Greenhouse AC RFI Questions new ones answered and old ones also attached. EW_RR.docx

RFI - 30 Ton HVAC completion work at USDA, ARS, SRRC, New Orleans, LA New Questions (2023):

1. In executing this project Is it acceptable to have the field superintendent cover supervision, QA/QC, and safety duties? Or do we need 1 person for each responsibility? This should be ok.

1. Are contractors required to issue a contract specific QA/QC Plan? Preferred

1. Are contractors required to issue a contract specific Safety Plan? Preferred

1. Is this project tax exempt? The US Government is always Tax Exempt

1. Contractor will warrant installation and USDA will warrant equipment as equipment is being supplied by USDA for this project. Please confirm. Yes Contractor will provide warranty on parts and labor on all equipment involved in this project for one year regardless of whether the new contractor or the old contractor has installed the equipment. Also all equipment used will have factory warranties in effect.

1. Slab will be pile supported. Does the owner have a geotechnical report for site? No.

1. Are either screw or driven piles acceptable to support equipment foundation? Yes. See answers in original questions below. There will be four, 2-7/8” Helical pier piles 20’ long.

1. What is required compressive strength for concrete? The required compressive strength is what is required to support the unit. Your concrete mixture will be one of the submittals and should be supported by good engineering practices. Please check the drawings

1. What material of construction will be used for underground conduit? PVC

1. Will underground conduit carrying power conductors be encased in concrete? No

1. Will packaged air unit need to be grounded? Yes. (with equipment ground). All your work should conform to standard industry practices and meet all installation guidelines for all equipment installed in this project before the project will be accepted as finalized

1. Is there a grounding loop around the existing greenhouse? No

1. No lightning protection is required. Please confirm. Lightning protection is not required.

1. A field drain will be installed for condensate from packaged air unit. Please confirm. Yes

1. Controls for unit heaters will be repurposed for HVAC control. Please confirm. Possibly, Yes.

1. Will unit heaters be salvaged or is contractor to dispose of equipment? Salvaged (turned over to USDA).

1. What are materials of construction for gas piping and fittings? Black Iron. Install gas piping and fittings to all Federal, State and local code requirements for gas piping and to manufacturers requirements.

1. Spare space exists in power panel to supply new packaged air unit. Please confirm. Yes.

1. What voltage and phase is packaged air unit being supplied by USDA? 208-volt, 3 Phase

1. A sheet metal panel is installed in greenhouse wall for flue gas exhaust and fresh air supply to unit heater. Will this panel be replaced with a new sheet metal panel or is contractor to remove sheet metal and install new polycarbonate glazing? Remove and replace with glass..

Answers to old questions:

Please see list of RFI Questions below for the above referenced project:

1. Can structural drawings and specifications with piling layout and piling details be made available?

No

1. Foundation and piling for the new HVAC unit will be installed per the existing foundation design. No new engineered drawings or design will be required of the contractor. Please confirm.

The foundation will be the same, however after further review we have decided to use four, 2-7/8” Helical pier piles 20’ long.

1. During the pre-bid site visit, a sewer access was found in the proposed location for the new 30 ton packaged air unit.

2. Are underground drawings available which detail the underground sanitary sewer lines and all other underground features in the area?

No

2. For the alternate location on the west side of the greenhouse, are underground drawings available which detail all underground features in the area?

No

1. It is assumed the existing electrical panel has sufficient space and electrical capacity for the installation of the new packaged HVAC unit. Please confirm.

Yes, confirmed

1. Contractor will wire controls from new HVAC unit to MicroGrow controller. Per statement of work, USDA personnel or others will connect wiring to controller and perform any needed configuration. Please confirm.

All control wiring must be installed and connected to the MicroGrow controller. This will be included in your cost.

1. Can wiring diagrams for the HVAC controls of the existing packaged HVAC units be provided?

1. Will the contractor be required to provide as-built construction redlines?

Yes, they will be provided when needed.

1. Potential routing to power the new packaged HVAC unit will exit the west side of the existing head house addition and then proceed southward and underground to the new unit. Are underground drawings along the west side of head the house addition, greenhouse #2 and greenhouse #4 available?

No

1. Are any additional electrical drawings and panel schedules for the existing head house addition, greenhouses, and packaged HVAC units available?

No

1. The existing package HVAC units are Trane; the basis of design for the existing, scheduled units found on the drawings is Daikin. During bid walk it was mentioned HVAC units which are technically equal are acceptable. Please confirm.

It was also mentioned that our preference was the Trane unit since the other three units are Trane units. It is easier to maintain one brand rather than two.

1. Is grounding required for the new HVAC unit? If so, does an existing underground grounding grid exist? Are there existing grounding drawings available for the area?

An electrical equipment grounding conductor is required. An underground grounding grid does not exist.

1. Lightning protection is not required. Please confirm.

Lightning protection is not required.