Operations and Maintenance Essentials
Green Professional Building Skills Training
To understand:
A.How to measure the performance of your building
B.The role of the building envelope and how to improve its impact on the interior environment
C.Ways to improve and minimize water use
D.How heating and cooling systems work and how they can be improved
COURSE OBJECTIVES
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GPRO Certificate Holders
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OPERATIONS AND MAINTENANCE IN GREEN BUILDING
LEED Gold Building, NY
A green building is designed, constructed and maintained to minimize adverse environmental impacts and to reduce energy consumption, while contributing to the health and productivity of its occupants.
A key component is consideration of the building's impacts and performance over its entire lifespan.
A Green Building
Sustainability is about using less by using smart
U.S. Potable Water Used in Buildings
U.S. Energy Used in Buildings
40% 12%
Why Sustainability in Building Operations Matters Page 2
All these complex systems work together, whether they are working well or not.
Why Sustainability in Building Operations Matters Page 3-4
The Whole-Building Approach
• Observe building systems• Monitor operating systems• Measure electric, water, and fuel use• Assess problems (high bills, tenant complaints)• Tune existing equipment• Install new green equipment• Auditing and Retro-Commissioning
The Role of Building Superintendents, Managers, and Engineers
The Role of Building Superintendents, Managers, and Engineers Page 5
TEST YOURSELF:
1. Why does sustainability in building operations and maintenance matter?
2. Why use a "whole-building" approach when thinking about operation of a building's facilities?
3. Give an example of how the operation of one facility system in a building affects another of the building's systems.
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2 BUILDING PERFORMANCE METRICS
Water Meter
• Gallon (gal): volume• Gallon per minute (gpm): fluid flow• Cubic feet (cf) and Hundred cubic
feet (HCF or CCF): large volumes
How Water Usage is Measured
How Water and Energy Usage is Measured Page 6
• 1 cubic foot (cf) = 7.48 gal• 1 HCF = 748 gal
Water Bill Analysis
How Water and Energy Usage is Measured Page 6
Electric Power = a rate, measured in Watts (W)• 1 kilowatt (kW) = 1,000 W• 1 megawatt (MW) = 1,000 kW
= 1,000,000 W
How Electric Power is Measured
High-voltage Power Lines
How Water and Energy Usage is Measured Page 7
Electric energy = an amount, measured in kilowatt-hours (kWh)•1 kilowatt (1,000 W) x 1 hour = 1 kWh •100 watts (100 W) x 10 hours = 1,000 watt-hours (Wh) or 1 kWh
How Electric Consumption is Measured
How Water and Energy Usage is Measured Page 7
Electric Meter
• Maximum power drawn during some time period, usually a month.
• Measured in kilowatts (kW)
Blackout, Eastern U.S. August 17, 2003
Peak Demand
How Water and Energy Usage is Measured Page 7
• Demand charges can be a substantial part of your utility bill.
Some measures can reduce demand load AND consumption.
Before Repair
After Repair
Hourly Electric Load Data
How Water and Energy Usage is Measured Page 8
• Electricity in kWh• Gas in therms• Steam in Mlb• Oil in gallons
How Fuel Consumption is Measured
Meters
How Water and Energy Usage is Measured Page 8
Fuel Type Energy Content
Natural Gas 1,030 Btu / cf
Propane (liquid) 92,500 Btu / gal
Propane (gas) 2,500 Btu / cf
#2 Oil 138,500 Btu / gal
#4 Oil 145,000 Btu / gal
#6 Oil 150,000 Btu / gal
Steam (@ 212°F) 970 Btu / lb
Electric Heat 3,413 Btu / kWh
1 therm = 100,000 Btu, or the energy equivalent of burning 97 cf of natural gas.
How to Compare Different Heating Fuels
How Water and Energy Usage is Measured Page 8
• Total amount of energy delivered to a building =
Fuel use (Btu) + electricity use (kWh converted to Btu)
• To convert electric energy to heat units:
Use 3,413 Btu/kWh
Site Energy
How Water and Energy Usage is Measured Page 9
EXAMPLE 1:SITE ENERGYQUESTION: A building consumes 500,000 ft3 of gas and 200,000 kWh of electricity per year.
