A guide to the latest HVAC developments, from in-room energy control to fully integrated management systems
Property management from every
field is facing a new set of challenges—in education and government, in the
hospitality industry, and across all forms of commercial property. Attention is
being focused on finding new ways to reduce and control energy consumption
against a background of rising energy prices and the focus on greener energy
policies. While facility HVAC efficiency is nothing new, there have been a host
of recent technology improvements that are having a fundamental impact on the
world of building automation. With so much energy at stake, alongside the
continuing price rises, HVAC efficiency is understandably under considerable
scrutiny. When you consider that HVAC costs typically account for more than 30%
of a building’s electricity overhead, this is one area where improved control
has real potential to deliver meaningful results.
Dynamic Trends in Energy
Control
There are a number of trends and
developments that are making this a particularly important and dynamic time in
terms of energy control initiatives. Property managers are being presented with
a much wider set of options, with an increasing amount of cross-fertilization
between different market sectors in terms of the available technology. We see
these initiatives consolidating into five key elements. The convergence of
automation networks through new technology is allowing a considerably greater
focus on efficiency to be realized, while the much wider adoption of these
networks is resulting in continual growth in current sectors, as well as a
dynamic expansion into new markets. System intelligence, particularly in the
form of intelligent thermostats, will play a large role in the future of
automation networks, both in the residential and the commercial marketplace.
Significantly, the enabling technology has created a market of choices capable
of handling all sizes of projects, rather than only being economically viable
for just large-scale projects, as has tended to be the case in the past.
Finally, smart grid deployment and the involvement of utilities will, without a
doubt, play an increasingly important role, driving technology development and
the degree of interoperability that can be achieved.
Energy Specifics: Examples From Hospitality
and Education
Building management systems (BMS)
have tended to be targeted at larger properties, but, with spiraling energy
costs and growing consciousness about the need to adopt greener policies, it is
often the smaller building that is challenged to find effective solutions. If we
take the example of the hospitality sector, we can chart this process quite
accurately. It is not at all uncommon for hotels to be equipped with the
lowest-cost HVAC available, based on a build focus of cost rather than
operational efficiency. However, the lowest-cost system can, frequently,
represent the highest operational cost, in terms of energy consumption. So, it
is not surprising to see that the American Lodging and Hotel Association is
suggesting that hoteliers start their green initiatives by putting an
occupancy-based HVAC solution in place.
Guest comfort is a priority in the
hospitality sector. The latest guest room Energy Management (EM) systems combine
this maxim with intelligent energy control, with solutions typically comprising
a thermostat, occupancy sensor, and, potentially, a door contact. There is a
range of options for detecting occupancy, from passive Infrared detection,
motion detection, and door contact to using the light level of the room to
determine whether it is day or night. Key card systems work in a similar fashion
to door contact solutions, locking a system into the occupied state if the key
is inserted into a key card slot. However, there are valid concerns about the
continuing use of key card systems, based on the accumulation of environmentally
unfriendly disposable cards that run completely counter to the concept of a
greener approach. The most successful solutions, however, put the system
intelligence within the room thermostat—using room occupancy to trigger the
optimum energy-saving settings.
A typical small- to medium-sized
hotel will generally have packaged terminal air conditioner (PTAC) units in each
room. Depending on the age of these units, they may work directly with an
intelligent thermostat or require additional equipment. Some PTAC manufacturers
have even started manufacturing their own intelligent thermostat systems as
optional add-ons. When installing Energy Management on a PTAC, there are some
important questions to ask first: Should this older system be EM-enabled, or
should it be upgraded first in order to achieve even more savings? Is the unit
sized correctly to the room requirement—as an undersized unit will not deliver
the expected savings?
In larger facilities, it is usual
to find fan coil units used with a central boiler/chiller plant. These present a
number of further considerations that can fundamentally impact the resultant
energy control, including whether they use two- or four-pipe systems, with
valves and multiple fan-speed options, and the issues of system control from
room-based intelligent thermostats. A new guest room energy system can have an
impact on the efficiency of a building’s overall HVAC plant, which can be
particularly difficult to estimate in larger facilities. Simple physics suggest
that bypassing the fan coil units will change the temperature of the hot/cold
water coming back into the boiler/chiller, making it difficult to prove the
exact efficiency obtained. These are real issues for property management and can
make it challenging to provide the payback calculation needed to justify the
investment in a new system. However, it is only by eliminating inconsistencies
in a system that the first steps to achieving energy savings can be
realized.
