The world is not what it used to be. A cliché statement that 2020 really brings meaning to. We have suddenly been pushed into the inevitable digitalisation of businesses, a disruptive working from home situation and the increase of health and virus awareness. With more people working from home than ever, the impact can be seen from both positive and less positive perspectives, but I can’t help to observe all the opportunities and areas of improvement that become clear in times like this. In this post, as the title already revealed, I’d like to share a few thoughts on how to save energy in commercial and non-residential buildings.
How is energy in buildings being wasted?
I wrote in my previous post that “there are studies and research showing that optimizing indoor air quality not only improves health and productivity, but can also increase building energy efficiency and reduce cost”. The latter part has become more apparent now when we spend less or close to no time at the office (or schools), due to the recent virus outbreak and the measures taken because of that. Many non-residential and commercial buildings still operate as usual, wasting a lot of energy, even though no one is there. This has been outlined in a clever way by my colleague Tommy. However, shutting down completely is not the solution.
Today there is a tendency to move focus away from buildings and focus solely on the occupants in the building, which mostly makes sense. That does not mean that the building itself should be forgotten, at least from an energy and sustainability point of view. We should observe and consider buildings and their occupants as a whole; meaning automating and finding the right balance between energy efficiency and creating a space condusive for employee wellbeing.
Energy is not only wasted in unoccupied buildings but also in inefficient buildings, leading to unnecessary costs and CO2 emissions.
Heating, Ventilation and Air Conditioning (HVAC) are the major energy drains, that can be well over 50% of the total energy consumed by a building1. Only around 20% of buildings have a BMS, even fewer of those have a demand-controlled operation. So improvements can be made. In fact, introducing Demand Controlled Ventilation (DCV) can have a huge impact. In buildings which have good energy performance, savings have reached 53% (from annual consumptions of 118 kWh/m2 to 56 kWh/m2 by introducing DCV operation)2. As non-residential buildings in the EU and US have an average annual consumption of 250 kWh/m23,4, it’s fair to state there are massive amounts of energy to be saved.
If we include indoor lighting as an energy parameter, operational emissions from buildings account for 28% of all carbon emissions in the world5. Therefore, if you are looking for a reason to do something good for the environment, you know at least one path. Introduce a demand-controlled operation.
How can I improve the energy efficiency in my office?
The first step is to monitor and collect insight to make better decisions in terms of optimizing the building. These insights could be sensor measurements, radon reports, threshold notifications, the list is endless. To start with, this is a manual process. It often requires facility managers to act on insights and execute the right decision. However, the real end goal is to integrate the sensor insights directly to the brain of a building, the Building Management System, to control HVAC and lights based on real-time demand. In my opinion, this is only possible if you have a system that continuously measures around the clock, so you can react to a constantly changing environment.
There is a saying that states “technology is evolving faster than our ability to adapt” which applies, in a rather fascinating way, to buildings across the world. There is still doubt about battery-
operated, wirelessly connected sensors. But when you can retrofit a complete sensor solution in a building, within a day, and get almost instant return of investment on energy efficiency insights, while reducing the global CO2 footprint, how can there be doubt? This is often a fraction of the cost of adding wired sensors , because of the cost of creating the wired infrastructure amongst other things.
1. Review the thermal profiles. Did you know that there are up to 5% energy savings for every degree celsius the temperature is lowered? Therefore a reduction of 4-5 C when buildings are empty (e.g. during the night, weekends and/or holidays), or in areas of the building that are not used for substantial periods, can provide savings of up to 25% in energy consumption6.
2. Review the pressure profiles. The indoor pressure will tell you how much over/under-pressure there is, which will lead to potential energy leakage and/or badly configured HVAC. i.e. Windwashing (cold air through insulation) and convective loops (air movement in walls or ceilings) can result in up to 20% heat loss alone7.
3. ImplementDCV. Adaptively control ventilation in a meeting (or class) room. Make sure to increase the airflow only when it's needed, i.e. pro-actively before high CO2 levels are reached. The same applies for radon gas and unhealthy VOCs that lingers in buildings as well, beyond meeting rooms. Even temperature, humidity and pressure can be impacted by the ventilation rate and flow. With so many different parameters, there is a need for an automated, insightful decision making process.
4. Optimize occupancy scenarios. There is no need for lights to be on when the building or floor is empty. Using schemes to reduce HVAC energy usage when the building isn’t used and optimize HVAC usage when the building is in use. Typicalutilization rates of office space are between 60-70%. Therefore, up to 40% of the space of an office building is not being used at any one time on a typical workday (while most often it is still being climatized)8.
Making the world a better place
Building integration is the most important part of our Airthings for Business solution today. As we make use of more advanced
learning technologies and automate our insights components further, we are quickly approaching a world where human intervention is minimized and only needed as a pro-active engagement. Actionable insights is the first step to a fully automated building and we are getting there. We are working towards the grander scheme of things; making the world a better place.
The European Green deal is pushing to reduce CO2 emissions with at least 50% by 2050 compared to 2008. We are doing our best to aid that. How can you contribute?
1. European Commission. Energy performance of buildings standards. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX%3A32019H0786&from=EN 2. https://arrangement.nemitek.no/mai2020-oslo/frokostseminar-vavdcv---digital-utgave/118345 3. https://ec.europa.eu/energy/eu-buildings-database_pt; https://ec.europa.eu/energy/eu-buildings-factsheets-topics-tree/energy-use-buildings_en 4. Balaras et al., 2017, Energy Use Intensities for Non-Residential Buildings (conference paper), Proceedings of the 48th International Congress and Exhibition on Heating Refrigeration and Air-conditioning, Belgrade, December 2017 5. Global Status Report (2017) Towards a zero-emission, efficient, and resilient buildings and construction sector. 6. https://www.enova.no/about-enova/ 7.http://web.ornl.gov/sci/buildings/2012/1985%20B3%20papers/055.pdf 8. JLL, 2017 Occupancy Planning Annual Report, https://www.jll.co.uk/content/dam/jll-com/documents/pdf/research/emea/uk/jll-occupancy-planning- benchmarking-report-2017.pdf
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