AHU q a 6-10-10.doc

(AHU Project Questions & Answers)

Posted June 11, 2010 Q:1 - Building 221 - In the equipment schedule, on #221-391 and on the drawings #221-398, it specifies to demolish and replace the motors bases, belt drives, isolators and fans in ACU #1,2,5, and 10. On drawing #221-400 under drawing notes it says that this equipment has already been replaced in these units. Which set of specifications is correct?

RESPONSE: A: 1- Drawing note #1 on drawing #221-400 should read ACU’s 6, 8, and 9.

Q: 2- Building 223 - In the equipment replace schedule on drawing #223-320, its shows ACU’s 1, 3, 5, 8, and 10 as ETR. On drawings #223-325 under drawings notes it specifies ACU-1, 2, 5 and 10 having already been done. Should that note read #1, 3, 5, 8, and 10 as showing already been done? Which specifications are correct?

RESPONSE: A: 2- Drawing note #1 on sheet 223-325 should read ACU’s 1,3,5,8 and 10.

Q: 3- Building 224 - In the equipment schedule on drawing #224-346 it specifies to demolish and replace the motors, motor base, belt drives, fans, vibration isolators and flexible duct work in ACU # 1, 2, 5, and 10. On drawing #224-353 under drawing notes it says that the equipment has already been replaced in these units. Which specifications are correct?

RESPONSE: A: 3- Drawing note #1 on drawings #224-353 should read ACU’s #3, 7, 8 & 9

Q: 4 – Building 226 - In the equipment replacement schedule on drawing #226-367, it specifies that the motors, motor bases, fans, vibration isolators and flexible connectors are to be demolished and replaced in ACU # 1, 2, and 10. On drawings #226-374, on drawings #226-374, under drawings notes it says that this equipment has already in these units.

Which specifications are correct?

RESPONSE: A: 4- Drawing note #1 on drawings #226-374 should read ACU # 3, 4 & 5.

Q: 5 - Building 231 - In the equipment replacement schedule on drawing #231-466 it specifies that the fan, vibration isolators and flexible ductwork have already been replaced on ACU # On drawing 231-475, in demolition and new work it specifies that this equipment is to be replaced.

Which specifications are correct?

RESPONSE: A: 5- The fan is to remain. Demolition and new work note #1 and 2 on drawing 231-475 should delete word “fan”. Delete note 3 entirely

Q: 6- Building 245 - In the equipment replacement schedule on drawing #245-486 it specifies that the fan vibration isolators, and flexible duct on ACU #1A have already been replaced.

On drawing #245-497 in new work notes and in demolition notes it specifies that this equipment is to be replaced. Which specifications are correct?

RESPONSE: A: 6- Schedule on sheet #245-486 is correct.

Q: 7- Building 245 - In the equipment replacement schedule on drawing #245-501 the print specifies replacement of a plenum fan but under the demolition and new work it specifies a modular unit. Which specifications are correct?

RESPONSE: A: 7- The fan needs to be a plenum fan.

Q: 8 – Building 245 - Is this a plenum fan or a modular unit?

RESPONSE: A: 8- It is a plenum fan.

Q: 9- Building 245 - In the equipment and replacement schedule on drawing #245-486 it states that the fans, vibrations and the flexible duct connector are to remain on ACU# 6A and 7. On the drawings #245-502 and #245-503 it specifies in the demolition and new work notes that this equipment is to be demolished and replaced.

Which specifications are correct?

RESPONSE: A: 9- Sheets #245-502 and 245-503 are correct.

Q: 10- In further review of the bid documents, the coil schedules lack the fin height (FH) and fin length (FL) dimensions. This is a critical component used to price coils accurately. As shown in the attached NIST Example.pdf, two or more coils could represent the Face Area square footage. A separate price would be associated with each size coil. How do we get clarification on the FH x FL dimensions?

RESPONSE: A: 10- See attached document. Non-typical plan dimensions are shown on floor plans for each building and contractor to field verify during the submittal phase and prior to demolition. Coil to match performance criteria per contract document. See attached Exhibit number 1.

Q: 11- Our pipe insulator would like to know if the new insulation requires canvas cover to match existing on piping and duct work?

RESPONSE: A: 11- New insulation shall match existing piping and canvas covers of adjacent construction.

Q: 12 – On the details of various AHUs, the units are labeled as being a type A, B, C, D, etc.; what do these types mean?

RESPONSE: A: 12- Type A, B, C, and D pertains to the quantity and configuration of coils in each air handler.

Type A equals 1 Coil.

Type B equals 2 coils stacked, one on top of each other.

Type C equals 2 coils side by side in the air stream.

Type D equals four coils, two coils stacked side by side in the air stream Q: 13 – Does Section 15725, titled “Modular Central Station Air Handler Units” pertain to all AHU’s in this contract?

RESPONSE: A: 13 - Section 15725 does not pertain to all ACUs. It applies to smaller units where casings are being replaced. The unit models are identified on the plans and notes.

Q: 14- The schedule for the coils state that most units are 100% outside air, but the air handler details have a return duct. Which system design will be used?

RESPONSE: A: 14- The coils are sized to match original capacity of 100% outside air. We understand that normal operation has minimum outside air and return air set points which are to be field tested before start of construction, however coils are to be provided per schedules.

