Shaping up with chilled beams
The demand for chilled beams has more than doubled over the past three years and its market value now exceeds that of fan coil units.
The term chilled beams covers all types but the most predominant is the multi service chilled beams, MSCBs, which represent about two thirds of this market. It has therefore been the increasing popularity of the MSCB that has really fuelled this significant growth.
This growth has not just been restricted to the UK market with many European and worldwide projects being completed by Trox. Initially these MSCBs were being specified by UK architects and consultants working on overseas projects, but now the benefits of these systems are being well accepted by local teams.
Many markets have old buildings within the city centres which are being refurbished and MSCBs are becoming the number one option given that they can be installed where headroom (i.e. floor to soffit dimension) is very limited.
Obviously with the credit crunch and the effect on investment into property, demand in the UK for 2009 will be lower for all terminal air conditioning systems. However those systems which can best meet the market drivers will be the ones to succeed in the future. So what are the main drivers or key issues and how do MSCBs shape up? Here are a few of the important ones.
Part L 2006 targeted a 28% reduction compared to the regulations contained in Part L 2002.
Part L 2010 will be aiming for a further 25% reduction with successive new regulations stipulating even further reductions beyond 2010. With the traditional life of the building and air conditioning system at twenty plus years what stance are future investors and property developers going to take to future proof their buildings?
It would be prudent to plan ahead and install the most energy efficient air conditioning system at the outset – costs permitting. This is where MSCBs really come into their own. By utilising higher chilled water temperatures of 14ºC flow and 17ºC return they benefit from an enormous amount of free cooling. They also don’t use a fan at the terminal to distribute the air, again saving energy.
The majority of building designers believe chilled beams are the most energy efficient terminal air conditioning system with claims of more than 15% saving compared to fan coils. Trox are currently undertaking a detailed building simulation project and will shortly be publishing the actual and real carbon emission savings.
Sustainability is becoming another major influence in the selection of air conditioning systems. With MSCBs the chilled water temperatures are elevated, this means that renewables such as ground water can be more effectively utilised. Also with sustainability you have the life of the building and system to consider. Most pre 1970 office buildings have a low floor slab to soffit height. Traditional comfort cooling solutions require a false ceiling which reduces this height too much. Hence, landlords tend to opt for expensive new build to ensure a modern office environment and sufficient space for the increased cabling and other services. However, MSCBs solve the space problem because they can be fitted directly to the soffit and be left exposed, meaning that there is no need for a false ceiling. So MSCBs offer the opportunity to modernise and recycle older buildings – a more sustainable solution.
Value for money
This has always been a major consideration but now following the credit crunch end clients will be far more focused on this issue. I can foresee consultants having to examine a much wider range of options with possibly greater emphasis on refurbishment rather than new build.
One major advantage of MSCBs is the low slab to soffit height that can be used as mentioned above. Trox, for example, have supplied MSCBs successfully down to 2.8m high which allows 100mm false floor and no false ceiling. The refurbishment option, apart from being eco friendly, can yield significant building cost savings. It also speeds up the whole process and can bring the building to the market much quicker than new build and enhance the revenue stream from rents during this period.
If new build is the favoured option, MSCBs incorporated into the design at an early stage can bring about huge savings due to the reduced height required. As a comparison on one project the reduction in just the cladding cost was sufficient to pay for the entire MSCB system.
There is a growing trend to go towards systems and products that can be integrated into a prefabrication programme. Most people in the construction industry acknowledge the benefits of prefabrication which include:
- Speed – ‘Just-in-time’ delivery of factory-finished components streamlines the construction process, making it faster, more efficient and less costly.
- Safety – Because on-site time is cut, the risk of accidents and product damage is reduced.
- Sustainability – Waste materials can be recycled more easily in the factory, and traffic movements can be reduced, which is good for the environment.
- Co-ordination – fit out services can be synchronised, reducing delays and cost overruns.
- Quality – The tight organisation of products during manufacture in controlled conditions in a factory results in consistently high quality.
- Certainty – Prefabricated units make the installation process highly predictable, and therefore relatively easy to plan.
- Efficiency – In traditional projects, different trades tend to fall over each other in a bid to get their particular element of the project completed.
Prefabrication allows the project to be planned in such a way that these conflicts do not arise. Offsite pre-assembly also reduces installation times and increases fast track programming.
Inherent in the MSCB design is the total prefabrication of all the M&E components into an architecturally designed beam. The MSCB can incorporate some or all of the following components: lighting, sprinkler systems, smoke detectors, PIR sensors, fresh air, BMS cables, voice and data cables, CCTV.
Whole life costing
Product or system life is an important factor which can often be overlooked in favour of first costs. However I see whole life costing becoming a major issue for basically two reasons, both of which I have highlighted as market drivers, i.e. value for money and sustainability. The value for money driver must bring more focus onto whole life costings because how else can a true comparison be made if not over a period of time such as the life of the building?
On the other issue if a system needs very little maintenance, replacement parts and has a long life then in sustainable terms it is meeting the best criteria.
With the MSCBs there are no moving parts, no fans, no filters, and as such the life of the unit is much longer than with a traditional air conditioning system. Typically fan coils have a life of 15-20 years, whereas with MSCBs it is in excess of 30 years.
These are the main market drivers and in my opinion the MSCBs shape up very well. I also don’t see these key issues changing that much over the next few years. So if the future of chilled beams is dependent on the market drivers I have identified then this terminal air conditioning system will become the number one choice.