Defro Duo

DERFO DUO is a flagship model of boilers with a distinctive logo of the company. This innovative construction has two combustion chambers: lower, equipped with an automatic fuel charger integrated with a retort burner; and upper, a permanently mounted pipe grate cooled by water and of wall thickness of 8.8 mm. The upper chamber allows for using, for example, wood chips as fuel and for emergency start-up of the device. A grate deck has also the function of water tubes and constitutes additional area for heat exchange. The boiler exchanger has been made only from boiler steel of thickness of 6-10 mm but elements exposed to fire and compounds contained in the flue gas have been made from steel of thickness of up to 10-12 mm.
The boilers are equipped with a number of sensors controlling its work. A fuel-container opening sensor is a novelty. The boiler is adjusted for installation of the additional automatic FIRE-FIGHTER water quenching system and a charge container lamp. On request, the boiler can be equipped with an innovative PID controller with a touch screen*.

Fuel type:

primary

substitute

pea-coal

coal

wood

Boiler’s advantages:

	5-year warranty for heat exchanger tightness, 2-year warranty for other elements and efficient operation of the boiler;
	the exchanger has been made from certified boiler steel ( P256GH type) of thickness of 6-10 mm, delivered by the following steel plants: Arcelor Mittal Poland S.A, Kraków branch and U. S. Steel Košice s.r.o.;
	high thermal efficiency, up to 90%;
	electronic boiler regulation; innovative controller with a touch screen cooperating with up to 4 pumps (central heating, hot utility water, circulatory and floor pump) and with the possibility of controlling mixing valves*;
	big combustion chamber with a highly-effective retort burner;
	fuel-container opening sensor;
	automatic water system for quenching fuel, includes a thermostatic valve*;

Technical data
Specification/boiler type	Unit	15	25	35	50	75
Nominal output	kW	8-24	10-31	13-42	16-53	23-75
Heating surface	m²	2,1	2,8	3,8	4,8	6,7
Heated room surface	m²	do 200	do 250	do 320	do 480	do 700
Single fuel load	kg	~230	~230	~400	~400	~400
Optimum heating efficiency	%	90,3-90,7	90,3-90,7	90,3-90,7	90,3-90,7	90,3-90,7
Max. work pressure allowed	bar	1,5	1,5	1,5	1,5	1,5
Required chimney flue	Pa	20	25	30	35	38
Water temp. on supply max	°C	80	80	80	80	80
Boiler weight	kg	504	594	684	858	1005
Boiler water capacity	l	76	99	110	122	197
Chimney cross section	cm x cm ø mm	14x14 160	16x16 180	19x19 210	21x21 230	25x25 280
Minimum chimney height	m	6	6	7	9	10
Power supply	V/Hz	230/50Hz	230/50Hz	230/50Hz	230/50Hz	230/50Hz
Power consumption	W	165	214	291	291	346
Width	mm	1208	1242	1414	1414	1513
Depth	mm	922	1031	1061	1279	1295
Height*	mm	1672	1672	1739	1736	1878
Supply and return diameter Dn	mm	G 1_1/2"	G 1_1/2"	G 1_1/2"	G 1_1/2"	G 2"
Flue pipe dimension	mm	ø159	ø178	ø194	ø194	ø245
*Boiler’s height can be additionally regulated by the use of the feet attached to it. The feet can regulate height by 38-50mm.




	A*	B*	C	D*	E*	F	G	H	I	J	K
15	115	1257	Ø159	1692	1570	498	1195	533	210	201	945
25	115	1257	Ø179	1692	1570	548	1219	641	210	201	1053
35	115	1305	Ø194	1739	1627	598	1388	641	240	201	1083
50	115	1305	Ø194	1793	1627	598	1388	865	240	201	1307
75	153	1402	Ø245	1916	1640	718	1508	865	250	201	1317

* In case of disclaimers of regulatory dimension increases from min. 38 to max. 50 mm.

The table below shows the dimensions of the opening for filling and combustion chamber.

	A (Width)	B (Depth)	C (Height)	D (Width x Height)
15	310	370	310	310x190
25	360	480	310	360x190
35	405	480	360	405x190
50	405	700	360	405x190
75	500	700	410	500x235

DEFRO company reserves the right to make equipment, technological or specification changes without notice due to continuing engineering and technological advances. The content of this website does not constitute an assurance within the meaning of Article 4.3-4 of the Act of 27 August 2002 on specific terms and conditions of consumer sale and amendments to the Civil Code ("the Act") neither is a product description within the meaning of Article 4.2 of the Act. This website and all the information it contains are issued for information purposes only and they do not constitute an offer within the meaning of article 66 of the Civil Code.

DEFRO company reserves the right to make equipment, technological or specification changes without notice due to continuing engineering and technological advances. The content of this website does not constitute an assurance within the meaning of Article 4.3-4 of the Act of 27 August 2002 on specific terms and conditions of consumer sale and amendments to the Civil Code (“the Act”) neither is a product description within the meaning of Article 4.2 of the Act. This website and all the information it contains are issued for information purposes only and they do not constitute an offer within the meaning of article 66 of the Civil Code.