BLT reference number: 131/06 BLT approval number: 044/07

Pellet burner

EVOTHERM P 50

Applicant and manufacturer:

EVOTHERM

Heiztechnik Vertriebs GmbH

Seeleiten 24

AT 5120 St. Pantaleon

AT 3250 Wieselburg, Rottenhauser Straße 1

Tel.: +43 7416 52175 – 0, Fax: +43 7416 52175 – 45

blt@josephinum.at, http://blt.josephinum.at

TEST REPORT
The BLT Wieselburg is an accredited burner test centre issued with identification number 112 according 

accreditation law BGBl. No. 468/1992. The quality management system complies with the requirements 

defined in ÖVE/ÖNORM EN ISOIEC 17 025.

Rottenhauser Straße 1

A 3250 Wieselburg

Austria / Österreich

Tel.: +43-7416-52175-0

Fax: +43-7416-52175-45

E-Mail: blt@josephinum.at

Internet: http://blt.josephinum.at

The test results detailed in this test report exclusively refer to the test piece specified in the chapter 

„Boiler plate information“.

The test report must be published only literally and unabridged.

Exceptions have to be authorized by Francisco Josephinum BLT.

Authorized translation

In the event of doubt the German original shall prevail.

Page I

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

TABLE OF CONTENTS

Page

1 DESCRIPTION ...................................................................................................................... 1

1.1 General.....................................................................................................................................1

1.2 Boiler plate information .............................................................................................................1

1.3 Diagram of the burner ...............................................................................................................2

1.4 Technical data ..........................................................................................................................2

2 TEST AND RESULTS ........................................................................................................... 3

2.1 Test setup – measurement methods .........................................................................................3

2.2 Performance of heating tests ....................................................................................................4

2.3 Interpretation of emission measurements..................................................................................4

2.4 Investigatory heating tests with wood pellets at nominal heat output..........................................5

2.4.1 Emission measurements...............................................................................................6

2.4.2 Evaluation ....................................................................................................................6

2.4.3 Output-related measurements.......................................................................................7

2.4.4 Flue gas composition....................................................................................................8

2.5 Investigatory heating tests with wood pellets at minimum heat output .......................................9

2.5.1 Emission measurements.............................................................................................10

2.5.2 Evaluation ..................................................................................................................10

2.5.3 Output-related measurements.....................................................................................11

2.5.4 Flue gas composition..................................................................................................12

2.6 Surface losses ........................................................................................................................13

2.7 Water-side resistance of boiler................................................................................................13

2.8 Electrical power consumption..................................................................................................14

2.8.1 Average electrical power consumption at nominal heat output, minimum heat output, 

on standby and ignition ...............................................................................................14

2.8.2 Electrical power consumption of main loads................................................................14

3 SUMMARY OF RESULTS ................................................................................................... 14

3.1 Heating tests...........................................................................................................................14

3.2 Function check / safety temperature limiter on the boiler.........................................................15

3.3 Function check to verify the rapid shutdown of the system ......................................................15

4 ASSESSMENT .................................................................................................................... 16

5 APPENDIX .......................................................................................................................... 17

5.1 Legal requirements (for information only)................................................................................17

5.2 Surface temperature measuring points....................................................................................18
Page II

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

APPLIED STANDARDS

[1] ÖNORM EN 303-5:1999 Heating boilers for solid fuels, hand and automatically stoked, 

nominal heat output of up to 300 kW

[2] ÖNORM EN 304:2005 Heating boilers. Test code for heating boilers for atomising oil 

burners

[3] EN 267:1999 Forced draught oil burners – definitions, requirements, testing, 

marking

[4] ÖNORM M 7135:2000 Compressed wood and compressed bark in natural state – Pellets 

and briquettes – Requirements and test specifications

[5] DIN 4702-1:1990 Central heating boilers – Terms, requirements, testing, marking

[6] DIN 4702-2:1990 Central heating boilers – Test code
Page 1 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

1 DESCRIPTION

1.1 General

The tested pellet burner EVOTHERM P 50 manufactured by Evotherm Heiztechnik Vertriebs 

GmbH with a nominal heat output of 49,5 kW comprises a hopper for pellets, the fuel feeding system with an integrated rotary gate valve, a drop shaft, the stoker screw, the burner with the combustion chamber and a vertically set up pipe heat exchanger. The burner is equipped with an electric ignition, an automatic cleaning system for the heat exchanger, a speed-controlled draught fan, 

a Lambda sensor and a microprocessor control system with associated switches and sensors.

