ENERGY MANAGEMENT
A combined design and management function which embraces the disciplines of
engineering
mathematics
accounting
operations research
software engineering
environmental management
THE ENERGY MANAGEMENT FUNCTION
THE ENERGY MANAGEMENT FUNCTION
Measure
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse Criticise
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse Criticise
GenerateOptions
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse Criticise
GenerateOptions
EvaluateOptions
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse Criticise
GenerateOptions
OptimiseEvaluateOptions
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse Criticise
GenerateOptions
Modify OptimiseEvaluateOptions
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse Criticise
Control GenerateOptions
Modify OptimiseEvaluateOptions
THE ENERGY MANAGEMENT FUNCTION
Measure Analyse Criticise
Control GenerateOptions
Modify OptimiseEvaluateOptions
REVIEW
ENERGY ACCOUNT
A balance sheet of energy
INPUTS
OUTPUTS
THROUGHPUTSflowing through a site boundary
The INPUT sideAn analysis of
FUEL
and
ELECTRICITY bills for a representative
annual period
The OUTPUT sidedetails the ultimate energy rejection to
the external environment via
• heat transmission through the building fabric
• heat lost to ventilating air
• flue gas losses
The THROUGHPUTS
What happens inside the building
may require microaudits or energy balances over individual items of
plant and equipment:
furnaces, boilers, refrigerators, compressors, etc.
to ascertain efficiencies and to quantify sundry gains
Energy Audit
Energy Audit
Energy Audit
Energy Audit
Energy Audit
Fuel
Energy Audit
Fuel
Combustion
Stack Loss
Energy Audit
Fuel
Combustion
Boiler
Stack Loss
Energy Audit
Fuel
Combustion
Boiler
Distribution
Stack Loss
Distribution Loss
Energy Audit
Fuel
Combustion
Boiler
Distribution
People Stack Loss
Distribution Loss
Energy Audit
Fuel
Combustion
Boiler
Distribution
People LightsStack Loss
Distribution Loss
Energy Audit
Fuel
Combustion
Boiler
Distribution
People Lights PowerStack Loss
Distribution Loss
Energy Audit
Fuel
Combustion
Boiler
Distribution
People Lights Power
Processes
Stack Loss
Distribution Loss
Energy Audit
Fuel
Combustion
Boiler
Distribution
People Lights Power
Processes
Stack Loss
Distribution Loss
Electricity
Energy Audit
Fuel
Combustion
Boiler
Distribution
People Lights Power
Processes
Stack Loss
Distribution Loss
Electricity
Fuels Fuel
Food
Energy Audit
Fuel
Combustion
Boiler
Distribution
Sundry Gains
People Lights Power
Processes
Stack Loss
Distribution Loss
Electricity
Fuels Fuel
Food
Energy Audit
Fuel
Combustion
Boiler
Distribution
Space Heat Delivered
Sundry Gains
People Lights Power
Processes
Direct Reject
Stack Loss
Distribution Loss
Electricity
Fuels Fuel
Food
Energy Audit
Fuel
Combustion
Boiler
Distribution
Space Heat Delivered
Sundry Gains
People Lights Power
Processes
Direct Reject
Stack Loss
VentilationFabric Transmission
Distribution Loss
Electricity
Fuels Fuel
Food
Energy Audit
Energy Audit Equation
Fuel Energy Input =
Energy losses during combustion
+ Energy losses during conversion
+ Energy losses during distribution
+ Energy losses during utilisation
+ Energy losses from utilisation
For a heated building, INPUT side
Heating fuel energy input
+ Sundry gains from electricity
+ Sundry gains from people
+ Sundry gains from directly-fired process plant and equipment
- Sundry losses to cold plant
For a heated building, OUTPUT side
= Energy losses in flue gases
+ Energy losses during conversion
+ Energy losses from external distribution pipelines
+ Energy losses via fabric transmission
+ Energy losses in ventilating air
+ Energy losses in process materials directly rejected to the external environment
Heat Loss = Fabric Transmission Losses+Ventilation Losses
Heat Loss (W)= U A DT + m cp DT
U = Overall U-value (W/m2K)A = Area for heat loss (m2)m = Ventilating Air (kg/s)cp= specific heat of air (J/kg K) DT= Temperature difference between inside and outside (oC)
Mean Annual Heat Loss (W)= U A DT + m cp DT
m = Ventilating Air (kg/s)
= number of air changes per second (1/s) x building volume, V (m3) x density of air, r (kg/m3)
Mean Annual Heat Loss (W)= U A DT + m cp DT
m = Ventilating Air (kg/s)
= number of air changes per hour, n (1/hr) x hours/second (1/3600) x building volume,V (m3) x density of air, r (1.2 kg/m3)
Heat Loss (W)= U A DT + m cp DT
cp= specific heat of air (= 1000 J/kg K))
Heat Loss (W)= U A DT + m cp DT
= U A DT + (r V n/3600) cp DT
= U A DT + (1.2 V n/3600) x 1000 DT
= U A DT + (V n/3) DT= (U A + nV/3) DT
Fuel Burnt by Boiler (W)
= ((U A + nV/3) DT) / h
whereh is the boiler efficiency (%) expressed as a fraction
Annual Heat Loss (kWh/annum)
= (U A + nV/3) DT x heating hours per annum/1000
