The document discusses research into insulating existing air cavity walls in buildings to improve energy efficiency. It outlines the background on air cavity wall construction and the benefits of filling the cavity with insulation. The research aims to assess different insulation materials and thicknesses to identify the most effective strategies. The methodology involves field measurements, computer simulations, and data analysis to evaluate the impact on thermal performance, energy consumption, moisture levels, and indoor comfort. Key findings are that cavities filled with 150mm of insulation provide better thermal insulation than thinner cavities, and that polyurethane foam is effective at moisture control and presents little risk of condensation. Filling cavities offers flexibility and can be incorporated into new or retrofit construction projects.

1. Air Cavity
Building Walls:
Paper Review
-Abinash Dev

2. TABLE OF CONTENTS
01
02
03
BACKGROUND
RESEARCH SUBJECT
METHODOLOGY
04 FINDINGS

3. BACKGROUND OF
THE RESEARCH
01

4. BACKGROUND
The paper intends to discuss the use of cavity wall insulation in existing
buildings for energy improvement. Air cavity wall construction is a method of
building exterior walls that incorporates an air gap or cavity between two layers
of masonry or cladding.
The technique is widely used in both residential and commercial construction
and offers several benefits, including improved thermal insulation, moisture
resistance, and soundproofing.
Air cavity walls already provide some level of thermal insulation due to the air
gap between the layers. However, the opportunity to further improve energy
performance lies in filling the cavity with insulation material. This approach
offers several benefits and can be a valuable strategy in enhancing the overall
energy efficiency of buildings.

5. INTENT OF RESARCH
 Assess Thermal Performance: The research aims to compare different
insulation materials, thicknesses, or installation techniques to identify the most
effective strategies for improving thermal performance.
 Investigate Energy Savings: Research aims to monitor and quantify energy
consumption in buildings with insulated cavity walls compared to traditional
non-insulated walls.
 Evaluate Indoor Comfort: Research aims to assess the impact of air cavity wall
insulation on indoor comfort parameters. This includes studying factors such as
temperature distribution, drafts, and humidity levels within insulated walls.
 Evaluation of Insulation Materials: Research aims to find materials suitable for
filling cavity walls. The choice of the most suitable material must be made
according to the specific objectives, the comparison with the reference values,
and the local climatic conditions

6. METHODOLOGY
 Research Design: Define the research objectives, research questions, and
hypotheses. Determine the scope of the study, target building types, climate
zones, and other relevant parameters. Decide on the specific variables to be
investigated, such as insulation materials, thicknesses, installation methods, and
measurement techniques.
 Field Measurements: Conduct on-site measurements to gather data on the
thermal performance of air cavity wall constructions with insulation. This may
involve installing temperature sensors, heat flux sensors, and moisture sensors at
various locations within the wall system. Measure parameters such as
temperature differentials, heat transfer rates, relative humidity, and moisture
content. Consider long-term monitoring to capture seasonal variations and
dynamic responses.
 Computer Simulations: Utilize computer simulation software, such as energy
modeling tools or computational fluid dynamics (CFD) software, to simulate the
thermal behavior and energy performance of air cavity walls with insulation.

7. Data Analysis: Analyze the collected data using appropriate statistical methods,
numerical analysis, or modeling techniques. Compare different insulation materials,
thicknesses, or installation methods to evaluate their impact on thermal performance,
energy consumption, moisture management, and indoor comfort. Interpret the
findings in light of the research objectives and research questions.

8. Legend for the
following figures:
AC = Air Cavity
CI = Cavity Insulation
CI + P = Cavity
Insulation + Thermo-
Plaster
(internal/external: Pi
and Pe when needed)
RW = Rock Wool
PF = Polyurethane
Foam
UR = Urea Resin

9. FINDINGS
In general, if a 150 mm cavity is available, its filling provides better results than
cavities with lower thicknesses, both in terms of thermal insulation and dynamic
parameters, while there may be a high interstitial condensation risk, depending
on the filling materials.
In the air cavity walls or cavities filled with polyurethane foam, there is no
interstitial condensation, even if the internal plaster is replaced. Polyurethane
foam has a high vapor resistance factor, and therefore, the risk of condensation
can be very low or absent.
Moisture Control: Filling the cavity with insulation can contribute to better
moisture control within the wall system. Insulation materials with moisture-
resistant properties help manage condensation by preventing the buildup of
moisture within the cavity. This reduces the risk of mold growth and potential
damage to the structure.

10. • Flexibility and Adaptability: Filling the air cavity with insulation does not
significantly alter the construction process or the structural integrity of the
wall system.
It can be incorporated during initial construction or retrofitting projects,
offering flexibility in implementing energy performance improvements.
Additionally, the choice of insulation material can be tailored to meet
specific energy efficiency goals and local building regulations.
The discussion presented on cavity walls, their diffusion, and insulation is
intended to stimulate the renovation actions on existing buildings focused
on this building element and to provide indication on the advantages of the
promotion of this technique not only locally by designers but in general by
public authorities and government bodies.