The HVAC schedule in most commercial buildings was set during initial occupancy and adjusted a handful of times over the years. It runs on a fixed weekly calendar: on at 6 AM, off at 8 PM, Monday through Friday. Maybe a Saturday morning half-schedule for when the office is sometimes used.
That schedule was set for a world that no longer exists in most commercial buildings.
Post-2020, hybrid work patterns mean office occupancy on a given Tuesday might be 40% of peak, and on a given Friday might be 20%. The building’s HVAC does not know this. It runs on the calendar. It conditions floors that are half-empty. It heats or cools spaces where nobody will be for hours.
The US Department of Energy estimates that HVAC represents 40–50% of commercial building energy consumption. A building that runs HVAC at full schedule for 2 hours before occupants arrive and 2 hours after the last one leaves wastes 25–35% of its daily HVAC energy on unoccupied conditioning.
VX-Olympus changes the operating model: HVAC follows actual building use, not the schedule set years ago.
The Current State of HVAC Control in Commercial Buildings
Most commercial buildings fall into one of three categories:
No BAS (smaller buildings): Individual thermostats or zonal controls, often set manually and rarely optimized. No remote visibility. No scheduling automation beyond basic programmable thermostats.
BAS with basic scheduling: A Building Automation System controls HVAC, lighting, and other systems on programmed schedules. The schedules were set during commissioning and have not been updated to reflect current occupancy patterns. The BAS is a sophisticated system running an outdated program.
BAS with occupancy integration: A small percentage of commercial buildings have BAS systems that integrate occupancy sensors and actively adjust conditioning based on real-time presence data. This is the target state — and it is achievable through VX-Olympus without replacing the existing BAS.
How VX-Olympus Optimizes HVAC
Occupancy Data Integration
VX-Olympus collects occupancy data from:
- CO2 sensors — rising CO2 indicates people are present; CO2 returning to outdoor ambient indicates space is empty
- PIR motion sensors — active occupancy detection in individual rooms and zones
- Access control integration — badge-in events indicate when people are entering the building and which floors/zones they access
- Wi-Fi probe counting — aggregate device presence as an occupancy estimate
These inputs create a real-time occupancy map of the building: which floors are occupied, at what density, and whether occupancy is increasing or decreasing.
Automated Schedule Adjustment
VX-Olympus rule chains translate occupancy data into HVAC control actions through integration with BAS systems (BACnet/IP, Modbus TCP) or smart HVAC controllers:
Pre-cooling/pre-heating based on predicted occupancy: When calendar data (from integrated room booking systems) shows that a floor will have significant occupancy from 8 AM, the HVAC begins conditioning from 7 AM. When the same floor shows no bookings and no access events, it remains in energy-saving mode until occupancy actually arrives.
Zone-level adjustment: A 10-floor building where only floors 3–5 are occupied on a given afternoon does not need floors 6–10 conditioned to full comfort setpoints. VX-Olympus adjusts unoccupied floors to a wider setpoint range (e.g., 65–78°F instead of 70–74°F) — saving conditioning energy without compromising the occupied floors.
Real-time occupancy response: When the last badge-out event occurs on a floor and CO2 returns to ambient (confirming the space is actually empty, not just that the last person went to the bathroom), VX-Olympus shifts that floor to unoccupied mode immediately. No waiting for the schedule to run the shutdown.
Demand-controlled ventilation: Ventilation rates are a significant fraction of HVAC energy — heating or cooling outside air before distributing it through the building. In low-occupancy periods, ventilation rates can safely reduce without compromising air quality. VX-Olympus CO2 monitoring provides the demand signal: ventilation ramps up as CO2 rises (more people, more CO2), and ramps down as CO2 drops (fewer people).
Remote HVAC Control
Building operators and facility managers need to change HVAC setpoints, activate conditioning for after-hours events, and respond to emergency conditions — without requiring physical access to the BAS workstation.
VX-Olympus provides remote control capability through the mobile and web interface:
Temporary override: An employee staying late needs the floor conditioned for 2 extra hours. They submit a request through the building’s occupant portal. VX-Olympus processes the request, extends the HVAC schedule for that floor for 2 hours, and automatically returns to the standard schedule afterward.
Event scheduling: A building hosting a Saturday event needs HVAC active from 8 AM to 5 PM on that day. The facilities manager adds the event to VX-Olympus from any browser — the HVAC activates and deactivates on the event schedule without requiring anyone to be in the building to manage it.
Emergency override: A HVAC fault occurs at 3 AM. The facilities engineer receives an alert, logs into VX-Olympus from their phone, reviews the fault status, and issues a restart command to the affected air handling unit — without driving to the building at 3 AM.
Multi-building management: A facilities manager covering 8 buildings manages all HVAC schedules, all setpoints, and all alert states from one VX-Olympus view. Building-level actions require drilling into the specific building; portfolio-level monitoring happens at the top level.
Energy Savings Quantification
VX-Olympus energy monitoring (Article #11 context) provides the measurement infrastructure to quantify HVAC optimization savings:
Baseline establishment: Run the building on its existing fixed schedule for 30 days while monitoring energy consumption. Establish the baseline kWh per day normalized for weather (heating degree days / cooling degree days).
Optimization deployment: Deploy occupancy-based control through VX-Olympus rule chains. Run for 30 days.
Savings calculation: Compare normalized energy consumption before and after. The difference is the documented energy reduction from optimization.
This measurement matters for:
- Utility incentive programs (many utilities offer rebates for demand response and energy efficiency investments)
- LEED and ENERGY STAR documentation
- Corporate sustainability reporting
- Internal ROI documentation for the facilities investment
Integration Without Replacing the BAS
VX-Olympus does not require replacing an existing BAS. It works alongside it through standard protocols:
BACnet/IP integration: Most modern BAS systems communicate via BACnet/IP over the building’s IT network. VX-Olympus reads current HVAC status, setpoints, and operating states from the BAS — and writes schedule and setpoint changes back to the BAS. The BAS remains the control layer; VX-Olympus provides the intelligence layer.
Modbus integration: Older BAS systems and direct-drive HVAC equipment often use Modbus RTU or Modbus TCP. VX-Olympus Modbus support connects to these systems without requiring BAS upgrades.
Standalone smart controllers: For buildings without a BAS, smart HVAC controllers (thermostats with MQTT or API support) install at the zone level and connect directly to VX-Olympus without a BAS intermediate layer.
The Outcome
HVAC optimization is one of the highest-ROI IoT applications in commercial real estate. The sensors exist. The controls exist. The intelligence layer that connects them to actual occupancy is what most buildings are missing.
Talk to our team about an HVAC optimization deployment for your building or portfolio.