Commercial HVAC Strategies
Brian A’Hearn, Project Implementation Manager
Commercial HVAC strategies
• Audience demographics:
– Owners
– Architects
– Engineers
– Contractors
– Energy Services Providers
5/6/2014
Brian A’Hearn, Michaels Energy
2
Commercial HVAC strategies
• What role do HVAC systems play in the
energy efficiency landscape?
• Why is strategy about HVAC important?
• Consider…..
5/6/2014
Brian A’Hearn., Michaels Energy
3
Commercial HVAC strategies
Focusing on Commercial and Industrial sectors
Industrial – 31%
Commercial – 18%
Residential – 23%
Transportation – 28%
Commercial and Industrial end users makeup a
substantial part of the “energy use” pie in the US.
5/6/2014
Brian A’Hearn., Michaels Energy
4
Commercial HVAC strategies
Building energy end-use breakdown
Heating – 19.8%
Ventilating – 12.7%
Air-Conditioning – 17.7%
HVAC total – 50.2%
Lighting – 7.8%
HVAC can be over 1/2 of the energy use in a building!
5/6/2014
Brian A’Hearn., Michaels Energy
5
Commercial HVAC strategies
The Industry has responded to these facts:
Building code officials implementing code changes:
Uniform Building Code family
International Building Code family
state and local Energy Codes
ASHRAE 90.1, 62.1 Standards (Energy and IAQ)
Utility companies are employing demand side management
techniques to drive change:
Audits, studies, rebates and various incentives for energy
efficient design and renovation.
Professional community has responded with:
Leadership in Energy and Environmental Design (LEED)
Sustainability in design and construction
Commissioning as a requirement in the process
5/6/2014
Brian A’Hearn, Michaels Energy
6
Commercial HVAC strategies
Manufacturers, Suppliers, Engineers and Contractors
are bringing:
– New systems
– New controls
– Modifications and upgrades for older systems
Owners
– Establishing “Best Practices” for the efficient,
effective management of the facility
5/6/2014
Brian A’Hearn., Michaels Energy
7
Commercial HVAC strategies
• What are the “BEST PRACTICES” ?
A best practice is a method or technique that has consistently shown
results superior to those achieved with other means, and that is used as a
benchmark. In addition, a best practice can evolve to become better as
improvements are discovered.
• “BEST
•
•
•
•
•
5/6/2014
PRACTICE” requires:
Measurement
Comparison to established benchmarks
Identifying opportunities and establishing goals
Acting upon those opportunities and goals
RE-measuring and RE-evaluation for continual,
sustained improvement
Brian A’Hearn., Michaels Energy
8
Commercial HVAC strategies
• Measurement:
• Existing Buildings:
• Measurement of systems and subsystems with
metering equipment
• New Buildings:
• Utilize modeling and predictive calculation methods
• Comparison to established benchmarks:
• ENERGY STAR® (EPA, DOE)
– Commercial Building Energy Consumption
Survey (CBECS)
– Internal benchmarks and energy efficiency goals
– Establishing a design baseline
5/6/2014
Brian A’Hearn., Michaels Energy
9
Commercial HVAC strategies
• Identify opportunities and establishing
goals
• System capabilities – equipment and controls
• Operating profiles and usage patterns
• Expected useful life and replacement
considerations
• Acting on those opportunities and goals
• First – Do no harm!!!!
• Making the “Business Case” for change
5/6/2014
Brian A’Hearn., Michaels Energy
10
Commercial HVAC strategies
• RE-Measuring and RE-Evaluation for
continual, sustained improvement:
•
•
•
•
Utility usage tracking
Use of Temperature Control Systems
Use of DASHBOARDS
Important features:
•
•
•
•
5/6/2014
Timely feedback
Weather normalization
Process normalization
Normalization for other changes
Brian A’Hearn., Michaels Energy
11
Commercial HVAC strategies
• Energy DASHBOARDS
5/6/2014
Brian A’Hearn., Michaels Energy
12
Commercial HVAC strategies
• Establishing and following “Best Practices” allows you
to know:
–
–
–
–
–
–
–
–
5/6/2014
How are we performing relative to others in our industry?
When will planned replacement of equipment be
necessary?
Are my utility costs too high?
How do my maintenance costs compare with others?
Are we experiencing too many unpredicted failures?
Are our employees comfortable in their environment?
Is it time to expand?
