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Project Summary:
Wireless
Project for In-building Use and Built-up Systems
This
project focuses on three aspects of wireless technology for building
operation: 1) adapting, testing, and demonstrating basic wireless
technology that is commercially available for other applications for use
in controlling, operating, and maintaining commercial buildings, 2)
identifying, assessing, and developing specific scientific and
technological advancements needed to make wireless sensors and controls
more affordable for building applications and the probable energy and
economic impacts of achieving these advancements, and 3) working with
industry and the user community to move wireless technology into the
practice operation.
This
project is conducted in close collaboration with industry to ensure that
the results are readily usable to provide technologies and services that
have major impacts on the energy efficiency, quality, and sustainability
of the national building stock.
The
project activities currently comprise three distinct parts: two independent field
tests/evaluations of commercially-available wireless technology in commercial buildings
characterizing the current state of wireless technology for use in
buildings and identifying critical needs to make the technology more
compatible with the demands in buildings, and developing and adapting new
technologies to meet critical needs for cost-effective building
applications.
The first task
focuses on assessing the technical feasibility of wireless technology for
building-equipment monitoring and operation using commercial, off-the-self
hardware, while identifying some of the practical limitations of its use. The
second task will provide a characterization of the
cost, value (including energy and peak load impacts), and problems/issues
associated with these sorts of uses of wireless technology in buildings.
It will also identify critical technological needs and opportunities to make
wireless technology for sensing, control, and service provision for
buildings cost effective and commonplace. Starting
in Fiscal Year 2003, the third task will begin to develop technological advances that lower
the costs of wireless technology for building operation.
Beyond mobility, which is the driver for many wireless applications, the
key promise of wireless technology in building operation is to reduce the
cost of installing data acquisition and control systems by eliminating the
wire. Installation of wiring can represent 20% to 80% of the cost of a
sensor point in an HVAC system. The availability of low-cost wireless
sensor systems could not only reduce sensor costs overall, but also lead
to increased use of sensors. While not the only answer, deploying more
sensors is a key factor in achieving the improved monitoring and control
necessary to establish and maintain highly efficient and effective
building operations.
In these projects, PNNL will characterize the physical performance and costs of off-the-shelf
wireless sensor and data-acquisition systems and describe how they can be
adapted to commercial buildings.
In these
projects, PNNL will characterize the physical performance and costs of
off-the-shelf wireless sensor and data-acquisition systems and describe
how they can be adapted to commercial buildings.
In-building
Use and Built-up Systems
 The
in-building test involves the design and deployment of wireless technology
from Inovonics, Inc. in a federal facility. Inovonics has cost
shared in the project by providing equipment, technical consulting,
development of a new hardware component, and on-site installation
assistance for the project.
Operations personnel at PNNL enthusiastically participate in the project
and use the data collected for building operation. The PNNL Facilities and Operations Office supports this project
with their own funds (beyond BT funding) by providing staff
time for participation in project planning, system design, wireless system
installation, system use, and data collection. This site and
technology also show promise for extension to wireless control of air
handlers in the building, which could serve as an excellent extension of
wireless technology beyond sensing into building controls. The value
of both wireless sensing and wireless control is in reducing the
incremental cost of better sensing/control by eliminating (or reducing)
the number and length of wires, which ordinarily cost from 20- to
80-percent of an installed control or sensor point. Better control
shows great promise for implementing and ensuring high-quality,
energy-efficient building operation.
The built-up
demonstration site is a heavy steel-concrete office building with a total
floor area of about 70,000 ft2 distributed over three floors. It is
located on the campus of Pacific Northwest National Laboratory (PNNL).
The HVAC system consists of central cooling, boiler, and ventilation
system with 100 variable-air-volume (VAV) boxes. The central energy
management and control system (EMCS) controls the central plant and the
lighting system. A wireless temperature sensor network with 33
battery-powered
temperature transmitters was installed to measure zone-air temperatures.
The zone-air temperatures are then used as input for a chilled-water reset
algorithm designed to improve the energy efficiency of the centrifugal
chiller under part-load conditions and reduce the building’s peak demand
without significantly increasing the energy use by distribution fans.
Rooftop
Packaged Systems
Application of
wireless radio frequency (RF) technology to collect data from packaged
rooftop HVAC units relaxes some of the demands imposed by in-building
applications of wireless communication. Equipment can be physically
located so direct lines of sight are preserved and obstructions
minimized. By simply positioning antennas sufficiently above the roof,
all transmitting antennas can “see” their corresponding receiving
antenna. As a consequence, lower transmission power can be used, greater
sources of interference can be tolerated, and communication protocols with
less sophisticated means for ensuring reliable data transmission can be
used. As a result, system and component costs are likely to be lower for
rooftop wireless data acquisition than for in-building systems.
Electrical power for the data collection equipment can generally be
provided at the packaged unit by tapping into the electrical power
supplied for operation of the HVAC unit, eliminating the need for
batteries.
 The
second field test of commercial wireless technology involves use of two wireless technologies to provide energy
monitoring and diagnostic services. The test involves using wireless
communication to collect sensor data from several package rooftop HVAC units
on a building at a central point on the roof. At this point, data
are pre-processed, then provided for use in the building or by a service
provider located remotely. Transmission of the data may be by wired or wireless networking. The data can be "picked up" by an energy service
provider, which can process the data further to produce easily used
information and then use it in-house or securely post results on the world
wide web for use by other HVAC service companies, owners, or building
operators.
This
type of system will be tested on an office building and fast-food
restaurants. The purpose of this test is to design/build such a
system, test the use of wireless technology in the two modes identified,
to evaluate cost of such systems, and to identify critical technological
advancement required to make this technology more cost-effective.
To date two
wireless data collection systems have been configured and laboratory
tested. One has been installed on a 10-ton packaged HVAC unit on
medium-size commercial building leased by PNNL. The second system
will be installed for initial testing on equipment in Fall 2003.
Installation on other field sites will follow.
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