Heat on credit

To sup­ply large amounts of heat, HPs are eas­i­ly con­nect­ed in cas­cade


The heat pump (left) fits well into the inte­ri­or of the kitchen

a biva­lent sys­tem was used in the pip­ing of the boil­er room- HP togeth­er with an elec­tric wall-mount­ed boil­er

ATdesign of the Robust brand heat pump uses a scroll com­pres­sor (THERMIA)

Pump mod­el Diplo­mat (THERMIA) with a capac­i­ty of 12kW with built-in heat­ing ele­ments ful­ly meets the needs of a fam­i­ly of four in hot water and heat­ing a log house with an area of ​​180m2

Options for lay­ing out soil col­lec­tors: in a swamp; in sol­id ground (“TEPLO-SERVICE”)

Some­times a sand embank­ment is made over shal­low trench­es.

It is per­mis­si­ble to drill a well for a probe even at the bor­der of the site


Assem­bly of heat-remov­ing loops with dis­trib­u­tor
col­lec­tors. A con­crete man­hole will be erect­ed around them lat­er.

Lay­ing the branch­es of the under­wa­ter col­lec­tor man­u­al­ly

Dis­tri­b­u­tion man­i­folds for under­wa­ter heat removal loops

Toa heavy anchor sleeve is sus­pend­ed from a probe filled with water and care­ful­ly low­ered into a fresh­ly drilled well

Wells for probes are drilled at a dis­tance of no clos­er than 2m from the walls of the house, so as not to dam­age the foun­da­tion

Dis­tri­b­u­tion col­lec­tor place­ment options
ditch: in the pit in front of the build­ing and in the house

The steel pip­ing at the head of the ver­ti­cal tube-in-pipe probe is not durable, but can be eas­i­ly replaced with new ones.

The place where the pipes of the ther­mal cir­cuit enter the boil­er room through the floor will be foamed, cov­ered with expand­ed clay for insu­la­tion and cement­ed after the sys­tem is debugged

The pip­ing of the heat­ing cir­cuit is often made of cop­per pipes.

Heat­ing sys­tem man­i­folds


ATexpan­sion tanks are required on both cir­cuits

A design option for the input unit to the boil­er room from the field dis­trib­u­tor

The sec­ondary cir­cuits of two HPs were con­nect­ed to the heat­ing mains in par­al­lel using polypropy­lene
new pipes

When using heat pumps, it is nec­es­sary to use steel pan­el radi­a­tors with an increased area due to the low water tem­per­a­ture

Since child­hood, we secret­ly believe that some mir­a­cle will hap­pen on the New Year, even a small one. BUTafter all, there is already a mir­a­cle in the world that brings great ben­e­fits to peo­ple, but we stub­born­ly do not notice it. We are talk­ing about heat pumps. They are able to col­lect crumbs of heat from the frozen ground, from under the ice or from the frosty air and cre­ate a com­fort­able micro­cli­mate in the house due to this.

Win­ter cold out­side the win­dow invol­un­tar­i­ly makes you think about reli­able heat­ing. For the inhab­i­tants of mil­lions of coun­try hous­es, where heat pipes from dis­trict boil­er hous­es have not reached, this is an acute prob­lem. After all, you can’t com­plain about DEZ and you can’t blame the author­i­ties for inac­tion. Mean­while, you can unin­ter­rupt­ed­ly receive cheap heat and hot water all year round. Andall thanks to heat pumps (HP). They have been known for 150years, and in pri­vate homes only 30years.

Arrange­ment of a boil­er room using a heat pump and a heat point cab­i­net (“KORSA”) con­tain­ing all the fit­tings, wiring and cir­cu­la­tion pumps of the pri­ma­ry and sec­ondary cir­cuits. These devices are pop­u­lar all over the globe, except for Europe. More­over, the pop­u­la­tion of devel­oped coun­tries uses them not only for heat­ing hous­es and obtain­ing hot water. They (although not all mod­els) are also able to cre­ate a cool atmos­phere in the room and work in a forced ven­ti­la­tion sys­tem, heat­ing cold fresh air or dehu­mid­i­fy­ing room air. Andwhat makes this not a huge rum­bling tech­ni­cal mon­ster, but a mod­est device resem­bling a refrig­er­a­tor. It can stand in the cor­ner of your kitchen (appear­ance allows) or take 2–3m2 in a small boil­er room. But most impor­tant­ly- in a dif­fer­ent. Approx­i­mate­ly 70% of the ener­gy to cre­ate a com­fort­able cli­mate in the house TN sim­ply gives its own­ers. Is free! Because he takes it from the sur­round­ing nature- from air, land or water. Isn’t it a mir­a­cle? Don’t be lazy, use it! About how “it” works, we wrote in N6 “IVD” for 2005G.

