S02_631-19-002 Steam Phase II - Controls Clarification.pdf
PDF 10 MB Posted
- Attached to
- Z2NZ--631-19-002 Upgrade Steam Distribution System Phase II Solicitation | Amendment 002
- Solicitation number
- 36C24126Q0472
About this file
This document is a Controls Clarification for a federal mechanical systems upgrade project that specifies direct digital control (DDC) requirements for HVAC systems across multiple buildings.
The project requires implementation of DDC for all low-pressure loads (approximately 5 psi) including fan terminal units, unit heaters, reheat coils, and fan coil units across six buildings (Buildings 1, 4, 5, 8, 9, and 15/16). The control system design categorizes spaces into three types: OEC (Occupied End-user Controls) with modulating controls for greater stability and comfort, OP (Occupied Public) with readout-only capability, and U/TEC (Utility) with economical on/off controls and temperature probes. The contractor must provide modulating controls for OEC/OP spaces while U/TEC spaces require basic probe and on/off functionality. Local PSHA500 low-voltage supply panels will support thermostats and controls, mounted in ceiling or mechanical spaces within 100 feet of low-voltage devices, with a ratio of approximately one panel per 20 devices. Pneumatic controls are explicitly prohibited as they are no longer economically viable. Selected thermostats must feature digital readout, BACnet capability, and remote setpoint adjustment for OEC areas; the document suggests the TEC3000 as a potential option but permits non-OEM alternatives. The project includes 161 thermostats and 240 control valves across all buildings, with specific breakdowns provided by building. Equipment branch line voltage is typically available from abandoned loads or within 75 feet of panel placements. Contractor responsibilities include providing complete system design in shop drawings with precise low-voltage and field controller layouts, and ensuring all ETR condensate pans have high-level float alarms.
View the file
Other files
On GovTribe
Work with this file
- Download the original file
- Contacts named in this file
- Similar government files
- Ask GovTribe AI about this file
Text version
Controls
Clarification
The intention is to have DDC for all loads. The Pneumatic controls and system once in place are beyond economical use, therefore there shall be no pneumatic devices called for.
See scanned new work plan drawing set highlighting loads and guidance to assist with cost estimation. The controls intention for each room or area is labeled as OEC (occupied end-user controls), OP -Occupied
Public (i.e. readout only), U/TEC for utility (a stairwell unit heater) – no read out, just a probe and economical controls such as on/off.
The intention will be distribution of local PSHA500s to support the T-stats and controls selected. Preference for OEC/OP spaces shall be modulating controls for greater stability and comfort. These low voltage supply panels shall be mounted above ceiling or mechanical spaces identified. They shall be located within 100 feet of the low voltage device. The summary below assumes 1 PSH to every 20 devices. Field controller selection and quantification to be DDC supplier responsibility with the assistance of the new work scans. Equipment branch line voltage is often available from abandoned loads or within 75 feet and rarely greater than 150 of PSH placements.
Requirements for selected Tstat chosen shall be Digital read out, ability for end-user to increase or decrease setpoint over a remotely settable range (OEC areas), BACnet capable. VA believes based on another project
TEC3000 would support this but there may be more economic offerings including non-OEM.
The following is a summary of low pressure ~ 5psi loads (FTR, UH [VUH, UH, CUH], CIR, FCU, etc.). It does not include new domestic water heaters, AHU, MAU, RHC, Humidifier, HX, Condensate alarms, or other DDC loads which are identified on the attached scans. Exact low voltage and field controller layouts shall be provided by contractor in shop drawings for means and methods. Contractor is responsible for providing a complete and functional system. Provide high level float alarm for all ETR CP
Total
OEC OP U/TEC PSH500
Thermostats 161 40 26
Control Valves 240 57 32 41
Bldg. 1 Summary
Thermostats 103 11 14
Control Valves 150 11 14 24
Bldg. 4 Summary
Thermostats 23 11 3 0
Control Valves 44 12 3 5
Bldg. 5 Summary
Thermostats 19 6 6
Control Valves 25 10 9 5
Bldg. 8 Summary
Thermostats 19 7 2
Control Valves 20 11 2 3
Bldg. 9 Summary
Thermostats 0 3 0
Control Valves 0 7 0 2
Bldg. 15/16 Summary
Thermostats 4 5 1
Control Valves 8 9 4 3
File details come from the government source that posted it. Updated .