Energy efficiency Contro Graeme Rees, vice president of t
discusses the efficient managem Technical Guide can help ensure
T
he world is certainly a very different place today than it was just six months ago, but with people beginning to return to work we are all wondering what the new normal will look like as we learn to live in whatever a normal world becomes. As we need to learn to adapt so too do our buildings. Many have been left empty for some time and with government advice to continue working from home if you can, a good proportion of general office spaces will
only be operating at a much reduced occupancy level and are likely to continue in this way for some time yet. CIBSE has issued guidance for building owners, occupiers and operators on procedures and practice to follow to ensure buildings are not only brought back online safely and efficiently but are operated slightly differently to ensure the safest environment for occupants. For example, adjustments to the control systems on ventilation plant to operate supply and extract ventilation at higher volume flow rates
s
and to avoiding recirculation wherever possible. Also, extending operating hours to at least two hours before occupancy and two hours after should a 24- hour operation not be possible.
s Safety first
Of course, at first glance these measures appear to contradict any energy saving routines one may have already deployed, indeed the situation today is without doubt a matter of safety first
without doubt a matter of safety first.
However, with a well-appointed, up to date, contro system, achieving adjustments of this nature are relatively simple to implement and may even be done remotely on the many premises that benefit from secure remote connectivity.
The current crisis situation aside, the principles of automatic adjustment based upon demand has been at the heart of building control philosophies for years. Scaling a setpoint back or ramping a speed up based on a sensor measurement is exactly what
p y
building controls do. Doing just this to keep occupant comfortable is the goal, doing it in the most energy efficient way the ultimate prize.
ts
Comfort and efficiency are the two key words. Where comfort once meant ‘warm’, today we conside comfort to also encompass elements of the well- being of the building occupant. Keeping occupants
ol e
w
www.heatingandventilating.net Ct olling effic ienc y
the Building Controls Industry Association (BCIA), ment of buildings post-lockdown, and how a new e building controls perform to their maximum potential
at a comfortable temperature is a given, but we also consider the amount of fresh air, the humidity, light levels, (including artificial vs natural daylight) noise, smells and the new agenda topper... occupancy level. Where once owner occupiers were concerned about people density per square metre, it is now a case of space between people…
..per square metre. Where once building control technology was used to guide an occupant to a free hot desk, this same
technology can be used to guide occupants through less dense areas of a building, avoiding crowds to clear, and cleaned, work spaces.
ly
All of the above relies on the building control systems, the vast majority totally hidden from sight. Doing all of the above efficiently relies on the skills and experience of the control system design engineers. To achieve logical operation is one thing, to achieve that in a super-efficient way requires training, experience and the tools, software and equipment that deliver
reliable and precise control of the mechanical and electrical systems within our buildings.
Getting it right
Comfort and efficiency is achievable whatever scale the building or budget, but not every building has the application for every system described, so where would you begin to understand what controls are actually needed? After all, our buildings account for over 40% of the global energy consumption with commercial premises more than half of that figure. Getting it right is clearly important from a cost perspective and importantly an environmental and sustainability perspective too.
Moreover, getting it wrong.….the lack of or simply poorly implemented building controls have been seen to be accountable for w of the 10 reasons our buildings do not perform as efficiently as they were designed, with energy consumption and costs being as much as twice as that intended.
er
The European directive BS EN 15232-1:2017 Energy Performance of Buildings: Impact of Building Automation, Controls and Building Management, gives control manufacturers and design engineers criteria and methodologies to achieve significant energy savings with well designed, commissioned and maintained control systems.
The BCIA
published guide whic sense of th European on the Ene subject ver of our build possible a
A has a helpful
ch makes he
directive; called The Impact of Controls ergy Efficiency of Buildings. Making the ry easy to digest, it helps the stakeholders dings understand what is essential, what is nd how to get the most efficient resu
ols he olders what is lts.
BAC CS EFFICIENCY
BS EN 15232-1:2017: Energy Performance of Buildi Controls
levels of Building Automation & Control System (BACS) efficiency, from A to D: A: High e
Building B: Advan C: Stand D: Non-e To ach
Management System (TBM ) nced BACS and TBM ard BACS
energy efficient BACS
the amount of energy delivered into a room or space sh the cons
effectively creating an accurate closed loop system. The energy demand signals could be derived by the interaction of the consumers themselves (e.g. adjustment of thermostats) or, more effectively – as defined within Class A system requirements - by automated measurement systems (e.g. occupancy sensors, temperature and CO2 measurement, light leve
hieve the highest level of efficiency, unt of energy delivered into a room or hould be based solely on the demand of umer(s), i.e. those occupying the space, ly creating an accurate closed loop system. rgy demand signals could be derived by action of the consumers themselves (e.g. ent of thermostats) or, more effectively – as within Class A system requirements - by ed measurement systems (e.g. occupancy
human interaction and, therefore, the potential to waste energy. BCIA m and syst
15232 Standard as a guiding light for control g g g
system d the BCIA control s perform C which, inefficien
member companies (manufacturers tems integrators alike) use the BS EN tandard as a guiding light for control
design and operation. As an Association, A recommends that all modern building systems should meet at least Class B ance rather than the baseline Class it is felt, leaves too many gaps for nt energy performance.
el sensors, etc.) which reduce or eliminate nteraction and, therefore, the potential to nergy.
5232-1:2017: Energy Performance ngs. Impact of Building Automation, s and Building Management, defines four f Building Automation & Control System efficiency, from A to D:
energy performance BACS and Technical (TBM )
A), w otential
24
September 2020
www
heatingandventilating.net
www.heatingandventilating.net
g.net
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48