2015 x472 class 10 - lcca

X472 HVAC System Design Considerations
Class 8 – Codes, Construction
Documentation and Coordination
Todd Gottshall, PE
Western Allied
Redwood City, CA
Reinhard Seidl, PE
Taylor Engineering
Alameda, CA
Fall 2015
Mark Hydeman, PE
Continual Energy, Inc.
mark.hydeman@continual.net
415-602-9982
www.continual.net

2
General
 Contact Information
Reinhard: rseidl@taylor-engineering.com
Mark: mark.hydeman@continual.net
Todd: tgottshall@westernallied.com
 Text
• None
 Slides
• download from web before class
• Log in to Box at https://app.box.com/login
• Username: x472student@gmail.com
• Password: x472_student (case sensitive)

3
Course Outline
Date Class Topic Teacher
9/02/2015 1. Introduction / Systems Overview / walkthrough RS
9/09/2015 2. Generation Systems TG
9/16/2015 3. Distribution Systems RS
9/23/2015 4. Central Plants TG
9/30/2015 5. System Selection 1 - class exercises RS
10/07/2015 6. Specialty Building types (High rise, Lab, Hospital,
Data center)
TG
10/14/2015 7. System Selection 2 - class exercises RS
10/21/2015 8. Construction codes and Project delivery methods TG
10/28/2015 9. 2013 T24 and LEED v4 MH
11/04/2015 10. Life-Cycle Cost Analysis and exam hand-out TG
There are three instructors for this class. Todd Gottshall (TG), Reinhard Seidl (RS)
and Mark Hydeman (MH). The schedule below shows what topics will be covered by
who, and in what order.

4
Outline
 LCCA – Overview and Terminology
 System Selection LCCA Example
 Answers to Final

6
Life-Cycle Cost Analysis
 Evaluate economic performance over
entire life of a building.
• “Whole Cost Accounting”
• “Total Cost of Ownership”
 Uses the “time value of money” to fairly
compare future costs with present costs.

7
Life-Cycle Cost Analysis
 Cannot compare Hp, Btu/h, tons, kW
directly, since it’s apples and oranges. But
can convert them all to the same units and
then compare
 Same with money: as its value changes
over time, we cannot compare the actual
face values. But we can convert to present
value (PV) for a common denominator.

8
Why LCCA Matters
 Campus
Classroom /
Office
Building
Gates Computer Science Building
30 Year Life-Cycle Cost
Utilities,
$18,300,000, 28%
Maintenance,
$3,900,000, 6%
Service,
$2,400,000, 4%
System
Replacements,
$2,900,000, 4%
Initial Project Cost,
$37,700,000, 58%

9
LCCA Possibilities
 HEATING/COOLING SYSTEMS
• Central-plant connected vs. stand-alone systems
• Utility connection options if connected to the central plant
• Equipment options for stand-alone systems (e.g., chilled water vs. direct-expansion
(DX) units)
 HVAC DISTRIBUTION SYSTEMS
• Air distribution systems (e.g., variable volume vs. constant volume, overhead vs.
underfloor)
• Water distribution systems (e.g., primary-only vs. primary-secondary)
 BUILDING ENVELOPE
• Roofing systems (various materials and insulation methods)
• Glazing, daylighting, and shading options
 SITING/MASSING
• Orientation, floor to floor height, and overall building height
• Landscape, irrigation, and hardscape options

10
LCCA Possibilities
 Generally for mechanical systems
• High first cost vs low energy/maintenance cost
• Low first cost vs higher energy or maintenance cost
• Balancing which of the two is better for overall customer needs is goal of LCC
0
2
4
6
8
10
12
14
Solution A Solution B
Which is better?
First Cost Energy Cost - 20 yrs
Solution ASolution B
FirstCost 5 8
Energy Cost- 20yrs 12 7.2