Note that the device itself does not gen­er­ate ener­gy, but only trans­ports it from a low-tem­per­a­ture heat source (LTH) to a high­er tem­per­a­ture lev­el.

“Don’t miss, Asunta!”

The TN mar­ket is very mod­est. Mod­els for water heat­ing offer IVT, MECMASTER, THERMIA, NIBE (Swe­den), VIESSMANN, STIEBEL ELTRON (Ger­many), OCHSNER (Aus­tria), CARRIER, AERTEC, FHP (USA), CLIMAVENETA (Italy), PZP KOMPLET, G‑MAR ( Czech Repub­lic), GEOTHERMIX (Cana­da). For air heat­ing mod­el type “soil- air” is sup­plied only by FHP. It is grat­i­fy­ing that among domes­tic man­u­fac­tur­ers (EKIP, NPF TRITON, RZP, NPO ENERGIA) a new­com­er- the com­pa­ny “KORSA”. It offers eight mod­els of “ground- water “with a capac­i­ty of 11–34.5kW at a price of approx­i­mate­ly 9.2thou­sandrub. for 1kW.

The pecu­liar­i­ty of the HP mar­ket lies in the fact that you can­not point your fin­ger at the unit you like, such as, for exam­ple, at a ket­tle. Mod­els are pre­sent­ed only in cat­a­logs, but they are not in stock. Your choice will only start the dis­cus­sion. The fir­m’s spe­cial­ist will care­ful­ly exam­ine the house (or project) to deter­mine the heat loss of the build­ing, and the site to assess its ther­mo­dy­nam­ic poten­tial. Accord­ing to the rec­om­men­da­tions of a pro­fes­sion­al, the mod­el you have cho­sen can be sig­nif­i­cant­ly changed by adjust­ing its para­me­ters to the needs of the house (like a suit accord­ing to the fig­ure). TN will be cre­at­ed at the plant, in fact, to order. Andyou will receive it throughmonth.

A boil­er room with a heat pump is easy to tie. The heat pump is adja­cent to the work­bench (“TERMOTEH‑M”) But the pri­ma­ry choice is extreme­ly impor­tant (it’s like a sight­ing shot from a sniper). The suc­cess of the busi­ness depends on how com­pe­tent­ly the para­me­ters of the HP itself, the low-grade heat col­lec­tion sys­tem (pri­ma­ry cir­cuit) and the house heat­ing sys­tem (sec­ondary cir­cuit) are coor­di­nat­ed.

First­ly, HP is rec­om­mend­ed to be used for low-tem­per­a­ture heat­ing sys­tems (Europe switched to them when using any type of ener­gy). The most prof­itable options- floor water or air heat­ing, in which the coolant is above 35C is not heat­ed for med­ical rea­sons. Sec­ond­ly, the house should be care­ful­ly insu­lat­ed, reduc­ing loss­es from the usu­al Euro­pean lev­el of 100W/m2 to “civ­i­lized” 50–60W/m2so that it doesn’t work out accord­ing to the proverb: “We col­lect in crumbs, but we lose in heaps.”

In addi­tion, it is rec­om­mend­ed to use HP in the so-called biva­lent heat­ing sys­tems and hot water sup­ply (DHW). The term means that in addi­tion to the HP, a sec­ond heat sup­pli­er works in the sys­tem. There are two rea­sons for its use: phys­i­cal and eco­nom­ic. The con­sumer often needs hot­ter water than the pump can “offer”. Typ­i­cal sit­u­a­tion: you need water with a tem­per­a­ture of 75–85C to san­i­tize the water tank. Or, let’s say you are think­ing of inte­grat­ing a HP into an exist­ing high-tem­per­a­ture heat­ing sys­tem (the idea is debat­able, but fea­si­ble).