A cuboid sheet metal storage container was used to perform the tests. The pellets are taken off 

from the storage container by a flexible screw conveyor situated in a ductile PLT-plastic pipe. This 

screw conveyor is leading to a driving motor situated on the back of the boiler which is then connected with the stoker screw by a horizontally and vertically slewable ball coupling system. In this 

drive unit the rotary gate valve, powered by a 12-Volt DC motor, is connected with the driving 

shaft of the screw by a chain drive. The stoker screw transports the fuel upwards from where it 

falls through a drop shaft and a down pipe on the boiler front side which is equipped with a photocell and an inspection glass. From there it can fall into the heat resistant metal burner. The boiler 

is periodically cleaned by turning down the grate, the residues fall into the ash drawer. 

The speed-controlled combustion fans direct the combustion air as primary air flow through the 

burner and as secondary air flow to the fuel gases. After reversing the combustion gases above 

the burner, the gases are directed through the three-pipe heat exchanger wherefrom they are suctioned by a speed-controlled draught fan towards the chimney. The burner and the heat exchanger 

are automatically cleaned by a separate motor which also opens the burner and cleans the heat 

exchanger pipes with rotating turbulators. The ash finally falls into an ash drawer which is installed 

below the heat exchanger. Both ash boxes can be extracted at the boiler front. 

The fuel is ignited with a hot air blower. The combustion is monitored by a photo cell. The volume 

of the fuel and the fuel gases are controlled by a Lambda sensor and regulated by a microprocessor system according to the required heat output level. The negative pressure in the combustion 

chamber is monitored by a load cell. The flames can be inspected through a sight glass fixed at 

the boiler front.

The combustion chamber and the heat exchanger are thermally insulated from the outside.

1.2 Boiler plate information
Page 2 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

1.3 Diagram of the burner

1.4 Technical data

Parameter – Overall dimensions of burner Value Unit

Overall width incl. storage container 1547 mm

Overall width of burner 709 mm

Overall depth incl. induced draught fan 984 mm

Overall depth incl. stoker unit 1294 mm

Overall height 1412 mm

Diameter of flue gas pipe 180 mm

Height to centre of flue gas pipe 885 mm

Flow / return connection 5/4 "

Water capacity (measured) 54 l

Emptying outlet 1⁄2 "

Thickness of sheets exposed to fire 5 mm

Thermal insulation 20 – 80 mm

Total weight incl. hopper 577 kg

Source: Measurements by BLT Wieselburg
Page 3 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2 TEST AND RESULTS

Measurements were taken to determine the heat output, boiler efficiency (direct method), flue gas 

composition, flue gas temperature in the measuring section, feed pressure (draught), emission 

characteristics and the electrical power consumption. The surface temperatures were measured at 

nominal heat output and at stationary operation; this allowed the surface losses to be estimated.

The measurement equipment and the measurement methods correspond to ÖNORM EN 303-

5:1999, ÖNORM EN 304:2005 and EN 267:1999. The measurement accuracy and the measurement uncertainty are stated in the procedures for verification in the quality management manual 

issued by the Federal Institute of Agricultural Engineering (Bundesanstalt für Landtechnik).

2.1 Test setup – measurement methods

BOILER TEST RIG WITH HEAT EXCHANGER: Heat output measurement by directly measuring 

the amount of water circulated through the heating circuit and its temperature increase (DIN 4702-

2:1990).

FLUE GAS EXTRACTION through a vertical measuring section, generating the feed pressure using a prefabricated flue pipe, diameter 200 mm, height above ground level 9 m, feed pressure limited by draught restriction flap.

HEAT OUTPUT MEASUREMENT: Determining the mass flow using the Coriolis mass flow meter 

PROMASS 83 F from Endress & Hauser, as well as the water temperatures at the boiler 

flow/return using a Pt 100 resistance thermometer, 1/3 DIN, calibrated as a pair.

FLUE GAS TEMPERATURE in the measuring section using a measurement system with 5 Pt 100 

resistance thermometers.

