Advanced Testing Methods for Better Real Life Performance

Advanced Testing Methods for Better Real Life Performance of Biomass Heating Appliances Marius Wöhler Prof. Dr. Stefan K. Pelz University of Applied Forest Sciences Schadenweilerhof 72108 Rottenburg am Neckar 1

Outline Introduction Background Method Results Conclusion 2

HFR – University of Applied Forest Sciences § Located in Rottenburg (50 km south of Stuttgart) § 1300 students § 2500 ha research forest Bachelor courses § § § Forest Sciences Renewable Energy Forest Products Water Resource Management Sustainable Regional Management & Tourism Master courses § Sustainable Energy Competence § § (SENCE) Resource-efficient Construction Tropical Forestry 3

§ Research from solid biomass feedstock to emissions and efficiency of small scale combustion appliances (up to 200 k. W) Feedstock Combustion Storage Logistics Pretreatment Residues Emissions § National and international research projects § Chemical laboratories to analyze all relevant parameters of feedstock, fuels and combustion-behavior and -residues § Two combustion laboratories to analyze emissions of combustion appliances § PM: gravimetric and optical measurement § Gaseous emissions: FTIR, NDIR, FID and various handhelds

Type testing Background - Notified body - Defined test method (e. g. EN 13240) Comply with thresholds (different in Europe) Sale of stove (identically constructed No inspection at operation place Type testing ≠ Real life operation New stoves ≠ low emissions in real life 5

Objective: Development of advanced testing methods for room biomass heating appliances to better reflect real life operation Method Knowledge about how stoves are used in real life operation is crucial Online Survey in Europe Field monitoring § 28 questions about heating appliance, § 9 pellet stoves were monitored for 100 § § § installation conditions, user behavior and fuel available in seven languages online for 14 consecutive weeks http: //www. bereal-project. eu/ § days in field operation Temperature and draught measurement

Results § 2205 completed questionnaires § Good regional distribution along different climate zones in Europe § Data evaluation separately for different types of heaters Pellet stoves n= 174 Firewood stove Tiled stove Cookers n= 1980 Wöhler M. et al. (2016): Investigation of real life operation of biomass room heating appliances – Results of a European survey. Applied Energy; 169: 240– 9.

§ § Average of pellet stoves: 3 years Average heat output: 11 k. W 5 – 10 m chimney height was most common 62 % of stoves were without water jacket Selected questions Installation place of the stove? Installation place Pellet stove Firewood appliances House 79 % 87 % Apartment 17 % 9% Other kind of building 2% 3% Non-residential building 2% 1% Is the installation room additionally heated by another heating system? Pellet stove Firewood stove Yes, but stove is primary heating system 59 % 31 % Yes, stove is secondary heating system 14 % 55 % No 28 % 14 % Results

Results How is the heat output of your stove controlled ? Adjustment of the heat output directly on the stove control panel 35 % The stove is controlled by a room thermostat 36 % The stove is controlled by a clock timer 25 % Control of the stove by using a web based system 0% None of the described 4% 71 % of the users stated that they adjust the heat output of the stove at the control panel even if a automatic control system is available.

Is the heat exchanger of your stove cleaned regularly? Yes, done by the user 61% Yes, done by a service technician 22% No, it has not been done yet 5% The stove provides an automatic cleaning system 6% I do not know 7% Results Good level of knowledge about the maintenance of pellet stoves Is your pellet stove serviced by the manufacturer, the installation company or other technician? Strong customer – industry relationship

Are the wood pellets which are you using tagged as "ENplus“? Where do you buy your wood pellets? Buying from specialized fuel dealer 61% Buying from do-it-yourself store or normal retailer 37% Buying from Internet shop 2% Other supply option 15% Results

Conclusion based on the online survey and the field monitoring § Start-stop-operation is common for pellet stoves in Europe § The initial combustion phase is a significant part of the total heating operation § § § (share of 39% of the operation time) Manual setting of the heat output by the user is common The operation in full load is unusual and was monitored at only 10% of the stove operation time It seems that pellet stoves in Europe are well serviced and operated mainly with certified pellets Type testing which reflects the real life operation should definitely included all steady and transient combustion phases in a realistic proportion.

ü Project is still ongoing ü Updated information available at: http: //www. bereal-project. eu/ The research leading to these results has received funding from the European Union Seventh Framework Program (FP 7 -SME-2013) under Grant Agreement n 606605. 13

Advanced Testing Methods for Better Real Life Performance of Biomass Heating Appliances Marius Wöhler Prof. Dr. Stefan K. Pelz University of Applied Forest Sciences Schadenweilerhof 72108 Rottenburg am Neckar 14