The “assis­tant” is espe­cial­ly use­ful when start­ing the HP for the first time in a cold house. Most often, an elec­tric heat­ing device (heater or elec­tric boil­er) is used as the “sec­ond”. In many mod­els, heat­ing ele­ments (with a capac­i­ty of 3–12kW) are already built into the design. Water, pre­heat­ed by a pump, they eas­i­ly bring to the desired tem­per­a­ture. The prob­lem is dif­fer­ent: where to find these addi­tion­al kilo­watts of elec­tric­i­ty. If a mono­va­lent sys­tem is used, then only the HP (or the HP cas­cade) pro­vides all the needs. But water in the DHW sys­tem will have to be sup­plied at tem­per­a­tures up to 45C (and to a large extent) so as not to cre­ate a “sana­to­ri­um” for bac­te­ria.

Most often, the biva­lent sys­tem is used for eco­nom­ic rea­sons. The share of the sec­ond heat source in annu­al ener­gy costs is 10–15%, and in gen­er­al the project becomes cheap­er. “Assis­tant” is cho­sen based on the most afford­able type of fuel. It can be a small gas, diesel, elec­tric or even wood-burn­ing boil­er.

Nev­er­the­less, for oper­a­tion in mono­va­lent mode, the mar­ket offers a line of HPs with a capac­i­ty of up to 100kW.

If it is impos­si­ble to get the required elec­tri­cal pow­er from the munic­i­pal net­work, you can mount a solar pho­to pan­el on the roof. Togeth­er with HP, it will pro­vide year-round heat­ing at home. It makes sense to talk in more detail about the cost-effec­tive­ness of using HP. It is not as stun­ning as it seems when read­ing adver­tis­ing book­lets. Indeed, about 70HP offers % of heat for free, although not with­out a “but”. First, the sup­pli­ers of the equip­ment col­lect their rent from the obvi­ous ben­e­fit of the offer. BUTtheir appetites are clear­ly not reg­u­lat­ed by the laws of cost (com­pare the design com­plex­i­ty of a car engine and a pump at the same price). Sec­ond­ly, the cost of arrang­ing the pri­ma­ry heat col­lec­tion cir­cuit is 70–150% of the equip­ment cost. Third­ly, local prices for elec­tric­i­ty and alter­na­tive heat sources are strong­ly affect­ed. Sav­ings from HP arise due to reduced ener­gy costs, depre­ci­a­tion (equip­ment ser­vice life- thir­tyyears, pri­ma­ry cir­cuit- fiftyyears) and main­te­nance. ATon aver­age, cap­i­tal invest­ments in HP reach 20–40.5thou­sandrub. for 1kW of pow­er and in rela­tion to diesel boil­ers pay off in 3–7years. Accord­ing to MZTA spe­cial­ists, the use of HP is no less prof­itable than gas heat­ing. Cal­cu­la­tions showed that the pump after 18–20years is even begin­ning to bring ben­e­fits. No oth­er com­pet­ing equip­ment can do this.- it just phys­i­cal­ly fails for such a peri­od.

Parameters of ground collectors from PE pipes, m

Firm Pipe pitch trench depth Con­tour length
VIESSMANN 0.7 1.5 100
THERMIA 2 one 400
GEOTHERMIX one 1.8 150
“HEAT-SERVICE” 0.6 1–1.2 200
KOPCA 0.5 2 200

heating meters

Our most com­mon source of low-tem­per­a­ture heat is the soil. Heat is tak­en from it by soil heat col­lec­tors of two types: a) hor­i­zon­tal soil col­lec­tors; b) ver­ti­cal geot­her­mal probes. ATThey con­tain a non-freez­ing coolant, which, heat­ing up from the ground, trans­fers heat to the HP evap­o­ra­tor using a cir­cu­la­tion pump. Stud­ies con­duct­ed by INSOLAR-INVEST have shown that suf­fi­cient­ly effi­cient heat removal can be car­ried out almost through­out Europe. What type of heat col­lec­tor is prefer­able for a par­tic­u­lar area, the spe­cial­ist decides.

