Casestudy of the HVAC systems for the LEED Platinum IGS Building A presentation by Joe Ventresca of Max Green Presented at the Columbus Green Building Forum's 2011 Green Building EXPO

1. HVAC Systems for Low Energy Buildings
50% More Efficient, LEED PLATINUM
. IGS Building Case Study:
HVAC Strategies (How)
HVAC Technologies (What)
Financial Metric for Cost-Effectiveness
Barriers
Questions ???
? What would you do differently
? Perspective of presenter (EE Evangelical)
More info: ASBO Publication & tour
Burning Questions??

2. IGS: ENERGY-OPTIMIZATION RESULTS
• IGS achieved about 50% more efficiency than the
baseline 90.1, 2004 energy code. Meet
‘Architecture 2030’ goal at time of design.
• Cost Effective: Achieved about 50% at about the
same or less cost for 30% efficiency. Energy
Investment Savings Pays for the Increase in
Mortgage Cost.
• This was done in spite of sub-optimal orientation
(N/S vs. E/W), that hurts passive design & day-
lighting effectiveness with harshest E &W glare.
• Synergistic energy savings and first cost
savings occurred from diligently pursuing
optimized energy efficiency.

3. Speaker’s perspective:
Energy Consultant to IGS
Master of Env. Science, (Miami U.)
Major: Energy (Individualized Curriculum):
Solar Architecture, Mech Eng, Economics
BS: Math & Chem. E (OU)
15 yrs: Innovative Energy Research &
Demonstration NLC/DOE Funded Grants
10 Yrs: Facilities Management, O&M (driver)
& New Construction –LEED AP
Above as City of Columbus Energy Coordinator

4. Speaker’s perspective: Experience
– 15 Yrs. NLC/DOE research & demonstration grants:
USDOE funded Columbus Energy Plan, 300 City
building’ audits, energy bond package, ‘portfolio
manager’ BTU/SF, Energy Use of Ventilation IAQ,
Green Lights project saved $500,000 & 10 tons CO2,
demonstrated VFD’s, DDC, O&M, etc.
- Energy Awards: Governor’s Energy Award, HUD
Award, OPFMA Award –Ohio Public Facilities award,
NLC-ETF Award –National League of Cities Energy
Task Force
- Published Results in Peer-Reviewed Energy
Science: ASHRAE (heating & cooling engineers)
Journal, AEE –Assoc of Energy Engineers, IAQ
Journal etc.

5. State of the art?

6. Where are we ? State of the art?

7. LEED is Great, but does not guarantee
optimal efficiency:
• LEED is not an energy optimization
procedure, it is a great
Green Building Rating System.
• LEED only requires 14% more
efficient than the energy code.
• Many LEED Certified & Silver are
about 25% more efficient,
many Gold about 30% more.

8. LEED is Great, but does not guarantee
optimal efficiency:
• IGS did Platinum Right: built on the
foundation of high (50%)energy efficiency
• INTENT of LEED is Integrated Design
• Low Energy Requires:
Energy-Efficiency-Optimized
Integrated Design
• Primary tool: Iterative Energy
Simulations

9. Commercial vs Residential:
Interior Core vs Perimeter

10. Commercial Building Energy Use
Why Can’t Just Pick a Super Efficient HVAC System
to get optimized efficiency:
heating + cooling = only 17%, so if cut it in half, still
not optimized efficiency for whole building.

11. VAV vs. DOAS with ER =cools & shuts off vs. re-heating.

12. DOAS Dedicated Outside Air System

13. Technologies to improve Energy Efficiency:
• Not an exhaustive list
• A Flurry of energy efficiency activity,
with all of these technologies improving
and competing at this time.
• Good design requires identifying the
strengths and weaknesses of each
technology
Those In Green on next slides=
what did in IGS’ design @2008-09.
Those In Red= what would do differently today=
Raise goal to 80%, achieve 60% cost effectively
= Arch 2030 Challenge, Ed Mazria, who wrote
Passive Solar Home Book, 1979 Rodale Press

14. Technologies to improve Energy Efficiency:
Efficient lighting
LED (bulb changing maintenance)
Day-lighting
Open ceiling
Light shelves
Exterior shading
Diffusers
Cloth Baffles

15. Technologies to improve Energy Efficiency:
Roof monitors
Diffusing panel
Day-lighting Computer simulation models:
Radiance, Daysim
Physical day-light models
Scotopic (OSU test, NASA Marshal Flight Center)
(sky blue+tint) vs Photopic
• Envelope: triple element glass
• DOAS
• ER-V=Energy Recovery Ventilation (humidity&drybulb)
• AF hi-eff fan
• IAQ-DCV
• “Sees cooking” kitchen hood exh fan control
• Solar Preheat of outside air/ventilation air
• Solar thermal

