5 tips for how to save energy in buildings.

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Between 15-20% of all energy consumption in buildings is wasted. And thus also large amounts of money that could be invested more purposefully instead. But: If you follow these 5 tips, you are surely on your way to big energy savings. We share our learnings from +1,000 energy projects with Denmark’s largest building owners, which together have saved +50 million DKK.

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1. Measure your buildings’ energy consumption

If you have a large property portfolio that needs energy optimisation, the first step is to measure your energy consumption so you know your starting point.

The most important thing is to get started and use the data that is most readily available. Therefore, use data that is already being collected rather than installing your own meters.

We always recommend using utility data where available. This gives you billing-valid and historical data – and better prices.

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Building owners based in Denmark

If you are based in Denmark, data on your electricity consumption is available free of charge. It takes about 5 minutes to authorise a supplier to gain access via Energinet’s DataHub. Here you can authorise access to your consumption data using NemID.

If you want to use district heating data, a separate agreement with your utility company is required. For some utilities, historical data is delivered quickly and in high quality – for others, it takes longer and the quality varies.

Even with the least digital district heating companies, it will be an advantage to use the utility company’s own data rather than installing new meters.

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Building owners based in other countries

If you are located outside Denmark, we can guide you in how to connect your consumption data with our platform. Simply call us +45 3939 3118 or send an e-mail to contact@ento.ai and we will help you get started.

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2. Analyse your buildings’ energy consumption

The purpose of all data analysis should be to create actionable insights. When the goal is to save energy, we need to find the insights that can create energy savings in your particular building portfolio.

As all buildings are unique and contain different technical installations (ventilation and cooling systems, server rooms, lighting, etc.), it can be difficult find the insights that actually give you a better understanding of your buildings’ consumption. Especially, if only simple key figures are used, such as consumption per square metre of heated area.

We therefore recommend that the analyses include factors that you know affect the energy consumption in your buildings. These are e.g.

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• calendar information such as days of the week

• technical information about the building

• the hourly outdoor temperature

• the opening hours of the specific building

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If your analysis takes all these factors into account, you can avoid arriving at trivial insights. Such as that a building with a heat pump uses more electricity in winter than a building with district heating.

Once you have a good data base, advanced analytics can give you real insights that can lead to the implementation of concrete operational or behavioural changes in your buildings. In some cases this may include investment in new technical equipment.

To put it all in a nutshell: A good consumption analysis gives you an expected energy saving for a specific action you can take.

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3. Prioritise your actions

Based on your analysis, you now need to make the best use of your resources to maximise your energy savings. Our recommendation is to prioritise your energy saving projects according to overall financial gain and payback time.

It is tempting to invest most in “visible” energy optimisations – such as photovoltaic systems, heat pumps or new LED lighting. However, our experience shows that operational optimisation of existing technical installations should be the first priority in virtually all property portfolios, as the effect can be large and the cost very low.

We therefore recommend starting with properties with possible operational optimisations on technical installations (e.g. ventilation and cooling systems, server rooms and lighting). In your consumption analysis, these will be properties with high or suddenly increasing energy consumption outside normal opening hours.

Set aside time in the team to

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• prioritise potential energy savings

• learn from each other’s experiences in the buildings

• follow up on energy projects at a fixed interval – for example, at a weekly or monthly meeting.

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In larger teams, each technician should have one, or at most a couple of properties to inspect before you meet again to ensure that the energy savings have been implemented correctly.

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4. Troubleshooting in the building

Technical installations are often switched on when no one is in the building. If you have a high idle consumption, the easiest way to optimise your energy consumption is to make sure that your installations are operating correctly.

We recommend starting by implementing operational optimisations on technical installations that currently use energy outside opening hours. We recommend the following troubleshooting process:

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5 typical starting points for optimisation

• Check time settings (especially weekly schedule) for technical installations (focus on ventilation, domestic water circulation and possibly cooling systems). Time schedules are checked on building management systems (BMS) or physically on the building.

• Assess if you can turn on ventilation systems a little later and turn them off a little earlier. Half an hour each day for each unit will add up to big savings for all your properties.

• Check if the air changes for fresh air on the ventilation systems are too high. There may be systems that during Covid-19 have been set to change the air more than what the Danish Working Environment Authority or other institutions normally recommend. Consider whether you can reduce the air change to your authority’s requirements with a set point of 1000 ppm.

• Assess whether there is lighting (e.g. outdoor lighting) that is automatically controlled (e.g. via BMS or switch clock) that can be turned off earlier than otherwise.

• We often see that the BMS is overridden by other systems, such as alarms, motion or CO2 sensors. If any of these are broken, technical installations can be left on even if the operating times appear to be set correctly.

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5. Measure your savings

You’ve integrated data, done your analysis, prioritised your potential savings, been out in the building and made an operational optimisation. Now it’s time to make sure that all the previous work actually pays off.

We therefore recommend that you carefully measure your energy projects to make sure that the expected benefits are achieved.

Make sure that the measurements take into account factors that you know affect energy consumption – just as we recommended in the general consumption analysis.

Whether you have invested time in achieving operational optimisation or money in new technical equipment, we recommend that you measure the savings.

New technical equipment can for example be set incorrectly, so measuring the consumption and calculating the savings is extremely important in the commissioning phase. Sometimes, unfortunately, we have seen that this has not been the case – and then, sadly, the potential savings quickly disappear.

If you are making expensive capital investments, we recommend making an agreement with suppliers on what happens if the savings do not live up to expectations. There are international standards for measuring energy optimisation projects that could be used.