A BEMS is the key to unlocking a more sustainable and resilient data centre

Sam Fitzgerald, Key Account Manager at Trend Control Systems

Sam Fitzgerald, Key Account Manager at Trend Control Systems

Sam Fitzgerald, Key Account Manager at Trend Control Systems, explains the functions of a Building Energy Management System (BEMS) and the vital role this technology can play in today’s state-of-the-art data centres.

In order to minimise the potential for downtime, data centres must be resilient, compliant with all relevant standards and operating procedures, while at the same time minimising overall energy consumption. BEMS have the proven ability to maintain the high levels of uptime and energy efficiency that are demanded by users by proactively monitoring, analysing, understanding and improving a data centre’s building services infrastructure.

Under control

A BEMS monitors, manages and controls building services and plant by ensuring that it operates at maximum levels of efficiency and reliability. It does this by maintaining the optimum balance between conditions, energy use and operating requirements.

By controlling an entire estate’s building services from a centrally managed location, it enhances the ability to interact with, and improve the quality of, the data centre infrastructure. Intelligently understanding and responding to patterns of usage means that, for example, cooling can be fully optimised and lighting turned off in unoccupied areas.

Being aware of the way a data centre works makes it possible to determine which best practices to implement in order to protect IT assets, while minimising costs and the potential for downtime.

Energy levels

It is estimated that data centres account for around three per cent of the world’s total energy consumption and with growing use of the cloud and the rise of the Internet of Things, that figure is only going to go up. Furthermore, according to the Digital Power Group, the sector uses 50 per cent more energy than global aviation and is now considered one of the major sources of global CO2 emissions.

Efficient use of energy is clearly no longer an option and there is a growing raft of legislation and regulation that is specifically designed to ensure that energy consumption and carbon emissions are measured accurately, and that any applicable data is available for analysis.

Given that up to 84 per cent of a data centre’s energy consuming devices can be directly under its control, a BEMS is without doubt the most effective way to gain a true understanding of where savings can be made, monitored and sustained. A properly specified, installed and maintained BEMS will ensure that building services operate in strict accordance with demand, which will also help to deliver the lowest power usage effectiveness (PUE) rating.

Far from being ‘fit and forget’, a BEMS can evolve with the building over a period of time. It must be regularly maintained and, where necessary, adjusted to ensure that it provides the best possible quality of service.

The bigger picture

Sustainability isn’t just about energy usage though. A BEMS can also limit wear and tear on plant equipment by using it more efficiently and making sure that any maintenance issues are highlighted.

In addition, a properly configured BEMS will be scalable, future proof and full backwards compatible. A system that allows easy upgrading and reconfiguration is always preferable – not all systems are the same and the costs of installation can vary depending on the protocol used.

Trend is committed to ensuring the backwards compatibility of its technology. For example, its new IQ®4 controllers are able to communicate with the very first device that it manufactured way back in 1982. The IQ®4 modules are also interchangeable for additional future proofing, scalability and system longevity – all of which can protect the financial investment in a BEMS.

Always on

According to research carried out by Emerson Network Power and the Ponemon Institute, the cost of data centre downtime is just over $7,900 per minute. Total data centre outages in 2013 averaged a recovery time of 119 minutes, equating to about $901,500 in total cost.

As well as being incredibly inconvenient, it’s the damage to mission critical data, impact on organisational productivity, harm to equipment, legal and regulatory repercussions and lost confidence and trust among key stakeholders that can prove difficult to recover from. A data centre should therefore look to build resilience into its operation via a BEMS, minimising any risks associated with situations such as plant failure or environmental conditions falling outside acceptable parameters.

Alarms can be programmed into a BEMS, so that in the event of equipment malfunction the problem can be identified and rectified as quickly as possible. For instance, on an air-handling unit, if a flow sensor highlights that airflow is decreasing it is likely to mean that a filter is blocked. Addressing problems like this early on will ensure that temperature conditions in a data centre remain within those agreed in a service level agreement (SLA), minimising the possibility of penalties. A BEMS can also minimise the amount of time required to carry out such tasks by either automating them or undertaking comprehensive data acquisition.

Rules and regulations

Compliance with statutory legislation, key performance indicators (KPIs) and SLAs are fundamental to the success of any data centre.

