Building Systems and Performance: an Introduction to Building Operator Certification – Lesson 11: Units and Conversions CUNY Institute for Urban Systems Building Performance Lab Lesson 11: Units & Conversions 2 Objectives • Explain basic principles of energy in its various forms. • Discuss common sources of energy data. • Read utility bills and/or other energy-use data reports • Convert energy units for use in cost calculations and energy management. 3 Energy Data - Sources • Meters • Meters for electricity, gas, and district steam • Why might you have multiple meters? • New buildings or additions • Points of service entry • Demand Meter and Consumption Meter • gas: Firm vs Interruptible (dual fuel boilers) • oil: A different story • Delivery is not use 4 Metering: Digital Data Added Value Converting meters to Digital • Record Time-of-use • New utility meter with Pulse • Know when peaks Output transmitter occur • Optical Reader • Real time reads • Remote reads • Direct to database 5 Metering: Smart Meters • The new world of digital smart meters • Interval Data • Real-time and remote reads • Direct to database • Time-of-use Data Source: Sub-meters 6 Advantages of Sub-Meters • Non-utility monitoring • Monitor energy use of: • Separate buildings in a multi-building complex • Individual floors • Specific location, such as a computer lab • Single piece of equipment • Help with internal billing or cost allocation • Track usage by setting up accounts in any energy- use database Energy Data - Sources 7 • Sub-meters • Non-utility metering, • When might they be used? • internal billing or cost allocation • setting up accounts in any energy-use database • EnergyStar Portfolio Manager (public and web-based, by US EPA) 8 Where is the Meter Number? Conversion Factor 9 Unit Cost for Electricity KWH-Demand-Block Rate • Consumption (kwh) vs. Demand (kw) • Higher unit cost where Demand is short duration. • This may be controllable! • Declining Block Rate – • Higher quantities of electricity have a reduced cost • Smaller buildings may have higher unit costs than larger buildings because they are not able to take advantage of the discounts 10 Data Sources – Utility Bills Electricity 11 Review & Pop Quiz • What were the units? • What was the cost per unit? • What is the Cost/MMBTU for Energy on the previous slide? 12 Data Sources - Electric More Detail 13 Data Sources: Utility Bills Steam 14 Review & Pop Quiz #2 • What were the units? • What was the cost per unit? • What is the Cost/MMBTU for Energy on the previous slide? 15 Data Source: Oil Consumption Tracking • Sticking the Tank • Compare each reading to prior one; divide by number of elapsed days • Flow metering • Watch out for re-circulation systems • Rated burner gpm x on-time • Watch out for firing-rate modulation Data Sources: Utility Bill for Oil 16 17 Tracking Oil Consumption Starting Inventory + Delivery – End Inventory = Use • “Sticking the Tank” • Compare each reading to prior one; divide by number of elapsed days • Flow metering • Watch out for re- circulation systems • Rated burner gpm x on-time • Watch out for firing-rate modulation 18 Review & Pop Quiz #3 • What were the units? • What was the cost per unit? • What is the Cost/MMBTU for Energy on the previous slide? 19 Data Sources: Tracking Oil Consumption • Delivery and inventory (storage) issue • Starting Inventory + delivery - end inventory = use • Dipping/“stick the tank” • Flow metering • Watch out for re-circulation systems • Rated burner gpm x on-time • Watch out for firing-rate modulation 20 Energy Data – Other Resources • The 3 ways to get your Electric Meter Readings • Reading and logging to PO-8 or spreadsheet • Energy bills • Portfolio Manager website For more information on your electric and steam usage go to - www.coned.com 21 Energy Fundamentals Common Building Fuel Types - Electricity - Natural Gas - Fuel Oil - Liquid Propane Gas (LPG) 22 Energy Fundamentals Common Units of Measurement Electricity Fuel Oil & LPG Ø kilowatt (kW) –demand Ø Gallon Ø kilowatt-hour (kWh)- consumption Natural Gas Ø Volume Cubic feet Ø Energy Content: therm • How do we determine and sum up the total energy usage of a building? à Convert to a common unit: Btu 23 Fundamental Energy Unit BTU = British Thermal Unit The amount of heat required to raise one pound of water by one degree Fahrenheit. 