Condensing gas boiler — choose from 6 different models

Accord­ing to sta­tis­tics, in order to cre­ate autonomous heat­ing in a home, most Euro­pean pur­chase gas heat­ing sys­tems, which are right­ful­ly con­sid­ered the most eco­nom­i­cal and envi­ron­men­tal­ly friend­ly.

Mod­ern indus­try offers a huge selec­tion of boil­er equip­ment, which dif­fers in many para­me­ters, among which the most com­mon is ther­mal pow­er, func­tion­al­i­ty, method of instal­la­tion and removal of exhaust gas­es. This pub­li­ca­tion will focus on hot water gas boil­ers, which have some design dif­fer­ences from tra­di­tion­al heat­ing instal­la­tions. We are talk­ing about boil­er equip­ment of con­dens­ing and para­pet type.


Energy from steam condensation

To under­stand what a gas con­dens­ing boil­er is, you must first con­sid­er the prin­ci­ple of oper­a­tion of a tra­di­tion­al boil­er instal­la­tion. When gas is burned, heat is released, which heats the heat exchang­er, and, accord­ing­ly, the coolant pass­ing through it. After that, the heat­ed coolant enters the radi­a­tors, where heat exchange takes place between the air and the coolant, and the com­bus­tion prod­ucts are removed through the chim­ney.

From the school chem­istry course, every­one knows that com­bus­tion is an oxi­da­tion process that occurs with a large release of ther­mal ener­gy. When the gas-air mix­ture is burned, car­bon diox­ide and water are released, which is in a vapor state. It takes a huge amount of ener­gy to turn water into steam.

The prin­ci­ple of oper­a­tion of a con­dens­ing gas boil­er is to con­vert the water vapor in the com­bus­tion prod­ucts of the fuel back into water. Dur­ing con­den­sa­tion, the steam gives off the accu­mu­lat­ed heat to the sur­face of the heat exchang­er.

It works like this: the return from the heat­ing sys­tem enters the con­dens­ing heat exchange cham­ber of the boil­er, through which the exhaust gas­es pass. The tem­per­a­ture of the coolant com­ing from the sys­tem is much low­er than the tem­per­a­ture of the water vapor from the com­bus­tion prod­ucts. The steam con­dens­es on the walls of the heat exchang­er, giv­ing off the accu­mu­lat­ed ther­mal ener­gy to the heat car­ri­er, which, being warm, enters the pri­ma­ry heat exchang­er, where it is main­ly heat­ed to the nom­i­nal tem­per­a­ture.The principle of operation of the condensing boiler

The heat­ed coolant is returned to the heat­ing sys­tem, and the con­den­sate is dis­charged through the drainage into the sew­er. The acid­i­ty of the con­den­sate, as a rule, does not exceed 3.5 units: its dis­charge into the sew­er does not vio­late the estab­lished stan­dards.

For boil­ers of this type, the effi­cien­cy reach­es up to 98%, with low­er fuel con­sump­tion (com­pared to tra­di­tion­al instal­la­tions with the same tech­ni­cal para­me­ters).

The effi­cien­cy of the boil­er depends on the tem­per­a­ture of the coolant enter­ing the boil­er equip­ment: the low­er it is, the high­er the effi­cien­cy of the device. The most effi­cient oper­a­tion of this device becomes at tem­per­a­tures of direct and reverse flow of the coolant 40/30°C.

Parapet installations

parapet boilerIn con­nec­tion with the huge range of heat­ing equip­ment pre­sent­ed on the Euro­pean mar­ket of cli­mat­ic equip­ment, many of our com­pa­tri­ots are inter­est­ed in the ques­tion: “What are para­pet gas boil­ers?”

Despite this some­what tricky name, these are com­plete­ly non-volatile boil­er units with a sealed com­bus­tion cham­ber, which are a kind of sym­bio­sis of a gas boil­er with a con­vec­tor. The scope of such equip­ment is exten­sive: from indus­tri­al premis­es to heat­ing city apart­ments and pri­vate hous­es, which do not pro­vide for a sta­tion­ary chim­ney. The removal of com­bus­tion prod­ucts and the sup­ply of air nec­es­sary for nor­mal com­bus­tion of gas is car­ried out through a coax­i­al chim­ney.

Since this type of heat gen­er­a­tors is non-volatile, it will be used only in heat­ing sys­tems with nat­ur­al cir­cu­la­tion of the coolant.