Another sector that provides
valuable insight into the challenges is education. The Austin Independent School
District (AISD) in Texas provides a good example of how a smaller facility can
achieve tangible energy savings by implementing current EM technology. The
School serves grades K–12 and has approximately 600 portable buildings, located
throughout the city of Austin and in Travis County, with each building
consisting of two classrooms. The project involved installing a state-of-the-art
EM system (the SmartEnergy System by Telkonet) in all of the AISD’s portable
buildings. This was part of a larger initiative, originated by the state of
Texas energy office and the City of Austin, to address energy wastage in the
portable buildings—the high summer temperatures (typically 100–120˚F)
necessitated that the air conditioning was run continually, even when the
classrooms were unoccupied. The project included replacing all lighting and
upgrading the HVAC controls in each of the portable buildings, and is estimated
to reduce costs by around $200,000 per annum.
So what can we learn from these
examples? In essence, as the price of electricity has climbed, improving energy
efficiency has become increasingly important, and there has been a commensurate
rise in the take-up of occupancy-based systems. There is also a growing trend to
integrate these with BMS, enabling the control of selected elements of a
facility’s HVAC system. We are increasingly seeing a process of
cross-fertilization, with products that were formerly specialized for a
particular marketplace now interoperating much more widely, driven by the common
goal of achieving enhanced energy efficiencies. This translates into solutions
for smaller commercial buildings, such as within the hospitality sector that
previously could not afford the large-scale building management systems on offer
from suppliers such as Johnson Controls or Siemens. Added to this is the wider
adoption of open protocols within the latest generation of building automation
systems, such as BACnet, which provides a solid foundation for interoperability.
However, there is another important technology development—namely, wireless
ZigBee mesh architecture—that is also gaining in popularity. We may ultimately
see a combination of these two platforms: integration of ZigBee in cooperation
with BACnet, providing the ultimate solution for many applications.
Technology Convergence: Playing a Role in
Enabling Greater Efficiency
We highlighted earlier the
convergence of automation networks through new technology as being a key enabler
for a greater focus on efficiency. Expanding on this theme, Web 2.0 is providing
a
common user interface to many devices and is therefore more easily
interactive. A case in point is the range of applications available on smart
phones, such as the Apple iPhone, which illustrates how more automation
capabilities are used once greater access and control is available. The second
technology that fits this argument revolves around the mesh capabilities and
standardization that ZigBee is creating (www.zigbee.org). ZigBee was conceived
to address the market need for a cost-effective, standards-based wireless
networking solution that supports low data rates, low power consumption,
security, and reliability. As such, it is the only standards-based technology
that addresses the unique needs of most remote monitoring and control and
sensory network applications.
Today, there is a vast amount of
support for the concept of quick and easy development on top of modules that
perform the complex nature of mesh communications. The upshot of this is that it
pushes forward the rapid development of new products that are much more capable
of complex intercommunications than was previously possible.
The Role of Intelligent
Thermostats
As automation networks evolve,
there is a fundamental and important role that the intelligent thermostat can
play. As a customer interface, it is the prime source of user data—the key to
unlocking a host of energy saving initiatives based on real-time information and
analysis. In the residential space, there are a myriad of projects already
underway as part of the smart grid that are enabling real-time billing and
demand management. One aspect of controlling a considerable load is through the
HVAC, principally via the air-conditioning unit. If real-time data can be
displayed on the thermostat to give the customer choices, and if remote options
for curtailment can be displayed on the thermostat, it can become a central
resource for automating a range of services—such as lighting and HVAC, as well
as other potential domestic services.
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| A range of new applications utilize automation capabilities. |
In the commercial environment,
there is a much wider picture to assess. If we retain the example of
hospitality, there are many similarities with the residential example, involving
focusing on providing greater user feedback and more intuitive
interfaces—enabling the end user to participate in the curtailment of load for
specific energy-consuming activities, such as heating and lighting. There is
also scope to use individual systems, such as occupancy-driven guest room Energy
Management, to provide basic efficiency savings in conjunction with other
initiatives across the network, including lighting and water heating.
Automation Networks: A Growing
Role
There is clear evidence that the
adoption of automation networks is expanding to new markets, alongside continued
growth in existing sectors. There is also no doubt that automation is closely
aligned with today’s green initiatives and the rising tide of interest in
renewable energy sources. Squandering alternate sources of energy in the same
way as with fossil fuels is simply not an option, nor is the need to watch
energy consumption. Both solar and wind power for example are not as easy to
harvest, reminding us constantly just how precious every last kilowatt-hour is.
As capabilities in alternative energy expand, there is a growing requirement for
appropriate monitoring to be put in place. The demand is for a completely new
level of intelligent control and automation, capable of meeting the rapid pace
of emerging technologies.
