What is cavity wall insulation?

Cavity wall insulation fills the gap between the inner and outer leaves of a wall with mineral wool, beads or foam. The material is blown in through small holes drilled in the outer wall.

How can a solid wall be insulated?

A solid wall can be lined with insulated boards inside or covered with an insulated render system outside. Solid wall insulation costs far more than filling a cavity.

Why is loft insulation a cost-effective improvement?

Warm air rises, so an uninsulated roof loses a large share of a home's heat. Mineral wool laid between and over the joists is cheap and quick to install.

What is meant by the air tightness of a building?

Air tightness describes how well a building resists uncontrolled air leakage through gaps in its fabric. Leaks occur around windows, doors, floors and service pipes.

CCEA A-Level Environmental Technology 3930

Fossil Fuels

Topic overview Coal, oil and gas in modern society Reserves, lifespan and accessibility Fossil fuel combustion and the IPCC evidence Carbon trading schemes Fossil fuel demand, emerging economies and fuel security Environmental impacts of fossil fuel use

Global Action on Energy Conservation and Climate Change

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Macrogeneration

Topic overview Conservation of energy and the simple generator Thermal power stations and steam turbines Direct and indirect renewable electricity Electricity transmission through the National Grid Smart grids and interconnectors Combined heat and power

Microgeneration

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Energy From Wind

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Energy Storage

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Plastics for the Future

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Renewable Energy Investigations

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Sustainable Development

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Waste Management

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Waste to Energy Technologies

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Land Contamination and Remediation

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Hydrogen Fuel Cells

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Transport System Challenges

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Energy Performance of Buildings

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Emerging Technologies

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Sustainable Urban and Rural Communities

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The Code for Sustainable Homes

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Energy Performance of Buildings

Insulation, air tightness and glazing

3 things to know
A2 1

Overview

How insulation works, where heat is lost, cavity, solid wall and loft insulation, air tightness and draught-proofing, controlled ventilation and heat recovery, double and triple glazing, gas fills, thermal bridges and poor installation.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

What does a building's air tightness describe, and why does poor air tightness waste energy?

Key term

How does insulation improve a building's energy efficiency?

Key term

Where does an uninsulated house lose most of its heat?

Questions from this subtopic

Each one with the model answer underneath.

1
How does insulation improve a building's energy efficiency?
Model answer
Insulation traps still air or gas in small pockets, which slows conduction and convection. Less heat escapes through the fabric, so less heating is needed.
2
Where does an uninsulated house lose most of its heat?
Model answer
The walls usually lose the largest share, followed by the roof. Windows, floors and draughts account for the rest.
3
What is cavity wall insulation?
Model answer
Cavity wall insulation fills the gap between the inner and outer leaves of a wall with mineral wool, beads or foam. The material is blown in through small holes drilled in the outer wall.
4
How can a solid wall be insulated?
Model answer
A solid wall can be lined with insulated boards inside or covered with an insulated render system outside. Solid wall insulation costs far more than filling a cavity.
5
Why is loft insulation a cost-effective improvement?
Model answer
Warm air rises, so an uninsulated roof loses a large share of a home's heat. Mineral wool laid between and over the joists is cheap and quick to install.
6
What is meant by the air tightness of a building?
Model answer
Air tightness describes how well a building resists uncontrolled air leakage through gaps in its fabric. Leaks occur around windows, doors, floors and service pipes.

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Fossil Fuels

Global Action on Energy Conservation and Climate Change

Macrogeneration

Microgeneration

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