BE0898 2014/15 Worton

BE0898: Advanced Measurement and Technology Student ID: 10033248

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BE0898 - Advanced Measurement and Technology

Building design and performance critique

Ellison Building

Module Tutor: Alan Davies

Submission Date: 10/02/15

Student ID: 10033248

Word Count: 2,723


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Table of Contents

Executive Summary ................................................................................................................................. 3

Power Generation ................................................................................................................................... 4

Combined Heat and Power ................................................................................................................. 4

Renewables ......................................................................................................................................... 5

Solar Panels ..................................................................................................................................... 5

Wind Turbines ................................................................................................................................. 5

Ground Source Heat Pumps ............................................................................................................ 5

Air Source Heat Pumps ................................................................................................................... 6

Water Efficiency ...................................................................................................................................... 7

Greywater Recycling ........................................................................................................................... 7

Rainwater Harvesting .......................................................................................................................... 7

Envelope Efficiency ................................................................................................................................. 8

Windows / Glazing .............................................................................................................................. 8

External façade ................................................................................................................................... 9

Mixed Mode Ventilation ................................................................................................................... 10

Combination of technologies ................................................................................................................ 11

Conclusion ............................................................................................................................................. 11

Bibliography .......................................................................................................................................... 12


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Executive Summary

This is report reviews a number of building elements and engineering systems within the

Northumbria University’s Ellison Building, and critically assesses them in order to suggest

improvements in usability and potential environmental performance.

Whilst the building is wholly suitable to serve the function of an educational and research facility

there were a number of improvements which could be applied with relative ease and minimal

disruption to the day to day function of the building including:

Power Generation – Combined Heat & Power (CHP), greater use of renewables

Water Efficiency – Greywater use, rainwater harvesting

Cooling & Ventilation – Mixed Mode ventilation, free cooling

External Envelope – Heat losses, glazing alternatives, air tightness

Lighting – Use of energy efficient systems

From these technologies there is a significant opportunity to improve the environmental

performance of the building as well as improving the usability overall by combination of the

technologies discussed.


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Power Generation

There are various technologies which are already present within the Ellison Building systems which

could be further developed and improved to provide benefits and generate savings through the

generation of power on-site.

Combined Heat and Power

Combined Heat and Power (CHP) or Cogeneration as it sometimes known is a government supported

technology and they simplistically describe it “as a highly efficient process that captures and utilises

the heat that is a by-product of the electricity generation process.” (Department of Energy and

Climate Change, 2015); it is supported by the government due to it’s environmental benefits and

further attracts benefits from incentive schemes such as Enhanced Capital Allowances and can

provide Climate Change Levy Exemption.

In principle a CHP plant works by generating the electricity in a traditional manner on site and then

recovering the waste heat produced in the process for beneficial gains such as hot water or space

heating. It does this by housing a prime mover or heat engine which can be thought of as akin to

traditional gas turbines. (The Carbon Trust, 2010)

Energy International sum up the overall implications of CHP very well in a single paragraph:

There are three fundamental objectives to using CHP: To reduce carbon emissions, avoid

fossil fuel depletion and to reduce energy costs. Emissions reduction and fossil fuel husbandry

are obviously highly desirable. In a capitalist society, though it is very often return on

investment that is the biggest factor in investment decisions.” - (Energy International, 2012)

The objectives are clearly in line with the focus of this report however it would remain to be seen as

to the full commercial case for the use of a CHP system. Energy International go on to discuss that in

order to achieve the full potential of such a system the intended building would be required to have

a very high occupancy rate throughout the year, and whilst occupancy would be reduced during the

holiday period there would rarely be any period where the building would be empty and should

there be sufficient gains elsewhere in any redevelopment case then it could become realistic for the

system to be switched off and maintained during these periods.

It is worth noting that the Ellison Building already houses a small Combined Heat and Power (CHP)

plant for demonstration purposes however the plant setup would not be compatible with a larger

scale implementation.


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Renewables

Another well documented but set of technologies for environmentally benign technologies are

renewables such as solar, wind, ground and air source heat pumps which could be utilised to a

greater extent on the Ellison Building site.

Solar Panels

There is a large area of available roof space on the plot and this in nearly all suitable for the

installation of either PV panels, for pure electrical generation, or for solar thermal systems to

provide heated water for use in washing or heating (EDF Energy, 2015). There are also a number of

candidate areas on the external walls which could be utilised as panel space however there would

need to be some greater calculations done to assess the realistic payback on investment when

compared to the expected power generation of wall mounted panels.

