locations. We request confirmation of our understanding of the work scope for pricing. Please confirm that the following will meet the intent of the Bid Solicitation:

Interior Work - Remove and replace the 2) VSCWP pumps and CP-1 circulation pump in the mechanical room.

That is the only work inside.

• Those are the only equipment replacements required. However, interior work must include TAB, Commissioning, and connection to the DDC of the new equipment.

Exterior Work - Remove 2 Cooling Towers (CCEC’s 3 & 4) as part of Bid Option #1

• Confirmed. Bid Option #1 is to demolish existing CCECs 3 & 4.

Install a single 400-ton CCEC in the location of the removed CCEC’s while utilizing the existing CCEC #1 which still operates along with any necessary piping modifications. Please confirm that CCEC #1 is the only unit that still runs.

• Confirmed.

Make up Water modifications.

• Confirmed.

Insulation and jacketing on all piping and equipment.

• Confirmed.

Heat tracing of piping as required (Under Electrical Sections).

• Confirmed.

BID OPTION #1 Remove CCEC 3&4 - The attached page is a marked-up copy of the As-Built Drawings that shows the new proposed work.

If the above listed work is acceptable, then the work in Bid Option #1 would be completed first and the bid option should be part of the Base Contract.

• The RFP states “Demolish existing CCECs 1 & 2 and install the new CCEC such that chilled water service is not interrupted to the building.” As CCEC-1 is the only functioning unit, CCEC-2 would be demolished first under the Base Bid and the new unit would go in that location while CCEC-1 remains operational. Once the new unit is functional, CCEC-1 would be demolished. Bid Option #1 is independent from the Base Bid.

23. UFC 1-200-02 implements ASHRAE 90.1-2019 for all projects starting design after 4/7/23 which would include this one. The RFP still references 90.1-2013. Please confirm which ASHRAE standard will apply.

Follow UFC 1-200-01 criteria depending on project award date.

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