Expert opin­ion

Expe­ri­ence shows that the most accept­able design of the heat col­lec­tion sys­tem is obtained by using poly­eth­yl­ene pipes PE PND6 with a diam­e­ter of 32mm filled with propy­lene gly­col (30%). So, for a house with an area of ​​100m2 we rec­om­mend a pipe with a total length of 300–400m. Enough two seg­ments of 200m. For lay­ing each branch, they dig a trench up to 50 longm, width 0.8m and depth 2m. A clay base is poured onto its bot­tom (5cm). Then, near the trench wall, a pipe filled with water under pres­sure is laid in the for­ward and reverse direc­tions 4atm. From above it is cov­ered with a lay­er of clay with a thick­ness of 10cm, which is rammed and spilled with water. Then lay the soil with a thick­ness of 20–30see, and on top, in a clay “pie”,- the rest of the pipe. Its ends lead into the room in such a way that there is not a sin­gle exten­sion joint out­side. The sec­ond branch is laid in the same way. In this case, the dis­tance between the trench­es is at least 10m. Vthe cir­cuit is embed­ded with a cir­cu­la­tion pump, which is coor­di­nat­ed with the para­me­ters of the cir­cuit and HP (the “cir­cu­la­tors” are delib­er­ate­ly not includ­ed in the design of our HP).

Ilya Moskalenko, Gen­er­al Direc­tor of KORSA

Ground col­lec­tors. They col­lect the heat accu­mu­lat­ed in the upper lay­ers of the soil (depth- 5–20m) as a result of solar radi­a­tion (direct heat­ing, pre­cip­i­ta­tion, air heat). Radi­a­tion radi­a­tion of the Earth, com­ing from the depths, does not exceed 0.12W/m2 and does not make the weath­er.

A soil flat col­lec­tor con­sist­ing of six loops is laid on the field. Each of them has a man­hole at the point of con­nec­tion to the dis­tri­b­u­tion
col­lec­tor The heat removal depends on the com­po­si­tion and struc­ture of the soil. The best results are achieved if it con­tains a lot of water, hard min­er­al con­stituents such as quartz and few air pores. The heat removal pow­er is 10–40W/m2 (with a pipe spac­ing of 0.5–0.7m). The removal of heat is accom­pa­nied by a cool­ing of the area around the col­lec­tor pipes until they freeze. Freez­ing tem­per­a­tures out­side exac­er­bate this dan­ger. With inten­sive heat removal, it is not pos­si­ble to achieve a bal­ance of heat removed from the col­lec­tor to the pump and received from adja­cent land mass­es due to the low ther­mal con­duc­tiv­i­ty of the soil. Sta­ble with­draw­al process- sup­ply” of heat occurs, accord­ing to “INSOLAR-INVEST”, only in the fifth year of oper­a­tion of the equip­ment. In this case, the heat out­put of the pump is reduced. There are instal­la­tions in which HP sends excess heat from the house back to the col­lec­tor and fur­ther into the ground for stor­age in sum­mer, but we are almost nev­er used.

For the effi­cient oper­a­tion of the sys­tem, experts, based on the char­ac­ter­is­tics of the soil at the site, offer a vari­ety of col­lec­tor designs. Of the two main groups- flat and spi­ral- the first ones are get­ting accus­tomed to us. Pipes are laid in trench­es, plac­ing them on a plane in the form of a snake, loop, spi­ral. After check­ing the tight­ness of the sys­tem, the trench­es are cov­ered with earth. The depth of the pipes, their spac­ing and lay­out are the know-how of the firms. The area of ​​the plot required for lay­ing the heat col­lec­tor is 2–3 times greater than the heat­ed area of ​​the house. Use this area only for a lawn or flower gar­den.

When the col­lec­tor is locat­ed at a great dis­tance from the house, they are inter­con­nect­ed by pipes with a diam­e­ter of up to 140mm to reduce hydraulic resis­tance. Heat col­lec­tors are made of PE HDPE pipes with a diam­e­ter of 25–40mm, designed for pres­sure 6–10bar. Zinc plat­ing is not allowed. The total length of the pipe is divid­ed into seg­ments of 100–200m. They are laid in sep­a­rate loops (cir­cuits) and con­nect­ed to two dis­tri­b­u­tion man­i­folds- serv­ing and return­ing. The con­tours are made only from a whole piece of pipe, with­out joints lying under a lay­er of earth. It is impor­tant that they have the same hydraulic resis­tance, oth­er­wise the less “clamped” one may freeze. After all, more antifreeze will flow through it and heat removal will become more intense.