It is worth noting that there are a few PV panels

already in place on the roof areas of the Ellison

Building which would be able to provide data for

calculations on the anticipated outputs as well as the

effectiveness of evacuated tube type systems and

more traditional panels.

Wind Turbines

The use of micro wind turbines has been a

questionable source of power generation for inner city

locations and was rebutted significantly by studies

conducted by the University of Southampton

(University of Southampton, 2014) which showed that

some installations used more energy than they

produced. New studies have suggested new designs

are significantly more effective and could be used on

the tallest of Ellison Building’s roofs to generate

electricity (Ingham, 2014).

Ground Source Heat Pumps

The building already utilises ground source heat to a certain extent as demonstrated to students

during their studies through a limited number of borehole source however the footprint of the

building is extensive and this number of boreholes could be increased to provide a greater amount

of energy gained through the use of this technology. Whilst there are initial capital costs associated

with the installation or expansion of these systems the running and maintenance costs are very low

Figure 1: Existing PV Panels & Wind Turbine


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and the amount of practical maintenance required is very low (GSHP Assoc., n.d.), and further they

can be reversed in the summer to provide cooling. Ground source heat pumps are also eligible for

government incentive schemes such as the Renewable Heat Incentive.

Air Source Heat Pumps

Similar to ground source heat pumps, air source heat pumps work as heat exchangers from the

natural environment and whilst they have a lower level of efficiency and stability of use they are a

far simpler to install and can be sited with greater ease on rooftops away from disruption (Yougen,

n.d.). As with ground source they also attract various incentive driven savings whilst also avoiding

issues surrounding planning. The building has some such units already installed on the roof spaces

as shown in Figure 2 below.

Figure 2: Existing Air Source Heat Pumps


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Water Efficiency

Water is a limited resource and is as Envirowise (Now WRAP) point out in their guide to tracking

water use (Envirowise, 2008) it is also becoming an increasingly expensive resource. Any building

with a high level of occupancy will almost inevitably have a reasonable requirement for water use

through welfare facilities, and as the Ellison Building also houses technology workshops and

laboratories this requirement is further increased, so any measures which can be taken to reduce

water usage and/or improve the quality of water recycled are beneficial to the sustainability criteria

of the building.

Greywater Recycling

Greywater recycling is a technology which takes the waste water from typical domestic services such

as kitchen water and personal hygiene and treats it to enable it to be reused in non-potable

applications, the potential savings made are significant as is has been estimated that such water

makes up 50 – 80% of a typical households waste water. (TheGreenAge, 2014)

The technology could be utilised to provide water for the external landscaping as well as a number

of academic applications within the building such as workshop activities relating to the build

environment school such as concrete mixing. The plant required can be housed in a relatively low

requirement of space within the building envelope however there would be a requirement to install

a significant underground storage tank and there would also be a requirement to complete pipework

commissioning during times of low/no occupancy to facilitate the piping changes required.

A case study conducted by Aquaco (Aquaco, 2013) demonstrated that a similar educational facility in

Bridgend which would serve 1570 students was designed and built in September 2013 and required

a 30,000 litre underground storage tank and 2 x 1,250 litre vessels in plant areas as the major items.

Rainwater Harvesting

The Aquaco case study further identified that the technology is ideally suited for integration with

rainwater harvesting. The Ellison Building is highly suitable for the use of this technology as many

areas of the roof are as previously mentioned, either principally flat or have a series of pitched faces,

allowing for easy rainwater

redirection and collection.

The water collected via this method

would be able to top up and

supplement the greywater tank and

would not require treatment before

use.

Figure 3: E Block Workshop roofs


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Envelope Efficiency

The most significant area of improvement in this report was identified to be the external envelope of

the building. Whilst some blocks of the building have been modernised through the use of better

window systems and insulated panel systems the majority of the building consists of inefficient

windowed areas and exposed brick & concrete systems. These aged systems represent significant

energy losses from the building by heat transferral. These items shall be addressed individually

below.

Figure 4: Existing single pane window and stone facade

Windows / Glazing

An important opening observation is made by the European trade association for glass manufacturer

when referring to buildings:

“Traditionally, glazing was regarded as the "weak point" of the building envelope. This was

because single glazing or uncoated double glazing had a relatively high heat loss compared

to other parts of the building fabric.” - (Glass for Europe, 2014)

The impact of glass on energy conservation is sometimes underestimated yet a considerable portion

of the surface area of most buildings is made up of glass in one form or another either in the form of

windows or as an entire external façade. The use of glass as an energy conservation method is not a

new discovery however and has long been studied for enterprises such as the Passivhaus standard

which completed it’s first building in 1991 (BRE Group, 2011) and whilst the goal of this project was

not focused upon glazing solely it made considerable use of the technologies available to improve

the energy conservation performance of any windows.


