2. REDUCING AIR CONDITIONING
UNITS & SYSTEMS
RACUS® ceiling tiles are installed into new or
existing suspended ceiling grids as a like for
like replacement tile that are common place
in old and modern commercial buildings.
Incorporating the latest bio-based phase
change technology, the passive RACUS® tile
gives instant energy savings over HVAC
systems without on going maintenance or
replacement costs.
3. How Phase Change Materials (PCMs) Work
Phase change materials store energy in a latent form, undergoing an endothermic
process to store heat energy when ambient temperature rises and an exothermic
process to release this energy when the temperature drops. In building applications,
these processes occur within a narrow temperature range close to the human
comfort temperature with large amounts of heat being absorbed and released.
Solid Liquid Solid
As the internal room temperature As the internal room temperature
increases, the PCM core goes from a cools, the PCM core goes from a
solid to liquid state and in doing so liquid to solid state , releasing the
absorbs and stores latent heat. stored latent heat.
During the transition phases, the core of the microcapsule will melt as the room
temperature reaches the transition temperature and in doing so will absorb latent
heat where it will be stored until such time that the room temperature cools.
Phase Change Material encapsulated in RACUS®
4. RACUS® Ceiling System
The RACUS® ceiling tile is designed to be incorporated into either an existing
suspended grid system as part of a commercial retrofit or new build project. The tiles
can be easily installed over a short period or out of hours so as to reduce the impact
on the building users and provides an instant solution to reduce the energy and
carbon footprint of the building.
As the tiles are not permanent fixtures
within the ceiling grid, the tiles can be
manoeuvred around the building to capture
areas of significant heat gains. This can be
around high glazed areas that suffer from
solar gain, above refrigeration units where
high heat gains are generated from the
motor to cool the unit or localised areas
such as meeting rooms with high
occupancy within offices.
It is often the case that the use of the
building changes, particularly regarding the
number of occupants. The result of which
would place a significant higher demand on
conventional HVAC systems. With the
RACUS® system, additional tiles can be
incorporated into the existing grid or
replaced with tiles with higher heat storage
capacities at a fraction of the cost of
upgrading or replacing HVAC systems
• Passive system with no energy or long term maintenance and life cycle costs
• Reduces the carbon footprint of the building through reduced energy costs.
• High heat storage capacity.
• Flexible
• Non invasive to building users or equipment
• Quick-fit solution
5. RACUS® Preformed Natural Mineral Tile
The RACUS® Preformed Natural Mineral Tile incorporates bio-based phase change
material to increase the thermal mass and latent heat storage capacity over
traditional mineral fibre tiles.
The RACUS® Preformed Mineral tile are used either as a replacement
tile for existing suspended ceilings as part of a retrofit project or as a
complete system for new build construction.
In addition to the heat storage capabilities, they have excellent
hygroscopic characteristics, absorbing the excess humidity in the
atmosphere, and then gradually restoring the balance in dry and hot
periods and as such improving the atmospheric microclimate in the
rooms.
The tiles are supplied with the option of two latent heat storage
capacities - 30Wh/m² and 65Wh/m² with a return of investment
around five years. Also in a choice of surface textures and edge details
including square or tegular.
Our bio-based phase change material has been tested to over 45,000
thermal cycles which is equivalent to a lifetime performance of over
122 years without loss of performance and biodegradability testing of
within 12 months compared to over 100 years for alternative paraffin
wax based PCMs.
The RACUS® Preformed Tiles
are 100% Recyclable
6. RACUS® Metal Ceiling Tile
Combining the performance of a metal ceiling tile with the ability to reduce the
energy and carbon footprint of a building through the incorporation of the RACUS®
PCM material, the RACUS® Metal Ceiling system is a passive solution that offers a
quality finish to new or existing suspended ceiling systems with a latent heat storage
capacity option of 85Wh/m² or 169Wh/m².
Through testing in thermal chamber testing and live exemplar projects, the RACUS®
metal ceiling tile has achieved up to 97% energy savings over existing HVAC systems
and a reduced room temperature of up to 7°C under zero ventilation conditions.
The RACUS® metal ceiling system is available as either a standard
plain metal ceiling tile or as a perforated tile where there is an
acoustic performance requirement. In both formats there is a choice
of latent heat storage capacities to meet the requirements of the
building.
Passive Product of the Year
2012
7. RACUS® ceiling tiles incorporating bio-
based phase change materials, allow
thermal mass to be incorporated into new
build and retrofit projects faster and more
economically compared to alternative
construction methods such as concrete,
both from a project cost and
environmental perspective.
8. Thermal Mass in Lightweight Structures
A thermal mass is a material that absorbs
heat from a heat source, and then releases
it slowly. In buildings, thermal mass is
provided by the structure of the building,
the level of which is determined by the
material the building is constructed from.