11
 Generally for mechanical systems
• High first cost vs low energy/maintenance cost
• Low first cost vs higher energy or maintenance cost
• Balancing which of the two is better for overall customer needs is goal of LCC
• Present potentially complex data sets in a simple comparison
LCCA Possibilities
Solution ASolution B
FirstCost 5 8
Energy Cost- 20yrs 12 7.2
0
2
4
6
8
10
12
14
16
18
Solution A Solution B
Which is better?
First Cost Energy Cost - 20 yrs

12
When to do LCCA and how much
effort?
 Complex analysis and significant effort when
• Potential first cost impact is high and potential operating
cost impact is high
• New or untested measures
• To prioritize competing or mutually exclusive energy
conservation efforts
 Simple or no analysis when
• Payback is obvious based on past experience
• First cost impact is low
• Cost of complex analysis is a large % of cost of
measure

13
LCCA Process
1. Establish Objectives
2. Determine LCCA Metrics and Criteria
3. Identify and Develop Alternatives
4. Gather Cost Information
5. Perform LCCA Calculations

14
LCCA Costs
 One-Time (First) Costs
• Design
• Construction
• Commissioning
 Recurring Costs
• Utilities
• Maintenance
• Replacements

15
Example System Lifetimes
(ASHRAE Handbook – 2003 Applications)

16
Time value of Money
 Time-dependent value of money is much like
temperature-dependent air volume:
 Which air handler supplies more air?
• 10,000 cfm
• 11,213 cfm

17
Time value of Money
temperature-dependent air volume:
 Which air handler supplies more air?
• 10,000 cfm = 714 lbs/min @ 35°F, 80% RH (intake)
• 11,213 cfm = 714 lbs/min @ 95°F, 9.8% RH (supply)
• Same AHU, heating mode

18
Time value of Money
temperature-dependent relative humidity:
 Which air handler supplies more humid air?
• 80%RH
• 9.8%RH

19
Time value of Money
temperature-dependent relative humidity:
 Which air handler supplies more humid air?
• 80%RH = 29.8°F dewpoint at 35°F
• 9.8%RH = 29.8°F dewpoint at 95°F
 Same AHU, heating mode

20
Time value of Money
 Asking “How much air” is like asking “How much
money”
• It depends on the psychrometric state of air
• It depends on the age of money
 But we can make a common denominator
• Using mass to compare airflows
• Using present value (PV) or future value (FV), and compare
investments made at different times by comparing them “at
the same common time” by accounting for their ages

21
Present Value
 Accounts the “time value” of money.
 Basic Discount Equation:
 Where:
• PV is the present value (in Year 0 dollars)
• FY is the value in the future (in Year Y dollars)
• DISC is the discount rate
• Y is the number of years in the future
Y
Y
DISC
F
PV
)1( 


22
Escalation
 Most items increase in price but do not track
overall inflation rate exactly.
 Basic Escalation Equation:
 Where:
• COSTYEAR-Y is the cost at Y years into the future
• COSTYEAR-0 is today’s cost (at Year 0)
• ESC is the escalation rate
• Y is the number of years into the future
Y
YEARYYEAR ESCCOSTCOST )1(0  

23
Study Life
 Term of study over which costs will be
accumulated
 Could be
• Life of equipment/system being analyzed
• Life of building
• As far into the future as you think you can
speculate
 Typically, because of discount rate, does
not matter much to go beyond ~15 years

24
LCCA Calculation Method
 The formula for the basic LCC equation:
 Where:
• LCC is the life cycle cost
• C is the Year 0 construction cost (hard and soft costs)
• PVRECURRING is the present value of all recurring costs
(utilities, maintenance, replacements, service, etc)
• PVRESIDUAL-VALUE is the present value of the residual
value at the end of the study life
VALUERESIDUALRECURRING PVPVCLCC 