The device of the para­pet boil­er unit:

  • Hous­ing made of thick steel. An eas­i­ly remov­able dec­o­ra­tive cas­ing with an inspec­tion door is installed on it. Thanks to per­fo­ra­tion, this heater, not con­nect­ed to the heat­ing sys­tem, per­forms the func­tion of a con­vec­tor.
  • Burn­er block with gas valve. The unit con­sists of a main and a pilot burn­er and is mount­ed on an eas­i­ly remov­able frame struc­ture. The pilot burn­er includes a ther­mo­cou­ple and a spark elec­trode.
  • Sealed com­bus­tion cham­ber.
  • Heat exchang­er with cop­per coil.
  • Coax­i­al chim­ney through which exhaust gas­es are removed and street air enters.
  • Block of non-volatile automa­tion and reg­u­la­tion.

This type of instal­la­tion is equipped with a ther­mome­ter, a piezo igni­tion sys­tem and a smoke and air unit.

Parapet octla deviceA dis­tinc­tive fea­ture of para­pet heat gen­er­a­tors is the design of a heat exchang­er with a cop­per or steel water heat­ing coil. Spi­ral tur­boliz­ers are installed in the inside of the heat exchang­er, which are designed to reduce the speed of the exhaust gas­es. This design allows you to sig­nif­i­cant­ly increase the con­tact of heat­ed gas­es with the sur­face of the heat exchang­er, and, con­se­quent­ly, heat trans­fer.

How to adjust the operation of a gas installation

Many own­ers of heat­ing equip­ment ask how to adjust the para­pet boil­er? We strong­ly do not rec­om­mend adjust­ing the boil­er your­self. Please note that this man­u­al is for infor­ma­tion­al pur­pos­es only.

Imme­di­ate­ly make a reser­va­tion that inter­fer­ence in the oper­a­tion of gas equip­ment is pro­hib­it­ed by law in our coun­try. Its inde­pen­dent adjust­ment of work can lead to a decrease in effi­cien­cy, equip­ment fail­ure and oth­er unde­sir­able con­se­quences. Con­dens­ing boil­ers must be adjust­ed by spe­cial­ists who are autho­rized and expe­ri­enced in this type of activ­i­ty.

The reg­u­la­tion of the boil­er, as a rule, con­sists in set­ting the gas valve. On the burn­er block (under the dec­o­ra­tive pan­el) there are two adjust­ment screws: adjust­ment of the max­i­mum and min­i­mum gas pres­sure.

  1. On a cold boil­er, start the pilot burn­er.
  2. Set the first mode.
  3. If the boil­er does not start, then turn the min­i­mum pres­sure screw (see the loca­tion in the pass­port) before start­ing.

You have adjust­ed the start of the boil­er. The cut­off is adjust­ed in the same way.

The con­dens­ing heat gen­er­a­tor is adjust­ed using a gas ana­lyz­er, the probe of which is installed in a spe­cial chim­ney sock­et. The max­i­mum and min­i­mum pow­er is reg­u­lat­ed by turn­ing the damper on the gas valve, based on the read­ings of the gas ana­lyz­er: at max­i­mum pow­er, the con­tent of car­bon diox­ide in the flue gas­es should not exceed 9.5%; resid­ual oxy­gen — no more than 4%.

Demanded models of heat generators

Today, in the domes­tic mar­ket of cli­mate tech­nol­o­gy, you can eas­i­ly find para­pet boil­er equip­ment from sev­er­al Euro­pean, Ukrain­ian and Euro­pean man­u­fac­tur­ers. The con­sumer quite often has a prob­lem with the choice. So, a dou­ble-cir­cuit para­pet gas boil­er: which man­u­fac­tur­er is bet­ter?

  1. AOGV 13 P DV “ROSS” is a dou­ble-cir­cuit heat gen­er­a­tor designed to cre­ate autonomous heat­ing and hot water sup­ply in domes­tic and indus­tri­al premis­es.AOGV 13 P DV

    This mod­el has a pow­er of 13 kW, which is enough to heat a room of 100 m2. Fea­tures of this mod­el: steel heat exchang­er; reli­able Ital­ian automa­tion; con­nec­tion of the sys­tem from any side, it can work on both nat­ur­al and liq­ue­fied gas. Small dimen­sions allow instal­la­tion of the unit in any con­ve­nient place, but no fur­ther than 5 m from the out­er wall. DHW capac­i­ty — 4l / min. Effi­cien­cy — 90%; fuel con­sump­tion 1.4 m3/h Cost — 230 $.

