COOLING TOWER RFIs --Answers (002).docx

COOLING TOWER RFIs 36C25621R0102

1. Spec Section 4.0-h.B&C: The scheduled closed circuit cooling tower has only one (1) available factory mounted and piped spray pump. Is a separate spare loose pump or field mounted and piped pump by Contractor acceptable?

Two (2) Factory mounted close coupled, bronze fitted pumps with mechanical seals. Manual Valves for manual switch over and pump isolation

1. Spec Section 4.0-h.E: Will comparable 301L low carbon stainless steel be acceptable for basin construction allowing for similar corrosion protection?

Needs to be Type 304 Welded Stainless-Steel Construction in Basin Water or better SS for corrosion protection

1. Spec Section 4.0-h.S: Is an internal maintenance walkway only required in the lower tower cold water basin section or is an elevated interior mechanical access platform with ladder required?

Internal Maintenance Walkway on lower section and Ladder going to the motor on the upper section. If the motor is accessible off the ladder no need for platform. Unless other maintenance is needed that cant be done off of the ladder then it needs a platform to do the maintenance

1. Spec Section 7 WARRANTY: Standard extended warranty is five (5) years from date of shipment on mechanical drive component materials. Is that acceptable in lieu of seven (7) years?

5 years is ok

1. Existing tower has discharge air dampers, actuators and controls installed for freeze protection of the coil section. This option is not listed in the equipment scope. Is it a required component?

The new tower needs to have freeze protection, but it doesn’t have to be a discharge air damper for freeze protection.

1. Existing tower is designed for split coil dual loop piping. Will the new replacement tower require the same two closed loop piping arrangement? Yes

1. Clarification needed: I just wanted to clarify I the SOW that the cooling tower is the only major equipment that needs to be replaced. The revised SOW states “installation shall include providing complete replacement of the condensing water system but not limited to the cooling tower, pumps, filtration system and building, valves, strainers, piping, drainage, supporting structure, controls, access to all components, electrical hoist for appropriate component replacement, asbestos removal, electrical, architectural, all associated components necessary to provide a fully functioning system.” For the pumps, does that refer to the pumps inside the building?

The electric and controls will have to go back to the source but everything else will start from the ground outside meaning that the whole tower will be replaced and the makeup water, condenser water will tie in at ground level before going back to the building

Other comments:

HVAC downtime needs to be minimal and agreed with COR. (Contractor needs to make provisions if downtime is longer than agreed with COR as buildings are occupied.)

*Staging and preparation (have all parts and materials ready and made up as much as possible) will help alleviate downtime waiting for parts or material.

Pad retrofit needs to be done per IMC and seismic requirement category D. (4” minimum, 6” preferred)

The SOW delineates the minimum requirements needed for the cooling tower. A Like for Like Tower will fulfill minimum requirements. Yet, we are open for other type of tower systems which can have different efficiencies, energy savings, etc. An HVAC technical specialist should be able to make quick load calculations using minimal information from us i.e.: sq.ft. of spacing to be covered, etc. which will allow them to understand requirements and be able to fully submit a recommended tower for our present needs; with good technical support for their recommendation. So, yes a Like for Like will fulfill minimal needs, but obviously there was not HVAC technical work done from the contractor to ensure implementation is done to the best quality and benefit of the customer.

This was answered in the technical questions request (RFI). The electric and controls will have to go back to the source, but everything else will start from the ground outside meaning that the whole tower will be replaced and the makeup water, condenser water will tie in at ground level before going back to the building.

No Asbestos is expected on this job as the equipment is not very old. All insulated piping that will be reworked (“connections to existing inlet and outlet pipelines”) is mainly above ground. But in case there is some insulation in question with potential asbestos the contractor needs to be able to abate issue. During the site visit it should have been noticed that the total insulated pipe footage is minimal.