We use many smart gadgets like electronic gates, parking sensors, automated switching of lights and fans, keycard operated lighting, etc., and most of them consume energy. Amongst all, Heating, Ventilation, and Air Conditioning (HVAC) systems consume a huge amount of power in any facility.
If solutions to decrease energy consumption by HVAC are implemented the operating costs of the facility diminishes sharply. For this, constant efforts and experiments are in progress. MEP engineers try different approaches, combinations of designs and principles in HVAC system designing aimed at energy efficiency. Many alternatives have become accepted of which use of smart HVAC products and BIM-optimized HVAC layouts are embraced with open arms.
BIM and Smart Layouts
The question of energy consumption arises when one cannot have a smart component for each and every unit of the HVAC system. This calls for a ‘smart’ and optimally designed HVAC layout. The units consuming the major amount of energy used for running the HVAC system are the compressor and the heat pump. Optimization in their energy utilization will lead to dramatic overall changes. For this, the layout plays an important role based on the location and orientation of the building.
BIM facilitates in deciding these factors. BIM software like eQuest and RELUX are used for the optimization of layout, for clash detection and resolution, and to optimize the layout to decrease the energy consumption. A leading engineering design solution firm created HVAC zones for energy consumption for a hospital facility in Dubai. The reason it requires a mention here is that it is a perfect example of optimized smart design of an HVAC layout. The HVAC zones of the building and another baseline model using the ASHRAE 90.1-2007 standards for the energy consumption were prepared. Based on this analysis and smartly redesigned layouts, the client ended up saving about 14% of the energy consumption, which was 2% more than what was expected.
In order to optimize the MEP designs, it is a must that the ‘non-smart’ components should be so chosen that they have a high coefficient of performance and their operation should complement the requirements of the facility. In commercial facilities like malls, hotels, offices, hospitals and the like, HVAC systems are the protagonist amongst the energy consuming devices.
Sensors and keycards come in very handy for automated switching on – off of these systems. This essentially reduces the unnecessary usage of electricity and has proved to be helpful in decreasing the energy costs by considerable amounts. The sensors automatically control the connection to the power supply of each unit and shut it off when it is not in use.
Smart HVAC Products
Another means, Smart HVAC control systems, has been accepted as an efficient innovation. The acceptance of smart HVAC systems became popular with the introduction of the smart thermostat. But, as of now, many components of a typical HVAC system are sensor operated which can trigger the on and off functions based on various factors like, ambient conditions and human density in the area.
A typical thermostat functions in sensing the room temperature and helps in cutting off the power supply, as and when needed. While on the other hand, a smart heat thermostat helps you remotely set and know the temperature, humidity, occupancy and other factors. Since the temperature and aforementioned factors are interrelated, a smart thermostat helps in deciding the temperature appropriately based on all these factors.
Now, while MEP engineers are designing the HVAC layout in the facility they are required to choose an appropriate place to fix this thermostat, as the surroundings will create a huge impact in sensing the temperature. Say for instance, when a thermostat is set too close to a boiler or heat pump the temperature reading will be higher than the normal average of the building or zone for which it controls, and the adjusted temperature might be uncomfortable to the people in this area of the building. Engineers must exercise intelligent rules for thermostat placement as no smart thermostat can fully counter the effects of its absence.
Smart Air Vents
The basic idea of smart air vents is to close the vents and stop the supply when the area is not in use. It has been quite a discussion that when the vents are closed the static pressure of the system rises, which can lead to disasters.
Despite how carefully manufacturers claim that their algorithms are structured to avoid such disasters, this suggests that air vents surely have a good impact on savings in lost energy provided the building can prevent unanticipated static air pressure changes. MEP engineers can develop system designs capable of doing this, using smart air vents; hence, the concept of hot and cold spots in facilities is becoming obsolete with these smart devices.
Smart dampers are electronically controlled dampers that open and close the ducts for the supply of air. These run by electronic circuit connection with the thermostat which decides the opening and closing of dampers for the air supply based on the temperature sensed. They are typically installed in conjugation with the smart thermostat.
The basic aim of any HVAC system is that the design is appropriate to cool or heat, maintain the temperature, humidity, cleanliness and freshness of air with minimum energy consumption. These booming demands lead us to the introduction of smart products for several units and optimized layout design. While ‘smart’ HVAC devices will inevitability lead to higher initial costs for a building, in the long run, they drastically save power consumption, resulting in energy savings for the building’s lifecycle.
About the Author
Bhushan Avsatthi is an Associate Director at Hi-Tech Outsourcing Services. Bhushan imbibes the prophecy of efficient and prudent use of energy in his day to day life and encourages his team to do so as well. He is also involved in green initiatives like nonprofit tree plantation project and promotes using cycles for commuting small distances. Bhushan handles a team of Architects, Structural and MEP engineers, LEED consultants and Energy modeling experts.