Gas energy content is 1,030 Btu/ft3. Electric energy content is 3,413 Btu/kWh.
What is the site energy?
How Water and Energy Usage is Measured Page 9
EXAMPLE 1:SITE ENERGYANSWER: The site energy is the sum of the energy content of the gas and electricity used:
SiteE = 500,000 ft3/year x 1,030 Btu/ft3 (Gas)+ 200,000 kWh/year x 3,413 Btu/kWh (Electricity)
515,000,000 Btu/year + 682,600,000 Btu/year = 1,197,600,000 Btu/year or 1,198 MMBtu/year (each "M" means 1,000, so "MM" means one million)
How Water and Energy Usage is Measured Page 9
The amount of energy used to generate electricity (which will be used by a building).
To convert electric energy to source energy:
Use 11,400 Btu/kWh
Source Energy
Useful electrical energy is only 1/3rd of source energy
How Water and Energy Usage is Measured Pages 9-10
EXAMPLE 2:SOURCE ENERGYQUESTION: What is the source energy of the building in Example 1?
The conversion value of the electric energy to source energy is 11,400 Btu/kWh.
How Water and Energy Usage is Measured Pages 9-10
EXAMPLE 2:SOURCE ENERGYANSWER: The source energy is the fuel delivered to the building added to the fuel used at the power plant to generate the electrical energy used in the building:
SourceE =
(500,000 ft3/year x 1,030 Btu/ft3) + (200,000 kWh/year x 11,400 Btu/kWh) =
515,000,000 Btu/year + 2,280,000,000 Btu/year = 2,795,000,000 Btu/year or 2,795 MMBtu/year
How Water and Energy Usage is Measured Pages 9-10
COMPARE:SITE ENERGY vs. SOURCE ENERGY
SiteE = 1,198 MMBtu/year SourceE = 2,795 MMBtu/year
How Water and Energy Usage is Measured Pages 9-10
Carbon Footprint
Carbon footprint from electricity generation varies dramatically depending on the fuel source.
U.S. electricity generation by type of energy in 2009
How Water and Energy Usage is Measured Page 10
POP QUIZ:
What is the most expensive fuel?
POP QUIZ:Fuel Type (unit)
Cost /unit
Btu /unit
Cost / million Btu
Natural Gas (mcf) $11.34 1,030,000 $11.01
Propane (gallons) $1.86 92,500 $20.10
#2 oil (gallons) $2.69 138,500 $19.40
#6 oil (gallons) $2.30 150,000 $15.30
Steam (lb) $.024 970 $24.70
Electricity (kWh) $0.110 3,413 $32.20
Data for Dec 2010-Jan 2011 updated April 2011
EXERCISE QUESTION:
What factors affect your energy bills?
• Consumption (kWh)
• Demand (kW)
• Supply and Delivery charges may be on separate bills (both have consumption and demand charges)
Electricity Bill Analysis
Water and Energy Bill Analysis Page 10-11
Benchmarking is an important component of any energy management program because it helps you establish a baseline of energy or water use.
Energy Use Intensity (EUI)•The most common measure for energy benchmarking •Represents the total fuel burned and electricity consumed on a per-square-foot basis, per year•Typically reported as source energy
Benchmarking: Determining Water and Energy-Use Efficiency
Benchmarking: Determining Water and Energy-Use Efficiency Page 12
Source EUI
Can be determined for different energy sources by following these steps:
1.Convert energy sources to Btu (see conversion chart 2.6 on page 8 in your manual)
2.Add up all Btu from all energy sources to find the total Btu used in one year (= source energy/year)
3.Divide the source energy by the building's habitable floor space (= source EUI in Btu/sf/year)
Benchmarking: Determining Water and Energy-Use Efficiency Page 12
What is the source EUI of the building we looked at in the section on site energy and source energy? It's useful floor area is 23,000 sf.
