Small details, big impact
Andrew Slater explains why the details of building services equipment efficiency are more important now that EPCs carry so much weight. His advice is to take a look at the finer points to make the most of today’s technology.
From recent round table discussions through MBS (November 2017 issue) and conversations throughout the industry, it doesn’t seem that the regulations for Minimum Energy Efficiency Standards (MEES) have been put forward with the force needed to ensure that there is widespread awareness or sufficient information throughout the non-domestic sector.
Property asset management teams and organisations with a significant industry presence have the knowledge and expertise to manage such changes in regulations, but what about the landlords owning or managing buildings, with a smaller portfolio or a single building? One of the most significant gaps in information is a lack of advice on planning beyond April 2018, yet this is very important in long-term plans for UK building efficiency.
The National Energy Efficiency Data Framework (2006-12 report) shows that 60% of the current non-domestic building stock will still exist in 2050, representing 40-45% of total available floor space. Calculations show an approximate 47% gap in meeting the fifth carbon budget in 2050. We should think beyond this year and well into the future if we are to improve building performance.
It has been mentioned that Minimum Energy Efficiency Standards could rise to D or even C as time progresses toward the next carbon budget. A poorly-managed approach to MEES could result in property owners trying to achieve the minimum regulatory requirements time and again. The property industry (landlords, investors and occupants) would be better served if this was a pre-planned, pre-informed and staged progression.
One of the key areas where lack of in-depth knowledge could cause problems is with EPCs themselves. EPCs are the basis of compliance with MEES. It is important to understand exactly what these certificates show, what information they’re based on – and what they won’t measure.
Take a snapshot
An EPC is designed as a snapshot reference into how efficient a building at a single point in time. It’s intended as an insight into the building and indication to a potential tenant or buyer of how much that building might cost to operate. It is an indication of potential – not actual – energy use.
The EPC takes no account, for example, of building usage patterns or how well the building services are managed. The EPC is not an operational rating. Studies have shown that a good EPC rating of A or B does not indicate actual low-energy usage in operation.
Another important point to bear in mind is that an EPC rating depends on the quality of data that is used by (or made available to) the assessor. Data on the performance of building services equipment is changing, and building managers should be aware of this too.
Find your data
The EPC assessment will reference published data on any installed equipment. But it is clear that assessors are analysing some buildings and the equipment in them without up-to-date values such as seasonal variations, so nominal figures are applied, almost inevitably lowering the potential EPC of that building.
Seasonal efficiency values (SEERs) are a case in point. These are quite contentious within the building services industry, as some efficiency measurements are not currently regulated by independent testing or methodologies. An understanding of how SEERs are allocated is very useful.
If we take examples of air conditioning systems below 12kW, there is a standard methodology as given in BS EN 14825 for testing and rating at part-load conditions and calculation of seasonal performance. But there seems to be misunderstanding in the market about how BS EN 14825 affects data for systems above 12kW.
The misconception is not helped by manufacturers who offer representative values of seasonal efficiencies that clearly show a base of BS EN14825 for reference of partial load data points through ambient temperatures and weighting factors, but not being clear on the exact methodology of how partial load conditions were simulated.
Know your labels
Through testing of its own products, LG has demonstrated that simulation of partial load conditions other than those required by BS EN 14852 results in increases in SEER figures of as much as 20% against those tested to the Standard’s requirements.
This may seem like a very detailed analysis in the face of MEES, but when clients are looking to improve their EPC rating with new equipment they will inevitably look for the ‘most efficient’ product. Unless testing and labelling are understood, they could be misled.
However, an end to such confusion is already here because from the 1st Jan 2018 the Eco Directive Lot 21 Tier 1 was implemented. This includes a regulated method of testing seasonal efficiencies of 'air heating products’ above 12kW capacity. And it allows for much clearer comparison of products for specifiers and end-users.
It is to be hoped that MEES and the EPCs they rest on create market conditions where regular certified assessment of buildings becomes the norm. With proper application, they could lead to a better understanding of both building and equipment performance. It would be an important step forward, enabling specifiers to select the most up-to-date building services kit, not simply the cheapest products. This is good news because highly efficient products, that are also better for occupants, have so often been overlooked due to cut-and-paste specifications that are based on old technologies.
For example, dual sensing control in LG’s Multi V systems, includes monitoring and reacting to both temperature and humidity conditions, coupled with smart load control, automated regulation to load can result in an energy efficiency increase of 33% over a year, as well as better thermal conditions for occupants.
Once EPCs are understood, there are many good reasons to go beyond the bare minimum MEES requirements. In fact, energy use should be considered only one factor in assessing how well a building operates. BREEAM and the WELL standards are two examples available to new and existing buildings, and the right equipment choice can deliver more than just energy efficiency.
Andrew Slater is senior engineering manager, LG Electronics, UK & Nordic