other names for ground loop - rockymtnashrae.com...heat recovery to oa ahu: 125 f hot water water...
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Commercial Ground LoopWater Source Heat Pump Systems
Presented byAlan NilesCommercial Regional Sales ManagerWaterFurnace International
Other Names for Ground Loop Systems
GeothermalGround SourceGround CoupledGeoExchange
Why a Ground Loop Heat Pump System
Tax Incentives
Lower Operating Costs
Lower Life Cycle Costs
Lower Maintenance Costs
Why a Ground Loop Heat Pump System
Tax Incentives
Lower Operating CostsNeed Building Loads and Ground Loop Design Software for Monthly Average Water Temperatures
Lower Life Cycle CostsNeed Ground Loop Installed Cost
Lower Maintenance Costs
Tax Credits: with no limit – until 1/1/2017
Energy Property Tax Credit: 10% of total system cost with no limit10% grant available in lieu of tax creditCombine with solar and wind tax credits
2010 IRS Form 3468 Investment Credit
Part III, LINE 12 r Energy credit: Geothermal heat pump systems
Basis of property placed in service during the tax year that was acquired after October 3, 2008, and the basis attributable to construction, reconstruction, or erection by the taxpayer after October 3, 2008 ..............$____________ × 10% (.10)
Federal Tax Incentives for Commercial GLHP Systems
Tax Deductions:
Energy Efficient Commercial Building Property Tax Deduction: ($1.80 per Sq Ft)Combine with other Qualified Section 179 Real Property Deductions
A software model of 3 installed components:1) the building envelop2) the indoor lighting3) the HVAC and hot water system
compared to the minimum ASHRAE 90.1‐2001 design. Combined, the 3 components must reduce energy by 50%. Or as individual parts, each component must reduce energy by 16.667%.
Tax Deduction:If all 3 components meetor exceed 50% Energy savings $1.80 per square foot of entire structure
If only the HVAC and Hot Water Systemmeets or exceed 16.667% Energy savings $ 0.60 per square foot of entire structure
Federal Tax Incentives for Commercial GLHP Systems
Tax Deductions:
Energy Efficient Commercial Building Property Tax Deduction:
Energy savings must be calculated using a qualified computer software approved by the IRS.
Some approved software: DOE 2.2, E‐Quest, Energy Plus, Energy Pro, HAP, TRACE 700
Filing:This answer is copied from website: http://www.efficientbuildings.org/about_the_provision.html#01
There is no special form to claim the deduction. The IRS instructions to business forms (e.g., Form 1120 for corporations, Form 1120‐S for S corporations, and Form 1065 for partnerships) indicate that the taxpayer should include the amount of the deduction in the amount in the "Other deductions" line of the tax return. … it is important that a taxpayer obtain and retain the necessary certifications and documentation to claim the deduction (see, IRS Notice 2006‐52 for these requirements).
Federal Tax Incentives for Commercial GLHP Systems
Tax Deductions:
Accelerated Depreciation:
1/1/2012 until 12/31/2012:50% first year bonus depreciation with the balance on a 5 year MACRS depreciation
2010 IRS Form 4562 Instructions
Part II Special Depreciation Allowance and Other DepreciationLine 14For qualified property placed in service during the tax year, you may be able to take an additional 50% special depreciation allowance.
Federal Tax Incentives for Commercial GLHP Systems
Example:
Federal Tax Incentives for Commercial GLHP Systems
New Construction: $2,000,000 to install geothermal heat pump system. Building occupied August 2012 (3rd quarter).
40% tax bracket when state income tax is included.