Buildings constructed of lightweight
materials such as steel or timber are not
considered to have good thermal mass
properties compared to concrete, brick and
stone for the reasons that they either have
low thermal conductivity performance
therefore a low ability to absorb heat, or
can absorb large amounts of heat but the
rate of heat release is also high. Concrete,
brick and stone are all materials that are
able to absorb and store heat until the
surface of the material is exposed to cooler
conditions and its temperature begins to
drop. When this happens, the stored heat
transfers to the cooler surface and is
released back into the building.
Stabilising effect of thermal mass on internal temperature – Source: The Concrete Centre
9. The ability to absorb and release heat in this way enables
buildings with thermal mass to respond naturally to changing
weather conditions, helping to stabilise the internal
temperature and provide a largely self-regulating
environment.
The role of a buildings thermal mass can be of benefit throughout the year. During
the warm weather in summer, heat will be absorbed by the thermal mass in order to
prevent overheating in the building, providing a more comfortable living or working
environment in naturally ventilated building or in air-conditioned building, reduces
the cooling demand on mechanical air-conditioning systems. Allowing cool air to
ventilate the building at night allows heat that has been stored throughout the day
to be removed.
This daily heating and cooling cycle works particularly well in countries such as the
UK where night time temperatures are typically around 10 degrees less than peak
daytime temperatures, making it an effective way of drawing heat from the structure
of the building. The benefits of thermal mass during winter when heating demands
are at their greatest, can help to reduce fuel consumption when used in a passive
solar design. In doing so, solar gains in winter, along with heat produced from
appliances, cooking, people and lighting, uses the thermal mass to absorb gains
which is then slowly released overnight as temperatures fall, helping to keep the
building warm and reducing the need for additional heating.
10. RACUS® Ceiling Tile Applications
Schools
Adopting an economic approach to the construction of school
buildings often results in the construction of lightweight structures
with very low thermal mass. This approach does not allow any high
heat gains to be absorbed by the thermal mass parameters of the
building.
In comparison to a typical office environment, classrooms have a higher density of
occupation which along with heat output from PCs, contributes to higher heat gain loads.
Thermal Mass can be improved using RACUS® ceiling tiles without the loss of internal floor
space.
Natural Ventilation is becoming increasingly popular in school design as a substitute for
mechanical ventilation systems but this only provides between 30 – 40W/m² . Combining
the RACUS® ceiling tile with natural ventilation system provides additional thermal comfort
of up to 169Wh/m² utilising a passive system
Commercial
The demand for air conditioning in buildings worldwide is growing
rapidly in response to increased building use and demands for
comfort cooling by occupants. As such the energy consumed by air
conditioning systems is expected to double from current levels by
2020 and already accounts for over 30% of a buildings total energy
use.
This increase conflicts with the Governments goals to reduce the UK’s total CO2 emissions
and makes it increasingly difficult for companies to meet its carbon reduction targets under
the Carbon Reduction Commitment.
A typical air conditioned building has double the energy costs and associated CO2 emissions
of a natural ventilated building as well as increased capital and maintenance costs. In the UK
there are relatively few days where the temperatures are very high, however using comfort
cooling for just this short period of time can cost as much as a whole years heating.
Incorporating the RACUS® ceiling tile into commercial buildings not only add thermal mass to
lightweight structures but will reduce the energy demand of existing air conditioning systems
by absorbing excess latent heat gains.
11. RACUS® Ceiling Tile Projects
Ofcom Head Office
As part of a project for facility management company
MITIE, the RACUS® ceiling tile was installed into one of the
meeting rooms at Ofcom’s London Head Office.
The performance of RACUS® was monitored and compared to an adjacent meeting room that
was both identical in size and layout and that used conventional fan coil units to manage the
room temperature.
In both meeting rooms, MITIE installed room three temperature loggers. One was to monitor
room temperature and two were installed on each of the FCU outlet grilles. These would
monitor when the FCU was providing heating or cooling to the room. The number of
occupants of each room and period of use was also monitored.
Monitoring was carried out over a 45 day period, the results of which concluded a 97%
reduction in the use of the fan coil unit in the room with RACUS®.
