In the article "The Expanding Role of Sensor in "Smart' HVAC Systems", Manz expressed the need for sensors in buildings as it will "reap significant energy savings". He explained that by connecting all the various systems in the building, especially the heating, ventilation, and air-conditioning (HVAC) system, will create an integrated and innovative monitoring software that observes the energy consumption of the building. Manz mentioned that over the years building owners neglected energy savings until the 1970s and 2000s when there was an increase in oil prices, making "power conservation is essential". Another aspect of the need for sensors is the advancement of technology. He mentioned that replacing the analogue sensors with a small-scale digital unit reduces installation time and "eliminate the need for recalibration". According to the article, sensors have changed the ways of energy management in a building. However, the author could have elaborated on the benefits of sensors in a smart building: determining the occupancy load in a room, monitoring the indoor air quality (IAQ), and integrating with various systems in the building.
The first benefit of sensors that Manz could have elaborated is
it can determine the occupancy load in a room. In the article “Occupancy-Based
HVAC Control with Short-Term Occupancy Prediction Algorithms for
Energy-Efficient Buildings”, the authors explained that the current HVAC system
in a building will operate at full capacity throughout the day which results in
"rooms are often needlessly over-conditioned, which may lead to
significant waste in energy consumption." For example, the HVAC system
will operate from 7.30 am to 6 pm and about an hour of the day, the occupants
in the building will be lesser. Since most of the rooms will be empty, it
causes an unnecessary waste of energy to cool down the building. Using an
occupancy-based sensor, it will sense the occupancy level in the room and
"cool" down the room accordingly. If the room has been unoccupied
after some time, the HVAC system will return to its preconditioned temperature
setting preserving the comfort level of the room. With an occupancy-based
control sensor, it reduces the energy consumption in a building and “avoiding
wasting energy for empty rooms.”
Another benefit Manz could have elaborated is sensors can
monitor the IAQ of the building. IAQ refers to the environmental characteristic
inside the building that would affect our health, comfort, or work
productivity. In a company blog post by Aeroqual, the post explained that
people spend at least 90% of their time indoors compared to outdoors and
continuously breathe in "indoor air" which has been recycled multiple
times throughout the HVAC system. Through this process, the number of
pollutants such as carbon monoxide and organic chemicals in the air inside the
system will start to accumulate which may irritate our eyes and nose. If the building has insufficient vent outlets
and inadequate ventilation, it will contribute to short and long-term
respiratory health issues. In a different blog post by Germain, he informed by
monitoring the level of carbon dioxide in the building, building managers can
determine if the IAQ is well ventilated and able to circulate with the outdoor
air. This will replenish the oxygen levels and clearing the pollutants within
the building. IAQ is an essential part of the HVAC system as it manages the
comfort level and increases work productivity as well.
Lastly, Manz could have
elaborated on is integrating HVAC with the various systems into a single
management network. From a newsletter by Searle, most HVAC system uses single
propriety monitoring management but it does not monitor overall systems in the
building such as lighting, fire system, security management, etc. As technology
advances, it is possible to integrate the various building systems into a
single management system. An example is an additional sensor that can be
installed to monitor the sunlight intensity within the room and a lower light
setting accordingly. It is ideal for building systems to evolve and become
smarter as it will "optimize performance and create the best possible
indoor environment".
In conclusion, sensors within the HVAC system is a crucial role
in energy management and assisted in maintaining the overall occupancy comfort
in the building.
References
D. Jin, C. Winstead, J. Nutaro & T. Kuruganti (2018). Occupancy-Based HVAC Control with
Short-Term Occupancy Prediction Algorithms for Energy-Efficient Buildings. Energies.
11. 2427. 10.3390/en11092427.
Aeroqual (2018, Sept 25) Why
monitor indoor air quality? Aeroqual.
aeroqual.com/why-monitor-indoor-air-quality
E. Germain (2011, Feb 2) The
Benefits of Air Quality in Building Management. Envirotech-online.
N. Searle (2018, April 4) Top five benefits of HVAC and
lighting control integration. CSE Mag.
https://www.csemag.com/articles/top-five-benefits-of-hvac-and-lighting-control-integration/