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The principle behind this performance is that when glass absorbs light or heat, that energy is then

transmitted via either convected away by moving air or radiated out from the surface of the glass

itself (Efficient Windows Collaborative, 2014). Therefore what type of glass is used, any coatings

that are applied to it, and how it is installed and laid out play a major role in how this heat is handled

by changing its emissivity. The goal of altering the system is to reduce the emissivity of the glass to

reduce the heat transfer through it and one of the typical methods of doing this is by the use of

special coatings.

Standard clear glass has an emittance of 0.84

over the long-wave portion of the spectrum,

meaning that it emits 84% of the energy

possible for an object at its temperature. It

also means that 84% of the long-wave

radiation striking the surface of the glass is

absorbed and only 16% is reflected. By

comparison, low-E glass coatings can have an

emittance as low as 0.04. Such glazing would

emit only 4% of the energy possible at its

temperature, and thus reflect 96% of the

incident long-wave, infrared radiation.

(Efficient Windows Collaborative, 2014)

Such glass is often referred to as solar control

glass has been developed which is takes into

account these qualities and allows light to

enter the building spaces whilst reflecting away

the sun’s heat. (Glass for Europe, 2014)

External façade

The existing façade of the non-modernised sections of the building are primarily concrete and stone

clad and whilst this may have been aesthetically pleasing at the time of install it is not an

environmentally sound system when referring to energy efficiency or sustainability criteria. In

simple terms it is also difficult to maintain, requiring specialist contractors in order to supply any

replacements or clean effectively.

Importantly it is likely that there will be some element of thermal bypass present in the wall due to

the deterioration facing surface. Thermal bypass is described by Building Design Online as a

movement or airflow through or around the insulation layers which effectively reduces its effect

(BDOnline.co.uk, 2009)

When this is combined with the previously mentioned window frames’ lack of airtightness around

the seals and the potential for thermal bridging then the energy losses will be significant regardless

of the U-value of the windows or the façade materials.

Figure 5: Efficient Windows Collaborative - Glass Emissivity


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To improve this external façade could be developed using a transparent insulation system such as

those described in Cinzia Buratti (Cinzia Buratti, 2011) which can produce low thermal conductivity

values, tested as being able to produce 0.010W/m2K, which are could be installed within a

lightweight aluminium framework directly in front of the existing façade; this could also open the

option of recovering and selling the slate currently in place. A more suitable option however could

be to use metal facing insulation sandwich panels to bring the building in line with the already

modernised sections and produce a uniform appearance. The use of such panels should be

incorporated with the installation of modern double glazed windows, again in keeping with the rest

of the building and further improving the thermal performance of the building. The panels are

typically produced with a core of high density mineral wool insulation (Hunter Douglas, 2015).

Mixed Mode Ventilation

There is a potential to utilise ‘Mixed Mode’ ventilation principles within the Ellison Building as the

improved insulation and energy conservation methods described if gainfully employed will ensure

that the internal temperature are warm and acceptable during the day but conversely may not abate

over night. CIBSE defines ‘Mixed Mode’ ventilation as below.

“’Mixed mode’ is a term used to describe servicing strategies that combine natural with

mechanical ventilation and/or cooling in the most effective manner. It involves maximising

the use of the building fabric and envelope to achieve indoor environmental conditions, and

then supplementing this with degrees of mechanical systems, in all or part of the building” -

(CIBSE, 2000)

Figure 6: D Block modern external façade & double glaze windows


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By utilising the height of the building and the changes to the external envelope it will be possible to

create a night purge system by installing or modifying the mechanical ventilation at the highest point

to allow the lower night temperatures to cool the building interior overnight, taking advantage of

natural pressure systems such as stack and wind pressure. (Green Building Advisor, 2015)

Combination of technologies

There are a number of solutions described in this report which could be combined to offer greater

benefits; the most suitable for the building would be a greywater heat recovery system which would

offer further recycling of energy to the CHP already described by adding a heat exchanger unit to the

greywater storage vessel (reAqua , 2013). This is a natural combination to adopt and if the

investment was being made to install a greywater recovery system then this should be adopted to

maximise effectiveness.

The potential to change the existing fuel supply to the boiler systems from fossil fuel sources to

biomass sources has not been explored here due to the likely issues encountered with planning

permission associated with the requirement of additional buildings/space utilisation for storing and

feeding of such fuel sources, as well as the potential for logistics issues surrounding delivery of fuel.

It must be noted however that if a CHP system could be combined with a biomass fuel source then

the environmental performance of the building would be greatly enhanced (Biomass Energy Centre,

2011) along with the sustainability portfolio of the university.

