Options for laying heating pipes in a private house


The heat­ing of a mod­ern pri­vate house depends on many fac­tors. This includes the choice of a heat­ing boil­er, the pres­ence of under­floor heat­ing sys­tems, the choice of a radi­a­tor con­nec­tion scheme. But the most impor­tant fac­tor affect­ing the ener­gy effi­cien­cy of the sys­tem is the lay­ing of var­i­ous heat­ing pipes in a pri­vate house, the choice of diam­e­ter and instal­la­tion method.

An exam­ple of the arrange­ment of a mod­ern boil­er room, in this case using a cop­per pipe

Types of pipes used for laying heating in a private house

Depend­ing on the project of the heat­ing sys­tem of a pri­vate house, the mate­r­i­al of the pipe for con­nect­ing radi­a­tors and dis­con­nect­ing the boil­er room may be dif­fer­ent. Let’s look at the main options used in the work.

Steel pipes

Allo­cate mate­ri­als from gal­va­nized steel, based on stain­less steel, from fer­rous met­al. The advan­tage of such prod­ucts is high ther­mal con­duc­tiv­i­ty, which allows you to give off heat not only to the radi­a­tors them­selves, but also to the sup­ply pipes. With the cor­rect arrange­ment of the heat­ing sys­tem, a sealed cir­cuit is obtained, which elim­i­nates leaks for many years.

Steel pipes in the heat­ing sys­tem. Side con­nec­tion option


From steel water and gas pipes, due to the large inter­nal diam­e­ter, it is pos­si­ble to equip inclined heat­ing sys­tems, which was active­ly used in the last cen­tu­ry. Such sys­tems oper­ate with­out the use of pumps. Steel is ide­al for lay­ing a sys­tem of cast iron radi­a­tors. Today, cor­ru­gat­ed mate­r­i­al is made on the basis of stain­less steel, which are quite con­ve­nient to install.

Copper pipes

Due to the high flex­i­bil­i­ty prop­er­ties, such sys­tems are often used to equip a boil­er room. To bend the pipe, it is enough to heat it to a high tem­per­a­ture, after which it is nec­es­sary to bend it, then cool it. Cop­per is capa­ble of with­stand­ing up to 400 MPa.

A big advan­tage of using cop­per is its resis­tance to tem­per­a­ture dif­fer­ences, so that the walls of the mate­r­i­al do not col­lapse even when the heat­ing cir­cuit is com­plete­ly frozen. The con­nec­tion of var­i­ous sec­tions is car­ried out using cap­il­lary sol­der­ing, or using com­pres­sion fit­tings. Prod­ucts are char­ac­ter­ized by high coef­fi­cient of ther­mal con­duc­tiv­i­ty, resis­tance to high and low tem­per­a­tures, min­i­mal hydraulic resis­tance, high dura­bil­i­ty. The main thing is not to com­bine heat­ing sys­tems by con­nect­ing cop­per and alu­minum pipes, since such con­tact will lead to a vio­la­tion of the strength of the over­all sys­tem.

An exam­ple of using a cop­per pipe for dis­trib­ut­ing a heat­ing cir­cuit

Polypropylene pipe

This mate­r­i­al is known to all. It has been active­ly used for many years, eas­i­ly with­stands pres­sure up to 10 atmos­pheres, and is con­nect­ed using fit­tings and tran­si­tions. In those places where it is nec­es­sary to switch to met­al, a tran­si­tion is used. Such pipes may well be laid on the sur­face, since they have an aes­thet­ic appear­ance, but they can also be “packed” in a fin­ished floor screed, walled up in walls.

For hot water, a polypropy­lene pipe with met­al rein­force­ment is used, which increas­es its strength when heat­ed. Instal­la­tion is car­ried out using spe­cial equip­ment, which involves heat­ing the pipe itself and the con­nect­ing fit­ting or tee, turn and oth­er ele­ments.

Along with polypropy­lene, met­al-plas­tic mate­r­i­al is used, which is used to equip under­floor heat­ing sys­tems. High strength allows pump­ing coolant for 50 years or more. Cross-linked polypropy­lene is also used for under­floor heat­ing sys­tems.