whereDT = mean annual temperature difference between inside and outside (oC)
Monthly Heat Loss (kWh/month)
= (U A + nV/3) DT x heating hours per month/1000
whereDT = mean monthly temperature difference between inside and outside (oC)
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
ENERGY IN
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ENERGY OUT
ENERGY AUDIT
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
ENERGY IN
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ENERGY OUT
ENERGY AUDIT
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterns
environmental temperaturesenvironmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDITInternal Data
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
COMPILE ENVIRONMENTAL PARAMETERS
degree-day dataoutside air temperatures
and humiditieswind speeds
solar databuilding orientation
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data External Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
External Data
DETERMINE DISTRIBUTION
LOSSES
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
EXAMINEPROCESS LOSSES
OR GAINS
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
EXAMINEPROCESS LOSSES
OR GAINS
ASCERTAINSUNDRY GAINS
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
ENERGY IN
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
ENERGY IN
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
ENERGY OUT
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
ENERGY IN
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ENERGY OUT
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
ENERGY AUDIT
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
ENERGY IN
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ENERGY OUT
ENERGY AUDIT
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
ENERGY IN
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ENERGY OUT
ENERGY AUDIT
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
OBTAIN DESCRIPTION OF PREMISES
purpose and functionnumber of occupantsoccupational patterms
environmental temperatures environmental humidities
lighting levelsventilation requirements
plans and details of constructionheating and cooling system details
FLOW CHART FOR AN ENERGY AUDIT
COMPILE ENVIRONMENTAL PARAMETERSdegree-day data
outside air temperatures and humiditieswind speeds
solar databuilding orientation
OBTAIN ENERGY ACCOUNTS COLLATE ACCOUNTS
AND CONVERT TO COMMON UNITS
Internal Data Fuel Data
TRACE ENERGY RELEASESYSTEMS AND ESTIMATE
OR MEASURE EFFICIENCIES
DETERMINE DISTRIBUTION
LOSSES
ENERGY IN
External Data
CARRY OUT SITE SURVEYESTIMATE U-VALUES AND AREAS
VENTILATION RATESEXHAUST AIR TEMPERATURES
ENERGY OUT
ENERGY AUDIT
ASCERTAINSUNDRY GAINS
EXAMINEPROCESS LOSSES
OR GAINS
ENERGY AUDIT
Energy Audit
Energy Audit kWh./annum, £/annum
Energy Audit kWh./annum, £/annum
Fuel Energy
Energy Audit kWh./annum, £/annum
Energy ReleaseFuel Energy
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Space HeatingHeat Delivered
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
Sundry Gains
Direct Reject
Space HeatingHeat Delivered
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
PeopleSundry Gains
Direct Reject
Space HeatingHeat Delivered
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
PeopleSundry Gains
Electricity
Direct Reject
Space HeatingHeat Delivered
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
People
Lights, Power, Processes
Sundry Gains
Direct Reject
Electricity
Direct Reject
Space HeatingHeat Delivered
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
People
Lights, Power, Processes
Sundry Gains
Direct Reject
ElectricityElectrical Space
Heating
Direct Reject
Space HeatingHeat Delivered
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
People
Lights, Power, Processes
Sundry Gains
Direct Reject
Electricity
Air compressors
Electrical Space Heating
Direct Reject
Space HeatingHeat Delivered
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
People
Lights, Power, Processes
Sundry Gains
Direct Reject
Electricity
Air compressors
Electrical Space Heating
Direct Reject
Space HeatingHeat Delivered
Compressor Loss
Compressed Air
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
People
Lights, Power, Processes
Sundry Gains
Direct Reject
Electricity
Air compressors
Electrical Space Heating
Direct Reject
Space HeatingHeat Delivered
Compressor Loss
Compressed Air
Ventilation
Fabric Transmission
Energy Audit kWh./annum, £/annum
Conversion LossesEnergy ReleaseFuel Energy
Distribution Distribution Losses
Processes
People
Lights, Power, Processes
Sundry Gains
Direct Reject
Electricity
Air compressors
Electrical Space Heating
Direct Reject
Space HeatingHeat Delivered
Compressor Loss
Compressed Air
Ventilation
Fabric Transmission