Conclusion

In conclusion there is are wide ranging options described within this report which could be utilised

to increase the usability and environmental performance of the Northumbria University’s Ellison

Building; increasing it’s sustainability portfolio as well as offering running cost reductions.

The technologies described herein are not an exhaustive list of with some simple options being open

to review such as the standardisation of lighting systems through the functional spaces and the

switching of these systems to more energy efficient systems. It was also found there that was an

amount of maintenance/remedial work which could offer short term gains such as the re-insulation

of exposed piping or ductwork as well as the reapplication of sealing joints to windows throughout

the building.


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Bibliography

Aquaco, 2013. Grey Water Recycling | Grey Water for Institutions. [Online]

Available at: http://www.aquaco.co.uk/Grey-Water/Grey-Water-Recycling-Institutions

[Accessed 7 February 2015].

BDOnline.co.uk, 2009. Passivhaus diaries, part six: Thermal bypass. [Online]

Available at: http://www.bdonline.co.uk/passivhaus-diaries-part-six-thermal-bypass/3145769.article


Biomass Energy Centre, 2011. Combined heat and power (CHP). [Online]

Available at:

http://www.biomassenergycentre.org.uk/portal/page?_pageid=75,37173&_dad=portal&_schema=P

ORTAL


BRE Group, 2011. Passivhaus: The Passivhaus Standard. [Online]

Available at: http://www.passivhaus.org.uk/standard.jsp?id=122


CIBSE, 2000. Mixed Mode Ventilation. London: The Chartered Institute of Building Services

Engineers.

Cinzia Buratti, E. M., 2011. Transparent insulating materials for buildings energy saving:

experimental results and performance evaluation. International Conference on Applied Energy, Issue

3, pp. 1421-1432.

Department of Energy and Climate Change, 2015. Combined heat and power - Detailed guidance -

GOV.UK. [Online]

Available at: https://www.gov.uk/combined-heat-and-power


EDF Energy, 2015. How electricity is generated through solar power | EDF Energy. [Online]

Available at: http://www.edfenergy.com/energyfuture/solar-generation


Efficient Windows Collaborative, 2014. Welcome to the Efficient Windows Collaborative. [Online]

Available at: http://www.efficientwindows.org/lowe.php


Energy International, 2012. Welcome to Energy International | z. [Online]

Available at: http://www.energyinternational.co.uk/CHP_Notes.htm


Envirowise, 2008. Tracking water use to cut costs, Harwell: Envirowise.

Glass for Europe, 2014. Glass and energy saving: Q&A on energy saving glazing solutions for a low

carbon economy. [Online]


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Available at: http://www.glassforeurope.com/en/issues/faq.php


Green Building Advisor, 2015. The Stack Effect: When Buildings Act Like Chimneys. [Online]

Available at: http://www.greenbuildingadvisor.com/stack-effect-when-buildings-act-chimneys


GSHP Assoc., n.d. What is Ground Source Energy?. [Online]

Available at: http://www.gshp.org.uk/ground_source_heat_pumps.html


Hunter Douglas, 2015. Hunter Douglas: Mineral Wool. [Online]

Available at: http://www2.hunterdouglascontract.com/en-

GB/facades/insulated/wool/index.jsp?t=productDetail


Ingham, L., 2014. REVOLUTIONARY URBAN WIND TURBINE TO TRANSFORM CITY POWER

GENERATION. [Online]

Available at: http://factor-tech.com/future-cities/3981-revolutionary-urban-wind-turbine-to-

transform-city-power-generation/


reAqua , 2013. The reAqua+ Unit Waste water heat recovery system AND grey water system. [Online]

Available at: http://www.reaquasystems.com/how-reaqua-works/test-page/


The Carbon Trust, 2010. Introducing Combined Heat and Power, London: The Carbon Trust.

TheGreenAge, 2014. Greywater Recycling - TheGreenAge. [Online]

Available at: http://www.thegreenage.co.uk/tech/greywater-recycling/


University of Southampton, 2014. Micro wind turbines | Engineering and the Environment |

University of Southampton. [Online]

Available at:

http://www.southampton.ac.uk/engineering/research/impact/micro_wind_turbines.page


Yougen, n.d. Heat Pumps. [Online]

Available at: http://www.yougen.co.uk/renewable-energy/Heat+Pumps/


Front Page Image Courtesy of Wikimedia Commons -

http://commons.wikimedia.org/wiki/File:Ellison_Courtyard,_University_of_Northumbria_(geograph

_1681975).jpg

BE0898 2014/15 Worton

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