25
LCC Discounted Payback Calculation
$0
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
$7,000,000
0 1 2 3 4 5 6 7 8 9 10
30 Year Study
CumulativeCost[PresentValue$]
300 6 12 18 24
payback in roughly 6 years
payback in roughly 9 years
EnergyAnalysisandLCCA

26
CSU LCCA Spreadsheet
 http://www.calstate.edu/cpdc/AE/

28
Case Study:
UC Merced Classroom Building
 90,000 sq. ft., 3 stories
 Classrooms, Offices
 Minimize energy use (20% below T-24)
– Heating and cooling
– Reheat
 Maximize thermal comfort
 Provide individual control
– Operable windows
– Integration with HVAC systems
 LEED Rating

30
What is Building Simulation?
 Allows prediction of energy use, dynamic
response, control optimization
 Options
• Custom spreadsheets
• Third party software
• Custom Visual Basic models
 3rd Party Software
• EnergyPro (DOE-2.1)
• eQUEST (DOE-2.2, www.doe2.com)
• EnergyPlus
• TRACE

31
DOE-2 Inputs
Detailed Input Required!
 Hourly Weather Data
 Building Geometry
 Glazing and Material
Properties
 Internal Loads
 HVAC Systems and
Equipment Efficiencies
 Utility Rates and
Structures

32
DOE2 Outputs
 500 pages text, 8 point font, minimum –
more depending on complexity and
reports
 Hourly values for any variable of any
object
 Predicts energy use
 Predicts energy cost

34
Simulation Results
UC Merced Classroom/Office Building
System Selection Analysis
Predicted Energy Use Summary
VAVR DFDD Change
[Mbtu] [Mbtu] [%]
Lights 768.8 768.8 0%
Equipment 612.0 612.0 0%
Heating 256.0 104.6 -59%
Cooling 880.1 862.5 -2.0%
Pumps 11.3 13.6 20%
Fans 172.8 172.0 -0.5%
Total 2,701.0 2,533.5 -6%

35
Energy Efficiency Component Analysis
 “Run-Around” Heat-Recovery Coils
 “Run-Around” Heat-Recovery Coils with
Direct-Evaporative Assist
 Heat-Pipe Heat-Recovery Coils
 Heat-Pipe Heat-Recovery Coils with Direct-
Evaporative Assist
 Air-to-Air Heat Recovery
 Indirect Evaporative Pre-Cooling
WHAT’S YOUR GUESS?

37
Maintenance Materials First Cost
Component Number Visits/Year Time Extension Item Extension Item Extension
[-] [min] [min] [-] [$] [$] [$]
Fans
CF 2 4 10 80 35,000$ 70,000$
HF 1 4 10 40 78,000$ 78,000$
EAF 2 4 10 80 6,000$ 12,000$
Coils
CC 4 4 10 160 7,500$ 30,000$
HC 4 4 5 80 incl above with HF
PHC 4 4 5 80 2,500$ 10,000$
Dampers
Each 6 4 5 120 5,000$ 30,000$
Filters
Cooling 70 1 5 350 75 5,250$ 150$ 10,500$
Heating 20 1 5 100 75 1,500$ incl above with HF
Penthouse
Each 2100 sq.ft 30$ 63,000$
Labor Time Total [hours] 18.2
Cost Subtotal 908$ 6,750$
($50/hr loaded rate)
Yearly Maintenance Total 7,658$
First Cost Total 303,500$
Base Case

39
Run-Around Coils
[-] [min] [min] [-] [$] [$] [$]
Fans
CF 2 4 10 80 35,000$ 70,000$
HF 1 4 10 40 78,000$ 78,000$
EAF 2 4 10 80 6,000$ 12,000$
OAF 2 4 10 80 6,000$ 12,000$
Coils
CC 4 4 10 160 7,500$ 30,000$
HC 4 4 5 80 inclulded above with HF
OAC 4 4 5 80 2,500$ 10,000$
EAC 4 4 5 80 5,000$ 20,000$
Wet-Side Run Around Coil Equipent
Pump 1 4 15 60 6,000$ 6,000$
Piping, etc. 100 linear feet 60$ 6,000$
Dampers
Each 7 4 5 140 2,500$ 17,500$
Filters
Cooling 70 1 5 350 75 5,250$ 150$ 10,500$
Heating 20 1 5 100 75 1,500$ inclulded above with HF
Pre-Heat 45 1 5 225 40 1,800$ 125$ 5,625$
Penthouse
Each 2880 sq.ft 30$ 86,400$
Labor Time Total [hours] 26
Cost Subtotal 1,296$ 8,550$