Enabling Technology: Creating
Choices
We illustrated earlier that
old-style building management systems were the preserve of large-scale buildings
and projects. Identifying what size of deployment today justifies a BMS,
involves taking into consideration a range of new factors—including the impact
of low-cost mesh technology and the wealth of new, small/medium-sized solutions
that are designed to facilitate building automation on a more flexible sliding
scale—from the smallest to the largest building project.
As the push for greater energy
efficiency by the utilities continues to grow, so does the adoption of new
technologies. As with the emergence of much new technology, it is industry
growth that eventually drives down manufacturing and overall costs. The
combination of the new technology and increasing market scope results in a
cyclical effect, lowering the ultimate cost of implementation. Another enabling
feature is the ease of installation offered by today’s wireless systems. Taking
hospitality as our example once again, the wide-scale adoption of wireless WiFi
over hardwired network lines has matched both the consumer demand and the need
to improve the efficiency of technology retrospectively in older buildings.
These same principles hold true for the many older properties requiring a new
type of energy efficiency system. The key to success is identifying the most
appropriate combination of solution for a given property challenge—often
requiring a combination of tried and tested methodology, alongside the latest
system innovations.
The Smart Grid: How Will It
Impact?
The utility companies are leading
the charge for improved energy conservation, recognizing the fundamental
responsibility of preserving energy rather than capitalizing on rising costs
with higher profits. As a direct result, it is the utilities that are the single
largest promoters of interoperability, pushing vendors to adopt standards such
as ZigBee and BACnet. The recent announcement last June, of the ZigBee Smart
Energy Profile, reflects this drive—enabling wireless two-way communication
between utility companies and common household devices, in the quest to empower
consumers to manage their energy usage more precisely. But above all, an
initiative such as ZigBee Smart Energy allows utility companies to implement
more sophisticated programs for greater energy management, as well as to respond
to government demands for energy efficiency. This, in turn, is forcing systems
developers to switch their focus from implementation to interoperability,
reflecting the need to apply common standards and promote equipment that it
increasingly intelligent, and part of a wider automation strategy.
What Does the Future
Hold?
We are in the initial phases of a
host of new technology enhancements that are requiring vendors to make a
fundamental change of focus—namely end user benefits and product features. One
of the most exciting developments for the future, without doubt, revolves around
the concept of systems collaboration. We are moving ever closer to realizing
more cohesive room systems that encompass every possible aspect—from HVAC,
lighting, door locks, access control, surveillance, security, and, specifically
for hospitality, services such as the mini bar, safes, and even the TV stations
of your preference or language. Standards-based wireless mesh technology enables
a true breadth of vision, consolidating the spread of systems vying for space
within the 2.4-gigahertz spectrum. This pattern is aided by the maturity of many
of the network technologies currently in use, providing the vital support for
mesh network products and helping them to succeed. After all, you need a
foundation of existing, reliable technologies operating beneath a mesh network,
such as powerline communications technology (PLC) and wireless networks. The
bottom line is that these enable easier access to a well-conceived overall
network infrastructure that will aid energy-efficient operation and effective
energy management.
A logical next step would be the
truly “smart” room—with all devices integrated together to fulfill consumer
demand for easier interoperation as well as greater efficiency. Knowledge about
how much energy each device uses throughout a property is an important
empowering tool, enabling us to make informed choices. Ultimately, having fully
automatic control of these integrated devices would allow us act on these
choices—either in real-time reactively or through advance planning by
programming our threshold against items such as utility rate changes or demand
reduction needs.
Through long-standing experience
in EM solutions, we have identified the optimum network deployment as having a
Personal Area Network (PAN) for every 50 nodes, enabling us to implement smaller
pockets of managed mesh thermostats or devices. This has proven to deliver the
best performance overall, combined with the ability to keep interconnection hops
low and communication at its most responsive. It is imperative to preserve the
system user experience, and minimizing latency aids system responsiveness.
Crystal ball gazing can be an
exciting occupation. For anyone interested in EM initiatives, we can predict the
impact of new technologies with great certainty. One with considerable potential
is radio-frequency identification (RFID), with its ability to track a specific
identity. Imagine a scenario whereby an energy system knew to turn on the air
conditioning as you walk through the door, simply because it had scanned your
RFID card. A host of individual preferences can be linked to a person’s ID,
enabling other amenities to be customized based on this knowledge. These
preferences could be tracked, or even changed, via your mobile device,
particularly with the emergence of smart phones. Taking this one step further,
your smart phone could provide this information seamlessly when you checked into
a hotel—automating the control of your environment even before you enter it.
These are compelling concepts, which are already within reach, and which will
play an important part in encouraging us all to control energy more wisely in
future. By adopting a genuinely integrated energy strategy, we stand to gain
both individually and collectively—making integration and automation the obvious
grail for effective energy conservation.