As we walked past a building in the center of Maribor, where Boris and his family live, we barely noticed, let alone heard, that there is an air/water heat pump in the building. The VERSI-I heat pump, which is manufactured by KRONOTERM, allows internal setup, extremely quiet operation, and easy installation.


Apartment size: 75m2

Construction of the object: in the 60s

Object type: multi-family building

Heating method: radiators

Heat pump type: VERSI-I

Heat source: air/water

Management: controller KT-2A, Cloud.KRONOTERM


Boris came to a point where it was necessary to renovate the old heating system in the apartment where he lives with his wife and son – a heating system powered by heating oil. The replacement was necessary because the chimney no longer allowed heating, as condensation had already accumulated under the chimney and in neighboring apartments. Because renovating the existing heating system would have been a considerable expense, he decided to completely renovate the system, which would not only be more modern but also more efficient. Since Boris family lives in a multi-family building, they had additional limitations in choosing a system: the challenge was not to interfere with the appearance of the neighborhood (otherwise, they could have used a geothermal probe). Based on his desires and needs, Boris was determined to get a heat pump with only an internal unit that would not change the environment around the building. Boris lives with his family in the center of Slovenian 2nd largest city, in a multi-family building with nine apartments. His apartment is approximately 75 square meters and has an ideal location as it is directly above their basement.

“A magic box where everything happens.”


When Boris researched the market and inquired about the desired heat pump with an internal setup, the authorized service technician and installer of KRONOTERM heat pumps suggested the VERSI-I heat pump. It is a dimensionally small, extremely quiet and unobtrusive heat pump, and most importantly, suitable for internal placement. The heat pump is installed in the basement of the building, which is located below their apartment, making it easier for him to connect to the existing heating system, to the radiators. Since Boris also decided to change the method of heating domestic hot water, he simply connected the VERSI heat pump to the hot water storage tank.

Would you like to know how the VERSI-I heat pump works? Air is brought into the heat pump through insulated ventilation ducts that are specifically designed for this purpose. You can choose between a facade or roof solution for air exhaust and intake, which includes a grille, perforated cover, or roof ventilation element.


Boris is extremely satisfied with the entire process from ordering to installation.

“The decision to purchase the VERSI-I heat pump was made in January 2022. Before placing the order, i also informed my neighbors about the replacement of the heating system and obtained all necessary permits for the work. The delivery of the heat pump was carried out in June, installation in August, and the connection to the existing heating system and radiators was done by KRONOTERM technicians in early September.”

He particularly praised the team, saying that everything went smoothly, and they provided him with proper education on using and operating the heat pump.





To control the VERSI heat pump, Boris uses the Cloud.KRONOTERM app on his phone, which he finds very user-friendly. He sets the room temperature, operation schedules (daily or weekly), and water settings on the app. At home, he controls the heat pump with the KT-2A controller, which is installed in the hallway of his apartment. The app allows him to set the temperature from his office and warm up the apartment before he gets home.

Boris also chose the VERSI heat pump because of the cost savings. After using it for a while, he says that he has already saved a lot. Previously, he heated the domestic hot water with an electric boiler, which was a large consumer of electricity. With the installation of the heat pump, he separated his water supply from the building’s shared water supply, allowing him to have his own account with actual water usage.

If Boris had to choose a heat pump again, he would choose KRONOTERM’s heat pump again and again. He likes that they operate quietly and do not disturb the surroundings. He jokes that even if he could install an outdoor unit, he would still choose KRONOTERM because he likes our outdoor units.

As one of the first people in Slovenia to have the VERSI-I heat pump installed, he concludes that he is very satisfied with it and would happily recommend it to his friends. Find out if his expectations have been met in the video below.


If you need information about the heat pump, or personal advice, please contact us here.