Construction technology & Innovation

Technology 6: Construction technology & Innovation

CW1 – Identify and evaluate innovative construction technologies

Contents

Abstract

Introduction

The building allocated – School of Social Science:

It’s existing, or proposed, construction:

The site and location:

Proposal

(a) Mineral wool

(b) Polyurethane

(c) XPS – Extruded Polystyrene

2. Windows: Double Glazing

3. Electricity consumption

Bulbs: LED Lights

4. Cool roofs

Cladding: Rainscreen:

Conclusion:

References:

Abstract

Generally, existing buildings comprises the largest segment of the built environment and as such, it is important to carry out energy conservation retrofit in order to reduce energy consumption, cost of heating, cooling and lighting in building

Dealing with energy loss from the buildings is one of the major objectives to reach greater suitability. It relates to innovation in building design use, through environmental impact and sustainability.

The report will demonstrate the understanding of construction technology (study of the method and equipment used to build structures), and how it can be applied to existing buildings in order to reduce their energy consumption.

The report will also provide proposals to help reduce the energy consumption, together with the rationale behind the proposals and how such proposals are compactable with the building allocated.

Introduction

An energy efficient building reduces maintenance and utility cost, and in most cases it improves durability, increases comfort, lessen noise and creates a healthy & safe indoor environment.

Buildings are responsible for almost 50 per cent of the UK’s energy consumption and carbon emissions. 

It is therefore crucial to reduce energy consumption buildings because it means fewer emissions of greenhouse gases, which is the main cause of global warming.

Heat energy is lost from a building by conduction through the built envelope and fabric components (walls, roof, windows and floor) of the building and this depend on:

• The Conductivity of the component (its U value – the amount of energy per second (Watts) for 1m2 of surface when there is 1 degree temperature difference between inside and outside )
• The Area of the component
• The Temperature difference across the component.

The building allocated – School of Social Science:

This report is based on an existing building of six story floor. The Westminster University owns the building and is used for academic purposes. The building houses the school of social science, which include the following departments:

• International relations
• Criminology
• Politics & international relations
• Sociology

It’s existing, or proposed, construction:

The building is referred to as the Wells Street Campus. It was built in the 60s as part of expanding its main campus in Regent’s Street. It is likely to have a cavity wall (the outer leaf made of brick, and the inner layer of brick or concrete block)

The site and location:

The school of social science is located at 32/38 Wells Street Fitzrovia London W1T 3UW. The building is located in the heart of London, surrounded by many commercial activities and close vast array of local amenities. It is within a short walking distance to both oxford circus and Tottenham road stations.

Proposal

For a building to be energy efficient, the important strategy is to first apply energy saving. Older buildings use a great deal of energy and as such retrofitting the premises with more sustainable measures like thermal insulation will be an appropriate step to take

The allocated building is suitable for thermal insulation because it meets the following criteria:

• The external wall are unfilled cavity wall.
• The brickwall of the building is in good condition.
• The walls are not exposed to driving rain
• The building is not at risk to flooding.

1. Thermal Insulation

Cupapizarras.com, states that “thermal insulation is a great solution to reducing energy consumption by preventing heat gain or loss through the building envelope”. The three main commonly used insulating materials are mineral wool, polystyrene beads or polyurethane foam.

(a) Mineral wool 

Mineral wool usually referred to as the “open vapour system” in the construction industry. Cupapizarras.com, 2015 explains that “the system works on the principle of moisture particles effectively finding their ways from one side to the other through the material and the walls. The mineral wool insulation also has the ability to resist a fire breakout for hours, allowing agent time to mitigate the issue. The crimp fibres on the wool absorb sound and therefore offers better acoustics as well as energy saving properties”. Because of these additional benefits (and considering the height of the building), the mineral wool insulation will be a suitable material for the insulation process.

U value for mineral wool is 0.313 (W/mK). (See below for calculations)

(b) Polyurethane

Combines the features of thermal conductivity and lightweight. It provides a highly effective air barrier and is water vapour and resistance to water. One of the benefits of using polyurethane insulation is that is requires no maintenance to keep the insulation working, air tightness and sound reduction.

U value for polyurethane is 0.219 (W/mK). (See below for calculations)

(c) XPS – Extruded Polystyrene

Extruded polystyrene is a solid granule of polystyrene resin. Herrenbruck, describes the advantages of polystyrene as its “ability to assist with moisture management, resisting both water absorption and freeze cycle”.

U value for extruded polystyrene is 0.288 (W/mK). (See below for calculations)

The approved documents states that “any new thermal element that are built must comply with Part L of the Approved document, schedule 1 to the building regulations. It also states that the renovation must be carried out as to ensure that the whole of the element complies with paragraph of schedule 1”.