1 LB Raised 1 degree Fahrenheit Water or 1 match 24 Energy Units & Btu Conversion • Natural Gas • Electricity • 1 Cubic Foot = 950 to 1150 Btu • 1 kW = 1000 Watts • 1 CCF = 100 Cubic Feet • 1 kWh = 3414 Btu (site • 1 MCF = 1,000 Cubic Feet value) • 1 Therm = 100,000 Btu • Steam • 1 CCF is approx 1 Therm • 1,150 Btu / pound • (1 million Btu per Mlb) • Fuel Oil • Number 2 = 140,000 Btu/Gallon • Number 4 = 145,00 Btu/Gallon • Number 6 = 152,000 Btu/Gallon • Coal • Lignite = 11,000 Btu/Lb. • Propane • Bituminous = 14,000 Btu/Lb. • LPG = 91,600 to 95,000 • Anthracite = 13,900 Btu/Lb. Btu/Gallon • Sub-bituminous = 12,600 Btu/Lb. • 1 BTU: Heat required to raise the temperature of 1 pound of • Miscellaneous water by 1 degree Fahrenheit • Wood = 8,500 Btu/Lb. • U235 = 75,000,000 Btu/gram 25 Energy Units: STEAM BTU for steam varies with state & pressure • Steam tables for properties of steam • http://www.engineeringtoolbox.com/saturated-steam- properties-d_273.html • Steam energy and change of state • Enthalpy • @ 212 dF, 180 btu/# liquid + 970 btu/# evaporated • For general purposes, 1,150 btu / pound • (1 million btu per Mlb) Steam Table 26 27 Site vs Source Energy Site value - heat value at building boundary Source value – heat value at the beginning of the process Greatest difference (site vs. source) for electricity Source: Shelly Dean and Fuller Energy Principles in Architectural Design 28 Dealing with Zeros M = K = 1,000 = 103 MM = 1,000,000 = 106 (some of the time in the Heating Language M = 1,000,000) Practice questions: • Express 24,000,000 in scientific notation • Express 24,350,000 in scientific notation • 38,000,000 BTU is how many KBTU? How many MMBTU? • 44,000 therms of gas is how many BTU? • Expressed as KBTU • Expressed as MMBTU • Expressed in scientific notation Dealing with Zeros 29 • Add 20 x106 + 30 x106 = • Add 20 x106 + 150 x106 = • Subtract 30 x106 - 20 x106 = • Subtract 30 x103 – 10.5 x103 = • Add 20 x106 + 30MM = • Add 20 x106 + 30,000 x103 = 30 Total Energy Usage in MMBtu Exercise #1 A building uses the following amounts of energy: Electricity : 300,000 kwh Natural Gas 45,000 therms #2 Fuel Oil 10,000 gallons • How many BTUs does it use? • Express in MBTU or KBTU, where M or K = 1,000 • Express in MMBTU, where MM = 1,000,000 31 Total Energy Usage in MMBtu Exercise #1 Energy unit Amount BTU M or K BTU MMBTU (BTU type (BTU x 103) x 106) Electricity kwh 300,000 (site value) Natural therm 45,000 Gas #2 Oil gal 10,000 TOTAL Total Energy Usage in MMBtu 32 Exercise #1 Energy unit amount BTU M or K BTU MMBTU (BTU Type (BTU x 103) x 106) Electricity (site value) kwh 300,000 1,024,200,000 1,024,200 1,024.2 Natural Gas therm 45,000 4,500,000,000 4,500,000 4,500 #2 Oil gal 10,000 1,400,000,000 1,400,000 1,400 TOTAL 6,924,200,000 6,924,200 6,924.2 33 Practical Project 3 – Whole Building & System Level Energy Consumption: Table 1 • Use the energy data for your facility to show the energy consumption on the whole building level and the system level • Review of Project Instructions • Use the energy usage data for your facility - Portfolio Manager • Review of Table 1 – Whole Building Annual energy Usage à Find out who at your organization was involved in benchmarking for LL84. à See about obtaining access to the Portfolio Manager account – OR – the raw data from the PM account. See: www.energystar.gov/benchmark TABLE 1 - Practical Project 3 34 TABLE 1 SUMMARY OF ANNUAL ENERGY USE BY ENERGY TYPE GROSS FLOOR AREA = SF FOR THE YEAR SEPT 1, 2009 - AUGUST 31, 2010 UNLESS OTHERWISE NOTED (12) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) unit QTY MMBTU $ unit cost $/MMBTU MMBTU / SF $ / SF % of BTU % of Cost (5)/(3) (5)/(4) (4)/(12) (5)/(12) (4)/(13) (5)/(14) Electricity kwh Nat Gas therm Fuel Oil, #__ gallon Steam mlb Total 0 100% 100% (13) (14) NOTES: per million 1. MMBTU of all energy types are calculated at the Site Value kwh 3414 0.003414 kwh 2. Building area (SF) is gross square footage, including basement nat gas 100000 0.100 therm oil, #2 140000 0.140 gal oil, #4 145000 0.145 gal oil, #6 152500 0.153 gal • Does this look familiar? • Columns 1 through 4 are the same as the table we just did. 35 Review and Reading Assignment • Basic principles of energy in its various forms. • Discuss common sources of energy data. • Discuss energy units conversion as used in cost calculations and energy management. Homework: Reading for Next Class (Class 12) • Portfolio Manager Handouts • Herzog, Chaps. 4 & 5 (begin reading).