Energi- och inneklimatsimulering av behovsstyrt FTX för flerbostadshus - Baserat på mätningar av VOC och fukttillskott i 24 lägenheter

Sammanfattning: Energy use and climate impact are important topics in today’s society. To combat global warming, the EU has set a goal framework with a 20 % reduction target until 2020 for domestic energy use compared to 1990. Today, the building sector in Sweden accounts for 30 % of the domestic energy use. To achieve the goals for energy and climate set by the EU, changes are required. The Swedish parliament has, in addition to a 20 % reduction in energy use until 2020, set a goal of 50 % reduction until 2050, both compared to the levels of 1990. Between 1964 and 1975 more than one million apartments were built in Sweden, during the so called “Million Program”. These buildings are interesting from an energy efficiency point of view because of their quantity, similarities and need of renovation. A crucial part of reducing the energy use in these buildings is to improve the HVAC systems, for example installing an MHRV (Mechanical heat-recovery ventilation) Wise Apartment Solution is a DCV (Demand Controlled Ventilation) with mechanical heat-recovery, developed by Swegon specifically for renovation of multifamily houses. The control parameters for this system are VOC (Volatile organic compounds) and moisture supply. In this thesis the HVAC system is evaluated from an energy efficiency and indoor air quality point of view, where the set points for the regulation are varied. This specific system is installed in a multifamily building in Norrköping. Measurements of VOC and moisture supply have been collected from 24 apartments for almost a year. Based on the measurements, simulations have been conducted in IDA ICE, which is an energy and indoor climate simulation software. Multiple simulations with different settings of the control parameters have been run. All simulations are compared to the conventional alternative, which is a CAV with heat recovery. The results from the simulations show that a potential in a reduction in energy use, and also a risk of increased energy use for the heating system, compared to the CAV. This largely depends on the control parameter set points, the users and the users’ behavior. For the indoor air quality, generally, a positive effect is achieved for all set points simulated. On average, the levels of VOC and relative humidity are lowered compared to the CAV. This also depends on how the comparison is done. The system can either reduce the energy used or improve the indoor air quality, depending on the set points. The differences in energy use between the DCV simulations and the CAV, whether increased or decreased, are relatively small. This shows that the main energy reduction cause is the heat exchanger and additional reduction is small. Compared to a DCV with CO2-control, the energy efficiency is marginally reduced. However, with the VOC-control, the indoor air quality can be improved due to the sensors ability to detect pollutants which a CO2-sensor is unable to.