Which heating system is better: one-pipe or two-pipe?

It is nec­es­sary to deter­mine what type of heat­ing sys­tem should be at the ini­tial stage of build­ing con­struc­tion. Heat­ing sys­tems are divid­ed into sin­gle-pipe and two-pipe. Sin­gle pipe sys­tems are much sim­pler. One pipe serves to move the coolant from the boil­er to the bat­ter­ies locat­ed in the apart­ments. This sys­tem has many dis­ad­van­tages, since the tem­per­a­ture of the bat­ter­ies can­not be reg­u­lat­ed, and the water sup­plied to the first floors of the build­ing is no longer so hot. But the two-pipe heat­ing sys­tem dis­trib­utes heat even­ly. One pipe sup­plies hot coolant to the bat­ter­ies, the oth­er is the return one. Despite the fact that a sin­gle-pipe sys­tem is much cheap­er, a two-pipe water heat­ing sys­tem is increas­ing­ly being used. Why? It allows you to reg­u­late the tem­per­a­ture in each room of a res­i­den­tial build­ing at will with the help of a con­trol valve. And there­fore it is bet­ter suit­ed for a build­ing of any con­fig­u­ra­tion with any num­ber of floors. Dur­ing the con­struc­tion of a res­i­den­tial build­ing, the cor­rect con­duct of com­mu­ni­ca­tions is of great impor­tance. There­fore, in this arti­cle we will ana­lyze in detail when the heat­ing of a pri­vate house should be done with a sin­gle pipe, and when a two-pipe heat­ing sys­tem is bet­ter suit­ed.

Types of two-pipe heating system

Hor­i­zon­tal sys­tem Recent­ly, it has become wide­spread, due to the fact that many new build­ings have a large length, and also do not have piers. Due to the intro­duc­tion of pan­el-frame struc­tures and the lack of piers, it is rather dif­fi­cult to place ver­ti­cal ris­ers. There­fore, a two-pipe hor­i­zon­tal heat­ing sys­tem is used, and ris­ers for its branch­es are placed in var­i­ous addi­tion­al rooms of the build­ing, for exam­ple, in cor­ri­dors or stair­wells. In such a sys­tem, heat­ing devices of one floor are con­nect­ed to a sin­gle ris­er, while in a two-pipe ver­ti­cal heat­ing sys­tem, heat­ing devices of dif­fer­ent floors are con­nect­ed to a sin­gle ris­er.

Two-pipe heat­ing sys­tem with bal­anc­ing and adjust­ment devices

1‑boiler; 2‑air vent; 3- ther­mo­sta­t­ic valve; 4- bat­tery; 5 – bal­anc­ing device; 6- tank; 7 — valve; 8 — pipeline fil­ter; 9 — pump; 10 – tem­per­a­ture manome­ter; 11 — safe­ty valve

Ver­ti­cal sys­tem heat­ing is some­what more expen­sive than hor­i­zon­tal, since more pipes are need­ed here, and the instal­la­tion itself takes longer. But it elim­i­nates the pos­si­bil­i­ty of air pock­ets in heat­ing devices, and it is also eas­i­er to oper­ate than a hor­i­zon­tal sys­tem.

Design fea­tures of two-pipe sys­tems

The choice of the direc­tion of move­ment of the coolant. There is a dead-end two-pipe heat­ing sys­tem and direct-flow. In a dead-end heat­ing sys­tem, direct and return water flow in oppo­site direc­tions, while in direct-flow sys­tems, the direc­tions of direct and return water are the same.

Vari­ant of water cir­cu­la­tion in the heat­ing sys­tem. Heat­ing sys­tems with nat­ur­al cir­cu­la­tion are used only in the con­struc­tion of small build­ings, with an area of ​​no more than 150 square meters. m. The two-pipe heat­ing sys­tem of a pri­vate house may well have nat­ur­al cir­cu­la­tion. Water cir­cu­lates under the action of its own den­si­ty, so the pipes of such a sys­tem have a large diam­e­ter, and they are laid at an angle in a hor­i­zon­tal plane. The dis­ad­van­tage of such a heat­ing sys­tem is that they are prac­ti­cal­ly unad­justable, and the advan­tage is that they are not depen­dent on the pow­er sup­ply.

In large build­ings, a two-pipe forced heat­ing sys­tem is used, which is much more effi­cient than a nat­ur­al cir­cu­la­tion sys­tem. How­ev­er, it needs a pow­er sup­ply that must be con­stant­ly present. In such a sys­tem, a cir­cu­la­tion pump is used, which allows you to mount pipes with a small diam­e­ter and lay them with­out a slope. The two-pipe heat­ing sys­tem of a mul­ti-storey build­ing can­not be based on the prin­ci­ple of nat­ur­al water cir­cu­la­tion.

In a one-sto­ry house, one-pipe heat­ing sys­tems are often used. In fact, this is not quite the right approach. The sys­tem should heat all rooms even in the most severe frosts, and a two-pipe heat­ing sys­tem is bet­ter able to cope with a sim­i­lar task. The two-pipe heat­ing sys­tem of a one-sto­ry house has one sig­nif­i­cant draw­back — it will cost the cus­tomer quite a lot. But it is bet­ter not to save mon­ey on the heat­ing sys­tem.

