Q and As (RFIs).docx

HVAC 2058 CONTRACTOR QUESTIONS

1.) Paragraph 1.1 states that all questions shall be submitted no later than seven (7) days after the solicitation and virtual site visit is posted. However, the date issued is blank on the posted solicitation. Please advise the solicitation date so as to define the last day that questions may be submitted?

Answer: The seven days start when the solicitation was posted (17Jul2020), so by COB 24Jul2020.

2.) The virtual site visit video capture of the chiller nameplate did not show a model number for the Trane chiller. Please identify the existing chiller’s model number? This is for chiller 1. Chiller 2 is

3.) The attachments did not include any As-Builts to determine the design parameters for the chiller. Please provide? Files for As builts are significantly large and cannot be uploaded on beta.sam. Please submit an email request to kalana.murdock.1@us.af.mil to receive a DOD Safe link for As-built drawings.

4.) The attachment for the Justification and Approval (J&A) for Other Than Full and Open Competition refers to a designated installation standardized chiller manufacturer. Please advise what chiller manufacture for the installation is the standardized manufacturer? Units will be with TRANE units. See Attached “Trane Letter”.

5.) Please provide contact information for the building DDC controls vendor? Manufacturer and contact name, number, & email if available? The existing Johnson Controls DDC controller will remain and the controls replaced are the unitary controls to be provided with the chiller. The SOW will be revised to reflect this change.

6.) Is the temporary chiller capable of handling the whole building load during the late summer/early fall? No, the portable 300-ton chiller is a temporary replacement of 240 ton failed chiller. The building load capacity is much higher than that.

7.) What size are the existing circuit breakers for each chiller? Refer to the photos attached of the chiller nameplate.

8.) The 60-day completion may be unachievable due to the time requirements of submitting, Government approval, and production weeks. Can the period of performance be increased to 180-days? The period of performance can be increased to 180 days.

9.) The virtual site visit instructs the contractor to reutilize the four (4) electrical disconnects and use the valves nearby as the chiller point of connection. This would make a number of items listed in the scope of work not applicable, correct? Please clarify. Correct. The contractor is to reutilize the four (4) electrical disconnects and use the valves nearby as the chiller point of connection. The goal is to replace as little of the existing equipment necessary in order to have the 2 chillers working.

10.) From site walk video, it does not appear that the branch chilled water piping serving Chiller #1 and Chiller #2 is provided with isolation valves on the supply and return piping where this piping connects to the existing chilled water piping at the exterior wall. As such, an outage will be necessary to install new isolation valves that will serve the new chillers. Please confirm if isolation valves on this piping are installed and are just not clear in the video. Also, please confirm that existing isolation valves are installed upstream of the chilled water branch piping (between the tees and the mechanical room). There are several isolation valves in the mechanical room. Here are some photos from the site where the work is to take place.

11.) Chiller #1 and Chiller #2 appear to be Trane RTAA240, 240‐ton chillers, but this is not clear from the video. Please confirm model number and serial number of existing chillers that will be replaced. Units will be with TRANE units. See Attached “Trane Letter”. Refer to question #2.

12.) . The scope of work states that the chilled water pumps are to be replaced, but the video does not include a visual of the current pumps. Are there pumps installed integral to the chillers or are they located within the mechanical room. Please confirm location of pumps and please provide make, model, type, flow rate, head, motor horsepower and RPM. Pumps are located on the bottom side of the existing chillers. The photos above are difficult to show.

13.) What is the scope of pump replacement? Will allow strainers, check valves, isolation valves, temperature and pressure ports, etc. be replaced as well? Please provide additional information on how much piping will need to be replaced in regard to the pumps (i.e. all piping within five feet of the isolation valve or new piping up to isolation valves, etc.). Isolation valves, temperature and pressure ports should be included. Piping: for bidding purpose - all piping within 3 feet of the isolation valves (existing piping cab reuse).

14.) Video refers to “As‐Built” drawings, but these drawings do not appear to be included. Please provide drawings as indicated in video. Files for As builts are significantly large and cannot be uploaded on beta.sam. Please submit an email request to kalana.murdock.1@us.af.mil to receive a DOD Safe link for As-built drawings.

15.) The SOW indicates that new DDC controls to be provided. Is there an existing DDC system (presumably Johnson Controls) already installed at this building? If so, will the new chillers simply be reconnected to the DDC system? Assuming that the chiller controllers will be interconnected with the existing building DDC system, what is the desired communication protocol for the new chiller controllers to communicate with the existing building DDC control system? BACNET MSTP, BACNET IP, LONWORKS, MODBUS, etc.? BACNET MSTP. The existing Johnson Controls DDC controller will remain and the controls replaced are the unitary controls to be provided with the chiller. The SOW will be revised to reflect this change.

16.) Section 01 35 26, paragraph 3.9.3 indicates that an Arc Flash analysis shall be required. Will the Government require the arc flash data to be modeled in specific software to allow for integration into an existing base wide model? If so, which software is desired? Also, will the DOR conduct the integration or will that be done by the Government? Arc Flash data analysis will not be required.

17.) No documents for “Design After Award” are provided. As such, what will be the anticipated submittal requirements for construction drawings and specifications? How many design submissions will be required? Design submittals are 35% and 95%, 100% final.

18.) Paragraph 2 of chiller J&A form indicates that a manufacturer selection list is provided in an Addendum that is attached to the J&A document; however, this addendum does not appear to be attached. As such, which manufacturers are approved for use on this project? Units will be with TRANE units. See Attached “Trane Letter”.

image5.jpeg image6.jpeg image7.jpeg image1.jpeg image2.jpeg image3.jpeg image4.jpeg