Benchmarking: Determining Water and Energy-Use Efficiency 12
EXAMPLE 3:SOURCE EUI
We found the source energy to be 2,795 MMBtu/year so:
Source EUI = 2,795,000,000 Btu/yr23,000 sf
= 121,522 Btu/sf/year
Benchmarking: Determining Water and Energy-Use Efficiency 12
EXAMPLE 3:SOURCE EUI
Portfolio Manager is EPA's tool to compare buildings to each other: https://www.energystar.gov/istar/pmpam/
Tools for Energy and Water-Use Efficiency
Benchmarking: Determining Water and Energy-Use Efficiency Page 13
What About the Weather?
What About the Weather Page 13-14
Building performance is directly affected by weather.
The more extreme temperatures are, the harder a building's systems will work to keep its occupants comfortable, which will use more energy.
A Heating Degree Day (HDD) is a measure used to compare the severity of winter temperatures.
• Help us estimate the amount of fuel used for heating in a winter season
• Compare buildings in different climates
To calculate the annual HDD:
1. Find average daily temperature
2. Subtract from 65ºF
3. Add all HDDs for entire season
Heating Degree Days
What About the Weather Page 13-14
CLASSROOM EXERCISE:Day's High
TemperatureDay's Low
TemperatureAverage
TemperatureHDD
40 20 30 35
15 -5
70 50
75 65
What About the Weather? Page 13
Heating Energy Intensity (HEI) = Btu / sf / HDD• Btu = Total energy used for heating per year• sf = Area of entire building (in square feet)• HDD = Heating Degree Day
Heating Energy Index
Heating Energy Index Page 14-15
Calculating Btu
HEI = Btu / sf / HDD
1.Add up all fuel used for the year
2.Subtract the amount used for domestic hot water
3.Multiply by the Btu conversion for each type of fuel
Heating Energy Index Page 15
Calculating Area
HEI = Btu / sf / HDD
1.Measure the floor space of the entire building in square feet
2.Include the basement spaces if they are conditioned
What About the Weather? Page 15
Calculating Heating Degree Days
HEI = Btu / sf / HDD
1.Take the average daily temperature
2.Subtracting it from 65° F (example: For a day with a high of 40° F and a low of 20° F, the average would be 30°F, HDD for that day = 35).
3.Add heating degree days up for an entire season
Heating Energy Index Page 15
GROUP EXERCISE:
See Classroom Exercise #1 on page 89 of your manual:
Calculate the heating energy index (HEI)for the sample building.
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TEST YOURSELF:1. When would you measure water by cubic feet rather
than by gallons?
2. Why is it important to measure energy and water consumption?
3. What is benchmarking and how does it help manage energy and water consumption?
4. Why pay close attention to water and energy bills? What is an example of something that could cause a jump in your building's fuel bill?
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3 THE BUILDING ENVELOPE
The Function of the Building Envelope
The Function of the Building Envelope Page 16
WET ROOF INSULATION LEAKS HEAT
AIR INFILTRATION BETWEEN DOUBLE-HUNG WINDOW SASHES
MISSING INSULATION AT SPANDREL ALLOWS HEAT TO ESCAPE
WARM AIR ESCAPES THROUGH LOUVERS AT TOP OF ELEVATOR SHAFT
MISSING WALL INSULATION ALLOWS HEAT TO ESCAPE
Three mechanisms of heat transfer:
• Conduction• Convection• Radiation
Heat Transfer
Heat Transfer Pages 16-17
• Air is a poor conductor of heat, especially if it can't move. This makes it a good insulator.
• Insulation is effective because it contains tiny pockets of air, which slow heat flow.
• Minimizing heat flow reduces the energy demands on equipment, operating costs, and environmental impact.
Managing Conductive Heat Transfer
Heat Transfer Pages 17-18
R-Value•Measure of thermal resistance•Expressed as heat flow per inch•Add up all the materials in the building assembly to get total R-Value•Insulation is only as good as the air sealing around it!
Thermal Resistance: R-Value
Heat Transfer Pages 18-19
Applying soy polyurethane spray-on foam
• Batts• Boards / Rigid• Blown-in • Spray-on foam• Pipe
Heat Transfer Pages 18-20
Which Insulation is Right for You?