2012 Tax Credit: $2,000,000 x 10% Credit = $ 200,000Depreciable Basis: $2,000,000 ‐ ($200,000/2) = $1,900,0002012 Bonus Tax Benefit: $1,900,000 x 50% bonus x 40% tax rate = $ 380,0002012 MACRS Tax Benefit: $190,000 x 40% tax rate = $ 76,000Total Tax Benefit for 2012: = $ 656,000
2013 MACRS Tax Benefit: $304,000 x 40% tax rate = $ 121,6002014 MACRS Tax Benefit: $182,400 x 40% tax rate = $ 72,9602015 MACRS Tax Benefit: $109,440 x 40% tax rate = $ 43,7762016 MACRS Tax Benefit: $109,440 x 40% tax rate = $ 43,7762017 MACRS Tax Benefit: $54,720 x 40% tax rate = $ 21,888
Total Tax Savings: $960,000Plus Tax Deductions from theEnergy Efficient Commercial Building Property Tax Deduction
Eligibility:Building located in U.S.Original use begins with taxpayerBuilding design must fall under the guidelines of ASHRAE 90.1 Energy Standard for Buildings Except Low‐Rise Residential Buildings
Federal Tax Incentives for Commercial GLHP Systems
Why a Ground Loop Heat Pump System
Lower Operating Costs
Use the ground’s constant temperature as the sourceof heat in winter and as a high efficiency heat sink in summer
85 FSupplyWater
95 FReturn Water
10F Across the Cooling Tower
GLHP Operating Costs Basics
95 F
90 FReturn Water
79 F
85 FSupplyWater
95 F
87 F
Only 5F Across the Cooling Tower
One unit in each zone with individual local temperature control
GLHP Operating Costs Basics
95 F
86.8 FReturn Water
79 F
85 FSupplyWater
95 F
84 F
Only 1.8F Across the Cooling Tower
Heat Recovery To OA AHUSnow MeltDomestic Hot Water Pre‐Heat130 F or 160 F Hot Water
Water‐to‐Water Unit
GLHP Operating Costs Basics
95 F
86.8 FReturn Water
79 F
85 FSupplyWater
95 F
84 F
Water‐to‐Water Unit
Boiler/Cooling Tower 20% to 25% of Total HVAC Operating Cost
GLHP Operating Costs Basics
95 F
86.8 FReturn Water
79 F
85 FSupplyWater
95 F
84 F
Heat Recovery To OA AHU:125 F Hot Water
Water‐to‐Water Unit
Supply Water approaches Ground Temperature
Only 1.8F to the Ground Loop
Operating Cost Basics
GLHP Operating Costs Basics
Typical Water Source Heat Pump Cooling Performance
Typical Water Source Heat Pump Cooling Performance
33% Increase
GLHP Operating Costs Basics
GLHP Basics
Typical Water Source Heat Pump Cooling Performance
33% IncreaseIMPORTANTGround Loops approach ground temperature when the Building is not at Peak Loads
80% ‐ 90% of the time, building loads are at 50% or less of the Peak Load
Installation Costs
GLHP Design Basics
NEED TO KNOW:
From the Ground: Thermal Conductivity and Average Ground Temperature
From the Building: Monthly/Daily Loads
From the Equipment: GLHP Efficiency of Each Specific Heat Pump
GLHP Design Basics
The Ground
GLHP Design Basics
20 10 Tm 10 20
4
8
12
16
20
24
28
Dep
th in
Fee
t
WET SOIL(0.96 sq. ft./day) or
(0.40 sq. ft./hr)
AVERAGE SOIL(0.6 sq. ft./day) or(0.025 sq. ft./hr)
LIGHT DRY SOIL(0.26 sq. ft./day) or
(0.011 sq. ft./hr)
GLHP Design Basics
Thermal ThermalConductivity Diffusivity
Material (Btu/hr-ft-F) (ft2/day)
Dense Rock 2.00 1.2Average Rock 1.40 0.96Heavy Soil, saturated 1.40 0.84Heavy Soil, damp 0.75 0.60Heavy Soil, dry 0.50 0.48Light Soil, damp 0.50 0.48Light Soil, dry 0.20 0.26
GLHP Design Basics
Thermal Conductivity Test
Required Test Duration – A minimum test duration of 36 hours is recommended, with a preference toward 48 hours.