16. Technologies to improve Energy Efficiency:
• Geothermal
Well field
Water well
Storm water pond
Ice prevention (cascading) vs
snow melt
• Radiant Floor
• VRF-VRV: Variable Refrigerant Flow/
Variable Refrigerant Volume
• Ice storage: large commercial
• Ice storage: Small size, 5-15 ton

17. Technologies to improve Energy Efficiency:
• Micro-turbine (100 units coal at power plant,
only yeilds 25 to 30 units at building)
• Chilled Beams
• Hi Efficiency Fan Coils
• Underfloor systems
• Natural /hybrid ventilation.
• CFD modeling
• Green Roofs: storm water, insulation, CO2
• Wind-building integrated wind
• Solar electric-smart grid

18. Technologies to improve Energy Efficiency:
• + ‘regulars’:
• Plug loads:
-All computers in computer center, only LED
Monitors @Desks
-Refrigerators, coffee pots
-USB plug loads
- timers
• DDC controls
• Commissioning
• Chillers
• Boilers & at low temp coil =94% Efficiency.
• O&M
• IAQ
• Experience:
• Knowledgeable & know how to evaluate
vs Know It All

19. Technologies to improve Energy Efficiency:
• As the list above demonstrates, it is
not possible for the building
administrator to become an expert on
all of these issues.
• Instead, Requires an
Energy-Efficiency-Optimized
Integrated Design
• Primary tool: Iterative Energy
Simulations (need a simulation for LEED energy
points anyway, so just do more and earlier +do from 3D BIM)

20. Energy Efficiency
• “If one views efficiency as an energy
resource, then it cost 3 to 10 times
less than any other energy resource,
including renewable energy.”
(Charleston SC Green Plan)
• “When you look at the options ...the
cleanest, fastest, cheapest, safest,
surest energy supply option
continues to be …efficiency of
energy end use”. John Holdren, PhD
President's science adviser

21. Energy efficiency
• It is the greenest energy because it’s
greener to not use energy at all, than
to use energy.
• Optimizing energy efficiency first, is
critical for achieving cost
effectiveness for any renewable
energy application.

22. Right way to simulate:
• 1st Simulate building efficiency,
Building is more permanent.
• Evaluate all options, holding HVAC
constant at 90.1 code system.
• Select efficiency package by shorter
paybacks.
• Last, simulate HVAC options &
renewables.

23. Don't limit it to only short paybacks
• Even a 15 year payback is OK with
building life of 40 to 100 yrs.
• 1st year energy savings is the
investment cost divided by 15 yrs.
• Cash flow cost is a fixed annual
amount added to mortgage.
• Annual energy savings will increase
as energy costs rise.

24. Financial Metric: Years to positive cash flow:
• The Critical Financial metric is
‘years to positive cash flow‘.
• Even for a worse case 15 yr.
payback, the increase paid on the
mortgage over the 1st 3 years is
insignificant.
• This is true regardless of the
technology: because this analysis is
independent of the technology.

25. Financial Metric: Years to positive cash flow:
• Energy Efficiency Investments:
The savings pays the additional
mortgage cost.
• Shown on the next 2 slides for an
additional mortgage amount of
$630,000 for a geo-thermal well-field
added to the original $20,000,000
estimated building cost.

26. Case study: invest @ 15 yr payback:
$630,000 for a geo-thermal well field
added to a $20,000,000 building:
1st year energy savings is cost */* 15=
$630,000 */* 15yrs = $42,000/ 1st yr
Cost of $630,000 added to mortgage:
@ 30 yr mortgage =
$5.93/mo. per $1000 borrowed=
$5.93 x 630 thousands =$3,736/mo.=
$44,831/ yr
Barriers: Developer buildings pass cost to
tenant; barrowing capacity, setting priorities.

28. Example of Energy Optimization Process:
• Next 3 slides show an example of
how it works.
• 1st is ‘typical high-efficiency’,
achieves about 28% more efficient.
• 2nd is aggressive energy efficiency:
continuing to do all efficiency
options with longer paybacks, to
achieve about 45% efficiency.
• 3rd Last thing, after greatly reducing
its size and cost, is adding a high
efficiency HVAC system.

