How to Automate an Existing VRV Air-Conditioning System

17 May 2026 · AmbiAutomation

Prerequisites: what your system needs to expose

VRV / VRF automation is possible whenever the system can speak BACnet IP or MODBUS RTU — either natively or via an OEM bridge box. Confirm this with your HVAC vendor before any deployment plan. The other thing worth confirming: are the indoor units addressable independently? Most are, but a few older systems group multiple units behind a single addressable point.

Step 1: Survey

A site survey is one or two days for a typical office building. The outputs we want from the survey are:

• Number of indoor units, by floor and by zone
• HVAC OEM, model, and protocol (BACnet IP / MODBUS RTU) on each system
• Operating hours and current schedules (or lack of them)
• Comfort complaints by zone, if any
• Energy bill (12 months) for baselining
• Existing IT infrastructure — Wi-Fi coverage, available LAN drops in the plant room

Step 2: Plan

The plan turns the survey into:

• A zone map (which indoor units belong to which schedule group)
• A schedule template (occupied / unoccupied / setback / lockout)
• Alarm thresholds (drift, runaway, comms-loss)
• A user list with role-based access (FM, ops, contractor, tenant)
• The on-site server location, power source, and backhaul (Ethernet preferred, Wi-Fi acceptable, cellular as fallback)

Step 3: Install

Physical install of the on-site server is typically a half-day per site. The HVAC Bridge Board mounts in or beside the existing HVAC controls panel and pulls 8–26 VAC from the same panel. It connects to your HVAC system over BACnet IP (Ethernet) or MODBUS RTU (RS485). Backhaul is whichever of Ethernet, Wi-Fi, or cellular is available.

This step does not require the HVAC to be powered down. Most installs happen during a regular operating day.

Step 4: Commission

Commissioning is where the abstract plan becomes a working deployment:

• Discover every indoor unit and confirm address mapping
• Apply the schedule template by zone
• Push setpoint caps and lockouts
• Provision app users and roles
• Walk-test a sample of zones: override, schedule, alarm

Step 5: Operate & tune

The first two weeks are observation. You want to see:

• Schedule compliance — did anyone override? where?
• Energy delta vs baseline — is the savings curve trending right?
• Comfort complaints — did setpoint caps create any?

From week three onward, tune setpoints, schedules, and occupancy thresholds against actual data. Most buildings settle into a stable operating pattern by week six.

FAQ

Does the building need to be shut down for install?

No. Installs happen during a regular operating day.

What if internet drops?

The on-site server runs edge logic. Schedules and alarms keep functioning. The app reconnects when internet returns.

What about indoor units we don't want to schedule?

Any unit can be excluded from group schedules and left under manual control via the app or wall remote.