Revised Q and As (RFIs) 10Aug2020.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”.

19.) After review of the answers provided, we respectfully request more information as it appears the chillers on the pictures are pictures of the smaller chillers not the large chillers that on the walk-through they said were being replaced. The pumps that are shown are for the smaller chillers the air separator in the valves that are shown or the backside of the smaller chillers there is no pumps shown for the bigger chillers I believe those are inside the mechanical room that they were walking into but never showed any video. Any help would be greatly appreciated. See Pics 1 thru 1 Photos of the units that are to be replaced. This is an attachment of #1 unit, #2 is the same. The Chiller #2 serial number is the equipment plate on the side of the unit. The attachment Ciller#4 Valves is mislabeled it is between unit#1 and #2.

Pic 1. This is a photo of the two units that are to be replaced.

Pic 2

Pic 3

Pic 4

Pic 5

Pic 6 Pic 7

20. There still seems to be some confusion regarding the Scope of Work.

Per the scope of work, the pumps would need to be replaced if we are to replace the chilled water pumps that serve Chillers #1 and #2; however, since the Government appears to think the pumps that are outside (CHWP 4-1 and 4-2) are the pumps that need to be replaced and the condition of those pumps is less than good, then perhaps the existing primary chilled water pumps that serve chillers #1 and #2 will not need to be replaced after all. It is also possible that the Government will want to replace the pumps that serve chillers #3 and #4 just because their condition is poor.

In other words, we really need to verify with the 502nd which pumps they want replaced and have them tell us if they want the three primary chilled water pumps that are inside the mechanical room replaced or the two chilled water pumps that are outside that serve chillers #3 and #4 or some other combination of pumps. The drawings provided clearly show that the three pumps within the first floor mechanical room (CHWP 1-1 to 1-3) are the primary pumps that serve chiller #1 and chiller #2, so these would be the pumps I would think would be included in our scope of work, but this needs to be cleared up so that we are providing bidding for the correct size and quantity of pumps, especially since the pictures provided are not the pumps that serve chillers #1 and #2. The only work that is done in the interior of the mechanical room is the connecting of the two chillers. The connection is the only thing to be accomplished inside the mechanical room. The units (chillers to be replaced) are self-contained. Please see the attachment Chiller #1 below. The equipment listed in the SOW relate to equipment under the fan coiled units in the photo. The controls to be replaced are the electrical boxes shown in the Electrical Panel by Chiller #1 & #2 photo below.

B_2058_Chiller #1

B_2058 Electrical Panel by Chiller #1 & #2

Annotation site showing units to be replaced image5.jpeg image6.jpeg image7.jpeg image8.jpeg image9.png image10.jpeg image11.png image1.jpeg image2.jpeg image3.jpeg image4.jpeg