Attachment 17 Ft Sill Mechanical Design Guide R03-14-2023.pdf

Revision 03/14/2023

1 Fort Sill DPW Mechanical Design Guide

Fort Sill, Oklahoma

Directorate of Public Works

Mechanical Systems

Design Guide

A. Boiler Kill Switch Location

Gas fired heating water boilers and hot water heaters must be equipped with a power kill switch in case of an emergency. The shutdown switch will be user operated in field. Locate it outside to the space of the boiler location. The switch shall shutdown power to the gas fired equipment. If the building has fire alarm/mass notification systems, tie the switch into the alert system for notification purposes.

B. Carbon Monoxide Detectors in Mechanical Rooms

Install CO detectors in mechanical rooms with gas fired equipment. Carbon monoxide detectors must be powered by the fire alarm control panel (i.e. 24 Vdc). Where a fire alarm system is not provided, 120 VAC carbon monoxide alarms are permitted. See UFC 3-600-01 Section 9-19.

C. Reduced Pressure Backflow Preventer Bypass Design

D. Boiler Venting Material

Exhaust venting material for condensing hot water heaters and heating water boilers shall comply with UL 1738 regardless of manufacturer guidelines.

E. Air Cooled Chiller Selection Options

Design and selection of air cooled chillers for HVAC systems shall follow the document “Ft Sill Air

Cooled Chiller Options.” Deviation from this document must be approved by the DPW mechanical engineer in writing.

F. Underground Chilled Water Piping Material

Recommended material selection for underground chilled water piping is HDPE. PVC and steel is acceptable upon submittal. Recommend pipe to pipe connections to be fusion welded. Include thrust blocks/ kickers at changes in direction per manufacturer guidelines.

G. Above Ceiling Equipment Access Height

Equipment located above ceilings such as (VAV’s, fan coils, etc.) shall not be installed at a height greater than the safe use from a below ceiling ladder. This is required in order to allow access for maintenance personnel. Also, all other systems shall be rerouted to provide a path for access.

Attachment 17- SEED Project 4702 W9124L-23-B-0001 0003 Fort Sill MATOC

2 Fort Sill DPW Mechanical Design Guide

H. Chilled Water Piping Heat Trace

All above ground external chilled water piping shall be heat traced from an independent circuit. This includes connected equipment such as buffer tanks, expansion tanks, pumps, valves, etc. Insulation and jacketing is still required.

I. 2” Minimum Sanitary Sewer Underground Piping

Sanitary sewer piping entering below grade shall not be less than 2” size. 1-1/2” is not acceptable.

J. HVAC Controls Network and Switch Request

Requests must be received less than 30 days after notice to proceed construction. HVAC controls integration and commissioning require written request to access to the NEC network and switches in advance. If a network/switch for frontend integration will be required for the project, please send a written request to Business and Plans Department at NEC (CC DPW IT. Even if a switch is in the building from an existing system, IT will need to verify its function and unlock the switch for points tie-in. Do not wait until the day this is required to make the request. IT will need 6 months advance notice in order to process the request.

K. Commissioning Warranty Beneficiary Occupancy Date

The warranty for all new equipment and services will begin the day after it is fully commissioned and BOD. This includes test and balance. We will not accept the shipment date, install date, or turnover date as the beginning of warranty.

L. Gas Meter/Regulator ONG Request

All projects installing gas fired equipment shall submit the document “Gas Load and Pressure Form” to ONG for meter and regulator verification. The form must be routed through the DPW energy office personnel. This must be submitted at least than 30 days after gas fired equipment selection.

The only exception to this is if the new equipment gas load matches exactly to the existing.

M. Antiterrorism UFC 4-010-01

All outside air intake for AHU shall be located 3 meters (10-ft) above the ground. Emergency shutoff switch for AHU located to be easily accessible by building occupants.

N. Equipment Locations

Indicate the location of the following items on the drawings: thermostats, humidistats, refrigerant gas monitor, CO detectors.

O. Roof Mounted Condensers

Roof mounted condenser or roof top A/C units: Scheduled operating ambient conditions should be at least 15 ⁰F above 1 % summer dry-bulb to account for radiant heat from roof affecting the condenser EAT.