32. IGS Energy Optimization 1 of 5:
• Lighting reduced 50%, +day-lighting
reduced additional 25% =62.5% total
reduction. Commercial bldg. lighting is
biggest cooling load, so this greatly
reduced AC size, fan energy, & cost.
Cost= Lighting cost less than original
design lighting + Day-lighting system
reduced blinds SF & their cost; slight
add for day-light diffusing glass.
• Plug loads reduced by 50+% by moving
all computers to computer center
=greatly reduced AC size & its cost.

33. IGS Energy Optimization –Continued 2 of 5:
• Once all computers were moved to a
computer center, it had to be cooled
continuously; that cooling generated
heat, which was put into the heat-
pump loop to provide ‘free’ heat
recovery. Very quick payback.
• Ventilation/IAQ: Heat/cool/humidity
from exhaust recovered into outside
ventilation air (total energy recovery).
Cost: typical payback about 7 yrs +
greatly reduce heating & cooling loads
& their equipment size & cost.

34. IGS Energy Optimization –Continued 3 of 5:
• Resultant heating & cooling size was
reduced about 45%, greatly reducing
cost of geo-thermal heat pump
HVAC system.
• Site energy 1: Put heat exchange
coils in the pond to reduce size of
geo-well field and save on first cost.
• Site energy 2: Put fountain in pond
to do evaporative cooling and use it
as a water tower to reduce costs.

35. IGS Energy Optimization –Continued 4 of 5:
• Site energy 3: Hydro-geology
assessment favorable, so used
water-well with injection-well and
isolation coils to eliminate corrosion,
to improve geo-thermal efficiency
and totally eliminate ground-coupled
well field, and save that $630,000.
• Net Result: With synergistic effects
of optimized-energy-efficiency
design, achieved 45%+ efficiency
with less first cost than most
systems that save 30% or less!

36. IGS Energy Optimization –Continued 5 of 5:
• Only after energy efficiency is optimized
should more expensive renewables be
added; remember, the Greenest Energy
is Energy Efficiency because it is greener
to not use energy at all.
• Site energy 4: Roof top Photovoltaics
to achieve about 50% total energy
reduction vs. 2004 90.1 energy code.
• Tax deduction for high efficiency, about
1.75/sf. =$175,000 =about $60,000 actual
tax reduction more than pays for additional
design cost and energy consultant.

38. Poor view, dark ceiling, innefficient

40. If you can’t afford energy efficiency….
• Then surely can’t afford higher
energy bills.
• Can't afford to come back
later=cost 5 to 10 times more.
Barriers? Local examples.
talk the talk, vs walk, vs run
= commitment & vision.
Energy consultant responsible to
owner & free = more than paid for
by tax deduction

41. An effective strategy for maximizing
energy efficiency:
• Hire an independent energy
consultant as the owner’s
representative for overseeing and
achieving energy efficiency
• extensive experience with energy
simulation
• previously achieved 40 to 50%
energy efficiency, cost-effectively

42. Energy consultant responsibilities
• Simulating, evaluating, & tracking
progress to achieve energy goal
• Regularly updates owner on status
throughout the project
• Critical since an aggressive goal
often inadvertently neglected or
water down, as result of the
multitude of issues in designing a
building, especially a green building.

43. Important advantage of using an
independent energy consultant:
• Can use trusted A&E even if have not
yet achieved a high efficiency design.
• An energy consultant specializing in
energy simulation and cost benefit
analysis can be an asset to the A&E firm.
• Can also be less expensive because that
is all they do; unlike the A&E who must
design and specify every aspect of the
building.

44. Procedure Summary
1. Define green energy as maximum
energy efficiency at lowest cost.
2. Set an aggressive goal:
50% energy reduction over the
energy code for each and every
area of building energy use.
3. From the beginning of conceptual
design, use energy simulations to
assess all energy efficiency
options with paybacks of 15 years
or less

45. Procedure, cont:
4. Simulate & assess building
efficiency prior to any
improvements to the heating and
cooling plants or the addition of
any renewable energy.
5. Select best payback options, then
simulate Higher Efficiency HVAC
&or renewable energy
6. Hire experienced independent
energy consultant as the owner’s
representative for overseeing and
achieving energy efficiency

46. Joseph Ventresca, MS Energy, LEED AP
MaxGreen Energy
614-309-7797
ASBO Paper:
email title=‘IGS Paper’
Tour: 1 to 4 Sunday, Oct 2, 2011
6100 Emerald Parkway, Dublin, OH. 43016

47. Daylighting Physical Models

50. Joseph Ventresca, MS Energy, LEED AP
MaxGreen Energy
614-309-7797
ASBO Paper:
email title=‘IGS Paper’
Tour: 1 to 4 Sunday, Oct 2, 2011
6100 Emerald Parkway, Dublin, OH. 43016