  2. AOGV 12.5 PV “Mayak” — a dou­ble-cir­cuit boil­er unit, with a ther­mal pow­er of 12.5 kW.

    AOGV 12.5 PV Con­nec­tion of the heat­ing sys­tem — uni­ver­sal (left — or right-hand), gas sup­ply only on the right. This device can be mount­ed on a wall, on a floor, and the small sizes allow to install it under a win­dow sill. DHW capac­i­ty — 4.1 l / min; Tem­per­a­ture lim­its in the heat­ing cir­cuit — 40/90 ° С. Effi­cien­cy — 90%. Gas con­sump­tion 1.4 m3/h The aver­age cost is 190 $.

  3. Aton Com­pact 12.5 MV — Europe. This dual-cir­cuit mod­el has become quite pop­u­lar, thanks to the reli­able Ger­man auto­mat­ics Mer­tik Max­itrol and high build qual­i­ty.Aton Compact 12.5 MV

    The body of the Aton Com­pact 12.5 MV boil­er unit is cov­ered with pow­der enam­el, which reli­ably pro­tects it from cor­ro­sion and makes it look attrac­tive. Instal­la­tion pow­er 12.5 kW; fuel con­sump­tion no more than 1.4 m3/h; DHW capac­i­ty — 300 l / h. Effi­cien­cy 90%. The aver­age cost is 180 $.

    Choos­ing the best mod­el and man­u­fac­tur­er is a mat­ter of taste and finan­cial con­di­tion of the user. But, more of our com­pa­tri­ots believe that the heat gen­er­a­tor AOGV 13 P DV “ROSS” is the best of the para­pet mod­els.

    If you decide to pur­chase con­dens­ing boil­er equip­ment for heat­ing and cre­at­ing hot water at home, we rec­om­mend that you famil­iar­ize your­self with the most pop­u­lar mod­els.

  4. Vail­lant AtmoTEC plus VUW 200–5 is a wall-mount­ed con­dens­ing dou­ble-cir­cuit gas boil­er from the famous Ger­man man­u­fac­tur­er Vail­lant Group.Vaillant AtmoTEC plus VUW 200-5

    A fea­ture of this mod­el is the lamel­lar design of the heat exchang­er in the DHW unit, which elim­i­nates the appear­ance of scale. The cop­per main heat exchang­er is coat­ed with Supral, which sig­nif­i­cant­ly increas­es heat trans­fer. Burn­er mate­r­i­al chromi­um-nick­el steel. The device is equipped with an LCD dis­play. The ther­mal pow­er of this mod­el is 22.2 kW; DHW — 9.6 l / min; Effi­cien­cy — 98%; Cost — 53.50 $.

  5. Chaf­foteaux TALIA GREEN EVO SYSTEM 12 FF is a 13.3 kW con­dens­ing heat gen­er­a­tor. Designed for autonomous heat­ing and hot water sup­ply in apart­ments and pri­vate hous­es with­out a sta­tion­ary chim­ney.Chaffoteaux TALIA GREEN EVO SYSTEM 12 FF

    A fea­ture of this mod­el is the high­est effi­cien­cy (99%), effi­cien­cy (up to 30%), mul­ti­func­tion­al­i­ty and automa­tion. This unit can work with an indi­rect heat­ing boil­er. Pow­er con­sump­tion 105 W. The aver­age cost is 570 $.

  6. BAXI DUO-TEC COMPACT 24 GA is a two-cir­cuit tur­bocharged mod­el with a closed com­bus­tion cham­ber, made in Italy.BAXI DUO-TEC COMPACT 24GA

    A fea­ture of this device is the abil­i­ty to adapt to the qual­i­ty of the fuel. The boil­er is equipped with a stain­less steel burn­er with pre­lim­i­nary gas-air mix­ture and adap­tive flame con­trol, due to which a reduced com­po­si­tion of CO and NOx is observed in the com­bus­tion prod­ucts. The effi­cien­cy of the instal­la­tion varies, depend­ing on the mode of oper­a­tion.
    97.6–107.6%. The aver­age cost is 600 $.

Based on user feed­back, the Vail­lant AtmoTEC plus VUW 200–5 is the best con­dens­ing boil­er in its class.

Tip: mak­ing the right choice of a heat­ing device is a rather dif­fi­cult task, espe­cial­ly for a per­son who has not encoun­tered these devices. In any case, before pur­chas­ing a gas boil­er, con­sult a pro­fes­sion­al.


Leave a Reply

You May Also Like