FEED PRESSURE with a ring balance meter.

WATER-SIDE RESISTANCE: Differential pressure transducer with ceramic measuring membranes DELTABARS PMD 70 from Endress & Hauser.

CARBON DIOXIDE AND CARBON MONOXIDE CONTENT: Non-dispersive infrared gas analyser 

NGA 2000 from Emerson; carbon dioxide: lowest measurement range 0 - 5 %, highest measurement range 0 - 20 %; carbon monoxide: CO Low - lowest measurement range 0 - 50 ppm, highest 

measurement range 0 - 2500 ppm; CO High – lowest measurement range 0 -1.0 %, highest measurement range 0 -10 %; measured in dry flue gas.

DUST CONTENT: Measuring device for gravimetric determination of total dust by company Paul 

Gothe GmbH with a nominal suction quantity of 6 m3/ h, dust separation on stuffed quartz wool filter; filter is located directly after sampling probe and elbow, determination of partial flow volume 

by dry gas meter and upstream drying tower. The sampling point for determination of dust content 

is arranged directly after the measuring section.

CONTENT OF ORGANIC GASEOUS SUBSTANCES: Flame ionisation detector JUM, Type VE 

5; samples taken via heated filter and heated pipe (thermostatically controlled to 180 °C); measured in damp flue gas.

NITROGEN MONOXIDE CONTENT: Gas analyser from ECO Physics Type CLD 700 E1-ht; 

chemiluminescent measurement principle; samples taken via heated filter and heated pipe; gas 

cooler; measured in dry flue gas.
Page 4 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

ELECTRICAL POWER CONSUMPTION: Modular energy meter ULYS ETD from ENERDIS, 

threephase 100-400 with a measurement accuracy for active energy corresponding to IEC 

61036/EN61036 C1.1. Maximum resolution of the pulse output: 0,1 Wh.

Power Analyzer Norma 4000 with 3 Power Phase PP40 with following specifications: 8 measurement ranges for voltage (0,3 / 1 / 3 / 10 / 100 / 300 / 1000 V), 6 measurement ranges for current 

(30 – 100 mA – 0,3 – 1 – 3 – 10 A). The measurement accuracy of +/- 0,1 % of measured value 

and 0,1% of measuring range, Sample Rate 341 kHz, bandwidth for voltage 3 MHz.

DATA LOGGING using TopMessage data logging system from Delphin Technologie AG, sampling 

interval 1 second, average value determined from 10 measurements, average data stored to media.

2.2 Performance of heating tests

HEAT OUTPUT: The measurements were carried out in accordance with ÖNORM EN 303-5:1999 

at nominal and minimum heat output (< 30 % of the nominal heat output) respectively. The nominal heat output measurements were performed after the burner had been in operation for at least 3 

hours in the nominal heat output range. The measurements themselves were taken over a test period of at least 6 hours. The efficiency was calculated by taking into account the heat stored in the 

boiler water.

EMISSIONS: Carbon dioxide, carbon monoxide, organic carbon and nitrogen oxide values were 

averaged over the whole test duration. For determining the dust content the extraction time per filter was limited to 30 minutes. The dust content was determined by 6 half-hourly averages, evenly 

distributed over the test duration. Calibration gases were used to check the gas analysers before 

and after every test period.

SETTINGS: The declared measurements relate to reproducible tests using optimised settings. The 

settings were made during preliminary tests based on recommendations of the manufacturer. It 

was aspired to maximise the carbon dioxide content whilst at the same time minimising the carbon 

monoxide content. 

FUEL: The measurements were performed with wood pellets according to ÖNORM M 7135:2000 

with a diameter of 6 mm and a water content of 5,8 % and 6,1 %. The water content, the ash content and the calorific value were determined; the average values of the chemical data relating to 

the water- and ash-free substance were taken from ÖNORM M 7132:1998.

FUNCTION CHECK of the temperature controller, safety temperature limiter and monitor and the 

installation to verify the rapid shutdown of the burner system. The measurements were performed 

as specified in 5.13 and 5.14 of ÖNORM EN 303-5:1999. 

