1. Assessing the Carbon Footprint of the University of Portsmouth
Residential Buildings and Identifying how it can be Reduced
Context
Climate change is an important reality of today’s society. As about half of the CO2 emitted by human
activity since the industrial revolution has remained in the atmosphere(1), World governments and Non-
Government Organisations (NGOs) have produced agreements such as the Agenda 21, Montreal
Protocol and Kyoto Agreement to reduce anthropogenic emissions to ‘a level which would prevent
dangerous anthropogenic interference with the climate system’(2).
In compliance with the Carbon Reduction Commitment (CRC) energy efficiency scheme, the University
of Portsmouth has committed to reducing its carbon emissions by 30% by 2016(3).
As buildings are responsible for 40% of the GHG emissions, the energy efficiency of the University
buildings is a key area for achieving the 30% reduction target(4).
Method
In order for the carbon emissions and energy efficiency of the buildings to be assessed the
electricity and gas consumptions had to be obtained from the University of Portsmouth Estates
department.
CIBSE Standards
The energy efficiency of the buildings was calculated by dividing the average of the total annual
electricity and gas consumptions between 2008 and 2011, by the gross floor area of the building
(kW h m-2 per year). These values were then compared to the CIBSE standards of ‘good’ and
‘typical’ energy rates for that building type(5).
Carbon Emissions
The total electricity and gas consumptions between the years 2008 and 2011 were converted into
carbon equivalent figures by multiplying the totals by conversion factors of 0.5246kgCO2e for
electricity and 0.1836kgCO2e for gas(6).
Degree-data
The monthly electricity and gas consumptions between the years 2008 and 2010 were plotted
against the degree data figures published by the Carbon Trust and based at 15.5°C. (7)(8)
Audits
The energy audits were compiled based on CIBSE guidelines and encompassed all forms of
energy use within the buildings.(5) The audits were carried out in cooperation with environmental
management and halls supervisors.
Discussion
Figure 1 and 2 show that Margaret Rule and Trafalgar halls are consuming far more electricity (m2
y-1) than would be typical, and only Harry Law hall is achieving ‘good’ or ‘typical’ energy
consumption (m2 y-1) for both electricity and gas. This may be due to the how CIBSE standards are
calculated, the age of the building, amount of occupants and ambient conditions are not considered
in the calculations, and may dramatically influence the energy consumption of the buildings.
Figure 3 demonstrates that although between 2008 and 2011 there has been a slight decrease in
the CO2 emissions, this has not been uniform. The high CO2 emissions of 2010 may be due to two
particularly cold winters within this year. This is reinforced by Figures 4-8 as the degree data shows
a 99.9% significance (p<0.001) between the ambient temperature and the energy consumption.
This can be combated by an increase in insulation and heating system efficiencies to reduce the
dependence of energy consumption on weather conditions.
Figures 4-8 also show a slightly curved relationships throughout, this may mean that there is poor
temperature control within the buildings which is leading to waste, the Owner Occupancy Schemes
currently in place and the efficiency of heating and electrics may be a target to reduce the wasted
energy.
Audits revealed that trial occupancy detector lights and other technologies are being run to
potentially reduce the affect of occupants.
References
(1) The Royal Society. (2010). Climate Change: A Summary of the Science [Electronic version]. London: Royal Society. (2) United Nations. (2012). United Nations:
Framework Convention on Climate Change: Article 2. Retrieved February 8, 2012, from http://unfccc.int/essential_background/convention/background/items/1353.php (3)
McCormack, I. (2010). Green Portsmouth. Retrieved January 26, 2012, from http://www.port.ac.uk/departments/services/greenportsmouth/targetsandstatistics/ (4)
Houghton, J. (2009). Global Warming: The Complete Briefing (4th ed.). New York: Cambridge University Press. (5) Chartered Institution of Building Services Engineers.