41
Run-Around with Evap Cooling
[-] [min] [min] [-] [$] [$] [$]
Fans
CF 2 4 10 80 35,000$ 70,000$
HF 1 4 10 40 78,000$ 78,000$
EAF 2 4 10 80 6,000$ 12,000$
OAF 2 4 10 80 6,000$ 12,000$
Coils
CC 4 4 10 160 7,500$ 30,000$
HC 4 4 5 80 included with HF above
OAC 4 4 5 80 2,500$ 10,000$
EAC 4 4 5 80 5,000$ 20,000$
Wet-Side Run Around Coil Equipent
Pump 1 4 15 60 6,000$ 6,000$
Piping, etc. 100 linear feet 60$ 6,000$
Muenters every 2 years
Equip 1 4 240 960 2,940$ 1,470$ 14,700$ 14,700$
Dampers
Each 7 4 5 140 2,500$ 17,500$
Filters
Cooling 70 1 5 350 75$ 5,250$ 150$ 10,500$
Heating 20 1 5 100 75$ 1,500$ included with HF above
Pre-Heat 45 1 5 225 40$ 1,800$ 125$ 5,625$
Penthouse
Each 2880 sq.ft 30$ 86,400$
Labor Time Total [hours] 42
Cost Subtotal 2,096$ 10,020$

46
Life-Cycle Cost Analysis Parameters
General Analysis Parameters
Study Life 30 years
Escalation Period 1 Ends in Year 5
General Inflation Rate 2.8%
Campus (Nominal) Discount Rate 6.5%
Real Discount Rate 3.6%
Annual Escalation Rates
Period 1: Years 1 to 5 Period 2: Years 6 to 30
Nominal Real Nominal Real
Maintenance 3% 0.22% 3.50% 0.71%
Materials 3% 0.22% 3.50% 0.71%
Natural Gas 5% 2.16% 4% 1.19%
Electricity 5% 2.16% 4% 1.19%
Electricity Rates
Summer Winter
(5/1 to 10/31) (11/1 to 4/30)
Demand Energy Demand Energy
[/kW] [/kWh] [/kW] [/kWh]
On-Peak* $16.00 $0.055 $10.75 $0.051
Off-Peak** $0 $0.037 $0 $0.033
* weekdays: 12:00 noon to 5:59 pm
** weekdays: 12:00 midnight to 11:59 am and 6:00 pm to 11:59 pm
** weekends: all day
Natural Gas Rates
Summer Winter
(5/1 to 10/31) (11/1 to 4/30)
[/therm] [/therm]
$0.590 $0.760
Chilled Water Rate
$5.06 /million Btu
Steam Rate
$7.20 /million Btu
Hot Water Rate
$3.60 /million Btu
Benefits to Campus Infrastructure
Peak Period
Utility Months Days Hours
CHW $1,000 /ton June-Sept M to F 3PM-6PM
CHW $100 /gpm June-Sept M to F 3PM-6PM
Steam $23 /pph Nov-Feb M to F 5AM-8AM
Electricity $300 /kW June-Sept M to F Noon-6PM
Hot Water $13 /MBH Nov-Feb M to F 5AM-8AM
Hot Water $100 /gpm Nov-Feb M to F 5AM-8AM
Discounted
Savings