2.3 Interpretation of emission measurements

The emission measurements were analysed by calculating the complete flue gas analysis using 

the carbon monoxide and carbon dioxide content averaged over the measurement period together 

with the fuel composition data. The speed of the flue gas at the measuring point was calculated 

from the flue gas volume taking into account the pressure and temperature.

The content of organic gaseous substances was measured in damp flue gas; the emissions were 

then converted for dry flue gas conditions and declared as organic carbon. The content of nitrogen 

oxides was measured in dry flue gas and declared as NO2.
Page 5 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.4 Investigatory heating tests with wood pellets at nominal heat output

 Number of test: HKA_1395

 Name of boiler: Pellet burner EVOTHERM P 50

 Nominal heat output: 49.5 kW

 Minimum Average Maximum

 value value value

Test conditions

 Start of test: 2006-06-21 07:28

 End of test: 2006-06-21 13:32

 Test duration: 06:03

 Ambient temperature: °C 23,3 25,5 27,6

 Outside temperature: °C 20,2 24,7 28,7

 Air pressure: mbar 992

Test fuel, heat input

 Test fuel Wood pellets 06_387 

 Water content kg/kg 0,058

 Ash content kg/kg 0,004

 Carbon content kg/kg 0,477

 Hydrogen content kg/kg 0,058

 Oxygen content kg/kg 0,403

 Calorific value of anhydrous

 and ash-free substance MJ/kg 18,8

 Calorific value of test fuel MJ/kg 17,5

 Applied fuel quantity kg 61,9

 Hourly fuel quantity kg/h 10,2

 Fuel heat input kW 49,8

Heat output, efficiency

 Water circulation kg/h 2077,5 2100,1 2120,8

 Flow temperature °C 57,4 57,6 57,9

 Return temperature °C 7 5,9 77,1 77,8

 Temperature difference K 18,3 19,5 20,3

 Heat output kW 47,8

 Utilisation % 96,6

 Boiler efficiency % 96,2

Measured values at flue gas measuring section

 Flue gas temperature °C 94,1 94,7 95,8

 Manometric pressure Pa 6,4 7,0 8,6

 Carbon dioxide % 11,8 14,4 16,5

 Carbon monoxide ppm 9,9 27,3 313,4

 Organic gaseous substances ppm 0,5 0,7 1,0

Nitrogen monoxide ppm 77,7 98,9 119,5
Page 6 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.4.1 Emission measurements

Measurement results test: HKA_1395

(Calculation depending on CO2-measurement)

Suction start: hh:mm 07:35 08:35 09:35 10:35 11:35 12:35

Suction period: min 30 30 30 30 30 30

Suctioned gas sample: m3 0,470 0,489 0,480 0,458 0,471 0,475

Measured CO2-content: % 14,2 14,5 14,4 14,2 14,4 14,4

Calculated O2-content: % 6,2 5,9 6,0 6,2 6,1 6,0

Density of gas sample:

Dry gas kg/Nm3 1,36 1,36 1,36 1,36 1,36 1,36

Humid gas kg/Nm3 1,30 1,31 1,30 1,30 1,30 1,30

Water content g/Nm3 82,8 84,6 84,0 82,9 83,6 84,0

Flue gas mass flow:

Dry gas kg/kg 8,5 8,3 8,4 8,5 8,4 8,4

Velocity:

At sampling point m/s 1,07 1,05 1,06 1,07 1,06 1,06

At probe head m/s 0,97 1,00 0,98 0,94 0,96 0,97

Dust content:

separated mg 4,8 4,9 5,3 5,5 5,8 7,0

separated relating

to sample volume mg/Nm3 12,1 12,0 13,2 14,3 14,7 17,7

2.4.2 Evaluation

 relating to relating to

 applied energy O2-content of

 10 % 13 %

 mg/MJ mg/Nm3 mg/Nm3

 Dust 5 10 7

 Carbon monoxide (CO) 12 25 18

 Organic gaseous

 substances(OGC) <1 1 1

 Nitrogen oxides (NOx) 73 153 111
Page 7 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.4.3 Output-related measurements

0 6

0

12

0

18

0

24

0

300 36

Time [min] 0

0

1

0

2

0

3

0

4

0

5

0

6

0

[kW]

Heat output

HKA_1395

0 6

0

12

0

18

0

24

0

300 36

Time [min] 0

0

5

0

10

0

15

0

20

0

25

0

30

0

[°C]

Flue gas temp.

