Energy consultants from Danfoss were called in to review the existing solution and to propose a new cost and energy efficient solution. After the analysis, the housing association decided to implement an automatic balancing solution for the heating system and to install new thermostatic valves on all radiators. With the new solution implemented, the housing association now saves more than 20% on the energy bill every year.
It all started with the residents on the 10th floor complaining about insufficient heating. When the energy consultant from Danfoss went through the building, it became evident that the heating system was not properly balanced. This resulted in poor living comfort for some residents and that energy was wasted throughout the heating system. “We proposed to use our simple tool to balance the existing two-pipe radiator system and to replace the existing radiator valves with lockable, thermostatic valves. In this way we achieved savings of more than 20% on the energy bill and a pay-back time of only three years on the total retrofit”, says Pär-Anders Liljeblach, Energy Consultant at Danfoss Sweden.
Apart from the energy savings, the housing association was pleased to be able to provide an improved indoor comfort to the residents. Since the completion of commissioning of the valves, no complaints from the residents have been received.
The tool used to analyze and configure the heating system is called Optimal 2, which is a smart and simple tool to balance existing twopipe radiator systems. With Optimal 2, you can design a two-pipe radiator heating system in a cost-efficient way. You can use the tool to select and size the required balancing valves and thermostatic radiator valves. Optimal 2 is also used for commissioning to achieve optimum heat distribution under any load conditions.
Facts about the solution installed• Radiator thermostats RA 2970• Danfoss radiator valves RA-N with locking function• Balancing valves ASV-M on the supply pipe and theASV-PV on return pipe
Bostadsbolaget AB is a public housing association with around 2500 apartments and more than 250 commercial buildings. One of the properties owned by Bostadsbolaget AB is the 10-storey building in Mjölby. The building consists of 25 apartments with a total floor space of 1876 m2.
Automatic balancing valves provide a dynamic balancing solution for HVAC applications. The valves eliminate pressure fluctuations occurring in variable flow systems, such as two-pipe radiator systems, at partial load conditions. These types of valves can also be used in floor heating and comfort cooling applications.
AB-PM is a combined balancing valve providing both differential pressure control and flow limitation. The valves eliminate pressure fluctuations at full load and partial load conditions and can be equipped with an actuator to allow zone control.