Basic Documentation

Rainwater Collecting Tank
BAS
Rainwater
Control
Panel
Greywater
Storage Tank
Water Treatment
Subsystem
From Gutters
and Drains
L
L
Greywater
Supply
L
Symbols
Level Sensor
Flow Sensor
Pump
Figure 4. Rain Water Collection Processes are Coordinated by the Building Automation System.
Pumps deliver the greywater for such uses as
landscape irrigation and cooling towers. The BAS
monitors water meters, pressure sensors and level
sensors to correctly operate the pumps and
treatment system, and to inform the building
operators. It’s important to integrate the rain water
system into the building automation system.
M&V Potable Water Use Reduction
In the long run, water efficiency depends on effective
management and that requires information. The
GGHC, WE2.1 requires meters on the facility’s water
sources and submeters for various identified uses
(for example, cooling tower makeup, boiler water
make-up, outdoor irrigation systems, purified water
systems, laundry, etc.).
The data can support maintenance and
troubleshooting tasks. In some cases, measured
data can affect billing arrangements with the water
and sewer utilities. It also sets a baseline for
evaluating improvements in this facility or a new
one.
Pure Water Systems
Hospital laboratory processes demands a grade of
water more pure than municipal tap water. Tap water
typically contains particles, dissolved organics and
dissolved inorganics that can disrupt laboratory
research or analyses. Water treatment systems
remove these contaminants through a combination
of technologies, including reverse osmosis,
deionization, UV photo-oxidation, ultrafiltration (UF),
and microfiltration.
Today, these treatment technologies are replacing
distillation because of the enormous energy savings.
To purify the same amount of distillation water, it still
may consume twenty-times as much energy as
reverse osmosis system. This fact eliminates
distillation as an option for sustainable facility.
In order to produce purified water for the lab, these
processes convert some of the tap water to
wastewater that flushes away the contaminants.
This reject rate can affect the overall water
consumption for facilities that require large volumes
of high-purity water. In the proposed standard,
7
ASHRAE limits the reject rate for laboratory
treatment systems to 60% or less. This target affects
equipment selection and system design.
Facilities that use large volumes of purified water
have the strongest reason to minimize the reject
rate. They often apply centralized, engineered water
treatment systems that can be optimized for low
water reject rate. Compared to systems that serve a
7. ASHRAE, BSR/ASHRAE//USGBC/IESNA Standard 189P
Page 4 of 12 Siemens Industry, Inc.
Document No. 1
49-822