Is it time to move?
Brian A’Hearn., Michaels Energy
13
Commercial HVAC strategies
• Alliant Energy Energy-Efficiency Programs
– Commercial and Industrial Energy Audit (directive –
high level)
– Feasibility Study (investment grade)
– Retro-Commissioning Study (investment grade)
– Commercial New Construction Programs
– Industrial New Construction Programs
– Custom Rebates
– Prescriptive Rebates
– Consult with your Key Account Manager or the
Business Resource Center to see which program is
a best fit.
5/6/2014
Brian A’Hearn., Michaels Energy
14
Commercial HVAC strategies
• Commercial and industrial energy audits
– Site walk through by a qualified engineer
– Building and systems description
– Facility benchmarking
– Annual energy use profile
– End use profile
– High level analysis of energy management
improvements (EMIs)
– Directive in nature
5/6/2014
Brian A’Hearn., Michaels Energy
15
Commercial HVAC strategies
• Feasibility study
– Focuses on capital improvements
– Investment grade analysis of alternatives
•
•
•
•
Intense engineering analysis
Comprehensive cost analysis
Detailed financial analysis
Presents a business case for choosing
– Look at the “system” not the “widget”
– Usually associated with one technology
5/6/2014
Brian A’Hearn., Michaels Energy
16
Commercial HVAV strategies
• Retro-commissioning study
– Focuses on low-cost no-cost energy
management improvements (EMIs)
– Investment grade analysis
•
•
•
•
Intense engineering analysis
Comprehensive cost analysis
Detailed financial analysis
Presents a 2 year payback package of measures
to implement – THAT’s a 50% ROI by the way!
• Presents a list of capital improvement measure too
5/6/2014
Brian A’Hearn., Michaels Energy
17
Commercial HVAC strategies
• Commercial and Industrial New
Construction Programs
– Adds value to the design process and
augments decision making
– Interaction at the schematic design phase
– Provides choices to consider
– Provides larger incentives for making energy
efficient choices
– Basis – ASHRAE 50% design guide
5/6/2014
Brian A’Hearn., Michaels Energy
18
Commercial HVAC strategies
• Custom and Prescriptive Rebates
– Cornerstones of Alliant Energy energy
efficiency programs
– Incentives for everything and anything that will
perform better from an energy use standpoint
than a code compliant solution of equal scope
and magnitude
– Based on paybacks greater than 2 years
(after incentive)
5/6/2014
Brian A’Hearn., Michaels Energy
19
Commercial HVAC strategies
What are the HVAC strategies that we see
being implemented given Alliant Energy’s
program opportunities and state of the
industry?
5/6/2014
Brian A’Hearn., Michaels Energy
20
Commercial HVAC strategies
Eight common yet effective energy savings opportunities in
buildings (HVAC specific):
•
•
•
•
•
•
•
•
Eliminate simultaneous heating and cooling
Employ fan speed controls
HVAC – supply temperature reset
Reduce over ventilation
Night set back and scheduling
Demand control ventilation
Pump variable flow controls
Upgrade controls to direct digital controls
Study produced for the Energy Solutions Center in Washington DC, September of 2011
(22 building data base of recent Retro-Commissioning studies by Michaels Energy)
5/6/2014
Brian A’Hearn., Michaels Energy
21
Commercial HVAC strategies
• Simultaneous heating and cooling occurs
in many systems. Where it can’t be
eliminated it usually can be minimized.
