Engineering notes
What does BMS equipment include? Field layer and DDC panel
BMS equipment list: sensors, valves, controllers, modules, protocol gateways, panel accessories. How to split the schedule when you price the job.
There is no ready-made “BMS kit” on a price list
A common question: “What does a BMS for a 10,000 m² building cost?” The accurate answer: a BMS is a set of measured and controlled points. Each point needs a device, or a group of devices. This note splits the schedule into two layers so owner and contractor can compare quotations.
Field layer
- Environment sensors: room temperature, humidity, CO2
- Duct and pipe sensors: water temperature, air temperature, pressure, filter differential
- Valves and actuators on chilled-water or air branches
- Contacts from the main breaker, generator, float switches, limit switches
- Energy meters if the file asks for metering
This is where buying goes wrong: an NTC probe into a 0–10 V input, or a 230 V valve on a 24 V panel.
Panel layer
- DDC, 24 V supply, panel UPS if required
- Analog in, analog out, digital in, digital out modules — count the points and leave about 10–15% spare
- Interposing relays, terminals, trunking, labels
- BACnet/IP or Modbus gateways when the plant talks to a chiller or a meter
Central layer — usually a separate contract
Server, software licence, graphics, user accounts. HTECH can quote the machine and the licence if the owner asks. Programming labour usually sits with the integrating contractor. Do not collapse that into one line called “BMS software” before the point count and user count are written.
Order of buying
- Lock the point list.
- Lock the controller family — modules do not mix freely.
- Buy sensors and valves that match the signal.
- Size gateways and the server.
Reverse the order — buy 200 sensors, then pick the controller — and you usually change the goods. HTECH builds the schedule from the drawings. BMS equipment · Choosing sensors.