Chapter 6 - Energy and Atmosphere Flashcards
Potential consequences of global climate change:
- rising sea levels leading to coastal floods
- severe droughts
- heat waves
- disease migration
Conventional fossil-based generation of electricity releases:
- Carbon dioxide
- Contributes to global climate change
Coal-fired electric utilities emit:
- Nitrogen oxide: key element in smog
- Sulfur dioxide: key element of acid rain
- Contributes to disruption of habitat and devastate landscapes
Natural gas is major source of:
Nitrogen oxides and greenhouse gas emissions
E&A credits focus on:
reducing energy use and demand and encouraging energy accountability and renewable energy
What is the Fundamental Commissioning and Verification intent?
To support the design, construction, and eventual operation of a project that meets the owner’s project requirements (OPR) for energy, water, indoor environmental quality, and durability
What is commissioning?
Is the process of verifying and documenting that a building and all of its systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the owner’s project requirements
What is an Owner’s project requirements (OPR)?
Is a written document that details the ideas, concepts, and criteria determined by owner to be important to the success of the project.
What does the OPR details?
It details the functional requirements of a project and the expectations of how it will be used and operated
What issues does the OPR addresses?
- Owner and User requirements: primary purpose, program, and use of the proposed project
- Goals: program needs, future expansion, flexibility, quality of materials, sustainability goals
Benefits of Commissioning:
- Reduced energy use
- Lower operating costs
- reduced contractor callbacks
- better building documentations
- improved occupant productivity
- verification of systems performance according to OPR
- improves energy efficiency by 5-10%
Cost of commissioning:
- may add 1% total project cost. Savings far outweigh this cost
- For existing buildings: $0.72/ft2, whole-building energy savings of 15% and payback time of 0.7 years
- For new constructions: $1.00 (0.6% of total construction costs), payback time of 4.8 years
Fundamental Commissioning and Verification prerequisites:
- Complete commissioning (Cx) process activities for MEP and renewable every systems and assemblies. According to ASHRAE Guideline
- Develop the OPR
- Develop a BOD
What is BOD?
Basis of Design is a written document that includes design information necessary to accomplish the OPR
What does the BOD include?
- Primary design assumptions: space use, climatic design conditions, space zoning, occupancy
- Standards: codes, guidelines, regulations
- Narrative descriptions: performance criteria of MEP and other systems that are to be commissioned
When should the BOD be completed?
By the Design team prior to the approval of contractor submittals of any commissioning equip. or system.
Commissioning plan is:
a document that outlines the organization, schedule, allocation of resources, and documentations requirements of the commissioning process. Plan to assign responsibilities and tasks
Commissioning authority (CxA) responsibilities:
- Review OPR, BOD, and project design
- Develop and implement a Cx plan
- Confirm incorporation of Cx requirements into the construction documents
- Develop construction checklist
- Develop system test procedure
- Verify system test execution
- Maintain issues and benefits log throughout the Cx process
- prepare final Cx process report
- Document all findings and recommendations and report directly to the owner
Current Facilities Requirements and Operations and Maintenance Plan must include:
- sequence of operation for the building
- building occupancy schedule
- equipment run-time schedule
- setpoints for all HVAC equip.
- set lighting level thruout the building
- minimum outside air requirement
- any change in schedules or setpoints for diff. seasons, days of the week, and times of day
- system narrative describing the mech. and elec. systems and equipment
- preventive maintenance plan
- commissioning program that includes periodic commissioning requirements, ongoing commissioning tasks, and continuous tasks for critical facilitites
CxA qualifications:
- Must have experience on 2+ building projects with similar scope.
- Must not be part of the project neither in the design or construction team
Enhanced commissioning (ECx) intent:
To further support the design, construction, and eventual operation of a project that meets the OPR for energy, water, indoor environmental quality, and durability
Additional CxA responsibilities in ECx:
- Gets involved early in the conceptual design and finishes late in the construction phase.