Examples include:
• Variable air volume systems with terminal
heating coils
• Multi-zone systems and dual duct systems
• Any system employing economizers
• Constant volume terminal reheat system
5/6/2014
Brian A’Hearn., Michaels Energy
22
Commercial HVAC strategies
• Fan speed controls
• Slow starts and stops improve belt/drive life
• Multiple fan speeds can be used in multiple
situations
• Occupied versus unoccupied
• Special events
5/6/2014
Brian A’Hearn., Michaels Energy
23
Commercial HVAC strategies
• Temperature resets – applies to heating hot
water, chilled water and air-side systems
• Hot water reset is absolutely critical for optimizing
efficiency of condensing boilers
• Chilled water reset is less critical but can still
save significant energy
• Air-side reset is another point to be optimized
which can minimize or prevent simultaneous
heating and cooling (humidity control must be
considered)
5/6/2014
Brian A’Hearn., Michaels Energy
24
Commercial HVAC strategies
• Reduce over-ventilation
• Reduce the volume of ventilation air provided
• Review variable air volume box minimum air flow
settings and consider enhancing control schemes
to reduce ventilation
• Convert existing constant volume systems, multizone and dual duct systems to variable air
volume
• Review and fine tune building pressure controls
• Decouple ventilation systems by using Dedicated
Outdoor Air Systems (DOAS)
5/6/2014
Brian A’Hearn., Michaels Energy
25
Commercial HVAC strategies
• Night setback and scheduling
• Turn things off when they are not being used
• Change room set points when spaces are
unoccupied
• Close outdoor air dampers when the building is
unoccupied
• Disable chillers and cooling equipment during
unoccupied hours if possible
• Reduce air conditioning loads whenever possible
by scheduling off lights, plug loads or any other
equipment contributing to the load
5/6/2014
Brian A’Hearn., Michaels Energy
26
Commercial HVAC strategies
• Demand control ventilation
• ASHRAE 62.1 - Use controls to minimize
ventilation air provided
• Measure CO2
• Use of occupancy sensors
5/6/2014
Brian A’Hearn., Michaels Energy
27
Commercial HVAC strategies
• Pump speed control
• Variable flow in chilled water systems
• Variable flow in hot water heating systems
5/6/2014
Brian A’Hearn., Michaels Energy
28
Commercial HVAC strategies
• Direct Digital Controls (DDC)
• Take advantage of robust temperature control
systems already in place. Dramatic
improvements from low cost changes may exist.
• A retro-commissioning study is a direct fit with this
opportunity
• DDC systems are also subject to problems that
cost energy, such as:
• Rogue zones
• Unfortunate zone sensor location
• Humidity sensitive areas combined with non-sensitive
areas
5/6/2014
Brian A’Hearn., Michaels Energy
29
Commercial HVAC strategies
• DDC system problems (continued)
• Non-similar thermal zones combined on the same
temperature control zone
• Inoperable economizers
• Failed building pressure control
5/6/2014
Brian A’Hearn., Michaels Energy
30
Commercial HVAC strategies
• Operation and maintenance:
• Tighten belts or maybe switch to synchronous
belts
• Refrigerant charge
• Clean outdoor coils (condensers)
• Keep filters clean
5/6/2014
Brian A’Hearn., Michaels Energy
31
Commercial HVAC strategies
• V-Belt drive versus synchronous belt drive
performance
5/6/2014
Brian A’Hearn., Michaels Energy
32
Commercial HVAC strategies
• V-Belt Drive versus Synchronous DriveContinued:
– Example:
– Energy costs: $ .10/kwh
– 40 HP motor running at 89% efficiency
– 8,736 operating hours per year
Annual Energy Cost:
$ 29,250.88
Annual Energy Savings: $ 1,462.54
Synchronous Belt Drive: $
342.83
SPP = .23 years
5/6/2014
Brian A’Hearn., Michaels Energy
33
Commercial HVAC strategies
• Effect of Refrigerant Charge
5/6/2014
Brian A’Hearn., Michaels Energy
34
Commercial HVAC strategies
• Effect of a dirty condenser coil
–
–
–
–
Example:
10 ton Air Conditioning System
Operating 1500 hours/year
Typical SEER/EER Rating
• 37% increase in operating costs
• 30% loss of cooling capacity
• Shortened Useful Life
5/6/2014
Brian A’Hearn., Michaels Energy
35
Commercial HVAC strategies
• Conclusion:
– Information is your friend
• Alliant helps with that!
– Be strategic
• Do benchmarking!
• Create a “Best Practices” document for your
enterprise
– Take action and reap the results!
5/6/2014
Brian A’Hearn., Michaels Energy
36
Commercial HVAC strategies
• Alliant Energy Energy-Efficiency Programs
– Commercial and Industrial Energy Audit (directive –
high level)
– Feasibility Study (investment grade)
– Retro-Commissioning Study (investment grade)
– Commercial New Construction Programs
– Industrial New Construction Programs
– Custom Rebates
– Prescriptive Rebates
– Consult with your Key Account Manager or the
Business Resource Center to see which program is
a best fit.
5/6/2014
Brian A’Hearn., Michaels Energy
37
Commercial HVAC strategies
Questions?
5/6/2014
Brian A’Hearn., Michaels Energy
38