Flow temp.

Return temp.

HKA_1395
Page 8 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.4.4 Flue gas composition

0 6

0

12

0

18

0

24

0

300 36

Time [min] 0

0

4

8

1

2

1

6

2

0

2

4

CO2 [%]

0

10

0

20

0

30

0

40

0

50

0

60

0

CO [ppm]

Carbon dioxide

Carbon monoxide

HKA_1395

0 6

0

12

0

18

0

24

0

300 36

Time [min] 0

Dust

0

2

5

5

0

7

5

10

0

12

5

15

0

Dust [mg/Nm3]

Organic C

0

2

5

5

0

7

5

10

0

12

5

15

0

OGC, NOx 

[ppm]

Nitrogen oxide

HKA_1395
Page 9 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.5 Investigatory heating tests with wood pellets at minimum heat output

 Number of test: HKA_1394

 Name of boiler: Pellet burner EVOTHERM P 50

 Nominal heat output: 49.5 kW

 Minimum Average Maximum

 value value value

Test conditions

 Start of test: 2006-06-20 07:03

 End of test: 2006-06-20 13:03

 Test duration: 06:00

 Ambient temperature: °C 24,1 26,1 27,6

 Outside temperature: °C 24,3 27,4 31,4

 Air pressure: mbar 995

Test fuel, heat input

 Test fuel Wood pellets 06_387 

 Water content kg/kg 0,061

 Ash content kg/kg 0,004

 Carbon content kg/kg 0,475

 Hydrogen content kg/kg 0,058

 Oxygen content kg/kg 0,402

 Calorific value of anhydrous

 and ash-free substance MJ/kg 18,8

 Calorific value of test fuel MJ/kg 17,4

 Applied fuel quantity kg 19,0

 Hourly fuel quantity kg/h 3,2

 Fuel heat input kW 15,3

Heat output, efficiency

 Water circulation kg/h 617,3 621,4 624,9

 Flow temperature °C 57,0 57,1 57,2

 Return temperature °C 75,7 76,5 77,5

 Temperature difference K 18,6 19,4 20,3

 Heat output in the

 boiler circuit kW 14,0

 Utilisation % 28,3

 Boiler efficiency % 91,9

Measured values flue gas measuring section

 Flue gas temperature °C 76,3 76,8 77,3

 Manometric pressure (draught) Pa 5,4 6,6 8,8

 Carbon dioxide % 5,5 7,7 11,0

 Carbon monoxide ppm 20,6 48,2 139,0

 Organic gaseous substances ppm 0,8 1,4 3,3

 Nitrogen monoxide ppm 30,5 44,3 63,1
Page 10 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.5.1 Emission measurements

Measurement results test: HKA_1394

(Calculation depending on CO2-measurement)

Suction start: hh:mm 07:10 08:10 09:10 10:10 11:10 12:10

Suction period: min 30 30 30 30 30 30

Suctioned gas sample: m3 0,461 0,476 0,472 0,455 0,476 0,496

Measured CO2-content: % 7,6 7,7 7,5 7,8 7,7 7,7

Calculated O2-content: % 13,1 13,0 13,1 12,9 13,0 12,9

Density of gas sample:

Dry gas kg/Nm3 1,33 1,33 1,33 1,33 1,33 1,33

Humid gas kg/Nm3 1,30 1,30 1,30 1,30 1,30 1,30

Water content g/Nm3 46,8 47,1 46,5 47,7 47,3 47,5

Flue gas mass flow:

Dry gas kg/kg 15,5 15,4 15,6 15,2 15,3 15,2

Velocity:

At sampling point m/s 0,56 0,55 0,56 0,55 0,55 0,55

At probe head m/s 0,43 0,43 0,43 0,41 0,43 0,45

Dust content:

separated mg 2,7 3,5 2,9 2,1 2,0 2,3

separated relating

to sample volume mg/Nm3 7,0 8,9 7,4 5,6 5,1 5,6

2.5.2 Evaluation

 relating to relating to

 applied energy O2-content of

 10 % 13 %

 mg/MJ mg/Nm3 mg/Nm3

 Dust 4 9 7

 Carbon monoxide (CO) 40 83 60

 Organic

 gaseous substances (OGC) 2 3 2

 Nitrogen oxides (NOx) 61 127 93
Page 11 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.5.3 Output-related measurements

0 6

0

12

0

18

0

24

0

300 36

Time [min] 0

0

4

8

1

2

1

6

2

0

2

4

[kW]

Heat output

HKA_1394

0 6

0

12

0

18

0

24

0

30

0

36

Time [min] 0

0

5

0

10

0

15

0

20

0

25

0

30

0

[°C]

Flue gas temp.