(2004). Energy efficiency in Buildings, CIBSE Guide F. Norwich: CIBSE Publications Department. (6) Carbon Trust. (2011). Conversion Factors. London: Carbon Trust. (7)
Carbon Trust. (2010). Degree Days for Energy Management. London: Carbon Trust. (8) Carbon Trust. (2010). Historical UK Degree Days Data. London: Carbon Trust.
Plates (1) University of Portsmouth. (2009). Bateson Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698503784/. (2)
University of Portsmouth. (2009). Harry Law Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698503930/. (3) University of
Portsmouth. (2009). Margaret Rule Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698505322/. (4) University of
Portsmouth. (2010). Rees Hall. Retrieved February 26, 2012, from http://commons.wikimedia.org/wiki/File:University_of_Portsmouth_Rees_Hall.JPG. (5) University of
Portsmouth. (2009). Trafalgar Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698503520/.
Conclusion and Further Work
The data show that the University of Portsmouth Residential buildings are consuming higher levels of
energy than is recommended by CIBSE levels. The degree data and audits show that occupants of the
halls of residence may be a key factor in reducing the energy consumption, and enable the 30%
decrease in carbon emissions by 2016.
Assessments of how insulation and heating efficiency can be improved, along with occupant’s
awareness, would be key to decreasing the carbon emissions.
Plate 1. Bateson Hall Plate 4. Rees HallPlate 3. Margaret Rule HallPlate 2. Harry Law Hall Plate 5. Trafalgar Hall
451718University of Portsmouth
Aim
This project aims to suggest ways to improve the efficiency of the
residential buildings. The principal objectives are:
◦to determine the energy efficiency of the University of
Portsmouth residential buildings and compare them to the Chartered
Institution for Building Services Engineers (CIBSE) standards.
◦to identify potential areas for improvement by conducting
energy audits and analysing the energy use compared to the ambient
temperature (degree-data analysis).
◦to investigate and suggest methods of increasing efficiency
and thereby decreasing carbon emissions.
0
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Margaret Rule Hall Trafalgar Hall
AverageElectricityConsumptionBetween2008-2011(kW
m2y-1)
Building
Figure 1. Shows the Average Electricity Use of
Residential Buildings between 2008 and 2011
compared to CIBSE Benchmarks (kW m2 y-1)
Figure 3. Shows the CO2 Emissions of Selected
Residential Buildings for the Years 2008-2011.
Figure 2. Shows the Average Electricity and Gas
Use of Residential Buildings between 2008 and
2011 compared to CIBSE Benchmarks (kW m2 y-1)
0
50
100
150
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300
Bateson Hall Harry Law Hall Rees Hall
AverageEnergyConsumptionbetween2008and2011(kW
m2y-1)
Buildings
Electricity
Fossil Fuel
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2008 2009 2010 2011
CarbonEmissions(kgCO2e)
Bateson
Harry Law
Margaret Rule
Rees
Trafalgar
y = -0.6465x2 + 602.17x + 27799
R² = 0.8597
0
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TotalEnergyConsumption(kWh)
Degree-Data
y = -0.8509x2 + 611.88x + 26798
R² = 0.8301
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TotalEnergyConsumption(kWh)
Degree-Data
y = -0.4733x2 + 542.39x + 48517
R² = 0.8858
0
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TotalEnergyConsumption(kWh)
Degree-Data
Figure 4. Shows the Total Energy Consumption
against Degree Data for Bateson Hall (kW h)
Figure 5. Shows the Total Energy Consumption
against Degree Data for Harry Law Hall (kW h)
Figure 6. Shows the Total Energy Consumption
against Degree Data for Margaret Rule Hall (kW h)
y = -1.1922x2 + 1237.7x + 72093
R² = 0.8551
0
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TotalEnergyConsumption(kWh)
Degree-Data
Results
y = -0.2934x2 + 453.38x + 33476
R² = 0.9129
0
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TotalEnergyConsumption(kWh)
Degree-Data
Figure 7. Shows the Total Energy Consumption
against Degree Data for Trafalgar Hall (kW h)
Figure 7. Shows the Total Energy Consumption
against Degree Data for Rees Hall (kW h)