• R-value comes from fluffiness• Air seal• Can have vapor barrier attached (foil face) on side that is
warm in winter• Don't compress (Always cut around obstructions)
Batts
Heat Transfer Pages 18-19
Insulation Batts Infrared Image: Compressed Insulation
• Standard thicknesses ½" to 6"• Easy to install• High R-Value/inch• Must be air sealed
Insulation Boards
Heat Transfer Page 19
Heat Transfer Page 19
• Loose fill or dense-pack• Can also act as air seal
Blown-In
Blown-in cellulose insulation
• Soy based• Acts as an air seal• Needs to be
professionally installed
• High R-Value/inch
Spray Foam
Heat Transfer Page 19
Applying spray-on foam
Install pipe insulation everywhere!
Pipe Insulation
Heat Transfer Pages 19-20
Polyethylene pipe insulation Fiberglass pipe insulation
• Minimize air infiltration through the envelope for energy efficiency.
• But maintain adequate ventilation to preserve indoor air quality.
Air Barrier Integrity
Air Barrier Integrity Page 20
A majority of a building's heat loss can be traced to air leakage.
Typical Air Leakage in a Home
Air Barrier Integrity Page 21
Wind Effect Stack Effect Mechanical Ventilation
Air Movement in Buildings
Air Barrier Integrity Pages 20-21
Isolate spaces to prevent tobacco, cooking odors or air contaminants (from labs and parking garages) from entering occupied spaces.
Compartmentalization
Air Barrier Integrity Page 21
• Seal and caulk wall penetrations at doors and windows
• Monitor temperature in winter and summer to prevent overheating or overcooling
• Seal wall between garage and occupied spaces to prevent CO infiltration
• Ensure air louvers are unobstructed
• Schedule cleaning and testing of ventilation shafts
• Provide flashings at parapets, window sills and any other penetrations to prevent water infiltration
• Weatherstrip all exterior doors
Air Barrier Integrity
Air Barrier Integrity Pages 21-22
Condensation Control Page 22
• Bulk Water (leaks)
• Condensation
• Vapor
How Water Enters Buildings
Leak at Exterior Wall
In a heating climate, install a vapor barrier on the warm side of the wall in winter.
Condensation Control: Vapor Barrier
Condensation Control Pages 22-23
A sling psychrometer measures relative humidity.
Condensation Control Page 22
DRY BULB TEMP (˚C)
WET BULB TEMP (˚C)
RELATIVEHUMIDITY(curves)
DEW POINT(100% saturation)
Psychrometric Chart
Condensation Control Page 22
POP QUIZ:
If the relative humidity in this room is 60%, and we raise the temperature, what happens to the relative humidity?
POP QUIZ:
As Temperature goes up
Relative Humidity goes down
Efflorescence on a brick wall
• Routine visual inspections
• Monitor renovation work
• Log tenant complaints
• Watch for increased heating or cooling demand
• Identify water leaks and repair
Addressing Envelope Problems
Addressing Envelope Problems: Options for Building Managers Page 23
TEST YOURSELF:1. What is the purpose of the building envelope and why is it
important that it works effectively?
2. What are the three types of heat transfer and how does the building envelope control them?
3. Explain the stack effect and two methods used to control it.
4. Describe three things building managers can do to maintain air barrier integrity in a building.
5. Describe how to prevent condensation of water in walls.
6. Describe three things you could see in your building that would indicate the building envelope is not functioning correctly.
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4 WATER USE
Reading the Meter
Consumption is measured in cubic feet (CCF or HCF used for 100 cubic feet)
Sample Reading 1
Single Dial Water Meter
Sample Reading 2
Compound High-Flow and Low-flow meter
Tracking Water Use
Tracking Water Use Page 24-25
SAMPLE READING 1:A 6-unit apartment building has 12 people living in it. The building has a single-dial water meter. The water rate is $4.27 per HCF.