Flow temp.

Return temp.

HKA_1394
Page 12 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.5.4 Flue gas composition

0 6

0

12

0

18

0

24

0

300 36

Time [min] 0

0

2

4

6

8

1

0

1

2

CO2 [%]

0

2

5

5

0

7

5

10

0

12

5

15

0

CO [ppm]

Carbon dioxide

Carbon monoxide

HKA_1394

0 6

0

12

0

18

0

24

0

30

0

36

Time [min] 0

Dust

0

2

5

5

0

7

5

10

0

12

5

15

0

Dust [mg/Nm3]

Organic C

0

2

5

5

0

7

5

10

0

12

5

15

0

OGC, NOx 

[ppm]

Nitrogen oxide

HKA_1394
Page 13 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.6 Surface losses

The heat loss through the boiler surface is determined using DIN 4702-2:1990 basing on radiation 

coefficients and arrangements of technical surfaces (according to Nusselt). Temperatures were 

measured at 38 points on the boiler surface during the test at nominal heat output. The measurement results are shown in the following table and the table of measurements in appendix 5.2:

Parameter Value Unit

Test number HKA_1395

Ambient temperature 25,4 °C

Flow temperature 77 °C

Flue gas temperature 95 °C

Heat output in the boiler circuit 47,8 kW

Radiation losses from boiler 0,15 kW

Percentage loss at nominal heat output 0,3 %

The surface temperature of the handles on the combustion chamber/ash door was max. 4 K above 

the ambient temperature.

2.7 Water-side resistance of boiler

The water-side resistance for the flow rates was determined at nominal heat output which occurred

at temperature differences of 10 K and 20 K respectively.

Flow rate Temperature 

difference

Water temperature Differential pressure

[kg/h] [K] [°C] [mbar]

2120 20 36,4 7,7

4240 10 35,9 29,9
Page 14 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

2.8 Electrical power consumption

2.8.1 Average electrical power consumption at nominal heat output, minimum 

heat output, on standby and ignition

Operating status Fuel

Meas.

duration

Electrical

energy

Average 

electrical power 

consumption

Percentage of 

nominal heat 

output

[min] [Wh] [W] [%]

Nominal heat output

Wood pellets

365 780 128 0,3

Minimum heat output 361 502 83 0,2

Standby position 60 8 8

Ignition procedure 14 66 280

2.8.2 Electrical power consumption of main loads

Load Leistung [W]

Draught fan 82

Secondary air fan 63

Drive motor – stoker screw 17

Drive motor – extraction screw 29

Drive motor – cleaning of heat exchanger 7

Ignition rod 1653

3 SUMMARY OF RESULTS

3.1 Heating tests

The tested EVOTHERM P 50 pellet burner from the company Evotherm Heiztechnik Vertriebs 

GmbH, with a nominal heat output of 49,5 kW, was tested in the power range of 14,0 to 47,8 kW 

using wood pellets compliant to ÖNORM M 7135:2000 having a diameter of 6 mm and a water 

content of 5,8 % and 6,1 %.

Since the boiler flue gas temperature is less than 160 K above room temperature at nominal heat 

output, the boiler manufacturer shall make recommendations in accordance with ÖNORM EN 303-

5:1999, regarding the flue installation in order to ensure sufficient draught and to prevent sooting 

up of the chimney and condensation. 
Page 15 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

The results of the emission measurements are as follows:

Nominal heat output Minimum heat output

Test fuel [-] Wood pellets

Water content [%] 5,8 6,1

Heat output [kW] 47,8 14,0

Fuel heat input [kW] 49,8 15,3

Flue gas mass flow [kg/h] 92,1 50,2

Load [%] 96,6 28,3

Flue gas temperature [°C] 94,7 76,8

Boiler efficiency [%] 96,2 91,9

Carbon dioxide [%] 14,4 7,7

[mg/MJ]

1) [mg/m3

]

2) [mg/m3

]

3) [mg/MJ]

1) [mg/m3

]

2) [mg/m3

]

3)

Dust 5 10 7 4 9 7

Carbon monoxide 12 25 18 40 83 60

Organic carbon <1 1 1 2 3 2

Nitrogen oxides 73 153 111 61 127 93

1) Emission values in mg/MJ (relating to applied energy), subject to legal requirements in Austria.

