Questions and Answers Part 2.doc

ARRA USGS in Menlo Park HVAC

Questions and Answers Part 2

1. In Project 1A, we are to provide a VFD for AHU-7 SF. Do you want a VFD for the RF as well?

Yes.

2. Section 25 35 00 Page 3 5.01 E Control Panels specify that all new exterior panels are to be stainless steel NEMA 4X enclosure. Can we provide a NEMA 3R panels to match the existing?

No. The site has had issues with weatherproof enclosures.

3. Are there isolation dampers on the exhaust manifolds in building 15 in order the meet the new sequence of operation (i.e.

exhaust fan staging)?

No. This new sequence is not a requirement. New dampers are not required.

4. Is there a makeup air intake in the exhaust manifolds of building 15 to ensure discharge velocity?

No.

5. Do existing CAV/VAV boxes have flow pickups?

The existing boxes have airflow sensors. It is not known if the existing boxes have brass barb fitting. New boxes are not required, but any new boxes that contractor determines to be necessary, are to have brass barb fittings.

6. General: Section 253500 6.02 D.6 +7 appears to have conflicts on “Control Wiring”. Please confirm if the use of J-Hooks and/or other non-EMT method is ok for concealed accessible spaces.

Yes, J-Hooks and/or other non-EMT methods are allowed in concealed areas such as plenum space. However, only approved wiring anchors shall be used, i.e., no zip-ties to such items as allthread or ceiling grid support wire.

7. Project 6: Would a Roof to Roof “Aerial Cable Run” between the bldg’s 1-2, be acceptable, instead of trenching.

No, see the revised scope of work. Trenching not required.

8. Project 6: Would a Hi Grade line of sight Wireless Ethernet Solution for bldg’s 1-2, be acceptable, instead of trenching.

No, see revised scope. Trenching not required.

9. Project 1A +1B: Are all existing 2 way Valves to remain and be reused for the associated Terminal Boxes.

Office Areas: Yes. Lab Areas: Yes, unless the contractor determines that the existing valves need to be replaced due to functionality or compatability.

10. Project 6: Please confirm any building that is pre-tensioned concrete. B3 identified as such on the job walk.

We only know that Building 3 is pre-tensioned concrete; not sure of other sites. Assume that other buildings are not pre-tensioned concrete; if core drilling is needed n other buildings and they proved to have pre-tensioned concrete we will negotiate a solution.