Braslovče Elementary School was struggling with the costs of energy for heating and warm water. How did they come to the right solution?

Use KRONOTERM heat pumps for the most energy-efficient public buildings.



Name Braslovče Preschool and Elementary
Location Braslovče, Slovenia
Building type Public institute
Building description 2 floors roughly 1000 m2 each, and a gym roughly 900 m2, with capacity around 600 people
Construction type: Typical brick masonry with 25 cm + 15 insulation
Total (heating) space approx. 2900 m2
Tap water usage approx. 2000 l/day
Original heating system Heating oil
Previous heating costs approx. €50,000/year
Challenge Excessive energy costs for heating and warm water
Appliance HP SV 80/90 T
Number of appliances 2
Heating capacity (kW) 158 kW
Source water/water 20x 100m
Year of HP construction 2013
Description of new system Radiator system, air heaters
Note of interest From signed contract to system roll-out in less than a month
SCOP 5.2
Usage after installation approx. 90,000 kW/year
CO2 reduction approx. 120,00 kg/year


Every parent wants their child to be happy, comfortable, and carefree at school, and to come home every day contented. Not to mention healthy. When you enroll your child at a particular school, it’s perfectly normal to ask yourself when the building was constructed and what its equipment is like. You wonder whether they will be cold in the winter, or whether there’s enough fresh air during the hotter months. All these questions make it crucial for schools to choose the very best heating solutions.



Elementary schools consume a lot of electricity; they need to be kept heated or air-conditioned all year round, and an endless supply of hot water must be ensured. The problem facing investors when they need to renovate a building to increase its energy efficiency is exactly how to cut down on consumption. Most schools are old buildings, constructed using traditional methods of thick walls and thin insulation. Braslovče was worried about its 25-cm-thick walls and 15 centimeters of insulation, and they were used to using a high-temperature heating regime. 




Not just the wall thickness, but investors were also worried about excessive costs of energy supply for heating and sanitary hot water, as Braslovče Elementary traditionally heated its facilities with oil. They also wanted to make sure that their sanitary water would never run the risk of a Legionella infection, which is a common occurrence in public buildings. When you choose KRONOTERM, adopting a new, modern, and technologically superior heating system with radiators and air heaters becomes a true pleasure. 



The two installed heat pumps now working to keep the students there warm and supplied with plenty of hot water are exactly what has slashed the school’s costs and boosted its energy efficiency. Kronoterm’s brine/water SV 80/90 T extracts heat from one of 20 vertical collectors, drilled 100 meters into the ground.  In the summer months, the process works the opposite way, with cool air from the boreholes being employed to cool the school passively. The KRONOTERM heat pumps warm up 2 floors, approximately 1000 m2 each, as well as a gym measuring 900 m2. The room temperatures hovers between 22 and 24 °C.

The new system has a 2000 l buffer tank and two 500 l reservoirs for sanitary hot water. It uses 90,000 kW per year, which completely covers the operation of both Kronoterm heat pumps.

Parents thus no longer have to worry about whether these 600 children are warm. After all, they attend an energy efficient elementary school. For the finishing touch to really put parents at ease, the heat pumps will also overheat the water to 80 °C, killing off any and all Legionella bacteria.




Braslovče Elementary, with its extremely efficient Kronoterm system, will surely be a little kinder on the environment. Its annual SCOP measurement is an impressive 5.2.

The investment, the result of a public/private partnership between Kronoterm and the municipality of Braslovče, is a textbook example of how to harness renewable resources and find a synergy with the local environment. It’s also easy on investors, who will see a return on investment within 5 years. A further testament to that is how quickly the project was completed: less than a month from signed contract to flipping the switch!