CHS Pool Addendum No. 1 - 230224.pdf

CHS POOL VENTILATION REPAIRS

PROJECT NO.: 230309-02

February 23, 2023

ADDENDUM NO. ONE (1)

PAGE 1 OF 1 (PLUS ATTACHMENTS)

THE FOLLOWING CHANGES, ADDITIONS, AND DELETIONS TO THE CONTRACT DOCUMENTS

DATED February 15, 2023 HEREBY BECOME A PART OF THE CONTRACT DOCUMENTS.

NOTIFY ALL SUBCONTRACTORS AFFECTED BY THIS ADDENDUM.

BID DUE: Thursday, March 9, 2023 at 4:00 PM

SPECIFICATIONS

a. Section 01 11 00 Summary of Work: Under Part 3, Scope of Work, add the attached narrative for further clarification and direction.

END OF ADDENDUM ONE (1)

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Centennial High School Natatorium Mechanical Refurbishment Project

The scope of work for the refurbishment of the mechanical systems is to essentially return the systems to their original functionality and design intent. Over the years, a number of changes were made to the mechanical systems which have negatively impacted the functionality and resulted in destructive corrosion of the various HVAC components. Recently some of the ductwork has been replaced with stainless steel ducting and this ducting will remain in place as part of this work scope. Additionally, the existing fan motor, bearings and shaft have been replaced recently which will also remain in place as part of this work scope. The following is a detailed list of deficiencies to be remedied under this work scope.

• Remove the existing galvanized sheet metal bulkhead that separates the outside air concrete vault into two vaults

(half outside air intake and half return air)

• Remove the existing exhaust fan located outside the natatorium on the concrete outside air vault, disconnect and remove the electrical connections from this area along with curbs, conduit, etc. Verify the existing grate is intact and spans the entire area of the outside air vault.

• Remove and discard the existing outside air preheat coils.

• Repair/replace the fan plenum sheet metal where rusted or broken. Install new access doors as necessary and install a new filter rack in front of the new heating coil which will replace the existing coil, albeit slightly larger.

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• Remove and replace air handler heating coils (see attached). Field verify the coil size, orientation, and spacing in the fan plenum housing. Replace the existing pneumatic heating coil valves with new electric actuated valves and connect to the existing heating water supply.

• Install new supply, return, and mixed air dampers with electric actuators. Coordinate the actuator signal type with the controls contractor. The following is NOT in the scope of this work and is documented here for the controls contract following this work scope: Connect new valve actuators to the new DDC control system. Install at a minimum a discharge air temperature sensor, heating water supply temperature sensor, return air temperature sensor, mixed air temperature sensor, zone (natatorium) temperature sensor, and heating water control valve with actuator all to be tied into and controlled by the new DDC system in the school.

• Replace corroded existing galvanized fan housing sheet metal as necessary.

• Replace existing PVC piping currently supplying hot water to the existing fan coil with black iron piping.

• Clean out the existing perimeter deck mounted supply diffusers ductwork and replace existing diffusers with similar with opposing blade dampers.

• Remove the (4) existing skylights over the pool and install (4) new exhaust fans with back draft dampers and ECM motors (see attached for example). Install new roof curbs for the fans if necessary and run electrical from the existing electrical panel in the pool mechanical room below deck.

• Install a hot water circulation pump for the new HVAC coil and a 3-way valve for the heating coil along with well mounted immersion sensors on supply and return lines. The confined nature of the piping in an existing tunnel may make this impossible as an existing return line does not exist to the boiler and running a new return line through the existing mechanical may be difficult at best. If running a return line is not possible, provide a bypass line from the discharge side of the pump with a circuit setter to be balanced by the test and balance contractor.

Original Design Parameters:

Supply Fan: 15830 CFM @ ¾ SP and 4000 FPM Coils (2): Ability to heat 7915 CFM from 55 degrees to 100 degrees using steam. 30” x 80” Exhaust Fans (4): 3800 CFM @ ¼ SP and 900 FPM

New Design Parameters:

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Supply Fan 15830 @ 1” SP Coil (1), EWT 158 , LWT 130.9 @ 45 gpm Exhaust fans (4): 4000 CFM @ ¼” SP

Note that the Fan Energy Index (FEI) is an overall efficiency (wire-to-air) metric which includes not only the impact of the fan efficiency, but also each of the drive components used to operate the fan.

The Fan Electrical Input Power (FEP) is the amount of power of a given fan at an operating point characterized by a value of flow and pressure.

Construction Features

Efficiency: Standard

Altitude: 0 ftTemperature: 70 °F

Approximate weight each, includes fan, motor and accessories.

312240DBCRD4

0.250 0.344813,800

TEFC115V/1/601,7501/2

BCRD - Centrifugal Roof Exhauster, Downblast, Belt Driven

Description Qty Model Size

Motor Data

CFM RPM

Performance

HP RPM Volt/Ph/Hz Encl

Wt (lb.)

Oper. BHPSP (in WC)

N/AN/A0.361.79

FEIDepartment of

Energy FEP (KW) System FEI System FEP (KW)

• Spun aluminum construction

• Backwardly curved, non-overloading wheel.

• Wheel, motor, and drive assembly are isolated from the fan supports by rubber isolators.

• Top cap provides quick access to the wheel, motor, and drive assembly.

• Re-greaseable pillow block ball bearings provide an average life of 500,000 hours.

• Curb cap/venturi assembly.

• Entire fan assembly is balanced and tested.

• Galvanized birdscreen.

• Disconnect switch.

7.151663847556063687276Level at Inlet Sound Data

Octave Bands 1 2 3 4

LwA: The overall (single value) fan sound power level in dB re.

dBA: Estimated sound pressure level (re:0.0002 microbar) based on a single ducted installation at 5 ft., using a directivity factor of 1.