Heat­ing wiring in the house using a polypropy­lene pipe. Option to install a col­lec­tor with a cir­cu­la­tion pump on the bypass

Types and schemes for laying heating pipes


It is impor­tant to choose the right pipe lay­ing method. Alter­na­tive­ly, a sin­gle-pipe and two-pipe lay­ing sys­tem is dis­tin­guished.

With a two-pipe lay­ing, the sys­tem has a sup­ply and a “return”. This increas­es the cost of the project, but increas­es the effi­cien­cy of the heat­ing sys­tem, since the cooled water direct­ly enters the return pipe, where, using a cir­cu­la­tion pump, it is pumped back to the boil­er and quick­ly heat­ed up. That is, the heat­ing boil­er needs to spend less ener­gy on heat­ing water than heat­ing it con­stant­ly.

Two-pipe heat­ing sys­tem

As for the one-pipe sys­tem, here, with less invest­ment, the con­sumer ini­tial­ly pays more. The fact is that the cooled water from the radi­a­tor enters the sup­ply, where it delib­er­ate­ly dilutes the water by approx­i­mate­ly 15–20%. Thus, the next radi­a­tor in the sys­tem will receive water at a tem­per­a­ture equal to 80–85 per­cent of the pri­ma­ry val­ues.

An exam­ple of a one-pipe heat­ing sys­tem

Atten­tion! The very last radi­a­tor in the cir­cuit will be sig­nif­i­cant­ly cold­er than the first one. This should be tak­en into account when con­struct­ing the heat­ing cir­cuit. Many peo­ple think that such prob­lems can be com­pen­sat­ed by using a cir­cu­la­tion pump, but this is not so, since pumps can only increase the inten­si­ty of water exchange with the boil­er.


It is the two-pipe heat­ing sys­tem that is the most effi­cient. Now you need to fig­ure out how to con­nect the radi­a­tor. There is a bot­tom con­nec­tion, lat­er­al, and diag­o­nal. Of all the above meth­ods, it is most con­ve­nient to con­nect the “bot­tom”. But, such a con­nec­tion is unable to 100% con­vert the ener­gy of the coolant into heat for your home, since the radi­a­tor is only half warm. The diag­o­nal con­nec­tion has the max­i­mum effi­cien­cy, which involves chas­ing and lay­ing sup­ply pipes into the wall.

With a diag­o­nal con­nec­tion, the “sup­ply” goes from above from the heat­ing boil­er, and the return goes from below, from where the cooled water is again sup­plied to the boil­er. With a diag­o­nal con­nec­tion, be sure to choose a two-pipe sys­tem so that the coolant cir­cu­lates faster in a closed cir­cuit.

As for the lay­ing meth­ods, if the heat­ing sys­tem changes in an already fin­ished house, for exam­ple, in a frame house, then noth­ing is ditched and pipes are laid over the floor or along the walls. To do this, it is nec­es­sary to install a pipe clamp every 70 cm, so that it is impor­tant for hot heat sup­ply, oth­er­wise the PVC mate­r­i­al is deformed. It is with such pipes that they often work, since their low cost and high dura­bil­i­ty can reduce the over­all cost of the project.

An exam­ple of lay­ing a heat­ing cir­cuit over walls by mount­ing pipes on clips and clamps

If the house is only being fin­ished, the floors have not yet been filled, then it is most con­ve­nient to lay PVC pipes under the fin­ish­ing screed. As a rule, it is nev­er less than 7 cm, so with this lay­er of con­crete you can orga­nize a hid­den lay­ing of polypropy­lene heat­ing pipes. With prop­er sol­der­ing of the pipe, you can elim­i­nate the vio­la­tion of tight­ness. The main thing is to pres­sur­ize the sys­tem before pour­ing the fin­ish­ing screed. For this, a sys­tem with a pres­sure gauge is used, designed to fill the cir­cuit with water, with the help of which pres­sure is cre­at­ed in the pipe of the order of 2–3 atmos­pheres. The con­tour is pressed and allowed to stand for about 5 hours. If dur­ing this time the pres­sure has not dropped, then the instal­la­tion was suc­cess­ful.