Meter Reading January 1: 001123 cf
Meter Reading March 31: 011623 cf
Amount of water used in 3 months:
011623__- 001123__
10,500 cf
10,500 cf100
= 105 HCF
Cost of water used:
105 HCF @ $4.27/HCF = $448.35
Tracking Water Use Page 25
SAMPLE READING 1:Cost per apartment per quarter:
$448.356 apts.
= $74.73/apt.
Water used (in gallons): (Remember: 1 HCF = 748 gallons)
105 HCF x 748 gal/HCF = 78,540 gal
Cost per apartment per year (at this rate):
$74.73 x 4 = $298.92/apt./year
Gallons per person per day:
78,540 gal / 90 / 12 people = 73 gal/person/day
Tracking Water Use Page 25
SAMPLE READING 2:A 30-unit apartment building is served by a compound meter that has a 2" (high-flow) meter and a ¾" (low-flow) meter.
Tracking Water Use Page 25
"Amount of water used" equals high plus low flows:105 HCF + 400 HCF = 505 HCF
SAMPLE READING 2:Cost of water used:505 HCF @ $4.27/HCF = $2,156.35
Cost per apartment per quarter:$2,156.35 / 30 apts. = $71.88/apt.
Cost per apartment per year (at this rate):$71.88 x 4 = $287.52/apt./year
Water used (in gallons):505 HCF x 748 gallons/HCF = 377,740 gallons
Gallons per apartment per day:377,740 gal / 90 days / 30 apt. = 140 gallons/apt./day
Tracking Water Use Page 25
• Log daily or weekly water consumption
• Logs will help detect hidden leaks sooner and help you understand patterns of usage
Water Use Logging
Water Use Reduction Practices Page 26
Indications of Leakage:•Condensation on toilet bowl: running flushometers•Corrosion on fixtures: dripping faucets
Monitor with:•Building water systems•Daily rounds•Drip gauges•Dye tablets•Moisture meters•Infrared cameras
Common Areas of Water Leakage
Water Use Reduction Practices Page 26
Ask occupants to:•Report leaks•Use low-flow fixtures•Purchase ENERGY STAR appliances and WaterSense fixtures•Turn off water when possible •Run washing machines and dishwashers only with full loads
Educate Occupants: Reduce Water Use
Water Use Reduction Practices Page 26-27
Water Broom
Instead of using a typical hose, try these alternatives:
Alternatives to Sidewalk Washing
Water Use Reduction Practices Page 27
• Sweeping with a dry broom
• Using a water broom
• Waiting for rainstorms to wash sidewalks naturally
Make sure to check mechanical system components for leaks:
•Excessive use of make-up water in boilers?
•Malfunctions in cooling towers?
•Wasted water in condensate tanks?
•Lost water in closed loop water systems?
Detecting Hidden Leaks in Mechanical Systems
Detecting Hidden Leaks in Mechanical Systems Page 27
• Look for WaterSense and ENERGY STAR labels on fixtures and machines
• Install low-consumption (LC) or high efficiency toilets (HET)
• Install low-flow showerheads
• Choose front-load washers, which are more efficient
Fixtures and Appliances
Fixtures and Appliances Page 28
Typical Water Use in Commercial Buildings
Water use in different types of buildings varies dramatically
Water Consumption Norms: Commercial
Water Consumption Norms Page 28
• Replace conventional plantings with native, climate-adapted plants
• Manage irrigation schedules
• Use a drip irrigation system instead of a hose
• Invest in a sensor and timer that will activate the irrigation system only when needed
• Maintain your irrigation system to prevent leaks
• Irrigate with greywater or harvested rainwater instead of potable water
Reducing Water Use for Irrigation
Reducing Water Use for Irrigation Page 29
BRAINSTORM:
What are ways you are already reducing your water consumption?
What are ways to get management to spend money on water efficiency upgrades?
TEST YOURSELF:1. How is using a single-dial water meter different
from using a compound water meter?
2. What are two ways to check for water leaks in boilers?
3. Name two or three causes of water use spikes.
4. Describe three or four ways tenants can reduce water consumption.
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LET'S TAKE A BREAK!
Green Professional Building Skills Training