WE Flashcards
WE acronym
Water Efficiency
WE overall purpose
Water efficiency credits deal with water holistically by looking at Metering Outdoor use Indoor use Specialized uses
The use of alternative add-on potable sources of water is recognized within the credits.
WE facts
Very little of Earths water is suitable an available for human use therefore creative reuse and conservation of water are important.
Most people without clean water live in sub-Saharan Africa
The United States uses approximately 20X the average amount of water per person globally
The United States has the 3rd highest amount of renewable water resource on earth
Approximately 8X the average amount of water use per person globally
The United States uses approximately 20X the average amount of water per person globally
Buildings use 13.6% of all
potable water in the United States
How is water in developed countries provided and what are the effects of the system
In developed countries, potable water only comes through a public water supply system from the remote site, and wastewater is piped to a remote processing plant and then discharged into a distant water body.
This standard pass-through system depletes aquifers reduces stream-flow in rivers, causing wells to go dry and water tables to drop.
WE: Cross-cutting issues
Alternative Water Sources: Projects using.. rainwater harvesting, greywater reuse municipally supplied wastewater, or Other reused sources
…are eligible too earn: WEC Outdoor water use reduction WEC Indoor water use reduction WEC Cooling Tower Water Reuse WEC Water Metering
Other reused sources
BUT… the same water cannot be applied to multiple credits unless there is sufficient water to cover the demand of all uses
Greywater Reuse
Lavatory/water closet combo
WE: evidence
Water efficiency categories includes three basic components:
Water metering Irrigation water Indoor water use Appliances Fixtures Processes
WE: cross-cutting documentation
Site Plans: document the location of water meters, sub-meters, and the location and size of of hardscape and vegetated areas
Floor Plans: document the location and quantity of fixtures, appliances and process water equipment such as cooling towers and evaporative coolers.
Fixture Cutsheets: manufacturers literature providing water consumption rates and other specifications required to prove water reduction.
Watersense
A product label program sponsored by the EPA (Environmental Protection Agency)
WaterSense labeled products are backed by independent, third–party certification and meet EPA’s specifications for water efficiency and performance.
On average
20% more efficient than required by IPC (international plumbing code)
Regulation
EPA Act of 2005 created 20% water use reduction in US federal facilities through 2% per year reductions from 2005-2016
Energy Policy Act of 1992 created mandatory requirements concerning the use of water conserving plumbing fixtures in industrial, commercial, and residential buildings.
Financial incentive
Reduced utility bills due to reduced consumption.
Typically Local and State level rebates and tax credits available for water saving devices.
WE: core concepts
WE Category applies an “efficiency first” model to reduce consumption.
2 Strategies…
- Reduce potable water demand
- Use water efficiently
Applied across 3 Water Use Categories…
- Indoor water use (toilets, lavs, showers etc)
- Outdoor water use (Irrigation, etc)
- Process Water (Cooling towers, industrial uses, etc.)
Reduce INDOOR potable water demand:
Reusing greywater
Capturing and using rainwater
Reduce water use via innovative wastewater treatment
Use waterless or high efficiency fixtures.
Reduce OUTDOOR potable water demand:
Use of native or adapted and drought tolerant plants.
Use of non-potable water for irrigation
Use of water efficient irrigation methods such as drip irrigation
Reduce potable water use for PROCESS water:
Efficiency via controls and sensors
Efficient management of cooling tower water
Use of non potable-water
WEP: Outdoor water use reduction
concepts
CONCEPTS:
Adaptive, Native and drought tolerant plants can:
Reduce or eliminate irrigation need
Create quality landscape design
Attract / support native wildlife
Integrate building site into surroundings
Reduce or eliminate need for pesticides & fertilizers that can degrade water quality when carried away by rainwater runoff.
LWR
Project teams can estimate the LWR (landscape water requirement) by developing a water budget.
This water budget can optimize water use and allow for the planting of irrigation system elements, plan to get city, plant types, and other design variables.
WEP: Indoor water use reduction
concepts
Efficient plumbing fixtures, fittings and equipment can easily reduce water consumption in new buildings.
Many fixture and appliances are readily available that reduce water use by 20—50% compared to code required levels without compromising effectiveness.
EPA WaterSense label was developed to identify products that are at least 20% more efficient than code minimum and without compromising effectiveness / quality.
Credit only addresses fixture efficiency because of “efficiency first” Model
Process and Outdoor water vary greatly from project to project so they are addressed separately.
WEP: indoor water use reduction
Requirements
Reduce aggregate water consumption by 20% from the baseline provided by LEED based on code minimums.
All newly installed toilets, urinals, lav faucets, and showerheads must be WaterSense labeled.
WEP: building level water metering
concepts
Many factors caused discrepancies between design and actual performance/operation of buildings.
In accurate assumptions about occupant behavior
Inadequate commissioning
Flaws in modeling / calculations
Lack of coordination in daily operation of building systems
Disconnect between construction and operations
LEED shares performance data it collects across low and high performing buildings to identify common features an improved building performance.
Meters must be installed to objectively track water use for verification and management
LEED shares performance data it collects across low and high performing buildings to identify common features an improved building performance.
WEC: outdoor water use reduction
Concepts
Using non-potable water sources and reusing potable water may further reduce potable water use.
2Pts: Show that the landscape does not require a permanent irrigation system beyond a maximum two-year establishment period. Or reduced LWR (landscape water requirement) potable water use by 100%
1Pt: Reduced LWR potable water demand by 50%
WEC: indoor water use reduction
concepts
Same as WEP indoor use reduction.
Accurate Occupancy Types and Loads for each specific project must be calculated accurately.
Core & Shell (CS) Projects must use provided Default Occupancy Factors.
Occupancy must often be converted to a total of FTE (Full Time Equivalent) occupants.
FTE = the number of hours of occupancy divided by 8
The number of transient visitors to a project can be calculated as the daily average over a 1 year period.
A 1:1 Male/Female ratio must always be used unless special permission is requested and granted by GBCI.
WEC: indoor water use
requirements
Reduce Potable water consumption relative to code minimum standards (tables provided by LEED)
WEC: cooling tower water use
concepts
Evaporative condensers (cooling towers) remove heat from the building by changing water into vapor as it absorbs heat.
As the water evaporates scale starts to deposit the condenser elements.
These systems use blowdown to remove a portion of the water to prevent the buildup of deposits
Makeup water is used to replace blowdown volume and evaporative losses causing a large portion of the buildings total water use in cooling towers.
Teams count the number of recirculation cycles the system can go through before blowdown in required to measure the water efficiency of the system.
Thousands of gallons of potable water can be saved by increasing the number of cycles during peak cooling periods.
Chemical analysis for optimization and special treatment of the water to remove dissolved solids can increase cycles.
Makeup water
the top layer to be removed from pond
WEC: water metering
concepts
Facility Managers can better track and optimize water consumption by metering subsystem water usage.
By sub-metering major systems, water consumption baselines can be established for each to:
Identify waste / savings opportunities
Track usage
Take and check corrective actions.