A BEMS provides overall visibility of plant energy use and allows personnel to see in real time what’s happening within a facility, therefore helping to make sure that equipment stays within a manufacturer’s specified temperature and/or humidity range. In addition, details of data centre conditions on a 24/7 basis can be logged to provide a full audit trail.

A growing number of data centre operators are also choosing to put an energy management system (EnMS) in place to achieve compliance with ISO 50001 or the standards used to measure data centre efficiency developed by The Green Grid. Having a BEMS in place will help demonstrate a desire to continually improve a data centre’s energy efficiency.

Therefore, the requirement for this technology in data centres is only set to increase.

For further information please call Trend Marketing on 01403 211888 or email marketing@trendcontrols.com.

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Best & Worst Practices Please!

Julia Evans, BSRIA Chief Executive

Julia Evans, BSRIA Chief Executive

BSRIA recently held a workshop on behalf of DECC identifying priorities to promote low carbon heating and cooling in non-domestic buildings as part of the development of its low carbon heat strategy.  Attendees were drawn from both the Young Engineers and Energy and Sustainability BSRIA networks.  Personal thanks to AECOM’s Ant Wilson for chairing the event.

It was a busy day.  It recognised that both new and existing buildings have a pivotal role in reducing greenhouse gas emissions, and by 2050 one of the key requirements will continue to be how we provide heating and cooling.

BSRIA’s Peter Tse and Ian Orme both gave excellent presentations which drew on both good and poor practices identified from more than 50 independently assessed case studies.  These, I felt, answered the questions “what does good practice look like”, as well as “what are the consequences when its not followed”.

The workshop session resulted in many suggestions as to priorities for the future.  There were a couple which caught my eye.

In response to the suggestion that one of the priorities for DECC should be identifying independently assessed best practice and developing exemplars of new technologies, a number of delegates felt that instances of “bad practice” were even more helpful.  It seemed to me that a priority for at least a part of the audience was to know what to avoid doing.  Perhaps this reflects the industry’s receptiveness to messages about risk, and that we often learn most when we make mistakes.  The emphasis on “independent assessment” also resonated.  Many have become sceptical about instances of self-identified “best practice”, and BSRIA’s independent guidance on what works, and what does not, is there to assist the industry do things better.

Another of the workshop themes was on “skills shortages”.  After many years of recession, construction companies have euphemistically “right sized”, and this means that we have lost a lot of great talent from the industry.  Now that there are green shoots of recovery in construction, there is already talk of an exacerbated “skills gap”.  This gap makes it even more challenging for the industry to deliver buildings which meet the needs of their occupiers and where innovation is required to help tackle climate change, and meet the UK’s commitment to “zero carbon” and “very low energy” buildings. This reminded me of another of BSRIA’s strengths – training provision.

BSRIA's 2014/15 Training Brochure

BSRIA’s 2014/15 Training Brochure

Finally there was an astute observation that our recent quest for low carbon buildings has meant that we have worried less about the efficient use of energy, with the net outcome that we can end up with an EPC A rating for carbon design, but a DEC G rating for energy in use.  The move to policies that move us to buildings which are both zero carbon and nearly zero energy use will hopefully remedy this, although I suspect this particular journey may contain further unintended consequences before we reach that goal.

The workshop identified many requirements if we are to create environmentally conscious buildings that meet user needs, and importantly maintain these elements over the life of the building.

BSRIA’s mission remains to “make buildings better”.  As part of my role, I’m listening to our members and the industry what they expect from BSRIA.  I’d like to extend this offer to you, so if you have ideas about BSRIA’s future role, please send them to me: Julia.evans@bsria.co.uk.

To learn more about the BSRIA workshop you can download all the presentations from our website. 

The hidden menace of corrosion in heating and cooling systems

Written by Reginald Brown, Senior Consultant at BSRIA

Written by Reginald Brown, Senior Consultant at BSRIA

Most buildings services engineers will have come across a heating or cooling system that has not received water treatment and still appears to function perfectly and another that has apparently been treated but experienced serious corrosion related failures. Why should one be vulnerable and the other not? The answer is that most common metals are subject to corrosion but the rate of corrosion and risk of failure depends on a variety of factors including the chemical and microbiological environment, temperature, flow rate and not least the thickness of the metal.