27
26
25
Temperature (°C)
24
23
22
Temperature
21 Difference of
20 4.33°C
19
Time (hh:mm:ss) Room without Room with
RACUS® RACUS®
12. With Without
Time
RACUS® RACUS®
09:00:00 22.67 23
09:30:00 22.67 23
10:00:00 22.67 23
10:30:00 22.67 23.33
11:00:00 22.67 24.67
11:30:00 22.67 25.67 Room
Room with
12:00:00 22.67 25.67 without
12:30:00 22.33 25.33 RACUS®
RACUS®
13:00:00 22.33 25
13:30:00 22.33 25 FCU Use (hours) 257.67 7.01
14:00:00 22.33 24.67
14:30:00 22 25.33
Total kWh Use 3092.04 84.12
15:00:00 22 25.33 KgCO2 1304.84 35.50
15:30:00 22 25.67
15:45:00 21.67 26
16:00:00 22 26
16:30:00 22 25 Estimated Savings £ KgCO2
17:00:00 22 24.67 Per Month (20 days) 121.79 564.15
Example of Monitored Data showing
temperature (°C) differences
Per Annum (250 days) 1,522.34 7051.90
Payback Period 2.92 Years
MITIE Summary Report
“MITIE has now trialled the RACUS® PCM products
on a number of its client’s buildings and the results
have been very positive. We are always looking
for innovative new technologies and solutions, and
are pleased to add this product to our tool kit as
part of the MITIE CarbonCare approach which
supports our clients to make financial savings and
reduce carbon emissions.”
Paddy Stanley, Technical
Solutions Manager at MITIE
13. RACUS® Ceiling Tile Projects
Department of Energy & Climate Change
The RACUS® ceiling tile was installed into the Department
of Energy & Climate Change (DECC) building as part of the
TSB Energy Efficient Whitehall initiative.
From a Dynamic Computer Simulated Model of the building
which was completed by the Institute of Energy and
Sustainable Development at De Montfort University,
projected energy and carbon savings of over 55% were
calculated.
Zone Annual Normalised Zone Annual Normalised
Cooling Annual Cooling Carbon Carbon
Ceiling Type
Energy Energy Emissions Emissions
(kWh) (kWh/m2) (kgCO2) (kgCO2/m2)
Conventional Tile 3177 128.6 1706 69.1
RACUS® 1441 58.4 774 32.35
Carbon Savings 932 37.7
Percentage
55%
Saving
Scaled across the total floor area of the building this
would equate to an electrical energy saving of over
811,000kWh and carbon saving of 256 tonnes per
annum.
These figures are based using Defra 2008 CO2
conversion factor of 0.537kgCO2 per kWh of electricity
and show a carbon saving (visual 14) of 37kgCO2 per
m2.
14. RACUS® Ceiling Tile Projects
Great Ormond Street Hospital (GOSH)
In August 2010, the RACUS® ceiling tile was installed into
one of Great Ormond Street Hospital’s consultation rooms
due to a serious problem of overheating.
The room, which is located on the lower ground level, is not serviced by any HVAC systems
and relies on only natural ventilation from the window and partial protection from solar gains
by a window canopy. Roller blinds have also been installed. Despite these measures, the
internal room temperatures have been reported between 30°C - 36°C.
Prior to the installation of the RACUS® ceiling tiles, Facilities
Management company MITIE installed room temperature
monitors in both the consultation room in which RACUS® was to
be installed and also an adjacent and identical size consultation
room, in order to capture baseline temperatures against which
the performance of the RACUS® tiles will be compared.
The existing suspended ceiling within the consultation room
amounted to 64% of the total ceiling area. Of the total area, 32%
of the existing tiles were replaced with RACUS® ceiling tiles.
The 600mm x 600mm, RACUS® ceiling tiles were pre-treated with an anti-microbial finish
and additional suspension hangers were also installed.
30
28
26
Temperature (°C)
24
22
20
3.67°C
18
Difference
16
14
Time (hh:mm:ss)
Room A Room B Outside
(without RACUS®) (with RACUS®) Temperature
15. RACUS® Ceiling Tile Projects
BRE (Building Research Establishment) Victorian
Terrace
Located within Building Research Establishment’s (BRE) site Project
in Watford, a disused Victorian terrace has been
refurbished into three energy efficient spaces to fit 21st
century living. The project aims to inform and provide
guidance to the industry on how to contribute to the
Government’s target to reduce CO2 emissions.
Part of the development incorporates an information and
training centre where visitors can learn best practice for
refurbishment and about new and innovative materials.
Within the presentation theatre, the RACUS® ceiling tile has
been installed along with acoustic mineral tiles.
“BRE recognise the significant
impact that Phase Change Materials
will have on the future design of our
homes, both of new build and
refurbishment. The use of the RACUS®
product in our Victorian Terrace
exemplar project here at BRE, will
allow us to monitor the benefits in
passive cooling, and the advantages of
building thermal mass into existing
structures to address climate change
and reduced energy use.”
John O’Brien, Principal Consultant,
Refurbishment & Regeneration, BRE
16. Datum Phase Change Ltd
www.datumphasechange.com
info@datumphasechange.com