Specifications

95Environmental Automation
Building Energy Measurement and Management
In the days of abundant, low-cost
energy, the consumption of energy
to run a building was treated as an
unavoidable and unmanaged expense.
But energy prices continue to climb
relentlessly and energy use increases in
response to the expanding population
of urbanized citizens. As a result,
building operators and international
organizations are focusing on this
large use of energy and responding
by seeking ways to reduce costs and
resource consumption. The challenge is
to reduce energy use while maintaining
quality of service to the building’s users.
As with any challenge, information
provides a window into the process,
highlights the best opportunities
for improvement, and allows
tracking of the results.
Electrical energy has the highest cost
per kilowatt-hour of any form of energy
used in buildings. The costs easily justify
its measurement and management.
Air conditioning systems (HVAC&R)
and several other building systems
such as elevators and escalators use
powerful electric motors to run the
pumps, fans, and equipment, consuming
very signicant amounts of electrical
energy in the process. Power companies
meter the total energy delivered into a
building and submetering is provided
for multiple-tenant buildings, but
greater granularity is justied when
individual components of a building’s
systems draw signicant amounts
of electrical power, especially when
these components can be managed
to modify their consumption.
The generation of usage data on
subsystems in the building and
subsequent analysis of usage history
and trends give operators concrete
information to manage energy
consumption. With this data, one can
quickly see where the bulk of usage is
occurring, and this can lead to eective
measures to reduce consumption,
possibly by changing usage habits.
For example, should the escalator
continue to run when nobody is
on it? Should the hotel room lights
remain on when the guest leaves?
Should the air conditioner in a room
start prior to a scheduled meeting?
Eective measuring of energy
consumption can also possibly reveal
the need to replace old, inecient
equipment with newer designs. This
data can catch faulty systems that
are drawing excessive power beyond
their nominal levels. Moreover, the
data can be used to qualify for LEED
credits, ISO 50001 certication, and
time-of-use billing adjustments.
Maxim has the technology to
precisely measure electricity usage
wherever desired, which can provide
the information needed to treat
energy consumption in buildings as
a manageable cost while maintaining
quality of service. Maxim’s 78M6618
octal power and energy measurement
IC can do this. The part measures up to
eight single-phase AC lines. The 78M6613
is a single-circuit version that can be
imbedded into individual equipment,
giving it the ability to measure and
report its own power usage. For
more information on Maxim’s energy
measuring capabilities, go to: www.
maxim-ic.com/energy-measurement.
Security Systems
Security systems include access
control, intruder detection, alarms, and
surveillance. Prior to automation, security
for the home relied on door and window
locks, and possibly a dog. Commercial
establishments used security guards
and doormen with keys for multiple
mechanical locks. Surveillance consisted
of security guards “walking the beat.”
The shortcomings of this system are
several: the need of many people, the
predictability of surveillance routes and
times, and the duplication of keys.
Everything changed with the advent
of modern electronics, networking,
and video cameras. Access control
is handled automatically, no people
are required to open locks for
others, security is pervasive with
“someone always watching” the
entire premises, and accounts are
enabled and disabled quickly.
Access Control
Access control may now be implemented
in a variety of ways. Individuals entering
a building interface with the automated
system using Wiegand keycard
readers, keypads (resistive touch-panel
controllers like the MAX1180 0 can be
used as keypad scanners to avoid the
use of mechanical switches, which
are costly and wear out quickly), RFID
keys (MAX66140), serialized iButton
keys with authentication (DS1961S),
magnetic stripe cards, or through
some other method such as biometric
authentication using ngerprint readers
or iris scanners. The systems needed for
these door-access devices include the
appropriate sensor, signal processing
(i.e., amplication, ltering, ADC), digital
processing to extract the information
that will eventually be compared to a
database, data encryption, and, in highly
security access points, security managers
(DS3600) in the door devices. To send
the data to the BAS, data transceivers
interface with networks as well as more
transceivers and computing systems
Small power distribution and circuit breaker panel suitable for
incorporation of energy measuring module.