Background
Commercial usable space requirement in India has gone up in demand in India during the last few years. Commercial spaces can be defined as buildings used for commercial purposes such as office buildings, IT buildings, government buildings, banks etc. In any commercial building, occupants generally spend 8 to 10 hours in a controlled environment. People do different activity and use different equipment inside the closed premises. Hence, they need fresh air, domestic water, proper drinking water, toilets, electricity, work stations and finally comfortable air temperature. For finding out the number of people using a commercial building, national building code of India specifies as 80 to 100 square feet per person. Each square foot of comfortable space needs nearly 80 BTU of air conditioning load and nearly 11 watts of connected electrical load. For a building manager, maintaining these loads is always a challenge and manually controlling all these services is next to impossible.
Major Equipment in Commercial Building
In any commercial building, there are number of mechanical equipment such as chillers, AHU, pumps, valve, electrical equipment such as switchgears, generators, panels, transformers, PHE equipment such as pumps, STP, boilers, treatment plants can be seen in any building along with measuring devices such as BTU meters, DB meters and energy meters. When these equipment get connected with one central point for a common goal, it will be known as Smart Automation System (SAS). SAS takes care at each equipment for saving energy as below:
- LED fixtures.
- Proper DG Back up
- Water and power efficient chillers
- VFD in pumps, AHUs
- Temperature sensor for conditioned area
- Water saving fittings
- STPs with sensors
- CO and CO2 sensors
- Oil indicators
There are lot many mechanical and electrical equipment not listed above which are found in any building and have optimised by design engineer in terms of power and water saving. But the main object will fulfill only with the help of proper and adequate IBMS.
HVAC automation system
HVAC plays a major role in building automation as it consumes 65 per cent of total energy and 50 per cent of operation staff. Not functioning of HVAC, reduced performance of the staff and over using of HVAC increase electricity bills. Chillers, pumps and AHUs are the important parts of HVAC control system in case of a chilled water system. However, VRV system comes within built automation system which does not need any external system to guide. Following points of HVAC can be connected to SAS.
Cooling towers are generally controlled automatically by the chiller panel and no separate automation system is required. But pumps need to get connected in automation system. Following points of pumps to be connected with the SAS and BMS.
Air handling units play a key role in automation of any commercial building as it is responsible for providing comfortable atmosphere to the occupants. Following points of AHU to be connected with the SAS and BMS.
Electrical automation system
Along with the HVAC system, plumbing, STP, electrical systems are also integral part of building automation and control. There are so many examples where HVAC system is controlled but other systems are left for manual operation. The point to be noted is that the only combined MEP automation can give the combined benefit.
Lighting Control System
A lighting control system is an intelligent network-based lighting control solution that incorporates communication between various system inputs and outputs related to lighting control with the use of one or more central computing devices. Lighting control systems are widely used on both indoor and outdoor lighting of commercial, industrial, and residential spaces. Lighting control systems serve to provide the right amount of light where and when it is needed.
Lighting control systems are employed to maximise the energy savings from the lighting system, satisfy building codes, or comply with green building and conservation programs. Lighting control systems are often referred to under the term Smart Lighting.
Lighting control strategies
- High-end trimming sets the maximum light level based on customer requirement in each space.
- Occupancy or vacancy sensing turns light on when occupants are in space and turn off when they vacant the space.
- Daylight harvesting dims electric light when daylight is available to light the space.
- Personal dimming control gives occupant the ability to set the light level.
- Scheduling provides pre-programmed changes in light level base on time delay.
- Controllable window treatments adjust shades to reduce solar glare and solar heat gain.
- Plug load control automatically turns off the load after occupant leaves the place.
- HVAC integration control heating, ventilation and air-conditioning system through contact closure, or BACnet protocol.
Advantages of lighting control
- Light control supports building operation staff by providing appropriate light for any task.
- Light control can also reduce the demand for building staff, allowing them to focus on the primary responsibilities with fewer distractions.
- With the use of the light control and having the ability to adjust light to a personal preference support staff to deliver the highest quality care.
- Light control has improved the staff performance by providing lighting levels that are the most appropriate for the task at hand.
- The lighting control has been able to provide biggest advantage of energy saving.
Conclusion
Commercial office spaces are the present requirement of the market. Any building can run for a longer time if its energy bill is minimum and its maintenance cost is less. This can only possible with proper installation of a smart automation and control system. Again, SAS and BMS help in getting 35 per cent of energy saving as compared to a normal building without the same.
Firoj Jena,
Chief Executive Officer,
Clancy Global Consulting Engineers,
Mumbai