TC Test: $8,000 to $12,000
GLHP Design Basics
Thermal Conductivity Test
Thermal Conductivity Test
Thermal Conductivity Test
Thermal Conductivity Test
Thermal Conductivity Test
Drillers Need to Know to bid competitively
Thermal Conductivity Test
Thermal Conductivity Test
Thermal Conductivity (k) =
3.412 (BTU/Whr) * W(watts)4 x L(ft of loop) x Slope(F)
Thermal Conductivity Test
Ground Loop Site Layouts
Reverse Return Piping for Ground Loop
Each Bore hole has identical pressure dropSo no balancing valves required under ground
GLHP Design
Ground Loop Site Layout
Valve Vault
400 Foot Bore Hole Layout
Ground Loop Site Layout
400 Foot Bore Hole Layout
Ground Loop Site Layout
400 Foot Bore Hole Layout
Ground Loop Site Layout
Mechanical Room
Ground Loop Site Layout
Ground Loop Site Layout
Drilling Holes
&
Installing Pipe
Typical vertical bore detail
Vertical Loop Cross Section
Typical vertical bore detail
Vertical Loop Pipe with U‐Bend
Typical vertical bore detail
Vertical Loop Pipe with U‐Bend
PE 3408 HDPE (High Density Polyethylene Pipe)
1” IPS SDR‐111.25” IPS SDR‐112” IPS SDR‐113” IPS SDR‐15.54” IPS SDR‐15.56” IPS SDR‐15.5 8” IPS SDR‐15.5
Standard Dimension Ratio (SDR) is the Side Wall Thickness to the Pipe Diameter Ratio
GLHP Design
Typical vertical bore detail
PE Pipe Cell Classification PE 355434C
PE: Polyethylene3: Density (0.941 ‐ 0.955 g/cm3)5: Melt Index (ASTM D‐1693, 10.1.4)
Molecular Weight5: Flexural Modulus4: Tensile Strength at Yield3: Environmental Stress Crack Resistance4: Hydrostatic Design Basis at 23CC: Color and UV Stabilizer
GLHP Design
Selecting Pipe Size for the Bore Hole
GLHP Design
Selecting Pipe Size for the Bore Hole
GLHP Design Design Goal: 15 Ft H2O pressure dropfor entire ground loop
Vertical bore without backfill
BentoniteGrout backfill
Geothermal pipe
Grout
Standard Bentonite Grout = 0.43 TC
Select Grout = 0.85 TC
Thermally Enhanced orThermal Select Grout = 1.0 to 1.4 TC
Adding silica sand increases the TC but also increases cost in both material and time
Grout
Grout
49 % Increase in Grout
600 Ton School Application - North Royalton, Ohio
North Royalton Middle School
Middle School, Ohio
Middle School, Ohio
• Built in 1996
• 1600 Students
• 239,000 square feet
• 140 units (average size 3 tons )
• 414 total tons
• 240 bore holes at 330 ft deep
Middle School, Ohio
• Mechanical HVAC System was installed for $ 10 per square ft
($ 2.4 million).
Ground Loop Portion Turn Key Cost: $ 500,000
$ 6.30 per foot of bore hole
• System projected to operate at 25 cents per square ft.
System actually operating at 18 cents per square ft.
Murray High School
New Public School built in 2006
Loop Field Layout
Construction Cost Comparison
1st Year Operating Cost Comparison
316 – 300’ boreholes Under North Parking Lot
High School Ground Loop Field
High School – Row of Vertical Loops
High School – Rows Connected
High School – Back Filling the Trenches
High School – Finished Ground Loop
MECHANICAL SYSTEM SAVINGS
• Conventional System Bid: $19.00 / sq ft
• Ground Source System Bid:
Mechanical/Plumbing bid: $3,065,161
Loop Field bid: $930,784
Total: $3,995,945
Mechanical Cost: $3,995,945 / 267,256 sq ft = $14.95 /sq ft
• Construction Cost Savings: 267,256 sq ft x $4.05 /sq ft = $1,082,387.00
• Total Bore Hole Length: 316 holes x 300 ft deep = 94,800 feet of bore hole
Ground Loop Installed cost: $930,784/94,800 = $9.20 per foot of bore hole
• Annual Geothermal System Utility Costs – Murray High School
Electricity = $156,505.11 (96%)
Natural Gas = $6,521.05 (4%)
Total = $163,026.16
Cost / sq ft = $163,026 / 267256 sq ft = $0.61 / sq ft
• Annual Utility Costs ‐ Comparable School, Salt Lake Valley
Cost / sq ft= $0.86 / sq ft
of which: Electrical = 77%
Gas = 23%
• Yearly Operating Cost Savings
$0.86 ‐ $0.61 = $0.25 /sq ft
$0.25 /sq ft x 267,256 sq ft = $66,814.00 (29%) Annual Savings
UTILITY COST (First Year)
Hybrid GLHP Systems
• Cooling Load is out of balance with the Heating Load
• Property Area is insufficient
• Reduce First Cost of the Ground Loop by taking advantage of the Part Load Operation of the Building
Hybrid GLHP Systems
Cooling Load is out of balance with the Heating Load
• Clark County School District (Las Vegas)
60% ground loop plus fluid cooler allows for winter, spring and fall operation on ground loop but runs a fluid cooler at peak loads.
