ASHRAE Standards & Guidelines for Building Energy Audits 6/5/2017 Konstantinos Laskos Civil Engineer, BEMP, BEAP Energy Planning & Savings Consultant Triantafyllos Triantafyllopoulos Mech. Engineer @ Menerga ASHRAE Hellenic Chapter President Elect 2016-2017
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ASHRAE Standards & Guidelines for Building Energy Audits 6/5/2017
ASHRAE and other entities have defined energy audits as processes in which engineering service providers identify and recommend efficiency opportunities to clients. The objectives of an energy audit are to identify and develop measures that: 1. will reduce the energy use and/or cost of operating a building 1. and/or will improve the indoor environmental quality experience by the
occupants.
Definition
What is Energy Audit ?
What is Energy Audit ?
In a Nutshell
1. How much energy are they using?
2. Where are they using it?
3. Are they using it effectively?
4. How can they use it more effectively?
What is Energy Audit ?
Basic Steps
1. Collect and analyze historical energy use.
2. Study the building and gather data on its operational characteristics and indoor environmental quality.
3. Identify potential measures that will reduce the energy use and/or cost and/or will improve the occupants’ indoor environmental quality.
4. Perform an engineering and economic analysis of potential modifications.
5. Prepare a list of appropriate measures and group measures into bundles that will capitalize on potential synergies and cost reductions.
6. Prepare a report to document the analysis process and results.
energyaudit
Energy Audit vs Energy Labeling
Basic Differences
predefinedopera/on realopera/on
energylabeling
vs
Energy Audit vs Energy Labeling
Basic Differences
energyusefor“condi/oned”spacesfor:
hea/ng
cooling
ven/la/on
DHW
ligh/ng
energylabeling energyaudit
vshea/ng
cooling
ven/la/on
DHW
interiorligh/ng
energyusefor:
exteriorligh/ng
plug-loads
motors
refrigera/on
etc
ASHRAE Standard 211P: Standard for Commercial Building Energy Audit
ASHRAE Standard 211P: Standard for Commercial Building Energy Audit
This standard applies to all buildings except: • single-family houses,
• multifamily structures of three stories or fewer above grade,
• manufactured houses (mobile homes), and
• manufactured houses (modular).
Scope
ASHRAE Standard 211P: Standard for Commercial Building Energy Audit
ASHRAE Standard 211P Preliminary Energy Use Analysis (PEA)
• Calculate the total annual building energy use, and divide by the gross floor area to obtain the Energy Use Intensity (EUI) i.e. kWh/m2.
• Calculate total annual building energy cost and divide by gross floor area to obtain the Energy Cost Index (ECI) i.e. €/m2.
• Benchmark the building’s normalized energy consumption relative to that of similar (peer) buildings for a minimum of 12 consecutive months (up to three consecutive years shall be used as available).
Benchmarking
ASHRAE Standard 211P Level 1 Energy Audit
Facility Site Survey
• Conduct a walk-through survey of the facility to accompanied by the building operator or maintenance staff member. Become familiar with its construction, equipment, operation, equipment schedules and maintenance.
• Identify major energy-using systems, processes, and equipment. Gather
control strategies and equipment information of major components from nameplates, as-built drawings, or other means.
• Interview the owner and/or operator and occupants to identify current space usage, special problems (especially relating to thermal comfort or indoor air quality).
ASHRAE Standard 211P Level 1 Energy Audit
Identify Low-Cost & No-Cost Energy Efficiency Measure Recommendations
• Changes to lighting and HVAC (e.g., thermostats) controls, to reduce lighting and HVAC in areas that are unoccupied or unused for substantial periods of time.
• Implementation of routines (and logs) to improve the efficiency of operations, or maintenance of such improvements after tune-ups.
• Education of building operators and/or occupants.
ASHRAE Standard 211P Level 1 Energy Audit
Identify Potential EEM Capital Recommendations
Identify potential capital-expensed EEMs including a preliminary qualitative estimate of the level of potential costs and energy cost savings.
Review EEMs with Owner’s Representative
Provide to the owner or their appropriate representative a list of identified measures, their brief descriptions, their qualitative impact, and approximate level of economic return. Receive feedback.