5 6 7 8 LwA dBA Sones

-12

Watts, ‘A’ weighted.

Accessories Included

Birdscreen - Aluminum

Backdraft Damper, ALUM

Stainless Steel Shaft

Stainless Steel Hardware

Coating: Exterior; Polyurethane Acrylic;

Polyurethane Liquid - Gray; Prep: Tool Clean & Wash; Curing: Air Dry

Variable Speed V-Belt Drive, 1.5 SF

Disc Switch-Unfused (NEMA 1), Shipped Loose

SUBMITTAL

Customer:

Job ID:

Job Name: CHS Pool

CHSPool July 29, 2022Date:

Tag: EF-1

All quotations per Twin City Fan Terms and Conditions found at www.tcf.com/terms-and-conditions

Ver 10.1 October 2018 - Created 07-29-2022 Updated 07-29-2022 Owner Eric Danielson Air Reps

Air/Gas PropertiesDescription Performance

Design Temperature

Inlet Temperature

Altitude above sea level

Outlet Velocity

Standard Power

Standard SP

Drive method

Wheel Diameter

Discharge

Rotation

Arrangement

Width

Model

Quantity

BCRD

Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .240D

N/A

N/A

Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N/A

N/A

DBD

28.0

Belt

Percentage width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100%

Percentage diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . .100%

0.34

Inlet Pressure 0.000

Oper. Power

Static Efficiency

44.03%

0.250

Estimated Density0.34

Max RPM for Class

Total Efficiency

Tip Speed

0.075

Outlet Area

Operating SP

RPM

49.08%

5.6

3,800

0.250

CFM

(in WC)

(in WC)

(FPM)

BHP

BHP

(sq.ft)

(FPM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(in)

(°F)

(°F)

(lb/ft³)

(ft)

(in WC)

Motor position

Volumetric Flow

FEI

FEP (KW)

System FEI

System FEP (KW)

1.79

0.36

N/A

N/A

FEG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .FEG60

Gas Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Standard air

Motor Data

Power (HP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2

Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .TEFC

Speed (RPM)

Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115V

Frame Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Unknown

Phase

Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60Hz

*To estimate dBA level for ducted inlet and ducted outlet (into and out of the room) type installation, deduct 20 from the LwA value

Using a directivity factor of 2. Estimated Sound Pressure based on free field, spherical (Q = 2) radiation at stated distance.shown.

Definitions:

Estimated sound pressure level in dBA (re: 0.0002 microbar) based on a single

* ducted installation:

dBA

LwA The overall (single value) fan sound power level, 'A' weighted.

-12

The environment for each fan installation influences its measured sound value, therefore dBA levels cannot be guaranteed. Consult AMCA Publication 303 for further details. A fan's dBA is influenced by nearby reflective surfaces.

Sound

Sound Power Levels in dB re.10 Watts:

531ftDistance in

555969dBA at inletLevel at Inlet Octave Bands

LwA

FAN DETAILS

Customer:

Job ID:

Job Name: CHS Pool

CHSPool July 29, 2022Date:

Tag: EF-1

SUBMITTAL

Customer:

Job ID:

Job Name: CHS Pool

CHSPool July 29, 2022Date:

Tag: EF-1

FAN DETAILS

Customer:

Job ID:

Job Name: CHS Pool

CHSPool July 29, 2022Date:

Tag: EF-1

Pricing Detail

300lbBCRD 240D Bare fan

0 lbBirdscreen - Aluminum

12 lbBackdraft Damper, ALUM

0 lbStainless Steel Shaft

0 lbStainless Steel Hardware

0 lbCoating: Exterior; Polyurethane Acrylic; Polyurethane Liquid - Gray; Prep: Tool Clean & Wash;

Curing: Air Dry

0 lbMotor 1/2 HP, 1750 RPM, 115V, 1Ph, 60Hz , TEFC - Standard

0 lbVariable Speed V-Belt Drive, 1.5 SF

0 lbDisc Switch-Unfused (NEMA 1), Shipped Loose

Extended Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1,248 lb

312 lbEach Weight

Coil Rating 4.8.4

Job Name:

Serpentine

Fin Height

Fin Length

Rows / FPI

Total Face Area

Conn. Location

Qty / Size

Return Connection

Tube Detail - Primary Surface

O.D.

Wall Thickness

Spacing

Internal

Thickness

Configuration

Date:

Type Material

Material

Tag: Pool 1

Construction

Supply Connection

Qty / Size

Type

Operating Conditions

Notes:

GPM - Total

EFT

EDB

Elevation

SCFM - Total

Entering Leaving

Sensible Heat

LDB

APD

LFT

Fluid Velocity

FPD

Quantity

1.000

60.00

48.00

20.0 sq.ft

Same End

MPT / Red Brass

MPT / Red Brass

1 / 2.50"

1 / 2.50"

5/8"

0.020"

1.5" x 1.299"

Smooth

Copper

Pool HW Coil

16,749 Corrected for Elev. & EDB

0 ft

Water

158.0 °F

76.4

0.0000

15,800

675,437 Btu/Hr

790 fpm

77.2 °F

0.39 in.WG

2.1 fps

140.0 °F

2.7 ft

40.0 °F

0.008"

Aluminum

5WC - 2 - 60 x 48 x 2 - 8 AL

7/29/2022

Hot Water

ACFM - Total

Fluid Type

FFI

Actual Face Vel.

Fin Detail - Secondary Surface

Corrugated, Waffle with Straight Edge

2 / 8

(FH > FL) falls outside the range of AHRI Cer<fied Coils

Coil is outside the scope of AHRI Standard 410.

Hot water velocity is below recommended minimum of 2.5 fps www.nortekair.com