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DC25SP

DC25SP

Combined boiler for wood and pellets.

  • Rated power 27 kW

  • Boiler efficiency 89,9 - 91,2 %

  • Emission class nr. 5 (Ecodesign)

  • Log lenght 530 mm

ecolabeling Dotovany kotel

DCxxSP(X)(T) boilers meets 5th emission class (Energy efficiency class A+), Ekodesign.

Advantages of ATMOS boilers

  • possible combination of individual types of fuels – fuel change without modifications on the wood + pellet boiler
  • high efficiency for individual fuels – practically the same as for special pellet boilers (up to 92.3 % at rated output)
  • cheaper solution – if we add up the costs of acquiring two boilers, their connection and fume extraction (chimney), we find that one boiler, although more expensive, is more economically advantageous
  • small built-up area – compared to more boilers
  • one chimney and flue
  • ecological operation – boiler according to EN 303-5:2012 class 5, EKODESIGN 2015/1189
  • subsidized boiler
  • choice of door R / L (right/ left) 
  • The boiler is equipped with the function of automatic start of the pellet burner after the wood has burned out

 

 

Installation

 

We recommend installing the boiler with Laddomat 22 or a thermo regulating valve with equalizing vessel 500 – 1000 litres. We also recommend installing the boiler with accumulating tanks of appropriate volume (e.g. 2000 litres), which allow utilising electricity for heat accumulation or connecting solar panels. If necessary, the boiler can be connected into a system without accumulating tanks. This comes into account if you use fuel oil.

Boilers regulation 

The operation of the boiler is fully automatic to heat up water to required temperature with high efficiency and in a good quality of burning. All this ensure:

  • HONEYWELL draught regulator
  • boiler (regulating) thermostat – fan control thermostat
  • waste gas thermostat
  • pump thermostat
  • main switch and changeover switch for boiler operation

Boilers and burners DCxxSP(X) (in version Model 2018/2019) are equipped with the function of automatic closing or opening of the air supply to the boiler/burner (using the actuator) when heating with wood or pellets. The boilers are equipped with an AGF2 flue gas sensor and a KTF20 boiler water temperature sensor for function of automatic burner start after the wood burns out. Than the boilers are equipped with two KTF20 sensors (TV and TS) for controlling the burner with two temperatures on the accumulation tank. The whole set is sold in maximum equipment, for fully automatic mode and easy installation “plug and play”.

 

 

Panel composition:
Main off switch, safety thermostat, thermometer, regulator thermostat and combustion thermostat

Electro-mechanical regulation is an optimum solution for easy management of the operation of the boiler (ventilator). The design of the panel with standard regulation is a basic design for all produced boilers.

Regulace ACD 03

Each boiler can be equipped with a modern touch electronic control ATMOS ACD 03 for controlling the entire heating system depending on the outdoor temperature, room temperature and time. This regulation is able to control the boiler itself with a fan with many other functions.

 

 

Technical information

 Description for DCxxSP(X) boiler drawing
1. Boiler body 25. Door filling – Sibral
2. Loading door (wood heating) 26. Door sealing – cord 18 x 18
3. Ash-pan door (wood heating) 27. Heatproof shaped piece
– half moon (door shield)
4. Exhaust fan 28. ATMOS A25 pellet burner
5. Heatproof shaped piece
– nozzle		 29. Primary air regulation
6. Control panel 30. Secondary air regulation
7. Safety thermostat
(Caution – in overheat condition must be depressed)		 31. Heat proof shaped piece
– spherical space (chamber for wood)
8. Air control damper 32. Heatproof shaped piece
– back side of the spherical space (chamber for wood)
9. Heat proof shaped piece
– extension of the spherical space (chamber for pellets)		 33. Pump thermostat
10. Heat proof shaped piece
– spherical space (chamber for pellets)		 34. Fuse (6,3A) T6,3A/1500 – H type
11. Sealing cord – nozzles – 12 x 12 35. Flue gas thermostat
12. Door for the pellet burner (bottom) 36. Changeover switch (wood-0-pellets)
13. Ignition (firing up) valve 37. End switch with button
14. Heatproof shaped piece
– back side of the spherical space (chamber for pellets)		 38. Capacitor of exhaust fan – 1 μF
15. Cleaning lid 39. Sibral seal under the burner
16. Primary air screen 40. Measurement point for the combustion gases – flue gas analyzer
17. Ignition (firing up) valve pulling rod 41. BELIMO Actuator with the flap
18. Thermometer 42. Modul AD03
19. Frame shield
20. Main switch with indicator light K  – the flue-gas duct neck
21. Flue gas brake (only DC30SPX) L  – the boiler water outlet
22. Draught regulator – Honeywell FR 124 M  – the boiler water inlet
23. Cooling loop protecting against overheating N  – filling valve pipe sleeve
24. Boiler (regulating) thermostat – fan control thermostat P  – sleeve for a sensor of the valve which regulates the cooling loop (TS 131, STS 20)