Single pipe heating system

In the Sovi­et Union, at one time, the con­struc­tion of res­i­den­tial build­ings gained such momen­tum that the min­istry was forced to think about the glob­al reduc­tion in the cost of the process. Among oth­er solu­tions, it was pro­posed to save on the lay­ing of engi­neer­ing com­mu­ni­ca­tions, in par­tic­u­lar, on heat­ing pipes — this is how not the best idea was born to use a sin­gle-pipe heat­ing sys­tem for res­i­den­tial apart­ments, and even indus­tri­al premis­es. In such sys­tems, there are no return ris­ers or water intake as a waste heat car­ri­er. In addi­tion, a ver­ti­cal sin­gle-pipe heat­ing sys­tem is much eas­i­er to install, and, con­se­quent­ly, it takes less labor to install, that is, there is a seri­ous pos­i­tive eco­nom­ic effect. The engi­neers of that time did not think too much about the prob­lems asso­ci­at­ed with its use.

Advan­tages and dis­ad­van­tages of one-pipe sys­tems

Know­ing the main dis­ad­van­tages and advan­tages of a sin­gle-pipe heat­ing sys­tem, you can decide on the design of heat­ing in your pri­vate house or coun­try cot­tage. We rec­om­mend mak­ing deci­sions only after a spe­cial­ist has inspect­ed the facil­i­ty, but already at the ini­tial stages of design, you can eval­u­ate the fea­si­bil­i­ty of such a sys­tem for the premis­es.

Argu­ments against”

The biggest dif­fer­ence that a sin­gle-pipe and two-pipe heat­ing sys­tem has is the ser­i­al con­nec­tion of radi­a­tors, which dur­ing oper­a­tion does not allow you to adjust the inten­si­ty of heat­ing of one of them with­out con­se­quences for sub­se­quent ones. That is, if the bed­room is hot enough and you need to low­er the tem­per­a­ture by press­ing the valve on the radi­a­tor, in oth­er rooms the water in the bat­ter­ies will also cool down.

The sec­ond seri­ous dis­ad­van­tage is that a sin­gle-pipe heat­ing sys­tem at home requires a high­er coolant pres­sure dur­ing oper­a­tion. The pow­er of pumps in boil­er rooms increas­es — oper­at­ing costs increase, more leaks appear, the sys­tem requires more water replen­ish­ment. The sin­gle-pipe heat­ing sys­tem of a pri­vate house is no excep­tion: a pump must be insert­ed into such a sys­tem, while in two-pipe sys­tems the coolant can move by grav­i­ty.

The third sig­nif­i­cant draw­back is that the one-pipe heat­ing sys­tem of a one-sto­ry house must have a ver­ti­cal fill­ing. That is, the expander tank must be installed in the attic, in this case act­ing as a tech­ni­cal floor. In the case when such a sys­tem is arranged in a mul­ti-storey res­i­den­tial build­ing, it is nec­es­sary to resort to addi­tion­al tricks to ensure the same tem­per­a­ture of the coolant on each floor. The fact is that from a ver­ti­cal spout, water descends through sin­gle-pipe heat­ing sys­tems, suc­ces­sive­ly pass­ing through radi­a­tors on each floor. Of course, in each radi­a­tor it gives off part of the tem­per­a­ture, reach­ing the first floors with a loss of heat ener­gy of almost 50%. There­fore, with such sys­tems, addi­tion­al jumpers are installed on each floor, and a larg­er num­ber of radi­a­tor sec­tions are installed on the low­er floors than on the upper ones.

Argu­ments for”

In addi­tion to all of the above, this heat­ing sys­tem has a num­ber of advan­tages that may well bal­ance the dis­ad­van­tages. First­ly, its main neg­a­tive aspects were char­ac­ter­is­tic of the Sovi­et era, when tech­ni­cal progress had not yet made many rev­o­lu­tion­ary upheavals in tech­nol­o­gy. Today, a sin­gle-pipe heat­ing sys­tem is one of the most com­mon sys­tems, espe­cial­ly for pri­vate con­struc­tion.

Sec­ond­ly, a big plus of such a sys­tem, of course, is the sav­ing of mate­ri­als. Con­nect­ing pipes, return ris­ers, jumpers and leads to heat­ing radi­a­tors — all this togeth­er gives a suf­fi­cient length of the pipeline, which costs a lot of mon­ey. A sin­gle-pipe heat­ing sys­tem allows you to avoid the instal­la­tion of extra pipes, seri­ous­ly sav­ing. Sec­ond­ly, it looks much more aes­thet­i­cal­ly pleas­ing.

Third­ly, there are many tech­no­log­i­cal solu­tions that elim­i­nate the prob­lems that exist­ed in such sys­tems lit­er­al­ly a dozen years ago. Ther­mo­sta­t­ic valves, radi­a­tor reg­u­la­tors, spe­cial air vents, bal­anc­ing valves, con­ve­nient ball valves are installed on mod­ern sin­gle-pipe heat­ing sys­tems. In mod­ern heat­ing sys­tems using a sequen­tial sup­ply of coolant, it is already pos­si­ble to achieve a decrease in tem­per­a­ture in the pre­vi­ous radi­a­tor with­out reduc­ing it in sub­se­quent ones.

Know­ing the main fea­tures of one-pipe and two-pipe heat­ing sys­tems, you can start design­ing heat­ing in a pri­vate house or coun­try cot­tage. How­ev­er, we rec­om­mend start­ing instal­la­tion work only after the site has been inspect­ed by a spe­cial­ist. Con­tact our engi­neers for help in design­ing com­mu­ni­ca­tions by phone +7 (495) 580–29-99 or leave a request on our installer search ser­vice montazh.online.

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