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HVAC Process OverviewTrack 1 - Introduction to RCx/Audits
2015 ASHRAE Illinois Spring Conference
by Josh GreenfieldVP, Energy Services Manager
PE, LEED AP BD+C, O&M, BEMP, REP, CEM
Primera Engineers, Ltd.
Why are you here?
Audit or Assessment?
For many reasons, assessment is preferable to audit…assessment carries none of the negative connotations of the word audit, which is commonly associated with an involuntary investigation of finances or taxes, where the perceived goal is to uncover mistakes and assess monetary penalty, and is often seen as a precursor to some kind of enforcement action or punishment.
Assessment also conveys more accurately the activity at hand – that is, assessing the current state of a building and making recommendations to improve its performance.
“The Auditors are here”
The Goal…
The Goal
•The goal for the energy professional is to understand how to maximize energy conservation and develop energy conservation opportunities without impacting any of the other basic goals the HVAC system is trying to achieve.
Traditional Goal = Identify equipment repair, upgrade, and replacement projects that will reduce the client’s expenses through avoided energy consumption.
World Class Goal = Identify, prioritize, and suggest alternative strategies for improving the client’s business performance through more effective energy choices.
O.M.G.
EEMECMECO
ECSM
EEOEMO
ECRMRCM
Efficiency vs. Conservation
Efficiency and conservation have slightly different meanings
• Efficiency refers to providing the same level of service with equipment that uses less energy.
Efficiency
• Conservation can apply to measures that offer a lower level of service or comfort.
Conservation
Energy Efficiency Measure (EEM) &
Energy Conservation Measure (ECM) Classifications
No-Cost/Low-Cost measures
Capital Investment measures
Demand Response measures
Demand Shifting/Load Shifting
measures
Self-Generation/Co-Generation
measures
O&M Savings measures
Is HVAC
Energy worth
saving?
YES!
HVAC Process
Pre-Site Analysis
Tools
Safety
Interviews
Walk-Through
Data Gathering
EEM/ECM Identification
Assessment Report
Action Plan
Implementation/Verification
Pre-Site Analysis
Review of drawings/specifications
Normalization of 24 contiguous months
of utility bills
Disaggregation of end-uses specific to
HVAC end uses
Peak vs. Non-Peak bill structures
Preliminary list of EEMs/ECMs related
to HVAC
Assessment Report Pre-Planning
Disaggregation
Data Loggers Power AnalyzerHygrometer/Temperature
Infrared Camera BAS Screenshots BAS Trending
Tools
Safety
Be Safe
•Electrical
•Respiratory
•Hearing
Interviews
• Owners and/or Financial
Decision Makers
– Financial Goals?
• SPP, ROI, IRR, NPV
– Should first costs include
energy rebate costs?
– Should first costs be
reduced to account for
any ‘due for replacement’
costs already
appropriated?
• Facility Managers
– What EEMs/ECMs would
they like to do?
– O&M issues?
– Comfort/IAQ issues?
– Broken equipment?
– Equipment in ‘HAND’?
– Planned upgrades?
– Equipment condition?
– Previous energy
assessments?
Financial Metrics
Simple Payback Period = SPP = (Initial cost) / (Annual savings). Goal: Set by Owner for ASHRAE Assessment, <18 Months for RCx
Return on Investment = ROI = (Annual savings) / (Initial cost). Goal: Positive
Internal Rate of Return = IRR = the effective interest rate returned on an energy investment. Goal: > Minimum Attractive Rate of Return (MARR)
Net Present Value = NPV = the difference between the present value of cash inflows and the present value of cash outflows. Goal: Positive
HVAC Systems
Variable Air Volume (VAV)
Underfloor Air Distribution (UFAD)
Primary/Secondary PumpingVariable Refrigerant Flow (VRF)
Radiant Heating
Radiant Cooling
Unit Ventilator
Induction Units
Parallel Fan Powered Boxes Series Fan Powered Boxes
Infrared HeatersDX Split System
PTAC
Window Shaker
4-Pipe Fan Coil Unit 2-Pipe Fan Coil Unit
Water-to-Water Heat Pump
Absorption Chiller
Condensing Boiler
Natural Draft BoilerCentrifugal Chiller
Scotch Marine BoilerGround Source Heat Pump
Variable Primary Pumping
Heat Recovery Chiller
Gas Fired Unit Heater Enthalpy Wheel
Run Around Coil
Vacuum Return System
Dual Duct System Dedicated Outdoor Air System (DOAS)
Warm Air Furnace
Packaged Rooftop Unit
Screw Chiller
Scroll ChillerFume Exhaust System
HVLS Fans
Reciprocating ChillerDuct FurnaceAxial Cooling Tower Refrigerant Condenser
Fluid Cooler
Mini Split Chilled Beam
Kitchen Hood
Reheat Coil Recirc Pump
Walk-Through
Data Gathering (i.e., data inventory)
– As part of the survey, try to document all the HVAC
systems and equipment in the facility, including
associated air flows, water flows, steam flows, and other
capacity and efficiency features of the equipment. Review
of design documents, one line diagrams, test and balance
reports, and control diagrams are excellent clues as to
how the system is intended to operate.
– Talk to contractors (BAS, Mechanical contractor, etc.)