 

 Description for DC40SPT boiler drawing
1. Boiler body 26. Door sealing – cord 18 x 18
2. Loading door (wood heating) 27. Heatproof shaped piece
– half moon (door shield) – (chamber for pellets)
3. Ash-pan door (wood heating) 28. ATMOS A45 SPT pellet burner
4. Exhaust fan 29. Heatproof shaped piece
– side
5. Heatproof shaped piece
– nozzle		 31. Heat proof shaped piece
– spherical space (chamber for wood)
6. Control panel 32. Heatproof shaped piece
– back side of the spherical space (chamber for wood)
7. Safety thermostat
(Caution – in overheat condition must be depressed)		 33. Heatproof shaped piece
– extension of the spherical space (chamber for wood)
8. Air inlet regulating flap 34. Pump thermostat
9. Heat proof shaped piece
– extension of the spherical space (chamber for pellets)		 35. Fuse (6,3A) 5×20/T6,3A/1500 – type H
10. Heat proof shaped piece
– spherical space (chamber for pellets)		 36. Flue gas thermostat
11. Sealing cord – nozzles – 12 x 12 37. Selector switch I-0-II
12. Door for the pellet burner  38. Limit switch with a push-button
13. Ignition (firing up) valve 41. Sibral sealing under burner
14. Heatproof shaped piece
– back side of the spherical space (chamber for pellets)		 42. Measurement point for the combustion gases – flue gas analyzer
15. Cleaning lid 43. BELIMO Actuator with the flap
16. Tube heat exchanger 44. Module AD03
17. Ignition (firing up) valve pulling rod 45. Heatproof shaped piece
– extension of the nozzle (cube)
18. Thermometer 46. Capacitator for exhaust fan – 1μF
19. Frame shield
20. Switch with an indicator light  
21. Regulating flap – BELIMO actuator K  – the flue-gas duct neck
22. Air inlet regulator – Honeywell FR 124 L  – the boiler water outlet
23. Cooling loop protecting against overheating M  – the boiler water inlet
24. Control thermostat (operation thermostat) N  – filling valve pipe sleeve
25. Loading door insulation – Sibral P  – sleeve for a sensor of the valve which regulates the cooling loop (TS 131, STS 20)

 

Boiler dimensions
DC18SP DC25SP DC30SPX DC32SP DC40SPT
A 1695 1695 1665 1772 1755
B1 757 957 957 957 1230
B2 1301 1501 1501 1501 1792
C 643 643 643 678 680
D 1375 1375 1375 1448 1445
E 150 / 152 150 / 152 150 / 152 150 / 152 150 / 152
F 65 65 65 70 87
G 207 207 207 184 204
H 1436 1436 1436 1507 1507
CH 212 212 212 212 256
I 212 212 212 212 256
J 6/4″ 6/4″ 6/4″ 6/4″ 6/4″

 

Specification Boiler type
  DC18SP DC25SP DC30SPX DC32SP DC40SPT
Boiler heat output
– pellets
– wood		 kW
4,5 – 15
20
6 – 20
27
6 – 20
30
6 – 20
35
9 – 30
40
Boiler thermal input
– pellets
– wood		 kW
4,9 – 16,2
22,2
6,5 – 21,9
27
6,5 – 21,9
33,4
6,5 – 21,9
39,4
9,7 – 32,3
43,9
Heating surface m2 2,5 3,3 3,3 3,8 4,9
Fuel shaft volume dm3 (l) 66 100 100 140 160
Filling hole dimensions mm 450 x 260 450 x 260 450 x 260 450 x 260 450 x 260
Specified chimney draft
– pellets
– wood		 Pa / mbar
15 / 0,15
20 / 0,20
18 / 0,18
23 / 0,23
18 / 0,18
23 / 0,23
18 / 0,18
24 / 0,24
20 / 0,20
22 / 0,22
Max. working water overpressure kPa / bar 250 / 2,5 250 / 2,5 250 / 2,5 250 / 2,5 250 / 2,5
Boiler weight kg 435 531 537 596 768
Gas-outlet pipe diameter mm 150 / 152 150 / 152 150 / 152 150 / 152 150 / 152
Ingress protection of electric parts IP 20 20 20 20 20
Electric input
– at start-up – pellets (max.)
– in operation – pellets (max.)
– in operation – wood (max.)		 W
522(572) / 1042 (1092)
42 (92)
50
572 / 1092
97
50
Electrical input in standby mode W 3,3 3,3 3,3 3,3 3,3
Ignition mode pellets / wood
   automatic / manual
Boiler efficiency
– pellets
– wood		 %
92,5
90,1
91,2
89,9
91,2
89,9
91,2
88,9
92,8
91,0
Boiler class 5 5 5 5 5
Boiler category  1
Operating mode non-condensing
Solid fuel boiler with cogeneration unit no
Combined device also for heating of DHW no
Energy efficiency class A+ A+ A+ A+ A+
Waste gas temperature at nominal output according to EN 303-5
– pellets
– wood		 °C
109
157
139
177
139
177
139
185
116
147
Waste gas combustion products flow
weight at nominal output
– wood		 °C / Pa
177 / 20
197 / 23
197 / 23
205 / 24
167 / 22
Waste gas combustion products flow
– pellets
– wood		 kg / s
0,008
0,010 
0,010
0,015 
0,010
0,017
0,010
0,018 		 0,015
0,023
Specified fuel  quality pellets with a diameter of 6 – 8 mm, lenght 10 – 40 mm, with a calorific value of 15 – 18 MJ.kg-1
Specified fuel  dry wood with a calorific value of 15 – 17 MJ / kg-1, water content 12 – 20 %, diameter 80 – 120 mm
Average fuel consumption at nominal output – wood
 kg.h-1 5,6 7,2 7,6 9,2 10,1
Per heating season
   1 kW = 1 stacked cubic meter
Maximum wood length mm 330 530 530 530 730
Combustion time at nominal output – wood Hours 2 3 2 2 2,5
Boiler water volume l 78 109 109 160 131
Boiler hydraulic loss mbar 0,22 0,23 0,23 0,23 0,23
Minimum buffer tank volume l 500 500 500 500 750 – pellets
2200 – wood
Connecting voltage V / Hz 230 / 50
EKODESIGN yes yes yes yes yes
Specified minimum temperature of water returning to boiler is 65 °C when in operation.
Specified boiler operating temperature is 80 – 90 °C.