P. Roof Mounted Equipment

Equipment on roofs are to be at least 6 foot from the edge or have guard rails and have a disconnect.

Q. NEC Hazardous Locations

The location and extent of the hazardous location shall be shown on the drawing. Equipment selected shall be designed to meet the proper division and classification rating. Placards shall be installed.

Attachment 17- SEED Project 4702

3 Fort Sill DPW Mechanical Design Guide

R. EQD Consultation

Fort Sill has nationally eligible historical landmarks. As such, project may require EQD consultation.

This is required when (not limited to) the following occurs: alteration to an interior or exterior historical building, ground excavation greater than 6 inches, or installation in the viewscape of a historical district. The contractor shall verify that EQD consultation is 100% complete prior to the beginning of work. Also, any deviation from the drawing or scope shall be approved by EQD before the change occurs.

S. IGIS Utilities

A map of existing utilities around a building on post can be obtained from the Ft Sill GIS team. A request must be submitted to DPW engineering or directly to the GIS team. Utilities are representative only and must be verified in field.

T. Gas Load Diagram

When gas fired equipment is replaced in a building, provide a drawing of the gas load diagram. The diagram shall show capacities and pressures.

U. Flexible Ductwork

No 90⁰ flexible ducts are allowed. This is a UFC 3-410-01-2013-C8 requirement.

V. HVAC Test and Balance

Adequate PETE's plugs or valves taps and thermos-wells are provided to verify capacity and operation of all hydronic equipment. Include straight runs of duct to perform pitot tube traverse

(minimum of 7-1/2 duct diameters) for each major branch of duct work.

W. Notched Balance Dampers

Ductwork balance dampers shall be infinitely adjustable and locked. Notched dampers are not acceptable for TAB.

X. Branch Isolation Valves

Provide isolation valves at each downstream branch connection as depicted to equipment.

Y. Equipment Screens

Chiller/condenser screens must have perforation in walls to allow airflow circulation.

4 Fort Sill DPW Mechanical Design Guide

Z. Occupied Zone Temps

Occupied zone temperatures for buildings on Ft Sill shall be designed to 70 ⁰F for heating and 74 ⁰F for cooling. Exceptions to this are allowed for critical spaces such as medical or specialized equipment.

AA. Flush and Purge

Hydronic piping systems that are installed or modified which exceed a total of 80 linear feet will need to be properly flush and purged per the following minimum criteria. Flushing velocity must be at minimum 2 ft/s. Include filtration in the form of bag filters or equivalent. Personnel shall have experience with projects of an equivalent scope and be IGSHPA certified. All filtered fluid must pass through a catch tank that will allow entrained air to precipitate out.

BB. Flush Bypass

On new hydronic piping installations, coil bypass piping must be installed in order to prevent flushed debris from entering HVAC coils.

CC. Automatic Heat/Cool Switch

DDC controls for all HVAC equipment must automatically changeover between the Heat and Cool modes without requiring any interaction from the occupants.

DD. Building Automation System (BAS) Frontend Integration

All renovated and new construction building projects that affect/change the BAS must be integrated into the Fort Sill DPW BAS frontend and must match current frontend layout. The current frontend is Trane Ensemble. Controls contractor will have access to the TU software available at the DPW

O&M shop. In addition, the following must be provided as deliverables to the DPW system admin:

-Provide a 3D graphic with adjustable setpoints of each BAS equipment.

-Provide a points list from the local devices with explanation/correlation of the point and its association to the graphic.

-Include the building floorplan in a graphic with the associated BAS systems shown.

EE. Water Meter Location The location of the water meter shall be placed external to the building. It is not allowed internal to the mechanical room unless it is a secondary meter to the main meter owned and operated by Ft Sill utility provider, American Water. Being external to the building provides AWE’s point of demarcation and allows them to have access to the meter at all times.

FF. Plumbing Fixture Type Fort Sill does not recommend electronically activated plumbing fixtures such a toilet/urinal flush valves and sink faucets. They require more maintenance than a manual valve. Electronic bottle fillers are acceptable such as at water fountains.