– Equipment Nameplate information…
How to Read Equipment Nameplates
Motors
How to Read Equipment Nameplates
Boilers
How to Read Equipment Nameplates
AC Unit
EEM/ECM Identification
No-Cost/Low-Cost measures
RCx & ASHRAE L1/2/3
Capital Investment measures
ASHRAE L1/2/3
Demand Response measures
ASHRAE L1/2/3
Demand Shifting/Load Shifting
measures
RCx & ASHRAE L1/2/3
Self-Generation/Co-Generation
measures
ASHRAE L1/2/3
O&M Savings measures
RCx & ASHRAE L1/2/3
Retro-Commissioning vs. ASHRAE Energy Assessment
Work with “The Goal”…
The Goal
•The goal for the energy professional is to understand how to maximize energy conservation and develop energy conservation opportunities without impacting any of the other basic goals the HVAC system is trying to achieve.
• ASHRAE 62.1• Ventilation Requirements
• ASHRAE 55• Temperature, Relative Humidity
Codes/Standards/Rating Systems Timeline
State Energy Codes: Current
OR
CA
NV
ID
MT
WY
COUT
AZNM
KS
NE
SD
ND
WA
TX
OK
MO
IA
MN
WI
IL
KY
OHIN
WV
TN
AR
MS AL GA
SC
NC
VA
PA
NY
ME
FL
LA
MI
VTNH
MD
DE
NJ
CT
RI
MA
ASHRAE 90.1-2010/2012 IECC equivalent or more energy efficient
ASHRAE 90.1-2007/2009 IECC equivalent or more energy efficient
ASHRAE 90.1-2004/2006 IECC equivalent or more energy efficient
ASHRAE 90.1-2001/2003 IECC equivalent or less energy efficient
D.C.
HIAK
[As of February 2015]
Energy Incentives = Assessment Checklist
• RCx (total % savings, 2014)– #1: Schedule AHU for Space
– #2: Duct Static Pressure Reduce/Reset
– #3: Economizer and Outdoor Air Control
– #4: Supply air temperature reset
– #5: Optimum Start for AHU
– #6: Reduce simultaneous heating and cooling
– #7: Reduce SA and Ventilation Air
– #8: Condenser water temperature reset
– #9: Setback Space Temperature
– #10: Reduce Ventilation
– #11: Chilled Water Temperature Reset
– #12: Demand Control Ventilation
– #13: Optimize supply fan performance
– #14: Optimize chiller sequencing
– #15: Reduce VAV Minimum Position
– #16: Eliminate unnecessary fans
– #17: Install efficient filters
– #18: Balance airside
• Standard/Custom– Variable Speed Drives
– Chiller upgrades (w/ or w/o VSD)
– CHW Reset controls
– Packaged or Split AC upgrade
– Advanced Rooftop Unit control
– Guest Room Management system
– Demand Control Ventilation (conditioned space, parking garage, kitchen)
– Exhaust Fan occupancy sensors
– Wireless DDC thermostat
– Air-side economizer
– Electronically Commutated Motor (ECM) on Fan-Powered Box
– High Efficiency Pumps and Pumping Efficiency Improvements
– Cogged V-Belts for HVAC Fans
– Energy Recovery Units
– Steam Trap repair/replacement
– Boiler Replacement
– Boiler cut-out and reset control
– Condensing units heaters
– Programmable thermostats
– Insulation
– DCV Kitchen Hoods
The Cost of Energy Efficiency
Source: Molina (March 2014). The Best Value for America’s Energy Dollar: A National Review of the Cost of Utility Energy Efficiency Programs.
Average Cost of Energy Efficiency (2009-2012) =
$0.028 per kWh&
$0.350 per therm
Average Cost of Energy =
$0.08 per kWh&
$0.49 per therm(commodity prices)
EEM/ECM Identification
Thermal Generation
Systems
Thermal Distribution
Systems
Ventilation Systems
Energy Recovery Systems
Refrigeration Systems
Co-Generation Systems
Steam Systems
District Systems
Compressed Air Systems
Exhaust Air Systems
Laboratory/Kitchen Systems
Controls
Assessment Report - Useful Equations…
kW/ton = 12 / EER
EER = SEER X 0.9
COP = EER / 3.413
Affinity laws
kW/ton, COP, EER, SEER equations
3-Phase motors
Assessment Report - Useful Equations…
Sensible/latent/total cooling
Steam leaks (Grashof’s formula)
Assessment Report - Calculations…
Simplified and/or Steady State
Weather Data
Energy Modeling / Simulation
Simplified and/or Steady State
Weather Data
HDD/CDD and BIN Data
Energy Modeling/Simulation
Action Plan
–Goal of the Action Plan =
An active, ongoing relationship keeps the
client apprised of changes to the costs and
benefits of potential energy improvements as
market variables change. (i.e., not just
another report sitting on the shelf)
Implementation/Verification
– Implementation
• Technical resource assisting with bids, shop
drawings, controls programming
–Verification
• Supports the “active, ongoing relationship”
A Note on Water Conservation
• Condensate recovery, cooling tower optimization, steam efficiency, distribution leaks
HVAC Water Conservation:
• Purposely not covered in this HVAC presentation
Domestic Hot Water:
Impact on Building Certifications
Resources
–Handbook of Energy Audits, 8th Edition
(Thumann, Younger, Niehus)
–Procedures for Commercial Building Energy
Audits, 2nd Edition (ASHRAE)
–Energy management Handbook, 7th Edition
(Doty, Turner)
Questions?Josh Greenfield, Primera Engineersp: 312.242.6392e: [email protected]: http://www.primeraeng.com