2) Emission values in mg/m3(relating to 10 % O2, 1013 mbar, dry flue gas), according to ÖNORM EN 303-

5:1999.

3) Emission values in mg/m3(relating to 13 % O2, 1013 mbar, dry flue gas), corresponding to various national and international requirements.

3.2 Function check / safety temperature limiter on the boiler

The functional check of the temperature controller and the safety temperature limiter and monitor 

on the boiler was performed in accordance with section 5.13 of ÖNORM EN 303-5. The requirements were fulfilled.

3.3 Function check to verify the rapid shutdown of the system

Since the tested pellet burner EVOTHERM P 50 from the company Evotherm Heiztechnik Vertriebs GmbH is not equipped with a device to dissipate the residual heat as described in section 

4.1.5.11.3 of ÖNORM EN 303-5:1999, the operating and fault conditions associated with a power 

outage and sudden loss of heat extraction were simulated in order to satisfy the definition of a 

burner system with a rapid shutdown facility.

During the course of the checks on the temperature controller, the safety temperature limiter and 

the rapid shutdown facility no dangerous operating conditions arose neither with the water system 

nor the burner.
Page 16 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

4 ASSESSMENT

Based on the test results, one can hereby confirm that the

Pellet burner EVOTHERM P 50

from

Evotherm Heiztechnik Vertriebs GmbH

fulfils the requirements governed by the agreements in Art. 15 a BV-G relating to “Protective 

measures for small burners” (1998) and “Saving energy” (1995).

For the

factual correctness:

Amtsdirektor Dipl.-HLFL-Ing.

Leopold Lasselsberger m.p.

For the

report and tests:

Ing.

Harald Baumgartner m.p.

Head of the

accredited test centre:

Hofrat Dipl.-Ing. Dr.

Johann Schrottmaier m.p.

Wieselburg, 20/06/2007

Translation: 31/07/2009
Page 17 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

5 APPENDIX

5.1 Legal requirements (for information only)

Legal requirements relating to small burner systems

for biogenous fuels in Austria

Agreement according to Art. 15 a B-VG concerning an amendment to the agreement according to Art. 15 a B-VG relating to protective measures for small burners (1998)

Small solid fuel burners must not exceed the following emission limits:

Solid fuel burners

Emission limits [mg/MJ]

CO NOx OGC Dust

Manually 

loaded

Biogenous fuels 1100 150*) 80 60

Fossil fuels 1100 100 80 60

Automatically 

loaded

Biogenous fuels 500**) 150*) 40 60

Fossil fuels 500 100 40 40

*) The NOx limit only applies to wood burners.

**) This limit value can be exceeded by 50% during partial load operation at 30% of nominal heat 

output.

Energy saving agreement according to Art. 15 a B-VG

The efficiency of small solid fuel burners should not fall below the following values:

Small burners used for solid fuel central heating:

Manually loaded

Up to 10 kW 73 %

> 10 to 200 kW (65,3 + 7,7 log Pn) %

> 200 kW 83 %

Automatically loaded

Up to 10 kW 76 %

> 10 to 200 kW (68,3 + 7,7 log Pn) %

> 200 kW 86 %

These federal requirements are implemented in local state law.
Page 18 of 18

Pellet burner EVOTHERM P 50

BLT reference number: 131/06

5.2 Surface temperature measuring points

K E S S E LT Y P E :

P O S IT IO N S B E S C H R E IB U N G T E M P . T E M P .

D E S B E D IE N U N G S G R IF F E S [ °C ] [ °C ]

2 8

29,2

T E M P . T E M P . T E M P . T E M P . T E M P . T E M P .