- review contractor submittals
- verify inclusion of systems manual requirements in CDs
- verify inclusion of operator and occupant training requirements in CDs
- verify systems manual updates and delivery
- verify operator and occupant training delivery and effectiveness
- verify seasonal testing
- review building operations 10 months after substantial completion. Warranty is still valid for many equip. and systems
- develop on-going commissioning plan
FCx vs ECx :
ECx covers all FCx plus:
- Review contractor submittals
- CxA participation in the design and construction phases
- CxA provides operational training
- Review building operations 10 months after completion
- Measurement and Verification of the commissioning plan
- Envelope Commissioning
Retro-commissioning is:
commissioning process that can be performed on existing buildings. Usually occurs at least one year after the building has been occupied
Building automation system (BAS):
- Collects data about a building’s systems and tract it over time
- Used to determine trends or anomalies
Minimum Energy Performance intent:
Reduce the environmental and economic harms of excessive energy use by achieving baseline building standards ASHRAE 90.1 2010
ASHRAE 90.1 2010
- provides minimum requirements for energy-efficient design of buildings
- LEED encourages design to have lower energy costs than standards
Minimum Energy Performance requirement:
- New buildings: 5% improvement over ASHRAE
- Renovation of existing buildings: 3% over ASHRAE
- Core and shell: 2% over ASHRAE
Most commonly energy code used in US:
International Energy Conservation Code
Min. Energy Performance comparison against baseline:
- LEED BD+C : ASHRAE 90.1
- LEED for homes: ENERGYSTAR for Homes
- LEED Homes and Multifamilies: HERS ( Home Energy Rating System)
We pay electricity based on:
Energy, btu and Power, KW
Energy Use Intensity (EUI):
- expresses a building’s energy use as a function of its size or other characteristics
- Energy/building area per year, Kbtu
- A low EUI = good energy performance
- LEED buildings’ EUI are 24% lower than typical buildings’.
EPA’s ENERGYSTAR Portfolio Manager:
- Used to compare buildings of a similar size and function or against itself over a period of years.
Process Energy:
generally comes from equipment that is plugged into a wall outlet
Examples of Process Energy:
Computers, office equipment, kitchen stoves, kitchen refrigerators, washer and dryers, elevators and escalators
Non-process Energy or regulated energy:
generally includes built-in building components
Examples of non-process energy:
Interior and exterior lighting, HVAC (heating, cooling, fans, pumps), hot water heating, toilet exhaust, parking garage ventilation
According to USGBC, on average, the max. and min. distribution of energy use by systems is:
- Max: Space heating: 36%
- Office Equipment: 1%
Six ways to save energy:
- turn it off
- turn it down
- increase efficiency
- reduce demand
- harvest energy/recover waste energy
- shift energy demand to off-peak periods
Turn it off strategy:
- Maximize day lighting
- Occupancy sensors
- Natural ventilation
Turn it down strategy:
- Reduce ambient lighting and complement with task lighting
- Use of dimmers
- Digital Control ( e.g chiller waste, fans, pumps, and condenser motors)
- Demand control ventilation
Increase efficiency strategy:
- Increase chiller efficiency (+tons/KW)
- Increase boiler effic. (+Mbtuh/KW)
- Increase effic. of domestic water heaters
- increase lighting efficiency (+lumes/kW) T5 fluorescent lighting
- Use more effic. design (displacement/under-floor ventilation)
What is Energy Efficiency?
The use of technology that required less energy to perform the same function as a conventional item
What is Lighting power density?
Is the installed lighting power per unit area - the amount of electrical power used to illuminate a space. (W)
Plug loads or receptacles are:
electrical current drawn by all equipment connected to the electrical system via a wall.
Are plug loads part of the building’s energy use calculations?
yes, for better efficiency try ENERGYSTAR fixtures
Cogeneration or Combined heat and power (CHP)
Is a electricity generation technology, which recovers waste heat from the electric generation process to produce simultaneously other forms of useful energy, such as heat or steam.
Benefits of Cogeneration:
- Converts more than 70% of fuel into usable energy
- reduces pollution and greenhouse gas emissions
District Energy System (DES):
Central energy conversion plant, transmission, and distribution system that provides thermal energy to a group of buildings. Does not include central electric energy systems
Reduce Demand strategy:
- passive design
- high performance glazing
- insulated exterior walls (high R factor)
- Increase thermostat setpoint as long as it does not exceed code requirement
Passive design:
use ambient energy sources instead of purchased energy like electricity or natural gas.
Examples of Passive design strategies:
- daylighting
- natural ventilation
- solar energy
Harvest energy/recover wast energy strategy:
- building integrated photovoltaics
- Wind energy
- solar thermal systems (for hot water)
- Geothermal heating and electric systems
How to increase building efficiency in building energy use?
by using LED lighting, ENERGYSTAR appliances and equipment, high efficiency HVAC systems and boilers.
