Domestic Hot Water Control for Dual Pressure Zones


JW Marriott Hotel Mexico City


Mexico City


The domestic hot water load for this hotel was split into a High Pressure and Low Pressure Zone which roughly split the hotel in half. Each zone was calculated to required 70 gpm / 260 lpm maximum simultaneous demand. A single Brain® Model DMC1-BS1-DS was chosen per zone. The hot water supply to The Brain® is 155°F/68°C and the system setpoint is 135°F/57°C.

Scope of Work:

Armstrong International recommended a single Brain® Digital Recirculating Valve (DRV) per zone. The hot water supply to The Brain® is 155°F (68°C) and the system setpoint is 135°F (57°C).

The Brain® provides safe consistent hot water to each zone. The integral RS485 Serial Port on The Brain® connects the DRV directly to a Building Automation System (BAS) to receive and communicate the setpoint, inlet/outlet temperature and over-temp alert inputs from The Brain®.


The Brain® has provided the JW Marriott with the following:

  • Safety: Constant and accurate water temperature prevents potential scalding.
  • Accuracy: Outlet temperature to system is +/- 2°F
  • Simplicity: Constant steam pressure prevents stall, therefore, no pump trap is required; instantaneous water supply does not require storage tanks; and a single integral digital control valve (DRV80) replaces multiple components.
  • Connectivity: The Brain and BrainScan™communicate through an onboard status display and remotely through a Building Automation System to provide self diagnostics, alarms and temperature trending.
~ North America
Solution type: 
Digital Water Temperature Control
JW Marriott Mexico City