Answers for 36C24720B0037 - 534-18-103 Expand Replace Direct Digital Controls.pdf

RFI Answers for 36C24720B0037 (534-18-103 Expand Replace Direct Digital Controls)

Question: 1 – Division 23 and the general requirements of the specifications reference commissioning of the mechanical system, but there is no 01 91 00 specification for this project. Please provide proper specifications.

Answer: 1 – See attached commissioning Specification Section 23 08 00 Commissioning of HVAC Systems.

Question: 2 – Will the CX agent be hired by the contractor or by the VA?

Answer: 2 – As mentioned in the specifications, the CX agent will be hired by the contractor.

Question: 3 – Under specification 01 45 00 it states the General Contractor shall have a designated QC manager. Does the VA require the QC position to be filled by a single person with no other collateral duties?

Answer: 3 – Can have other duties.

Question: 4 – In Section 3.4 “Communication” subpart A, reference is made to adhering to ANSI/ASHRAE Standard 135 – 2008 BACnet. In several places throughout the specification reference is made to all devices being BACnet IP. Does this apply to the existing and new BACnet floor level application specific controllers which currently communicate via BACnet MSTP (which is included in Standard 135)?

Answer: 4 – VA wants to standardize on BACnet IP. MSTP can be used if it can fully integrate with BACnet IP. BACnet IP should be used between the Server and the “Field Level Controllers” (for CMI this is the PXC or PXM controller). BACnet MSTP can be used between the “Field Level Controllers” and the “Device Level Controllers” (i.e. VAV controllers, fan control units, VFDs, etc.).

Question: 5 – What work or installation is required for the 500 room thermostats?

Answer: 5 – There are approximately 500 existing old digital thermostats. Remove and replace with state-of-the-art digital thermostats. The intent of the 500 thermostats is to replace existing thermostats that are not 100% compatible with BACnet communications. The existing conduit and wire may be re-used or replaced if necessary, but the physical thermostat needs to be replaced and reprogrammed. The intent is to have one manufacturer system for the entire facility.

Question: 6 – Is the intent to have one manufacturers system for the entire facility or can you integrate to the existing Siemens and Trane BACnet devices and provide a third system for the new work?

Answer: 6 – It is the intent to have one manufacturer for entire facility. No integrators allowed.

Question: 7 – “Bid Item 0002 Deduct 500 Digital Thermostats” also name “Alternate No. 1:” does not have a description on the plans or in the specs. In the pre-bid meeting on 8/14, it was stated that this is for 500 pneumatic boxes to be upgraded to DDC. Please confirm that the scope of work for these 500 boxes is to do the following:

a. Run 120V power for controls to boxes

b. Run BACnet MS/TP Network Buss to each of the boxes

c. Replace pneumatic control valve with an electronic proportional control valve.

d. Replace pneumatic controller on VAV box with a BACnet DDC controller.

e. Replace pneumatic thermostat with thermostat with digital display.

Answer: 7 – Answered above in question 5.

Question: 8 – Under 1.2 Existing Systems A. lists over 250 proprietary controllers.

f. If the manufacturer of these controllers is awarded the contract, is it the intent of this project to replace these proprietary controls?

g. Is the communication for VAV boxes that are non- proprietary BACnet MS/TP?

h. Would any BACnet Devices need to be replaced?

Answer: 8 – f. Yes

g. Needs to be fully compatible with BACnet IP.

h. Needs to be fully compatible with BACnet IP.

Question: 9 – In the meeting it was asked if under Specification 1.1 A. 3. one of the control bidders other than Trane or Siemens were awarded the project, is that contractor allowed to integrate to the existing controllers. It was stated in the meeting that it was the intent of the VA to have all the same controls. So if (1.1.A.1.) Trane was to win the project they would need to replace all of Siemens controllers, if (1.1.A.2.) Siemens was awarded the project they would need to replace all of Trane’s controllers, and if a (1.1.A.3.) 3rd party was to be awarded the project they would need to replace all of the Siemens and Trane controllers and integration was not the intent of 1.1 A.3. Is this correct?

Answer: 9 – No Integrators allowed; one system must use all their controllers.