Atten­tion! It is rec­om­mend­ed to check the sys­tem for oper­abil­i­ty before pour­ing the fin­ish­ing screed. This will help elim­i­nate the nar­row­ing of the plas­tic pipe. The rea­son for this is over­heat­ing of the fit­ting.

As for the choice of the con­nec­tion scheme for radi­a­tors, today the beam scheme is active­ly used. The beam scheme is the con­nec­tion of each radi­a­tor to a cen­tral col­lec­tor, which is installed in the boil­er room. From the col­lec­tor to the heat­ing boil­er there is a main pipe, which is often larg­er in diam­e­ter than the diam­e­ter of the sup­ply pipes. Thanks to the radi­al con­nec­tion, met­al-plas­tic pipes or cross-linked polypropy­lene can be used.

Here it is not at all nec­es­sary to lay polypropy­lene heat­ing pipes in the wall, as well as to observe rec­tan­gu­lar turns. It is enough to lay them under the floor, which will facil­i­tate instal­la­tion and increase the pace of work. This scheme is con­sid­ered the best for sol­id pipes that do not sol­der.

Descrip­tion. An exam­ple of a radi­ant heat­ing scheme from a col­lec­tor in a pri­vate house.

SNIP requirements


The gen­er­al SNIP reg­u­lat­ing ven­ti­la­tion and heat­ing is reg­is­tered under the num­ber 41–01-2003. There are oth­er rules, among which are:

  • SNiP 2.04.05–91 (clause 3.58). Reg­u­lates the instal­la­tion of dec­o­ra­tive screens and grilles on radi­a­tors.
  • SNiP 41–01-2003 (p. 6.5.13.). Indi­cates the need to install shut­off valves, except for rooms with a high prob­a­bil­i­ty of freez­ing of the coolant.
  • SNiP 3.05.01–8 (clause 3.18). Reg­u­lates the slope of the heat­ing cir­cuit with a pipe length of more than 500 mm.
  • SP 40–108-2004 (clause 3.2.1). Reg­u­lates the con­nec­tion of a cop­per pipe to a boil­er with alu­minum leads.

Sealing and thermal insulation

Only met­al con­nec­tions have to be sealed. The fact is that when work­ing with HDPE pipes, they are sol­dered, which does not require addi­tion­al seal­ing. With regard to met­al-to-met­al con­nec­tions, plumb­ing linen must be used. This is the most inex­pen­sive way, which, togeth­er with the paste, allows you to achieve 100% tight­ness.

It is nec­es­sary to wind the flax in the direc­tion of move­ment of the object that will be wound onto the thread so that the flax does not turn when screw­ing on. Instead of flax and paste, you can use fum tape, as well as oth­er means.

An exam­ple of apply­ing san­i­tary flax with paste for addi­tion­al pro­tec­tion against leak­age of thread­ed con­nec­tions

As for ther­mal insu­la­tion, there is a spe­cial insu­la­tion on sale, which is made to fit the diam­e­ter of the pipe. It is rec­om­mend­ed to iso­late the coolant that is sup­plied from the boil­er to the heat­ing radi­a­tors. This should be done espe­cial­ly if the pipes lie against the wall under the floor, since it is here that the max­i­mum lev­el of heat loss is observed. As a heat-insu­lat­ing mate­r­i­al, you can choose basalt wool, glass wool, poly­styrene foam and oth­er insu­la­tion.

Impor­tant! Don’t save. When lay­ing under­floor heat­ing sys­tems, it is def­i­nite­ly rec­om­mend­ed to install the pipe on the insu­la­tion. For the cen­tral part of Europe, at least 5 cm of foam plas­tic is used.


