2011 expo-smart grn-energy

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??

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.

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

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.

State of the art?

Where are we ? State of the art?

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.

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

Commercial vs Residential: Interior Core vs Perimeter

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.

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

DOAS Dedicated Outside Air System

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

Technologies to improve Energy Efficiency:

Efficient lighting

LED (bulb changing maintenance)

Day-lighting

Open ceiling

Light shelves

Exterior shading

Diffusers

Cloth Baffles

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

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

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

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

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)

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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!

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.

Poor view, dark ceiling, innefficient

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

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

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.

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.

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

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

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

Daylighting Physical Models

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