Technical Solutions to the Performance Gap
The amount of energy that we use in our buildings needs to be reduced.
The UK is responsible for over 505 million tonnes of CO2 equivalent emissions.
The built environment is responsible for ~40% of that, and space heating making up about ~17% of the total emissions.
As we drive down emissions on the journey towards net-zero, our industry is maturing and starting to measure the whole life carbon of our buildings.
This can be quite a complex topic, but one area where there is clarity, is energy.
The amount of energy that we use in our buildings needs to be reduced.
Unfortunately however, there is a performance gap.
The performance gap exists for a myriad of reasons, all of which an expert panel and I dissected in detail on an Elemental webinar which can be viewed here.
We discussed a host of available solutions, covering demand reduction and increased energy efficiency measures of our systems, achieved through behaviour change, with data and monitoring, increasing ownership and responsibility as well as designing for performance.
Everything is needed. Everywhere. All at once.
An area I’d like to delve a little deeper into though is the systems we are using in our buildings.
HVAC systems are responsible for ~40% of the built environment emissions.
As our host and expert asked me during the aforementioned webinar (playing devils advocate) “Isn’t the performance gap the manufacturers fault?”
Hint; it’s not.
It is the responsibility of all of us, across the whole supply chain, we must all work together to drive down emissions.
There is a very real need for existing technology to be better utilised and improved.
This is not a sales pitch.
It is however a walk through of some of the technology that exists today, and can be implemented to help reduce the performance gap.
I’m going to use real-life examples from a Daikin VRV system; this is an Air-to-air heat pump system, that can offer heating, cooling and DHW.
Let’s start at the end.
In-use Monitoring.
It’s impossible to reduce the performance gap without measuring the in-use performance.
This is a key reason that NABERS is gaining so much traction in the UK.
Unlike design-based energy ratings, NABERS UK measures and rates the actual energy use of offices, helping building owners to accurately track and communicate the energy performance of their buildings. It also helps identify areas for savings and improvements.
I fully expect we will see other well-known Green Building certification schemes follow suit in coming years.
Daikin Cloud Service
Daikin Cloud Service is a cloud-based remote control and monitoring solution for VRV systems.
Using enhanced control, monitoring and predictive logic, Daikin Cloud Service provides real-time data and support from Daikin experts to help building owners identify cost-saving opportunities, increase the lifetime of the equipment and reduce the risk of unexpected issues.
Data is key to measure and understand building performance; we can utilise controls to measure the systems energy performance as well as identifying any hotspots or outliers where users may possibly be incorrectly using systems and we can use positive engagement to encourage behaviour change.
Scheduling and energy management
Daikin offer a touch screen mini BMS control system (iTouch Manager* and iTab Controller — dependant on building size/ client needs) which the Cloud Service integrates with.
Many BMS systems are deployed across commercial and non-domestic buildings, often they’re not utilised to their full potential. It’s important to ensure there is a proper handover provided to the users of the building on the control strategy.
Setting up a sensible building control strategy, which includes schedules, is key to ensure systems don’t continue to run unnecessarily outside of required hours.
Individual tenant billing is a function that also often gets overlooked.
If you are a building owner or real-estate company with high ESG targets, understanding individual tenant energy usage will be a key component to achieving your own goals.
Energy management systems can help measure tenant usage, identify patterns and if looking to change behaviour, analysing this and perhaps using it for internal competition (gamification) could be highly advantageous.
Design stage:
There is a suite of technology that exists within Daikin products that is in-built as standard, to help increase the operational performance and energy-efficiency of the systems — not least VRT — which is similar to weather compensation for those who are more familiar with wet systems, as well as changing of refrigerants to high performing but low-GWP choices.
But not only do we want to make sure systems are running efficiently and being used effectively, we need to make sure they are being designed correctly.
Under sizing Vs oversizing.
In the UK we love CAT-A.
All across the country, buildings are fit-out with brand new HVAC systems, with a design team involved who have no real data on who the future tenants are going to be or how they’re going to use the space.
So allowances are made, and flexibility is king.
Earlier this year, BCO released an updated briefing note to their Guide to Specification in light of the significant changes we’ve experienced since the original document publication in 2019 — namely COVID and a higher focus on Carbon.
A key take-away is their recommendation to use 1 person per 10 m2 and 80% utilisation (rather than 1 person per 8 m2 at 80%), this should result in lower operational emissions (and embodied carbon emissions)!
We need as much data up-front as possible, to help inform design decisions around the sizing and selections of HVAC systems, so as to not drastically over or under-size.
Forced behaviour change
Or limiting choice?
I have done too many site surveys and found heating systems on with windows open.
Or even underfloor heating on with cooling units also running within the same room!
A very sexy-not-so-sexy? solution is to utilise RTDs — these are essentially sensors that can control and interlock multiple systems.
I.e. window contacts or heating interlocks.
By no means are these revolutionary bits of kit, but the amount of wasted energy through poor management or understanding of systems is huge, which results in higher carbon emissions and bills for you.
Commissioning & Maintenance
It’s imperative to make sure the client and design team agree upfront how the system should operate from day 1, and pass this information onto the respective contractor/ specialist installer/ commissioning engineer.
Systems should be set up and running as designed and agreed with the client from the get-go, with sufficient handover information shared across the supply chain to ensure the relevant schedules are in place and operational.
It is the responsibility of manufacturers to make their systems as easy to commission as possible.
Smart tech has come leaps and bounds in the last few years.
Utilising more advanced settings and copy functions for commissioning via smartphones to help simplify the process and speed up time on site without hampering performance.
HVAC systems play a crucial role in reducing emissions from the built environment and wider energy sector.
Reducing operational energy is a clear way to lower carbon emissions and help us get towards net-zero.
It will also massively help with the overall demand on our grid and required renewable energy supply.