Shift energy demand to off peak periods strategy
- use cooling thermal energy storage
- use absorption chillers
ASHRAE 90.1 standards and requirements are assigned based on:
the building’s climate zones
Energy Simulation:
Computer- generated representation of anticipated energy consumption of a building. 5 energy simulation runs are required:
- 1 Proposed Design simulation
- 4 Baseline Design
-
Proposed Design simulation:
models the building as designed . The total annual energy cost taken by this simulation is called “Proposed Building Performance”
Baseline Design simulation
usually 4 identical models that only orientation for each is modified. The average of total annual energy cost is taken as a Baseline Building
Performance
Whole-Building Energy simulation- credit + prerequisite:
- Comply with ASHRAE 90.1
- Perform energy model to show cost savings
Prescriptive Compliance: ASHRAE advanced Energy Design guide- credit + prerequisite:
- comply with ASHRAE 90.1
- follow ASHRAE 90.1 advanced energy design guide requirements
- eligible projects: K-12 schools, hospital over 100k sf, office buildinds < 100k sf, retail buildings between 20k and 100k sf
Prerequisite Compliance: Advance Buildings Core Performance Guide- Prerequisite only:
- comply with ASHRAE 90.1
- Design process strategies
- Core performance requirements
- implement enhanced performance strategies
- projects must be > 100k sf
- healthcare, warehouses, or laboratories are not eligible
Enhanced performance strategies:
- Supply air temperature reset (VAV)
- premium economizer performance
- Variable speed control
Optimize Energy Performance intent:
To reduce environmental and economic harms of excessive energy use
Optimize Energy Performance requirements:
- Whole-building energy simulation
- prescriptive compliance: ASHRAE advanced energy deisgn
- Prerequisite compliance: advanced building core performance guise
Optimize Energy performance Responsible parties
- energy analyst
- architect
- MEP engineer
Components of the building envelope that would be included in the energy model?
- roof
- spray foam insulation
- windows
What are some strategies to increase energy performance for EA credit 1?
- Reduce demand by optimizing the building orientation
- use ventilation cooling for space conditioning
Building-Level Energy Metering intent:
To support energy management and identify opportunities for additional energy savings by tracking building-level energy use
Building-Level Energy Metering- all rating system adaptations except core and shell:
- provide energy metering devices for all energy inputs
- commit to sharing whole-building energy usage data for 5 years or until a change in ownership or lesse
Building-Level Energy Metering - Core and Shell:
same as all rating system adaptations but pertaining only the base building
Advanced energy metering intent:
To support energy management and identify opportunities for addition energy savings
Advanced energy metering - all but core and shell requirements:
install advanced energy metering for all whole-building energy sources and any individual energy end use that is 10% or more of the total annual use
Advanced energy metering - core and shell:
- install advanced energy metering for all base building energy sources
- install meter for future tenant spaces
- minimum one meter per energy source per floor
Advanced energy metering must meet:
- meters are permanently installed, max. record level of 1h, and transmit data to a remote location
- electric meters must record consumption and demand
- data collection system must use a local area network, building automation system, wireless network, or comparable communication infrastructure
- system must be capable of storing all data for at least 36 months
- data must be remotely accessible
- all meters in system must be able to report hourly, daily, monthly, and annualy
Energy use data over time can assist in the identification of which following issues?
- solar panel failure
- boiler malfunction
Fundamental Refrigerant Management intent:
To reduce stratospheric ozone depletion
what are refrigerants?
working fluids of refrigeration cycles that absorb heat from reservoir at low temperatures and reject heat at higher temperatures
What are halons?
substances used in fire suppression systems and fire extinguishers in buildings. These substances deplete the stratospheric ozone layer.
Types of refrigerants:
- Chlorofluorocarbons (CFCs)
- Hydrochlorofluorocarbons (HCFCs)
- Hydrofluorocarbons (HFCs)
CFCs refrigerants:
have long atmospheric life that causes harm to the ozone layer. CFCs are man-made
HCFCs refrigerants:
cause significantly less depletion of the stratospheric ozone layer compared to CFCs
HFCs refrigerants:
do not deplete the ozone layer. However, some HFCs have high global warming potential, thus are not environmental benign
Fundamental Refrigerants Management prerequisites:
- do not use CFC-based refrigerants in new HVAC&R systems
- if existing systems contain CFC-based refrigerants, complete CFC phase-out conversion before project completion
Fundamental Refrigerants Management requirements:
- Base building HVAC&R equipment: any permanently installed equipment that contain more than 0.5 lb of refrigerant.
- Low values of ODP and GWP on refrigerants
Enhanced Refrigerant Management intent:
To reduce ozone depletion and support early compliance with the Montreal Protocol
Montreal Protocol:
- Banned CFCs
- Phase-out HCFCs after 2030
- 90% of HCFCs phase-out by 2015
Enhanced Refrigerant Management credit requirements:
- No refrigerants or low-impact refrigerants use
- Calculation of refrigerant impact: all HVAC&R equipment
Enhanced Refrigerant Management credit requirements (LEED retail only):
- Refrigerant must have 0 ODP
- HFC charge of 1.75 lb per 1000 Btu/h total evaporator cooling load
- show 15% or less annual refrigerant emission rante. Conduct leak testing using GreenChill’s guidelines
Enhanced Refrigerant Management strategies:
- refrigerants should have small ODP and GWP
Minimize refrigerant leakage - Select equipment with efficient refrigerant charge
- Select equipment with long service life
Demand Response Intent:
To increase participation in demand responses technologies that make energy generation and distribution systems more efficient, increase grid reliability, and reduce greenhouse gas emissions
What is demand response?
allows utilities to call on buildings to decrease their electricity use during peak times
Demand response requirements:
- demand response thru load shedding or shifting in buildings.