Being at the stage of cal­cu­lat­ing the heat­ing cir­cuit, pro­ceed from the fact that 1 sec­tion is select­ed based on 1.2 square meters of the room. Do not for­get to take into account the mar­gin, if in your room two walls are adja­cent to the street, you need to add a mar­gin of up to 30%. That is, for a room of 15 square meters in con­tact with the street, in which there will be a warm floor, it is rec­om­mend­ed to install a radi­a­tor with at least 12 sec­tions.

In order to cre­ate excess inter­sec­tion­al pres­sure in the cir­cuit, it is nec­es­sary to oper­ate with the diam­e­ter of the sup­ply pipe. That is, from the boil­er to the main col­lec­tor there must be a pipe of at least 32 mil­lime­ters in diam­e­ter. Fur­ther, a pipe of the same diam­e­ter will go to each cir­cuit, approx­i­mate­ly 4–5 meters for each wing. This will cre­ate excess pres­sure in the cir­cuit. Next, you need to nar­row down, choos­ing a diam­e­ter of at least 25 mm to each radi­a­tor. When lift­ing water to the radi­a­tor, it is nec­es­sary to nar­row it up to 20 mm, inclu­sive.

The use of fit­tings when weld­ing polypropy­lene pipes

More isn’t always good. It is imprac­ti­cal to use pipes of larg­er diam­e­ter every­where, since the per­me­abil­i­ty of water will be bet­ter, but its amount will increase, which will lead to heat­ing of a larg­er vol­ume of liq­uid. Hence the extra heat­ing costs. The rise of the coolant to the floor above is car­ried out through a pipe of at least 32 mm.

One radi­a­tor comes with an instal­la­tion kit. These are two cranes, a plug, a Mayevsky crane, 2–3 hooks. Tees, tran­si­tions, cou­plings are con­sid­ered indi­vid­u­al­ly, depend­ing on the num­ber of radi­a­tors in the house, their loca­tion, and the method of lay­ing the pipe.

Recommendations for operation and repair


The norms of SNiP require the instal­la­tion of radi­a­tors in an ide­al geo­met­ric plane. It is nec­es­sary to set the radi­a­tor accord­ing to the lev­el, oth­er­wise air­ing will occur and the coolant will not flow fur­ther. It is nec­es­sary to install a Mayevsky crane for an alu­minum radi­a­tor. Alu­minum, when inter­act­ing with water, releas­es a gas that must go out­side. That is why after a cou­ple of weeks, the pres­sure in the cir­cuit may drop by 0.1–0.2 from the nom­i­nal val­ue.

Impor­tant! Con­sid­er the nuances. A sup­ply tap must be pro­vid­ed in the cir­cuit, which is delim­it­ed from the main water sup­ply cir­cuit in the house by a check valve.

Using the Mayevsky tap on the radi­a­tor to vent air from the sys­tem

Try to lay polypropy­lene heat­ing pipes in the floor screed only when the prod­uct has a war­ran­ty peri­od of at least 40 years. Oth­er­wise, the pipe must be ser­vice­able so that you can always make repairs.

When installing a radi­a­tor, make sure that the win­dow sill does not cov­er it by more than 30%. The rec­om­mend­ed height of the radi­a­tor from the floor is 6–8 cen­time­ters, from the radi­a­tor to the win­dow sill no more than 10. Be sure to install taps on each heat­ing radi­a­tor in order to be able to adjust the coolant.

Instal­la­tion of valves on the radi­a­tor in order to fur­ther adjust the tem­per­a­ture of the coolant and the pos­si­bil­i­ty of com­plete­ly iso­lat­ing the radi­a­tor from the sys­tem in case of repair

At the bot­tom of the heat­ing cir­cuit, water must be drained to the sew­er. This is nec­es­sary in case of repair. At the top of the heat­ing cir­cuit there should be air vents that will allow air to escape with­out cre­at­ing an air lock. When using under­floor heat­ing, be sure to install a sep­a­rate pump on the man­i­fold. It is installed on the sup­ply, in the direc­tion from the boil­er to the warm floor. Be sure to use taps at each con­nec­tion and branch, which will facil­i­tate future repairs.


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