Q: 15- If there is to be asbestos found who will be executing the removal of it?

RESPONSE: A: 15- NIST is responsible for the removal of the asbestos. Contractor is to notify the COTR when and if asbestos is found.

Q: 16- In the solicitation section L, Volume III(c) states: “The Offeror shall submit price of each AHU and DDC system and summarize price of AHU and DDC system per each building separately”. Does this statement mean that NIST is requesting a breakdown of each AHU or each building?

RESPONSE: The contractor is to submit a cost proposal as described in solicitation L Volume III (c). The CLIN is to list the offeror’s total price for all work related to the requirements of that CLIN. The NIST expects the offeror to provide sufficient backup detail to determine the how the offeror arrived at the price for each CLIN. The AIA breakout will probably require the identification of the AHU and DDC requirements separately.

Q: 17 – In the specifications page 01000-1 Part 1 General 1.3 (a) states, all materials must be stored in the lay down area. Will there be any designated area for storage of equipment and material? If not, will payment be made on received equipment and material stored off site?

RESPONSE: The contractor is allowed one “C” container in the proposed contractors parking and staging area west of building 304. The contractor cannot disturb more than 5 AHUs at a time during the construction period. The contractor is responsible for the offsite storage material. The forklift and loading carts can be stored at the NIST site. The contractor is responsible for offsite storage material and equipment.

Q: 18- In the Solicitation line item 0002 labeled BASE CONTRACT, is building 202 included in the total base contract, or is building 202 a separate line item from the total?

RESPONSE: Building 202 is actually CLIN 0002. The header data concerning the Base contract is provided for informational purposes. The Base Contract requirements include CLIN 0001 through CLIN 0010.

Q: 19- Are subcontractors required to submit a safety plan for their work or is the prime contractor responsible for submitting a master safety plan for all contractors involved in the execution of this project?

RESPONSE: A: 19- -Safety plan is not required as part of the technical proposal. However, both prime and sub contractors shall submit safety plans as per spec 01546-1.5.D

Q: 20- The specifications for the Modular AHU's call for service lights in the AHU's. Do the existing units have light in them already? If not, where will electric be accessed from?

RESPONSE: A: 20- New modular units do not require services lights.

Q: 21 – On the detail drawings for all AHU's filter sections there is a note #12 at the filter section. There is not a note #12. Is there any work to be done on the filter sections like the replacement of frames or filters or both?

RESPONSE: A: 21- There is no work to be done on the filters or filter banks for built up units unless documents call for unit replacement.

Q: 22 – In Section L Volume III (c) is there a particular AIA/CSI form for the cost breakout?

RESPONSE: NIST does not require the offeror to purchase the AIA forms. NIST requires that the format used by each offeror follow the AIA format for pricing details and totals.

Q: 23- The specification section 15900 2.2, A., 1 Thermistors calls for (0.2 degree F), but the industry standard (and the previous NIST specification) has been (0.5 degree F).

The M drawings under “EXISTING CONTROL SYSTEM FLOW DIAGRAMS” list the existing sensors as “ETR”. (Existing To Remain)

Was it NIST’s intent to change this tolerance or was that a generic section of the spec. that was overlooked?

This has a serious impact on this project because there are hundreds of sensors existing to remain and hundreds that need to be replaced RESPONSE: A: 23- The maximum A/D conversion resolution error shall be kept a tolerance of plus or minus 0.5 degree F

Q: 24- Do we need to use .049 thick wall copper tubes. We offer thinner wall copper if acceptable, if not we do offer .049. Please confirm if .049 is required RESPONSE: A: 24- .049 copper tubes are acceptable.

Q: 25- Type A, B, C and D has to do with the quantity of coils in each air handler according to the schedule. Type A equals 1 Coil. Type B equals 2 coils stacked, one on top of each other. Type C equals 2 coils side by side in the air stream. Type D equals four coils, two coils stacked side by side in the air stream. This makes the types relevant to pricing. Is this valid? or can we put 1 large coil in each air handler?

RESPONSE: A: 25- Refer to response to question 12.

Current access to the coils does not facilitate the installation of one large coil without significant AHU casing demolition and re-construction. New coils to follow existing coil configuration as shown on plans.

Q 26- This is to confirm that the fin type is .010 aluminum without coating. Please verify.

RESPONSE: A: 26- Provide .060 copper fins without a protective coating.

Q 27- We are looking for clarification on the fin thickness of the coils (Chilled Water and Steam) and whether or not a coating is actually required. The specification section 15761 calls out…

F. Fins: Copper, minimum 0.010 inch thick.

I. 7. Coating: Catholic epoxy e-coat. USA Coil and Air, the basis of design for the cooling coils, can provide one of the following choices.

0.010 Aluminum Fin with or without coating.

0.060 Copper Fin with or without coating.

The specified 0.010 Copper Fin is not available.

Typically we see the need for Aluminum coils with a coating OR copper fins without a coating. Please let us know what is actually required.

RESPONSE: A: 27- See response to question 26.

Q: 28 – Specification 15182 -3.1.A and B specifies low pressure steam piping schedule 40 and condensate piping specifies schedule 80 for same pressure and temperature. Is this correct?

RESPONSE: A: 28 – The piping material for the low pressure steam pipes and condensate pipes shall be schedule 80 for both application.