• Lincoln Public Schools
Boiler hybrid to eliminate anti‐freeze and the 30% pumping penalty from anti‐freeze.
Hybrid GLHP SystemsCooling Load is out of balance with the Heating Load
Property Area is insufficient
Hybrid GLHP Systems
Take Advantage of Part Load Operation
Commercial Building Loads are only 50% or less of the Peak Load
for 80% ‐ 90% of the Year
Hybrid GLHP Systems
Take Advantage of Part Load Operation
50% of the hours In the year
27% Flow
80% of the hoursIn the year
54% Flow
552 GPM System (2.8 GPM/ton) with VFD Pumping
Hybrid GLHP Systems
Hybrid GLHP SystemsTake Advantage of Part Load Operation
Bin Weather Data: 8760 Hours/Year
205 Hours or 2.3%
Hybrid GLHP SystemsTake Advantage of Part Load Operation
Cooling Tower Project
Project name: Las Vegas Motor Speedway
Description: Media Center64,000 Sq. ft.Vertical Loop w/ Cooling Tower
Ground Temperature: 73.5 – 77.5ºF
Cooling load: 4,500,000 BTUH (375 tons)EFLH (cooling): 1325 ‐ 1000
Heating load: 2,640,000 BTUH (220 tons)EFLH (heating): 400
Hybrid GLHP Systems
Hybrid Loop Field W/ Cooling Tower
Loop Details Hybrid Full Geo
Number of bores: 150 563
Depth of bores: 400 feet 400 feet
Bore hole spacing: 25 feet 25 feet
Loop field installed costs: $ 780,000 $ 2.1 million
Building energy consumption/yr: $ 98,000 $ 92,700
Maintenance costs / yr: $ 11,856 $ 8,250
Summary
Hybrid Loop installed costs reduced by $ 1,320,000
Operating costs increased by $ 5,300 / yr.
Maintenance increase $ 3,606 / yr.
Hybrid GLHP Systems
Hybrid Loop Field W/ Cooling Tower
Loop Details Hybrid Full Geo
Number of bores: 150 563
Depth of bores: 400 feet 400 feet
Bore hole spacing: 25 feet 25 feet
Loop field installed costs: $ 780,000 $ 2.1 million
Building energy consumption/yr: $ 98,000 $ 92,700
Maintenance costs / yr: $ 11,856 $ 8,250
Summary
Hybrid Loop installed costs reduced by $ 1,320,000
Operating costs increased by $ 5,300 / yr.
Maintenance increase $ 3,606 / yr.