ASHRAE Standard 211P Level 2 Energy Audit
The Level 2 audit shall follow upon, and take into consideration the findings of, a Level 1 audit and also incudes the following additional steps*:
Breakdown of the annual total energy cost by component
*If no separate Level 1 audit has been conducted, shall comply with all the procedural requirements for a Level 1 audit.
1. A calculated method that estimates energy use according to the size, load, method of control and efficiency of equipment, and its operating hours 1.
2. A building energy model 2.
3. Sub-metered energy use in the building.
1 Assumptions used in this analysis must be the same as those used for calculations of energy and demand savings. 2 The same simulation must be used as is used for calculation of energy and demand savings.
ASHRAE Standard 211P Level 2 Energy Audit
List Energy Efficiency Measures and Group Interactive Measures*
• Opaque Elements Insulation, Roof Painting • Windows Replacement, Glazing Replacement
• Reduce Distribution Losses (Insulation, VSD, Economizers)
• Identify the measures that meet the owner’s economic or other criteria, whether individually, or in aggregate.
• Note the ancillary benefits of each measure or group.
ASHRAE Standard 211P Level 2 Energy Audit
Quality Assurance Review
• Evaluate the feasibility and appropriateness of identified measures, as well as the reasonableness of energy savings projections, implementation cost estimates, and all observations and findings of the energy audit report.
• Compare the energy savings, cost savings, costs, and ROIs for each measure to expected ranges for the type of measure specified to verify reasonableness.
• Validate savings by calculating the percent savings of each measure in relation to total energy use of the relevant end-use category.
ASHRAE Standard 211P Level 2 Energy Audit
Review EEMs with Owner’s Representative
• Provide to the owner or their appropriate representative a list of identified measures, their brief descriptions, energy, energy cost, and non-energy cost savings, available incentives, simple ROI, and simple paybacks.
• Obtain from the owner or owner’s representative their comments about which measures are preferred for implementation or further study.
• After the review with the owner or owner’s representative, the audit shall be revised to show the recommended measures, measure groups, and measures identified but not recommended.
ASHRAE Standard 211P Level 3 Energy Audit
Schematic diagram of each of the recommended EEMs
*If no separate Level 1 & 2 audit has been conducted, shall comply with all the procedural requirements for a Level 1 & 2 audit.
The Level 3 audit shall follow upon, and take into consideration the findings of, a Level 2 audit and also incudes the following additional steps*: Review the accepted EEMs considering system interactions to create bundle of measures
ASHRAE Standard 211P Level 3 Energy Audit
The simulation software shall meet the requirements of ASHRAE Standard 140. Indicative software:
Annual building energy modeling is required for envelope measure analysis
ASHRAE Standard 211P Level 3 Energy Audit
The model shall be calibrated with respect to the building’s actual energy use per the methodology in ASHRAE Guideline 14.
𝐶𝑉(𝑅𝑀𝑆𝐸)=100×√∑↑▒(𝑦𝑖− 𝑦𝑖 )2 /𝑛−1 /𝑦
𝑁𝑀𝐵𝐸=100×∑↑▒(𝑦𝑖− 𝑦𝑖 )/(𝑛−1)× 𝑦
CVRMSE = coefficient of variation of the root mean square error NMBE = normalized mean bias error
𝑦 = measured value 𝑦 = model predicted value 𝑦 = mean value of the measured data n = number of data points in sample
data CVRMSEmax NMBEmax
Monthly 15% 5%
Hourly 30% 10%
ASHRAE Standard 211P Level 3 Energy Audit
Lifecycle Cost Analysis (LCCA)
CashFlows
Out-lows
InitialInvestmentReplacement
CostsMaintenance
Costs
Taxes
EnergyAuditCosts
M&VCosts
In-lows
EnergyCostSavings
DemandCostSavings
WaterCosts
Procedures for Commercial Building Energy Audits 2nd Edition (2011) – Best Practices
Procedures for Commercial Building Energy Audits 2nd Edition (2011) – Best Practices
The energy assessment provider may be one person or a team with several members depending on the complexity of the site. The team usually includes the following:
• A building envelope expert or construction engineer • A mechanical engineer • An electrical systems expert • A control systems expert • An energy modeler
Performance Measurement Protocol for Commercial Buildings & Best Practices
ASHRAE Guideline 14 (2014): Measurement of Energy, Demand & Water Savings
The purpose of this document is to provide guidelines for reliably measuring the energy, demand, and water savings achieved in conservation projects.