By the SightShield team · · 3 min read
Paying to light and cool empty space
Offices in Bangalore often run lights and air conditioning from morning to night across whole floors, even when hybrid schedules leave large areas empty. Toilets, pantries, store rooms, cabins and meeting rooms sit unused for much of the day. Occupancy sensors switch things off when nobody is there and give facility managers data on how space is really used.
Sensor types
| Type | How it detects | Best for |
|---|---|---|
| PIR | Body heat moving across zones | Corridors, toilets, store rooms |
| Ultrasonic | Changes in reflected sound waves | Rooms with partitions and obstacles |
| Dual-technology | PIR plus ultrasonic or microwave | Cabins and meeting rooms |
| mmWave presence | Radar sensing small movements | Desks and rooms where people sit still |
| Desk sensors | Under-desk presence detection | Hot-desking utilisation |
Where they save the most
- Toilets and washrooms: lights and exhaust fans on demand.
- Meeting rooms and cabins: lights and AC off when empty.
- Pantries and store rooms: short time-outs.
- Open areas: switch zones off when a section is unused on quiet days.
- Corridors and staircases: dim rather than switch off, for safety.
Avoiding the “wave your arms” problem
The most common complaint about occupancy sensors is lights switching off while someone works quietly. It is solved with the right sensor type (presence or dual-tech rather than basic PIR in work areas), correct placement covering desks, sensible time-outs of around 15 to 20 minutes in work areas, and dimming to a low level before switching off. Manual override switches remain in every room.
AC control
Linking sensors to AC — split units through IR controllers or VRF systems through their central controller — saves more than lighting control, because cooling is the larger energy load. Set AC to switch off after a longer delay than lights, and to return to a sensible setpoint such as 24 °C, the default BEE recommends for room air conditioners, when people return.
Office automation for lighting and AC →Data for space planning
Aggregated occupancy data shows peak and average use of each area, which teams come in on which days, and how many desks are really needed. Use summary data only, inform staff about the sensors, and avoid tracking individuals. Many companies use these figures to consolidate floors or redesign layouts in hybrid offices.
Hybrid work and office security →Wired or wireless?
- Wired sensors suit new fit-outs and are maintenance-free.
- Wireless sensors suit existing offices; replace batteries every year or two.
- Choose sensors compatible with your lighting control or building management system.
Typical savings areas
| Space | Typical setting |
|---|---|
| Toilets | Lights and exhaust on with presence, off after a few minutes |
| Meeting rooms | Lights and AC on with presence, off after about 15 minutes |
| Cabins | Lights off after about 20 minutes; AC to standby |
| Open office zones | Dim when empty, off after hours |
An example
An office of 180 seats in Domlur added dual-tech sensors to cabins, meeting rooms and toilets, and mmWave sensors over open-plan zones, linked to lighting and AC. On Mondays and Fridays, when attendance is low, whole zones now stay dark and cool only where people sit. The facility team also learned that one wing was almost never used on those days and now closes it, saving cleaning and power.
Planning and installation
We survey offices, choose sensors for each space, and integrate them with lighting, AC and booking systems.
Office automation services →Quick answers
Do occupancy sensors really save energy?+
Yes, especially in rooms used intermittently and when linked to AC, which is the larger load.
Why do lights switch off while I am sitting at my desk?+
Usually a basic PIR sensor or a short time-out. Presence or dual-tech sensors and longer time-outs fix it.
Can sensors control split ACs?+
Yes, through IR controllers, or through the central controller for VRF systems.
Do occupancy sensors track individuals?+
They should not. Use aggregated data for planning and inform staff.
What time-out should sensors use?+
Short time-outs of a few minutes in toilets and stores, and around 15 to 20 minutes in work areas, with dimming before switch-off.
Do sensors work with LED panels?+
Yes. LED lighting switches and dims well with sensors; check the driver supports dimming if you want it.
Can they be added to an existing office?+
Yes, wireless sensors make retrofit easy.