alternative water supply technologies
DESCRIPTION
5. Alternative Water Supply Technologies. The New Green Building Hydrologic Cycle. Re-think use of potable water! Water sources: Traditional Potable Water Harvested Water Treatable Wastewater. Pages 41-43. The New Green Building Hydrologic Cycle. New Ways of Supplying and Reusing Water: - PowerPoint PPT PresentationTRANSCRIPT
Alternative Water Supply Technologies
5
Re-think use of potable water!
Water sources:•Traditional Potable Water•Harvested Water•Treatable Wastewater
Pages 41-43
The New Green Building Hydrologic Cycle
New Ways of Supplying and Reusing Water:
•Harvested Water•Treatable Wastewater
Page 43
The New Green Building Hydrologic Cycle
Rainwater Harvesting Systems
Page 48
How Alternative Systems Work
Greywater Treatment and Reuse Systems
Pages 50-51
How Alternative Systems Work
Blackwater Treatment and Sewer Mining
Pages 52-54
How Alternative Systems Work
• Biological Materials: Pathogens
• 3 Main types of Biological Digestion
Aerobic Processes
Anoxic Processes
Anaerobic Processes
Pages 46-47
Wastewater Treatment: Basic Biology
• Ensuring reclaimed water is used safely and appropriately is extremely important
• Be aware of potential cross-connections in plumbing systems
• Install backflow prevention from nonpotable to potable systems
Pages 54-55
Precautions with Reused Water
TEST YOURSELF:1. What are the three sources of harvested water? Where
are they collected, and what can the water be used for?2. Describe greywater systems, and how the greywater is
purified and used.3. What is the primary public health issue related to
wastewater treatment?4. Describe the three main types of biological digestion, and
what type of wastewater treatment they are appropriate for.
5. What are the risks associated with reused water?6. What are the recommendations of the American Water
Works Association (AWWA) in terms of backflow prevention?
Energy Savings6
• Direct: Self-contained unit and energy is transmitted directly to heat the water
• Indirect: Uses heat from secondary source to heat water
Direct vs. Indirect Water Heating
Direct Energy Heating EquipmentPrimary source to heat water• Storage water heaters• Condensing water heaters• Instantaneous water heaters
Page 58
Potable Water Heating: Direct-energy
Indirect-energy Heating EquipmentRely on external sources• Coil-in-tank• Shell-and-tube system• Tube-in-tube system
Page 61
Potable Water Heating: Indirect-energy
Solar Energy
Page 61
Solar Thermal “Wet” SystemsEnergy from the sun used to
heat a domestic water supply• Flat plate collectors • Evacuate tube collectors
(direct-flow and heat-pipe)
Page 64
Potable Water Heating
• Direct Circulation Systems • Cannot tolerate freezing
temperatures• Drain-Back Systems
• Must be sloped to ensure water drains to reservoir
• Indirect Circulation Systems• Pumps circulate through
a non-freezing heat transfer liquid
Pages 66-67
Potable Water Heating
Ground-Source Energy• Draw heat from the
ground during winter• Deposit heat from indoor
air during the summer• Primarily for homes• “Desuperheater”
Page 67
Potable Water Heating
• Converts waste heat that accompanies electricity production into usable thermal energy
• Microturbines
Page 68
Cogeneration (CHP) Systems
• Drain-Water Heat Recovery
• Steam Condensate Heat Recovery
• Condenser Heat Recovery
Pages 70-72
Energy Recovery
• Preheaters• Condensing
Boilers/Water Heaters• Instantaneous Water
Heaters• Circulation Balancing• Pipe Insulation
Page 72
Special Issues in Retrofitting DHW Systems
TEST YOURSELF:1. Explain the differences between direct and indirect
heating2. What are the issues to be aware of with instantaneous
water heaters?3. What are the benefits and drawbacks of indirect-energy
water heaters? Condensing boilers?4. Describe and compare direct flow and heat-pipe
evacuated tube collectors.5. What is cogeneration? What are the benefits?6. What are the forms of energy recovery and how do they
work?
Managing Green Projects7
• Many work practices, product specifications, and technologies are unique to a successful green building project
• Be aware of what is involved to ensure conformance with the overall project requirements
• Know how the building codes address new technologies
Page 73
Contractor and Subcontractor Roles
Work practices must be followed to ensure sustainability goals and/or LEED certification
• Low-VOC materials• Air sealing• Moisture control
Page 74
Work Practices: Indoor Air Quality
Construction & Demolition Waste Management
Aim to recycle 50-95% of the total waste-stream
• Sorting recyclable materials on site• Co-mingled waste sorted off-site
Page 74
Work Practices: Construction & Demolition
• LEED projects require additional documentation submitted to the USGBC/GBCI
• Required LEED documentation primarily relates to IAQ and low-flow fixtures
Page 75
LEED Documentation
• All information for documentation is found on product MSDS sheets• Need to ensure LEED certification for the project• Make sure new materials procured meet specified standards• Need to be reviewed by the sustainability coordinator
Page 75
LEED Product Specifications
Work practices that may affect your schedule • Commissioning/building flush-out• Product documentation• Value engineering
Page 76
Cost and Scheduling Issues
Flush out
Coordination with commissioning agent (CxA)• Pre-functional and start-up testing of installed equipment
Building Flush-Out• Measuring air quality• Purge contaminants using a high exchange of inside air with fresh outside air• Done prior to or just at occupancy
Page 76
Commissioning
Value Engineering• Generally occurs in the design phase before the plumber has a bid on the job• May be required to provide costing for proposed or determined changes
High probability of green elements being eliminated if the budget gets tight• Newer technologies are more expensive to install • Owners and engineers may see them as expendable
Page 76
Value Engineering
Needed changes to existing building codes may not have been made yet
Often no regulations regarding the use of rainwater or reused wastewater to supply bathrooms
Understand how new technologies and installation practices are or are not addressed by your local jurisdiction
Page 77
Code Compliance
TEST YOURSELF:1. What are the indoor air quality work practices specific to
plumbers that need to be followed to ensure sustainability?
2. What work practices should the plumbing contractor be aware of in regards to commissioning?
3. Explain the two forms of construction and demolition waste management: sorting and co-mingling.