We make geothermal heating at home with our own hands


Heat­ing a cot­tage or sum­mer house is not an easy task, requir­ing care­ful atten­tion, a com­pe­tent and ratio­nal approach. Giv­en the inten­sive growth in ener­gy prices, even eco­nom­i­cal gas appli­ances are some­times not the best choice. In terms of lack of oper­at­ing costs, do-it-your­self geot­her­mal home heat­ing looks the most advan­ta­geous. This scheme involves the use of under­ground heat gen­er­at­ed nat­u­ral­ly. This option, for sure, will appeal to peo­ple who are not indif­fer­ent to envi­ron­men­tal issues, there is sim­ply no harm to the envi­ron­ment.

For the first time, such meth­ods were test­ed in the 70s of the last cen­tu­ry in the Unit­ed States, when the first eco­nom­ic crises broke out. Of course, these sys­tems could hard­ly be called per­fect, which was reflect­ed both in effi­cien­cy and in the cost of arrange­ment. In today’s world, for­tu­nate­ly, things are quite dif­fer­ent.

Common misconception

There is an opin­ion that geot­her­mal heat­ing of a pri­vate house can be cre­at­ed only in fair­ly warm regions, where hot springs and springs beat around. This is absolute­ly not true. A clear exam­ple of this is Green­land, an island with harsh cli­mat­ic con­di­tions, most of whose ter­ri­to­ry is hid­den by snow. How­ev­er, the vast major­i­ty of local hous­es, farms and agri­cul­tur­al land is heat­ed by under­ground heat.

Working principle

You can com­pare the oper­a­tion of such a heat­ing sys­tem with a refrig­er­a­tor, but vice ver­sa. The inner lay­ers of the earth main­tain a suf­fi­cient­ly high tem­per­a­ture con­stant­ly, heat­ing up from the core, regard­less of exter­nal con­di­tions. It remains only to under­stand how to “extract” this ther­mal ener­gy.

For this pur­pose, a heat pump is mount­ed at the top, a shaft is pulled out into which the heat exchang­er is immersed. Ground­wa­ter pass­es through pumps, heats up, and by enter­ing pipes and radi­a­tors heats the air in the premis­es. The sys­tem includes two cir­cuits:

  • Inter­nal cir­cuit — a clas­sic build­ing heat­ing sys­tem, con­sist­ing of radi­a­tors, pipes, bat­ter­ies and oth­er things;
  • The out­er cir­cuit is direct­ly a heat exchang­er locat­ed deep in the ground.

It is worth not­ing that both ordi­nary water and antifreeze can be used as a coolant.

Formation options

You can heat your home accord­ing to one of the fol­low­ing schemes:

  • Pump and heat exchang­er of ver­ti­cal type. The depth of the well in this case varies from 50 to 200 meters, so drilling is asso­ci­at­ed with sig­nif­i­cant finan­cial invest­ments. Ther­mal ener­gy is tak­en from deep ground­wa­ter, the tem­per­a­ture of which is very high. The heat pump pro­vides the move­ment of the liq­uid, the heat exchang­er takes ener­gy, then the water is dis­charged back. Do not be afraid of the ini­tial invest­ment, the cal­cu­la­tions clear­ly show that the result jus­ti­fies the means, the dura­tion of oper­a­tion reach­es a cen­tu­ry.
  • A tech­nique based on the instal­la­tion of a rein­forced tank with antifreeze heat­ed by soil in a mine about a hun­dred meters deep has a lot in com­mon with the described scheme. A heat pump is also used to keep the antifreeze mov­ing.
  • A hor­i­zon­tal heat exchang­er is a less expen­sive and more struc­tural­ly sim­ple scheme. The main require­ment is that the pipes are below the mark at which the soil freezes dur­ing the cold sea­son. The heat­ing effi­cien­cy in such a sit­u­a­tion is less, and there­fore it has to be com­pen­sat­ed for by the total col­lec­tor area, which should be approx­i­mate­ly 2 times the area of ​​the heat­ed room. Of course, this val­ue is approx­i­mate, the exact coef­fi­cient depends on many fac­tors.
  • Final­ly, the last scheme is suit­able if there is no more than a hun­dred meters between the heat­ed build­ing and the near­est body of water. The advan­tage of this tech­nol­o­gy is a small finan­cial invest­ment, the absence of sig­nif­i­cant vol­umes of earth­works. The heat exchange cir­cuit is locat­ed so that freez­ing is not observed at depth, there must be at least a meter of water under the ice. Ide­al­ly, there should be no cur­rent in the pond that could dam­age the probes locat­ed at the bot­tom. It is these probes that are absorbers of ther­mal ener­gy.

Poly­eth­yl­ene-based pipes are excel­lent for form­ing the out­er con­tour. When cal­cu­lat­ing, it should be assumed that from 40 to 50 W of ther­mal ener­gy should fall on the meter of the col­lec­tor. It turns out that in a sit­u­a­tion where the pump capac­i­ty is 10 kW, the drilling depth will be up to 200 meters.

It is worth remem­ber­ing that in some sit­u­a­tions it is more ratio­nal to drill not one deep well, but sev­er­al small­er ones. So that in such a sit­u­a­tion the appear­ance of the site is not spoiled, the clus­ter method is used — sev­er­al pil­lars diverge from one start­ing point in depth.

Solution Benefits

So, the geot­her­mal method is char­ac­ter­ized by the fol­low­ing set of pos­i­tive fea­tures:

  • Inex­haustible free ther­mal ener­gy is used.
  • There is no risk of fire, det­o­na­tion, short cir­cuit and oth­er dan­ger­ous phe­nom­e­na.
  • There is no need to erect a sep­a­rate build­ing for the orga­ni­za­tion of the boil­er room, the unit itself takes up lit­tle space, there is no need for addi­tion­al space for fuel stor­age.
  • The scheme is ide­al from the point of view of envi­ron­men­tal safe­ty. In the process of use, there are no com­bus­tion prod­ucts and emis­sions that pro­voke air, soil and water pol­lu­tion.
  • The sys­tem does not need reg­u­lar main­te­nance and con­trol, the cor­rect­ness of the para­me­ters is main­tained by automa­tion. Econ­o­my is also ensured by this fea­ture.
  • Vari­abil­i­ty. The heat­ing cir­cuit, locat­ed direct­ly in the build­ing, is no dif­fer­ent in its design from tra­di­tion­al water heat­ing sys­tems. The own­ers can bring to life both the mod­ern idea of ​​u200bu200bunderfloor heat­ing, and the more tra­di­tion­al radi­a­tor scheme.

Summing up

The main prob­lem of this tech­nol­o­gy is the high price, due to the sig­nif­i­cant amount of exca­va­tion. How­ev­er, giv­en the fur­ther advan­tages, this dis­ad­van­tage seems insignif­i­cant. Prac­tice shows that full pay­back is achieved in just a few sea­sons!


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