These proposals are compatible with the building because it allows the existing wall to contribute to thermal mass. Thermal insulation do not in most cases leave any mess behind once work is completion.

No damage is done to the existing wall as holes of around 22mm in diameter is usually drilled into existing wall at interval  with special designed equipment, and insulating material blown into the holes. Once completed the holes in the brick wall are then filled. 

Benefits of insulating external wall:

• Reducing heat loss and energy bills
• Reducing draughts and increasing the sense of comfort
• No disruption during installation
• No reduction in floor area
• It allows wall to contribute to thermal mass
• It improves weather proofing and sound resistance
• It increases the life of the wall
• It reduces condensation on internal wall

2.     Windows: Double Glazing

Upgrading the existing windows of the allocated building to double glazing will also help reduce the energy consumption.

Double glazing windows works by preventing heat loss through the windows, stopping draughts through the window and frames and work as an insulator just like cavity wall insulation.

For heat energy to be transferred from hot to cold area, a conductor is required but because the trapped air in – between the glass is a poor conductor, it will reduce the heat loss from the inside of the building, making the building to stay warmer for longer period.

3.     Electricity consumption

Most commercial buildings consume more electricity than they do need and as such can be brought down by making sure lights are turned off when not required (e.g. at nights), lowering the temp in heated rooms and increasing it slightly when it’s cold

Bulbs: LED Lights

• Use of energy efficient bulbs
• Daylight co which is capable of controlling light when required
• A system such as infrared sensor which will switch off lights in common space such as toilets, corridors, and stairwells.
• Replacing tubes with bulbs to reduce lightly level

Using LED light can provide many environmental advantages to reduce carbon emissions. Sepco states that “LED lights are up to 80% more efficient that traditional lighting such as fluorescent tube lights. Around 95% LED energy is transformed into light and 5% is wasted as heat.

Equipment in building

Sufficient energy efficiency savings can be achieved by upgrading computers and other devices

As the building is mostly used for academic purposes, equipment such as computer consume a lot of electricity and as such should be put in their most efficient setting and switched off when not in use.

4.     Cool roofs

The roof of the building can also be painted white (or light coloured) coating. This will reflect solar radiation by about 85%, which will reduce heat transfer and cool roof can also be combined with solar panel placement

Conclusion:

An energy efficient building reduces maintenance and utility cost, in most cases it improves durability, increases comfort, lessen noise and creates a healthy & safe indoor environment. It crucial to reduce energy consumption in a building because it means fewer emissions of greenhouse gases, which is the main cause of global warming.

Before embarking on such a huge project in retrofitting the building for energy and sustainability improvement, it is important to consider the following constraints.

Location – because the building is located in a busy area, every effort should be made to minimize disruption to a minimum. One way of achieving is to carry out the works during weekends or holidays when the building is empty.

Cost- additional costs such as erection of scaffolding and removal or replacement of pipes and cables that are fixed to the wall may be incurred.

External insulation is less troublesome and it keeps the walls warm and dry, decreasing the worry of moisture. However there may be need to extend the eaves, window sills and reveals. This is because disruptive to external plants, as well as pipework. This type of insulation transforms the appearance of a building.

Internal wall insulation is cheaper to install, though it loses some of the floor space and it is troubling to cabling, fixtures such as skirting boards and door frames and pipework, however the appearance of the building does not change.

References:

• Bautexsystems.com. (2017). Energy Efficient Buildings: 71 Ways to Make Your Building More Energy Efficient – Bautex Systems. [online] Available at: https://www.bautexsystems.com/company/news-events/energy-efficient-buildings [Accessed 23 Dec. 2018].
• CSANYI, E. (2016). 8 actions to improve energy efficiency in heating systems | EEP. [online] EEP – Electrical Engineering Portal. Available at: https://electrical-engineering-portal.com/8-actions-to-improve-energy-efficiency-in-heating-systems [Accessed 23 Dec. 2018].
• Richmondglass.co.nz. (n.d.). Double glazing benefits | reduces condensation, heat loss, energy usage, noise, interior fading. [online] Available at: http://www.richmondglass.co.nz/benefits-double-glazing [Accessed 23 Dec. 2018].
• Schneider Electric. (2018). How to Reduce Energy Consumption in Commercial Buildings – Schneider Electric. [online] Available at: https://www.schneider-critical.com/blog/reduce-energy-consumption-commercial-buildings/ [Accessed 23 Dec. 2018].
• Sepco-solarlighting.com. (2013). The Advantages of LED Lights for the Environment. [online] Available at: https://www.sepco-solarlighting.com/blog/bid/145611/the-advantages-of-led-lights-for-the-environment [Accessed 23 Dec. 2018].

Appendix

Calculations for U value