NR. F LÄ C H E [ °C ] NR. F LÄ C H E [ °C ] NR. F LÄ C H E [ °C ] NR. F LÄ C H E [ °C ] NR. F LÄ C H E [ °C ] NR. F LÄ C H E [ °C ]

1 A 1 31,0 2 1 E 1 30,5 4 1 I 1 6 1 M 1 6 1 Q 1 6 1 U 1

2 A 2 31,3 2 2 E 2 31,2 4 2 I 2 6 2 M 2 6 2 Q 2 6 2 U 2

3 A 3 31,0 2 3 E 3 28,3 4 3 I 3 6 3 M 3 6 3 Q 3 6 3 U 3

4 A 4 31,4 2 4 E 4 29,1 4 4 I 4 6 4 M 4 6 4 Q 4 6 4 U 4

5 A 5 2 5 E 5 27,8 4 5 I 5 6 5 M 5 6 5 Q 5 6 5 U 5

M ittelw ert 31,2 M ittelw ert 29,4 M ittelw ert M ittelw ert M ittelw ert M ittelw ert

6 B 1 28,0 2 6 F 1 32,7 4 6 J 1 6 6 N 1 6 6 R 1 6 6 V 1

7 B 2 27,9 2 7 F 2 31,6 4 7 J 2 6 7 N 2 6 7 R 2 6 7 V 2

8 B 3 26,9 2 8 F 3 28,9 4 8 J 3 6 8 N 3 6 8 R 3 6 8 V 3

9 B 4 26,9 2 9 F 4 31,2 4 9 J 4 6 9 N 4 6 9 R 4 6 9 V 4

1 0 B 5 26,9 3 0 F 5 30,2 5 0 J 5 7 0 N 5 7 0 R 5 7 0 V 5

M ittelw ert 27,3 M ittelw ert 30,9 M ittelw ert M ittelw ert M ittelw ert M ittelw ert

1 1 C 1 30,0 3 1 G 1 31,2 5 1 K 1 7 1 O 1 7 1 S 1 7 1 W 1

1 2 C 2 30,5 3 2 G 2 28,7 5 2 K 2 7 2 O 2 7 2 S 2 7 2 W 2

1 3 C 3 30,8 3 3 G 3 32,3 5 3 K 3 7 3 O 3 7 3 S 3 7 3 W 3

1 4 C 4 29,6 3 4 G 4 29,3 5 4 K 4 7 4 O 4 7 4 S 4 7 4 W 4

1 5 C 5 30,3 3 5 G 5 5 5 K 5 7 5 O 5 7 5 S 5 7 5 W 5

M ittelw ert 30,2 M ittelw ert 30,4 M ittelw ert M ittelw ert M ittelw ert M ittelw ert

1 6 D 1 29,8 3 6 H 1 29,9 5 6 L 1 7 6 P 1 7 6 T 1 7 6 X 1

1 7 D 2 29,5 3 7 H 2 30,3 5 7 L 2 7 7 P 2 7 7 T 2 7 7 X 2

1 8 D 3 27,1 3 8 H 3 29,8 5 8 L 3 7 8 P 3 7 8 T 3 7 8 X 3

1 9 D 4 26,9 3 9 H 4 29,5 5 9 L 4 7 9 P 4 7 9 T 4 7 9 X 4

2 0 D 5 28,2 4 0 H 5 29,8 6 0 L 5 8 0 P 5 8 0 T 5 8 0 X 5

M ittelw ert 28,3 M ittelw ert 29,9 M ittelw ert M ittelw ert M ittelw ert M ittelw ert

E V O T H E R M H eiztechnik V ertriebs G m bH

M uschelgriff F rontverk leidung

M uschelgriff W ärm etauscher

K E S S E LF A B R IK A T :

M E S S P U N K T

B E Z .

 M E S S M E S S

M A T E R IA L

(M E / P O / K U )

P O S IT IO N S B E S C H R E IB U N G 

 D E S B E D IE N U N G S G R IF F E S

Z 1

Z 2 Z 4

K U

K U

Z 3

 M E S S M E S S M E S S . M E S S

B E Z .

M A T E R IA L M E S S P U N K T

(M E / P O / K U )

P elletsfeuerung E V O T H E R M P 50

H1...H5 Floor area