| |
|
The systems that control HVAC and lighting for guest
rooms, lobbies, meeting rooms, and convention areas
should be fully programmable and scheduled to operate
only when the areas are in use. This type of system
operates on a flexible schedule that ensures proper
temperatures and adequate lighting, thus reducing energy
consumption.Calibration of indoor and outdoor building sensors such as thermostats and humidistats should be checked periodically to ensure they are operating within original design specifications. If not checked periodically, controls that operate in conjunction with a building’s HVAC system can cause the system to operate inefficiently and unexpectedly.
Sub metering
Sub metering is an important component that can be utilized to effectively collect and measure data.
Energy sub metering involves measuring and collecting detailed energy-use data for one or more departments in a facility. Sub metering can be done with simple handheld instruments, complex data loggers, or as part of a state-of-the-art control system. Data from sub metering can result in a 1-2 percent reduction in energy use simply through increased awareness and accountability. The information also allows hotel personnel to identify energy conservation and process control measures that can lead to a total energy reduction of 5-10 percent.
Benefits
-
Identifies energy waste.
-
Identifies equipment operating out of control.
-
Allows management to allocate energy costs to departments based on actual use.
-
Helps evaluate performance and identify problems.
-
Makes it easier to identify energy-saving measures and quantify benefits.
-
Can be implemented at various scales and levels of process integration.
How to use the data
The data collected through sub metering can be used to
help make both short– and long-term adjustments that can
significantly decrease energy use over time. On an
hourly level, sub metering will indicate overall usage
patterns, uncontrolled equipment usage, and if there is
high usage during unoccupied periods. From a monthly or
seasonal perspective, sub metering will provide data on
load and use variance, demonstrate when demand is at its
peak, and expose billing errors. The annual information
will enable hotel personnel to identify base and peak
energy loads ("valleys" and "hills"), the Energy
Utilization Index (EUI, how many BTUs per square foot
per year are used) and Energy Cost Index (ECI, how many
dollars per square foot per year are spent on energy) of
each location, and allow energy expenditure comparisons
with other, similar, locations in outside facilities
(benchmarking). Finally, sub metering will allow a
general comparison of the relative costs of different
energy sources.
Monitoring and Targeting (M&T)
Energy monitoring and targeting is primarily a
management technique that utilizes energy information
(fuel, steam, refrigeration, compressed air, water, and
electricity) collected through control systems as a
basis to eliminate waste, reduce and control current
level of energy use, and improve existing operating
procedures. It is imperative to have data from control
systems available on a regular basis to set targets,
identify and interpret variances, and establish remedial
actions to be implemented. The premise for monitoring
and targeting builds on the principle, "You
can't manage what you don't measure." It
essentially combines the principles of energy use and
statistics.
Elements of a Monitoring & Targeting System
The essential elements of an M&T system are:
-
Recording - Measuring and recording energy consumption.
-
Analyzing - Correlating energy consumption to a measured output, such as occupancy.
-
Comparing - Comparing energy consumption to an appropriate standard or benchmark.
-
Setting Targets - Setting targets to reduce or control energy consumption.
-
Monitoring - Comparing energy consumption to the set target on a regular basis.
-
Reporting - Reporting the results, including any variances from the targets which have been set.
-
Controlling - Implementing management measures to correct any variances which may have occurred.
References
Kramer, Dr. Robert. NiSource - Combined Heat and Power
and Advanced Control Systems Installed in a Hilton
Hotel. U.S. DOE.
www.eere.energy.gov/de/pdfs/conf-04_micro_apps_wkshp/zaltash.pdf
International Performance Measurement and Verification
Protocol
www.ipmvp.org
Misuriello, Harry, The Basics of Facility Energy
Management. Alliance to Save Energy, p.15.