This article presents the field test of the developed demand response system installed in the central heating systems of existing apartment buildings. The buildings are occupied by students and located in Tampere, Finland, which is within the northern climate zone. The studied buildings are connected to the local district heating network. The presented demand response system takes into account weather forecasts, indoor temperatures and decreases in space heating temperatures when demand for domestic hot water is the highest. The owner of the buildings benefits from peak demand control and can save in fixed fees. If enough buildings would have this kind of demand response control system, there would be a decreased need for utility companies to use peak power plants that typically use fossil fuels for heat production. In this field test, the peak load decrease was 14%–15% on average. During the test, the heating period of February and March, the normalized energy consumption of eight buildings was reduced by 11%, which represents a 9% annual cut in energy, costs and greenhouse gas emissions. Demand Response (DR) heating aims to help in reaching the objectives of the National Energy and Climate Strategy for 2030.

This article presents a field test of how deep renovation affects indoor climate quality. The studied apartment building was built in 1968 and is located in Finland, within the Nordic climate zone. The deep renovation included façade repair with extra insulation, new windows with trickle vents, new balcony glass and doors, and the installation of an exhaust air heat pump into the existing mechanical exhaust air ventilation. The indoor climate conditions and building envelope tightness were measured before and after the renovation. As a result of these energy renovation measures, the building envelope tightness improved by nearly 40% and the uncontrolled supply of air (draughts) decreased by approximately 24%. The overall energy consumption of the building decreased by 45%. Above all, the long testing period gives credibility to the study. The field test brought up the challenge of supplying an adequate amount of fresh air. This article highlights the fact that windows are part of a mechanical ventilation system if fresh air is not controlled by being led through inlet ducts. The supply air flow and volume must be ensured by correctly dimensioned valves, and therefore we stress the importance of the technical cooperation of technical designers.

The city of Tampere in Finland aims to be carbon-neutral in 2030 and wanted to find out how the electrification of public transport would help achieve the climate goal. Research has covered topics related to electric buses, ranging from battery technologies to lifecycle assessment and cost analysis. However, less is known about electric city buses’ performance in cold climatic zones. This study collected and analysed weather and electric city bus data to understand the effects of temperature and weather conditions on the electric buses’ efficiency. Data were collected from four battery-electric buses and one hybrid bus as a reference. The buses were fast-charged at the market and slow-charged at the depot. The test route ran downtown. The study finds that the average energy consumption of the buses during winter was 40–45% higher than in summer (kWh/km). The effect of cabin cooling is minor compared to the cabin heating energy needs. The study also finds that infrastructure needs to have enough safety margins in case of faults and additional energy consumption in harsh weather conditions. In addition, appropriate training for operators, maintenance and other personnel is needed to avoid disturbances caused by charging and excessive energy consumption by driving style.

The European bu d ng stock s mature, and expand ng c t es need nc us ve and nnovat ve renovat on so ut ons for a c t zens wh e ntens fy ng c ty dens f cat on. The European project EU-GUGLE a ms to reduce pr mary energy consumpt on by 40% to 80% and ncrease renewab e energy use by 25% through near y zero energy bu d ng renovat on mode s for n t at ng arge-sca e, Europe-w de rep cat on n c t es and commun t es. About 200,000 m² of res dent a and pub c bu d ngs are be ng refurb shed by mp ement ng a ba anced m x of techn ca , soc o-econom c and f nanc a so ut ons adapted to oca needs. S x EU partner c t es are part c pat ng, each rev ta z ng an urban d str ct: Aachen, Brat s ava, M an, Sestao, Tampere, and V enna. The comprehens ve ntegrated approach used n EU-GUGLE s n ne w th the European Smart C ty n t at ve, and each part c pat ng c ty has created near y zero-energy Smart C ty master p ans based upon owest energy therma renovat ons coup ed w th nnovat ve renewab e energy serv ces ncorporat ng every aspect of smart d str ct fe. A stages of the p ann ng, construct on and post-occupancy phases of the arge-sca e d str ct renewa s are be ng documented, mon tored and eva uated to create susta nab e d str ct renovat on methodo og es for "smart renovat ons for smart c t es" to meet the object ves of the European Comm ss on s Smart C t es and Commun t es In t at ve for reduc ng 40% of greenhouse gas em ss ons w th n the European Un on by 2020. The paper out nes the approach each c ty has taken and h gh ghts case stud es of the nd v dua so ut ons created n three of the s x c t es.

The Energy Performance of Buildings Directive together with the Energy Efficiency Directive and Renewable Energy Sources Directive define the frame and target state for energy performance of the existing building stock. This should be very energy efficient and decarbonised by 2050. The Finnish target is more ambitious, to achieve the target state already in 2035. In this paper, we discuss and concretise the role of HVAC in overcoming the challenge. Buildings in the Nordic countries are already very energy efficient. Structural improvements of energy efficiency are relatively expensive and have limited potential for energy saving. The best cost-benefit ratio can be obtained by combining HVAC with dynamic building automation systems. Also the EPBD calls for improvement of building automation systems and related measurements in new as well as existing buildings. The performance of buildings can be verified and deviations can be detected by monitoring-based commissioning during their life cycle. This means that special attention must be paid to the instrumentation level and an improved online reporting system for stakeholders. As a conclusion, we see that HVAC systems are in a key role in decarbonisation of existing buildings and a strategic sector on the way to a carbon-neutral society.