- electric utility program must participate
- if no electric program is available, infrastructure for future participation is required
Demand Response strategies:
- Demand Response Event: defined period of time when the utility calls for a reduction in peak demand by users
Demand Response benefits:
- Reduce energy costs
- reduce reliance on fossil fuels
Renewable Energy Production intent:
To reduce the environmental and economic harms associated with fossil fuel energy by increasing self-supply of renewable energy
Renewable Energy Production requirements:
Use on-site renewable energy to offset 1%. 5%, 10% of building energy cost using energy model or CBECS database
% renewable energy calculation
Equivalent cost of usable energy produced by the renewable energy/ total building annual energy cost
Eligible Renewable energy sources:
- Electrical systems: photovoltaics, wind, low-impact hydro, wave, tidal, and certain bio-fuel based electrical production such as, untreated wood waste, agricultural wood waste, animal waste, organic waste, landfill gas
- Geothermal systems: using deep-earth water or steam sources (not using vapor compression systems for heat transfer)
- Solar Thermal systems: Active solar thermal energy systems such as hot water tank
Not Eligible Renewable sources:
- Architectural features: passive solar and daylight strategies
- Geo-exchange systems: a.k.a geo-thermal or ground source heat pumps
- Green power: green power products
- Some bio-fuels: combustion of municipal solid waste, forest biomass waste, wood coated with plastic, laminate, or paint, wood with hazardous chemical preservatives
Renewable Energy Production strategies:
- Net metering
- Net-zero Energy
- water balance
- Carbon neutrality
Net-Zero Energy building:
it relies on renewable sources to produce as much energy as it uses, usually as measured over the course of a year. Starts with energy conscious design.
water balance is:
is the use of no more water than which falls on the site as precipitation
What is carbon neutrality?
Is emitting no more carbon emissions than the project can sequester or offset
Which could be sources of onsite renewable energy?
- bio-fuel made from agricultural waste
- wood chips left over from a mill
- low-impact hydroelectric
Green Power and Carbon offsets intent:
To encourage the reduction of greenhouse gas emissions thru the use of grid-source, renewable energy technologies, and carbon mitigation projects
Green Power and Carbon offsets requirements:
- Engage in a contract to purchase 50% or 100% of the project’s energy from one or more of the following for a minimum of 5 years:
- Green Power
- Carbon offsets
- Renewable Energy Certificates (RECs) for at least 5 years
- Determine the % of gree power or offsets based on the quantity of energy consumed, not the cost
- Green power and RECs must be Green-e Energy certified
- Carbon offsets must be Green-e Climate certified
Renewable Energy Certificates (REC):
- REC represents the environmental, social, and other attributes of power generated by renewable sources. May be sold separately from electricity
- REC represents the reduced emission of renewable energy compared to conventional fossil fuels. Sold separately. Anyone can purchase a REC
- RECs have no geographic constraints
- RECs are also called green-tags and compensate Green-e generators for the premium of production over the market rate
Carbon offsets:
- A unit of carbon dioxide equivalent that is reduced, avoided, or sequestered to compensate for emissions occurring elsewhere
- Can be purchased to help fund projects
- one way to achieve carbon neutrality is to purchase carbon offsets
Projects eligible to get funds by purchasing carbon offsets:
- reforestation
- wind farm
- truck stop electrification projects
- planting trees
- preserving forest
- changing land-use
- methane abatement
Which is true for projects using both electricity and natural gas energy inputs, related with green power and carbon offsets?
- Both gas and electric use must be considered when attempting green power
- the project must purchase green power, carbon offsets, or RECs to earn green power
What renewable energy systems are not eligible for EA credit 2 on-site RE?
- Passive solar architectural features
- Tradable renewable certificates
Demand Reduction strategies:
- Reduce the amount of energy needed for building operations
- Focus on design strategies such as positioning a building to optimize sunlight and including large, operable windows for light and ventilation
- Reduce the economic and environmental impacts of excessive energy use
Energy Efficiency strategies
- Focus on mechanical improvements such as installing energy-efficient appliances
- increase energy performance compared to a baseline building or energy code
Generate on-site energy:
refers to clean, carbon-free energy produced on the building site from sources such as solar panels, solar hot water, and wind.