 

The Pellet burner

Pellet burners for combined boilers DC18SP, DC25SP, DC30SPX, DC32SP, DC40SPT

PELLET BURNER ATMOS A25 (for models DCxxSP(X)) – Code: H0048

PELLET BURNER ATMOS A45SP (for model DC40SPT) – Code: H0352

The burners in the version for models DCxxSP(X)(T) are equipped with the function of automatic closing or opening of the air supply to the burner, by means of an actuator, when heating with wood or pellets.

Prescribed fuel: quality wood pellets (white) with a diameter of 6 to 8 mm, a length of 10 to 40 mm and a calorific value of 15 – 18 MJ.kg-1.

Burner display: used to display the current status of the burner and to set its functions

Burner control: electronic control AC07X, which controls the operation of the external conveyor, two ignition coils and the fan according to the requirements of the boiler and the heating system. The electronics are protected by a boiler safety thermostat, a safety thermostat on the pellet supply to the burner, a fan speed sensor and a photocell for flame sensing. The burner operation is signaled on the electronic control display.

Fuel ignition: automatic by means of two electric ignition coils.

Basic burner functions:
Possibility to use two backup outputs R and R2 for different applications
Possibility of connecting four different sensors TS, TV, TK and TSV
TS – lower sensor on the tank
TV – sensor upper on the tank
TK – boiler sensor or middle sensor on the tank
TSV – flue gas sensor or solar panel

  • burner control according to two temperatures on the expansion tank
  • control of the boiler fan from the burner by means of a reserve output
  • control of the boiler pump from the burner by means of a reserve output
  • control of the solar system directly from the burner
  • automatic burner start after wood burning for DCxxSP(X)(T) boilers

Burners are able to burn only good quality white pellets from soft wood without bark ø 6 – 8 mm, lenght 10 – 25 mm with heating power 16 – 19 MJ.kg-1. Burners are not able to burn pellets with high caking property in the burning chamber. In such case it is needed to clean the burning chamber in period once a day.

Appropriate conveyors for ATMOS A25 burner:

  • Auger pellet conveyor for burner ATMOS A25 – DA1500 lenght1,5 m and diameter 75 mm
  • Auger pellet conveyor for burner ATMOS A25 – DA2000 lenght 2 m and diameter 75 mm
  • Auger pellet conveyor for burner ATMOS A25 – DA2500 lenght 2,5 m and diameter 75 mm
  • Auger pellet conveyor for burner ATMOS A25 – DA3000 lenght 3 m and diameter 75 mm
  • Auger pellet conveyor for burner ATMOS A25 – DA4000 lenght 4 m and diameter 75 mm

Appropriate conveyors for ATMOS A45 burner:

  • Auger pellet conveyor for burner ATMOS A25 – DRA50 lenght 1,7 m and diameter 80 mm
  • Auger pellet conveyor for burner ATMOS A25 – DRA50 lenght 2,5 m and diameter 80 mm
  • Auger pellet conveyor for burner ATMOS A25 – DRA50 lenght 4 m and diameter 80 mm
  • Auger pellet conveyor for burner ATMOS A25 – DRA50 lenght 5 m and diameter 80 mm

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