In many respects water is the ideal heat transfer medium for building services. It has a reasonably high specific heat, is liquid over a convenient temperature range and is non-flammable, non-toxic and freely available. The downside is that water is an electrolyte that facilitates corrosion in metallic pipework and components. One might think that the obvious solution is to use plastic pipework but this can actually increase the risk of corrosion of the corrodible components that remain.In a steel pipework system, the dissolved oxygen in the system water will rapidly be used up as it reacts with the large area of corrodible surface but the loss of metal thickness should be insignificant. In a plastic pipework system there are few corrodible components so oxygen concentration will remain higher for longer and the corrodible materials will continue to corrode at a high rate. This means that almost all water based heating and cooling systems should have some form of water treatment to control corrosion, and it may be even more important in plastic pipework systems.

The usual construction programme for large building projects involves installation and pressure testing of pipework followed by pre-commission cleaning and commissioning several months later. During the gap between pressure testing and pre-commission cleaning the system may be both stagnant and still contaminated with manufacturing and construction residues. This is an ideal environment for the development of biofilm and corrosion.

In traditional steel pipe systems (using BS 1387:1985 or BS EN 10255:2004 medium or heavy grade pipe) this is not too much of a problem. The relatively thick pipe (at least 3.2 mm for 1 inch nominal bore and larger) can tolerate the initial corrosion due to the oxygen in the fill water and biofilm development during subsequent stagnation conditions. Provided the pre-commissioning cleaning is carried out effectively, ideally with a biocide wash prior to chemical cleaning, there should be minimal impact on the lifetime of the system.

Thin wall steel pipes and steel panel radiators may not be so fortunate. The thickness of 25 mm nominal bore thin wall carbon steel pipe is only 1.5 mm while a typical steel panel radiator is only 1.3 mm thick. If the initial corrosion was spread uniformly across the metal surface it would not be problem but what tends to happen is that small patches of the surface become anodic relative to their surroundings and are preferentially corroded leading to rapid localised pitting. If dissolved oxygen levels persist or are replenished due air ingress, continuing additions of fresh water or permeation through non-metallic materials then the pitting can progress to perforation. Components that should last 25 years can be perforated in a few months. This is one of the most frequent types of corrosion failure reported to BSRIA and can result in expensive remedial works even before the building is occupied.

Water treatment chemicals work by inhibiting the corrosion process, either by coating the surface of the metal (anodic inhibitors) or otherwise blocking the corrosion reactions (cathodic inhibitors). However, inhibitors are not the solution to poor closed system design or operational deficiencies and certainly won’t work to best effect in a dirty system i.e. one with a high level of suspended solids and/or biological contamination. Also, the system operation must allow the inhibitors and other water treatment chemical to be maintained at an effective concentration and circulated throughout the year.

In summary, the factors necessary to avoid pitting corrosion of steel components in closed systems are:

  1. Minimise the delay between first fill and pre-commission cleaning.
  2. Carry out effective pre-commission cleaning of the pipework system.
  3. Establish, monitor and maintain effective water treatment and water quality as soon as possible in the life of the system.
  4. Circulate water throughout the system on a daily basis to avoid stagnation.
  5. Avoid ingress of oxygen from inadequate pressurisation or excessive fresh water additions.
What happens in the first few weeks of the system can prevent pipe corrosion like this over the next 25 years

What happens in the first few weeks of the system can prevent pipe corrosion like this over the next 25 years

What happens in the first few weeks of the life of the system will influence its fate over the next 25 years. You can’t easily see what is going on inside a pipe but get it wrong and you could be looking at major remedial works in a tenth of that time.

A detailed discussion of corrosion and the use of inhibitors and other chemicals is contained in BSRIA BG50 Water Treatment for Closed Heating and Cooling Systems. Pre-commissioning cleaning is described in BSRIA BG29 Pre-commission cleaning of pipework systems. Guidance on the monitoring of water quality in closed systems is contained in these documents and BS 8552 Sampling and monitoring of water from building services closed systems – Code of practice.

BSRIA also runs a Pre-commission cleaning of pipework systems training course and provides independent failure investigations for all types of building plant and systems including pipweork corrosion.

This article was first published in Modern Building Services.

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