Civil Engineering Reference
In-Depth Information
to lightweight elements such as boards, blocks, glass etc. The advantage over traditional
heat-storage media is that weight and volume are reduced (for comparable performance)
and the phase change temperature can be programmed according to specific needs.
Very interesting fields of application include highly-insulated, lightweight buildings
with small need for thermal storage, or refurbishment of existing, poorly performing
buildings lacking in thermal storage (in this case, mass cannot be added to the existing
structure). PCMs can be used to store solar energy during the day, to shave the peak cool-
ing loads in summer, to store off peak energy during the night, etc.
Some studies showed the potential to integrate PCMs in building components that can
stabilise indoor temperatures either passively or in synergy with (typically radiant) heat-
ing/cooling systems (Imperadori et al.
2006
) (Figs.
3.2
,
3.3
).
The correct use of thermal mass in highly-insulated buildings requires accu-
rate studies, especially in warm climates; thus it is necessary to spread the use of
dynamic simulation tools (assessment of dynamic behaviour of building) to ensure
correct design of insulation, thermal storage capacity, glazed components and ven-
tilation. A mixed approach could be adopted, whereas, under certain conditions,
standard buildings would be audited with steady-state calculations while more
complex buildings would be designed using dynamic simulation tools. California
pioneered this double prescriptive/performance approach in its 2005 energy regu-
lations, updated with the 2008 standards (California Energy Commission
2008
).
Example: Arup Office, Solihull, UK
The workplace pavilions are designed to
include generous ceiling heights and roof pods for natural ventilation and maxim-
ised daylight, occupant control, excellent air-tightness, exposed thermal mass for
passive cooling, visual and direct links between all floors and with the surrounding
landscape and internal spatial flexibility.
The bespoke timber facade consists of cladding with louver timber shutters in
Western Red Cedar controlling solar gain. Members of staff have manual and
motorised control of the shutters and windows.
Fig. 3.2
The “PCM blanket”
developed in the European-
funded project Changeable
Thermal Inertia Dry
Envelopes (C-TIDE)
