Passive thermal comfort from the most advanced phase change technology

Datum Phase Change

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.

REDUCING AIR CONDITIONING UNITS & SYSTEMS

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.

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.

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.

How Phase Change Materials (PCMs) Work

As the internal room temperature increases, the PCM core goes from a solid to liquid state and in doing so

absorbs and stores latent heat.

As the internal room temperature cools, the PCM core goes from a

liquid to solid state , releasing the

stored latent heat.

Solid Liquid Solid

Phase Change Material encapsulated in RACUS®

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

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.

RACUS® Preformed Natural Mineral Tile

The RACUS® Preformed Tiles are 100% Recyclable

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.

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

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.

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

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.

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.

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

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.

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.

RACUS® Ceiling Tile Projects

Ofcom 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®.

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.

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Tem

per

atu

re (

°C)

Time (hh:mm:ss) Room without RACUS®

Room with RACUS®

Temperature Difference of

4.33°C

Time With

RACUS®

Without 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

12:00:00 22.67 25.67

12:30:00 22.33 25.33

13:00:00 22.33 25

13:30:00 22.33 25

14:00:00 22.33 24.67

14:30:00 22 25.33

15:00:00 22 25.33

15:30:00 22 25.67

15:45:00 21.67 26

16:00:00 22 26

16:30:00 22 25

17:00:00 22 24.67

MITIE Summary Report

Room without RACUS®

Room with RACUS®

FCU Use (hours) 257.67 7.01

Total kWh Use 3092.04 84.12

KgCO2 1304.84 35.50

Estimated Savings £ KgCO2

Per Month (20 days) 121.79 564.15

Per Annum (250 days) 1,522.34 7051.90

Payback Period 2.92 Years

Example of Monitored Data showing temperature (°C) differences

“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

RACUS® Ceiling Tile Projects

Department of Energy & Climate Change

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.

The RACUS® ceiling tile was installed into the Department of Energy & Climate Change (DECC) building as part of the TSB Energy Efficient Whitehall initiative.

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.

Ceiling Type

Zone Annual Cooling Energy (kWh)

Normalised Annual Cooling

Energy (kWh/m2)

Zone Annual Carbon

Emissions (kgCO2)

Normalised Carbon

Emissions (kgCO2/m2)

Conventional Tile 3177 128.6 1706 69.1

RACUS® 1441 58.4 774 32.35

Carbon Savings 932 37.7

Percentage Saving

55%

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.

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.

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Te

mpera

ture

(°C

)

Time (hh:mm:ss)

Room A (without RACUS®)

Room B (with RACUS®)

Outside Temperature

3.67°C Difference

RACUS® Ceiling Tile Projects

BRE (Building Research Establishment) Victorian Terrace Project

Located within Building Research Establishment’s (BRE) site 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

Datum Phase Change Ltd

www.datumphasechange.com

info@datumphasechange.com