47
First Costs
Unmodified Modified
Maintenance First Cost Electricity First Cost
Run Description Cost Cost Peak Dist'n Peak Dist'n Peak Cost
[$] [$] [$] [$] [$] [$] [$] [$]
0 Base Case $7,658 $303,500 $303,500
1 Run Around Coil - w/o Evap $9,846 $364,025 -$46,000 -$4,416 -$1,406 -$244 $7,860 $319,819
2 Run Around Coil - w/ Evap $12,116 $378,725 -$58,083 -$5,576 -$1,406 -$244 $7,500 $320,916
3 Heat Pipe - w/o Evap $9,796 $378,025 -$55,750 -$5,352 -$1,610 -$280 $5,370 $320,403
4 Heat Pipe - w/ Evap $12,066 $392,725 -$70,699 -$6,787 -$1,610 -$280 $5,250 $318,599
5 Air-Air Plate HX - w/o Evap $9,796 $349,525 -$66,048 -$6,341 -$1,692 -$294 $3,300 $278,450
6 Indirect Evap Pre-Cooling $10,225 $351,500 -$63,429 -$6,089 -$1,166 -$203 $4,830 $285,443
Infrastructure Benefits
Chilled Water Hot Water

48
Energy Use and Cost
Electricity Chilled Water Hot Water
Run Description Annual Peak Cost Annual Peak Cost Annual Peak Cost
[kWh] [kW] [$] [Mbtu] [Btu/hr] [$] [Mbtu] [Btu/hr] [$]
0 Base Case 465,036 201.9 $48,592 1,822 2,346,000 $9,219 309 656,000 $1,112
1 Run Around Coil - w/o Evap 500,503 228.1 $53,795 1,751 1,794,000 $8,860 141 546,000 $507
2 Run Around Coil - w/ Evap 508,456 226.9 $54,139 1,702 1,649,000 $8,612 141 546,000 $507
3 Heat Pipe - w/o Evap 491,904 219.8 $52,293 1,703 1,677,000 $8,617 119 530,000 $429
4 Heat Pipe - w/ Evap 492,461 219.4 $52,304 1,701 1,497,617 $8,607 119 530,000 $429
5 Air-Air Plate HX - w/o Evap 483,239 212.9 $50,916 1,693 1,553,428 $8,567 113 523,566 $405
6 Indirect Evap Pre-Cooling 502,848 218.0 $52,733 841 1,584,852 $4,255 153 564,759 $549

49
LCC Results
UC Merced Classrooom / Office Building Life Cycle Analysis
$0
$500,000
$1,000,000
$1,500,000
$2,000,000
$2,500,000
0 5 10 15 20 25 30
Study Year
CumulativeCost[PresentValue$]
Run 0 - Base Case
Run 1 - Run-Around Coil w/o Evap
Run 2 - Run-Around Coil w/ Evap
Run 3 - Heat Pipe w/o Evap
Run 4 - Heat Pipe w/ Evap
Run 5 - Air to Air Plate HX w/o Evap
Run 6 - Indirect Evap Pre-Cooling
Life Cycle
Run Description Cost
[present dollars]
0 Base Case $2,112,503
1 Run Around Coil - w/o Evap $2,481,282
2 Run Around Coil - w/ Evap $2,307,405
3 Heat Pipe - w/o Evap $2,433,117
4 Heat Pipe - w/ Evap $2,223,283
5 Air-Air Plate HX - w/o Evap $2,223,283
6 Indirect Evap Pre-Cooling $2,204,087

50
Another Tool – Weighted Comparison
Table

51
Class Example
 System 1: CRAC units
• First cost: $672,000
• Annual energy cost: $223,000
 System 2: Central CHW plant and CRAHs
• First cost: $2,664,000
• Annual energy cost: $75,600
 Energy cost escalation 4%
 Depreciation 8%
 Inflation 2%
 No major replacement for either system
 At what year does the central plant break even?

2015 x472 class 10 - lcca

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