Too warm, too cold, and no chance to regulate the heating inside the individual apartment – those were the issues facing the residents in a 9-storey apartment building in Tallinn, Estonia. By upgrading the existing one-pipe system into a two-pipe system with automatic hydronic balancing, the residents now enjoy improved comfort and 25 percent savings on the energy bill.
Improved comfort and substantial energy savings for all the residents
It was the same every year. In January, when the winter was bitterly cold, the residents furthest away from the substation felt chilly. With envy they would watch the open windows from other apartments located close to the heat source. There the over-heating also caused discomfort.
The housing association owning the building decided to do something about the poorly balanced heating system. They were open to new, advanced solutions to provide better comfort for the residents. At the same time they wanted to increase the efficiency of the heating system and save on the energy bill. After careful considerations it was decided to replace the old one-pipe system with a brand new two-pipe system. The new system was equipped with Danfoss automatic balancing valves type ASV to ensure equal distribution of heat at all times throughout the entire building. At the same time, Danfoss thermostatic radiator valves type RA-N with sensors type RAW 5116 were installed in all apartments to allow individual heat control. In addition, all radiators were equipped with heat cost allocators for a fair allocation of heating costs.
Substantial energy savings paid back in only six years
Five years into the operation of the new two-pipe heating system, the documented energy savings amount to 25 percent on average through cold and milder winters. A significant part of the savings comes from the two-pipe solution and the perfect hydronic balancing achieved with the Danfoss ASV solution. The investment in new TRVs and individual heat allocators on all radiators also contributes to the savings as residents could now control their comfort and knew they had to pay their own share of heat consumption. This led to a huge change in user behavior in regards to heat consumption.
“The room-by-room control of the heating and the fact that the heat costs are now allocated to the individual apartment created a new awareness of energy consumption among the residents that were happy to see the savings on their energy bills. We are pleased to see how improved user comfort and energy savings go hand in hand. Since the new heating system was put into operation, we have received no complaints”, says Housing Association Manager Anatoly Utjemov.
The energy renovation was designed by OU Dipro and carried out by Alice Grupp that was familiar with the advantages of the ASV solution supplied by Danfoss to previous projects.
“We have a lot of experience working with Danfoss automatic balancing solutions and are very satisfied with the simplicity of setting and adjusting the differential pressure. It makes the commissioning of the system fast and easy. Basically, you just have to set the correct design flow per radiator with the RA-N pre-setting valves, validate whether or not the required flows are achieved, and then your system is up and running within hours”, says installer Igor Smolkov from Alice Grupp.
Advantages of Automatic Balancing Valves
Automatic balancing valves provide a simple, reliable and cost-effective way to create hydronic balancing in two-pipe heating systems. This was also the case in Tallinn where the ASV solution now secures an even flow in the system – even to the most remote apartments.
“The Housing Association wanted to improve comfort, reduce the energy bill, and avoid problems with noise on partial load operation in the tall building with many radiators. Therefore, they decided to go with the ASV valves from Danfoss due to the technical features and the documented benefits that would secure fast return on investment”, says Marko Moring, Sales Manager Danfoss Heating.
Automatic balancing valves
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.