Hybrid GLHP Systems
Turn Key Cost about $13 per ft of bore hole
Pond Loops
Spacer
Surface Water / Lake Loop
Great River Medical Center – Burlington, Iowa2002 ASHRAE Technology Award1500 Tons in a 15 Acre Man‐made Lake
Pond Loop
Ground Loop Software
SOFTWARE VENDOR
GLD2010 Gaia Geothermal
GLHEPRO 4.0 IGSHPA
ECA ELITE SOFTWARE, INC. BRYAN, TX
Geo CALC FERRIS STATE UNIVERSITY, BIG RAPIDS, MI
GchpCalc ENERGY INFORMATION SERVICES, Tuscaloosa, AL
GL‐SOURCE KANSAS ELECTRIC UTILITY, TOPEKA, KS
G L Design GBT, Inc., Maple Plain, MN
GS2000 Buildings Group, Natural Resources Canada
LUND Programs University of Lund, Sweden
Wright‐Loop Wrightsoft, Lexington, MA
75.5 Connected Tons of GLHP’s97/77 F Summer; 28 F Winter
Ground Loop Software
Ground Loop Software
Ground Loop Software
1.19 Thermal Conductivity
74.6 F Ground Temperature
Ground Loop Software
Ground Loop Software
Alt # 1
Alt # 2
Alt # 3
Basis of Design
Loop Cost Impact
Basis of Design:60 bore holes x 305 ft per hole x $10/ftTotal: $ 183,000.00
Add for Alt #1:60 bore holes X 5 ft per hole = 300 bore ftPlus 8 holes X 310 ft = 2,480 bore ftTotal: 2,780 bore ft X $10/ft = $ 27,800.00
Add for Alt # 2:16 holes X 305 ft = 4,880 bore ftTotal: 4,880 bore ft X $10/ft = $ 48,800.00
Add for Alt # 3:60 holes X 10 ft per hole = 600 bore ftPlus 16 holes X 315 ft = 5,040 bore ftTotal: 5,640 bore ft X $10/ft = $ 56,400.00
Efficiency Effect on Ground Loop
Alt # 1
Alt # 2
Alt # 3
Basis of Design
Building and Heat PumpInformation
Ground and LoopInformation
Ground Loop Software
Ground Loop Software
Ground Loop Software
Ground Loop Software
Ground Loop Peak Water Temperature Design
Ground Loop Software
Building and Heat PumpInformation
Ground and LoopInformation
Ground Loop Software
Ground Loop Software
Ground Loop Software
Ground Loop Software
Ground Loop Software
Ground Loop Software
Ground Loop Peak Water Temperature Design
Ground Loop Software
If Guessing at 1.0 Thermal ConductivityGround Loop Software
Using correct 1.44 Thermal ConductivitySaved 9,708 feet of bore hole drilling
Ground Loop Software
Hybrid with 20% BoilerReduces bore hole drilling by another 10,384 feet
Ground Loop Software
Ground Loop Peak Water TemperaturesAre only for brief periods of time
Ground Loop Software
Ground Loop Software
Maximum Peak Loop Temperature in 30 years during the cooling mode
Ground Loop Software
Loop Design Using Original Peak Loop Temperatures and the resulting WSHP Efficiencies
Ground Loop Software
Modify the Peak Loop Temperatures resulting in new WSHP Efficiencies (19.4 EER versus 16.9 EER) at the system’s maximum peak. Now model the energy savings properly
GLD 2009
Maximum Average Loop temperature during the cooling mode is even lower than 80F
WSHP Basics – System Schematic
WSHP Basics – System Schematic
I told you this is
IMPORTANT
LEED‐NC Version 3.0
Energy and Atmosphere Credit 1: Optimize Energy Performance
Points are awarded for exceeding the prerequisite energy performance for the entire building
LEED‐NC Version 3.0
Energy and Atmosphere Credit 1: Optimize Energy Performance
Baseline ASHRAE 90.1 for GLHP: 13.4 EER
Most GLHP’s at AHRI Rating (77 F EWT):
17.0 EER to 30.0 EER
20 EER = 49% Increase
Life Cycle Costs
Life Cycle Costs
Life Cycle Costs
Life Cycle Costs
Installed Las Vegas Schools
Sep 09 - Aug 10 School Year
Usage (kWh) Area (SqFt)
Total Use
(kWh/SqFt)
NWCTA 548 2,105,712.83 217,000.00 9.7
Information Needed To Price the Ground Loop:
Thermal Conductivity Test
Building Loads
GLHP Efficiency
IMPORTANT
Model the Building Operating Efficiency Properly
Take Advantage of Tax Incentives
Commercial Ground LoopWater Source Heat Pump Systems