|
|
Current thermal research
The use of BMS to control facades
The use of double facades to facilite on demand ventilation
MODCELL: an innovative straw bale building system
Hempcrete
|
The use of BMS to control facades |
|
Status
|
Starting 1 January 2007
|
|
|
Duration
|
18 months
|
|
|
Partners
|
Centre for Window and Cladding Technology (lead)
Council for Aluminiun in Building
Carillion
Faber Maunsell
Max Fordham
SE Controls
Velfac
|
|
|
Objectives
|
There are two objects to this research. One is to identify
barriers to the use of BMS controlled automated facades and to report
on the ways that these barriers may be broken down. The other is
to look at additional functionality that will tip the balance in favour
of using BMS controlled automated facades.
|
|
|
|
This project will: |
•
Review operable components of facades that are currently available;
•
Review the limitations of current control strategies for facades,
particularly the control of glare;
•
Review the current actuator technology including how it interfaces
with BMS and its reliability;
• Report on the process of designing buildings with
BMS controlled automated facades, based on interviews with designers;
• Report on the construction of buildings that incorporate
BMS controlled facades;
• Investigate the additional functionality that
can be achieved by using sensors in different combinations, especially
to develop an actuator that can be used for controlling glare and limiting
solar over heating;
• Produce two reports. One aimed at clients
and architects to show the benefits of automated facades and how to design/specify
them, and the second for contractors explaining how these systems are
integrated with one another and with the façade and the building.
|
Top of page
The use of double facades to facilite on demand ventilation
|
|
|
Status
|
Starting 1 January 2007
|
|
|
Duration
|
24 months
|
|
|
Partners
|
Allies and Morrison
Bennetts Associates
Centre fro Window and Cladding Technology (lead)
Council for Aluminium in Building
Carillion
Hoare Lea
Sir Robert McAlpine |
|
|
Objectives
|
The objective of this work is to establish virtual precedents
of the use of double facades that will provide a pressure moderated
plenum from which air can be drawn for demand controlled ventilation.
|
|
|
|
This project will: |
• Undertake a desk study of wind events
in the UK. This will include a review of the minimum conditions
required to activate ventilation on demand;
• Postulate façade geometries for a
number of building layouts to optimise the use of the thermal stack effect;
• Model the performance of a pressure moderated
plenum of the double façade using CFD analysis. Different
geometries will be looked at;
• Study existing building projects to determine
the typical demands for ventilation and other factors controlled by the
building envelope including daylight, solar gain, and heat transfer;
• Determine rules for use at the outline design
stage using the information found above;
• Produce two reports. One will be written
for use by clients and architects and will present information required
to allow the inclusion of an effective double façade. The
other will present an engineering methodology for use by the cladding
and building services engineers.
|
Top of page
MODCELL: an innovative straw bale building system |
|
|
Status
|
Starting 1 January 2007
|
|
|
Duration
|
24 months
|
|
|
Partners
|
Agrifibre Technology Ltd
Centre for Window and Cladding Technology
Eurban Limited
Integral Structural Design
Lime Technology Ltd
University of Bath (lead)
White Design
|
|
|
Objectives
|
This project aims to further develop an innovative sustainable
building system using straw bale construction technology. Modcell
building and cladding panels comprise a timber frame in-filled with straw
bale insulation. The bales are compacted and reinforced with steel
bars and protected with lime or cement based plaster coats. The
project seeks to investigate and perfect the manufacturing methods and
develop robust design data. The study will comprise laboratory and
analytical research investigations, design studies, environmental performance
modelling, life cycle assessment, and in-situ monitoring of prototypes.
|
|
|
CWCT are involved in the thermal analysis and condensation risk
assessment of the constructions. We will be carrying out:
|
• A literature review of material properties
to obtain representative values for the thermal conductivity and vapour
resistivity of straw bales;
• One-dimensional static thermal analysis
and condensation risk assessment in order to investigate the effect of
bale and render thickness;
• One-dimensional dynamic thermal analysis
and condensation risk assessment in order to investigate the effect
of bale and render thickness;
• Two- or three-dimensional thermal/moisture
transfer analysis at the junctions between the Modcell panels and windows
and doors;
• Three-dimensional thermal/moisture transfer
analysis at localised thermal bridges.
|
Top of page
|
Hempcrete |
|
|
Status
|
Current
|
|
|
Duration
|
3 months
|
|
|
Partners
|
Lhoist UK
Lime Technology Ltd
University of Bath
|
|
|
Objectives
|
Hemp construction is considered environmentally friendly and highly
sustainable. The hemp can be mixed with lime to form ‘Hempcrete'
and can then be used as a building material in place of brick/blockwork.
A project at Haverhill in Suffolk built two houses out of Hempcrete
and these will be used as the basis of some of the following work.
These houses were identical to some traditionally constructed houses
so comparisons between the two could be made.
|
|
|
CWCT will be studying the thermal performance of the Hempcrete
construction. This will include:
|
• Reviewing the construction details and comparing
them with those of a traditional building with the same geometry and
usage;
• Assessment of all the building elements
by either simulation or calculation;
• Dynamic heat transfer analysis to compare
the temperature variation of hemp wall over the course of 24 hours with
that of a brick-block wall with identical geometry;
• The effect of the surface finish.
Different finishes will result in a different surface emissivity, and
affect the therefore the U-value;
• Looking at, and comparing, the heat loss
due to air leakage through both houses at Haverhill;
• Inputting data obtained previously into
whole building energy consumption software to calculate the overall CO
2 emission rate for the hemp house and the brick-block house
at Haverhill.
|
Top of page
|