7 tips for everyday energy optimisation of buildings

Here are 7 valuable tips on how, for example, a building superintendent can ensure the most energy-optimal solutions in residential buildings.

1. Cooling tariffs and cooling penalties

Most district heating suppliers require consumers to sufficiently cool the district heating water. The general requirements for district heating cooling are usually a temperature range of 31°C +/- 1°C. This means that if, for example, during summer you receive district heating at 80°C, the return temperature must not exceed 49°C.

This can be easier said than done with older district heating systems because older cooling requirements were not as strict as they are today. Insufficient cooling can therefore be an expensive issue to manage in some systems. Proper adjustment and the use of, for example, summer shutdown are a must.

A quick tip and an easy indicator as to whether the hot water tank still meets today's requirements is to feel the bottom of the tank. It should be cold, while the top of the tank should be warm.

2. Summer shutdown – a simple energy saving

The summer shutdown essentially involves shutting off the supply to the radiators in the building during the summer months. This is usually done by identifying and closing the shut-off valve for the central heating and turning off the central heating circulation pump.

When turning off the circulation pump, we recommend activating it at least once a month and letting water run for 15 to 20 seconds before turning it off again. This prevents the pump from seizing.

Most control panels in boiler rooms are equipped with a 'summer cut-off' function. This function helps a lot but does not do all the work unless it has direct control over the heat pump.

3. Aligning expectations about heating levels

Many residents struggle with insufficient heat in their apartments. However, a 'pleasantly warm' apartment is subjective. Some people are comfortable at 19°C, while others prefer up to 25°C. Therefore, we recommend arranging a general meeting to align expectations on what temperature an apartment should be able to reach.

From FORCE Technology, we suggest 21°C. The estimated additional consumption per °C above 21 typically results in a 5% to 8% increase in energy usage.

Lack of heat can be due to many factors including lack of system balancing, low system pressure, incorrect valve settings, or something as simple as air in the radiators. As a general rule, always check if an individual radiator is partially full of air, which will cause problems.

There are many online videos from professionals and handymen explaining how to bleed a radiator, which can be helpful. However, we strongly recommend having a small bucket and cloth handy. If this is not enough, you should contact a consultant.

4. Low temperatures and poor flow in pipes increase the risk of bacterial growth

Many control panels for central heating also regulate the temperature of the hot water tank. Many of these panels offer night-time temperature reduction. At FORCE Technology, we advise against using this function, as a low temperature in a hot water tank can and will increase the risk of bacterial growth, including Legionella.

A hot water tank should be kept within a temperature range from 53°C to a maximum of 60°C, depending on the building's size, height, and length. Larger apartment buildings should also have circulation valves. These valves should be checked a few times a year. Even a single failing circulation valve may pose health risks to residents.

There are many chemical and semi-chemical systems that can remove and continuously clean domestic water of bacteria and are often reasonably priced. However, note that these systems can damage the building’s plumbing, so we always recommend a proper adjustment and dimensioning of the system.

If there is suspicion of bacterial formation in a domestic water system, action should be taken immediately.

5. Proper adjustment of the district heating system controls

Proper adjustment of the property’s district heating system can lead to greater comfort and greater savings. It is therefore often worth spending time with the control's user manual to figure out how to set up the system correctly. Maybe the settings have crept too high over the years?

6. Draining and cleaning – is it done often enough?

Draining simply means opening the drain valve on the hot water tank for a few seconds and then closing it again. Repeat until only clear water comes through the drain pipe.

Most hot water tanks are equipped with an electrolysis unit, which protects the tank and pipes. Such a unit sheds a little harmless aluminum. In addition, lime deposits and other debris collect at the bottom of a hot water tank. Therefore, we recommend draining the hot water tank weekly or monthly, depending on size and type. Check the system documentation or contact us for advice and guidance.

In the case of larger tanks, we also recommend contacting companies that offer in-depth cleaning of hot water tanks. They can also descale the tank’s heat exchanger coil, resulting in better cooling.

7. System sizing, temperature settings, and optimisation – get an external assessment

Sometimes, an older system cannot meet today’s standards. The system should therefore be reviewed for optimisation possibilities by a consultant from, for example, FORCE Technology. We can help you find the right solutions and identify how to best achieve increased comfort, safety and the lowest possible operating costs.

Often, retrofit solutions can yield good savings with an acceptable payback time and increased comfort when replacing individual components.

If you would like to learn more about solutions for energy optimisation of buildings, feel free to contact us or sign up for our inspiration emails concerning public building and renovation.