Dis­trib­u­tors can be locat­ed both near the house (in a con­crete pit) and in the build­ing itself. Access to con­nec­tions and ther­mal insu­la­tion of pipes should be pro­vid­ed at the point of entry into the house and at a length of at least 3m in front of the house. ATas a coolant in the cir­cuits, a 30% solu­tion of propy­lene gly­col or eth­yl­ene gly­col is used, less often- alco­hol solu­tions.

Expert opin­ion

Prac­tice shows that even in the north­ern lat­i­tudes, heat pumps are able not only to pro­vide a com­fort­able micro­cli­mate in the house, but also to keep the aver­age annu­al tem­per­a­ture poten­tial of the soil at the same lev­el. Good results are obtained by schemes using an IVT-com­pact col­lec­tor in the pri­ma­ry cir­cuit and a Green­line heat pump (IVT) paired with a VBX-IVT unit. The IVT-col­lec­tor is assem­bled from mod­ules in the form of a lat­tice of PE M40 pipes (mod­ule width- 1.5m, height- 2m). The col­lec­tor branch is often locat­ed in a trench with a width of 0.5m and depth 3m ver­ti­cal­ly and con­nect­ed to the house in the usu­al way. The build­ing is equipped with a forced ven­ti­la­tion sys­tem. The VBX recu­per­a­tion unit built into it is con­nect­ed to the HP evap­o­ra­tor, trans­fer­ring the heat of the exhaust air to it, and to the con­denser, heat­ing the fresh air. In warm weath­er, excess heat is tak­en away by the col­lec­tor coolant and the soil. ATas a result: a) the ground around the col­lec­tor does not freeze and the per­for­mance of the HP increas­es; b) a favor­able micro­cli­mate is cre­at­ed in the house; c) it becomes pos­si­ble to short­en the heat col­lec­tion cir­cuit (since part of the heat is sup­plied by air), which makes it pos­si­ble to reduce the cost of earth­works.

Oleg Prokhorov, tech­ni­cal direc­tor of the com­pa­ny “TEPLOSERVICE”

geot­her­mal probes. They extract heat from greater depths, where the ground tem­per­a­ture is more sta­ble (about 10FROM). The probe is low­ered into a well with a diam­e­ter of 110–150mm and depth up to 100–150m. Each meter of its length allows you to divert, depend­ing on the prop­er­ties of the soil, 30–100watts of ther­mal pow­er.

The base of the U‑shaped geot­her­mal probe with an eye for hang­ing the “anchor” (“EC “SOLAR TECHNOLOGY”) The main advan­tage of the probes- small instal­la­tion area. Flaw- high cost of drilling (up to 1thou­sandrub. for 1lin­earm).

Two types of ver­ti­cal col­lec­tor designs are com­mon: pipe-in-pipe and U‑tube. ATthe first case is a plas­tic pipe (diam­e­ter 32–50mm) runs along the axis of the steel pipe (diam­e­ter 100–120mm), which is weld­ed at the bot­tom and pro­vid­ed with a con­nect­ing flange at the top. This design suc­cess­ful­ly resists ground move­ment and pro­vides good heat trans­fer, but is dif­fi­cult to assem­ble. After all, sec­tions of a steel pipe have to be weld­ed not only very reli­ably (God for­bid antifreeze leaks!), But also quick­ly so that the walls of the well do not have time to crum­ble.

The tubes of the probe are con­nect­ed to the met­al base, filled with water and pressed under a pres­sure of 6 atm to check the tight­ness. In the sec­ond design, plas­tic pipes (PE) with a diam­e­ter of 25- 40mm are her­met­i­cal­ly con­nect­ed at the bot­tom, form­ing a long U‑shaped chan­nel filled with antifreeze. Such loops are most often used in pairs, but there may be more of them in the probe. The pipes are pressed with liq­uid and low­ered into the well when filled. After that, the space around the probe is filled with drilling flu­id or con­crete-cement mix­ture (to pro­tect pipes from mechan­i­cal dam­age and bet­ter heat trans­fer). If the well will pass through aquifers, per­mis­sion from the author­i­ties must be obtained to car­ry out the work. These trou­bles can be avoid­ed if the well depth is reduced to 20–40m, and their num­ber- increase, plac­ing no clos­er than 5m from each oth­er. At the top, pipes are led through a trench to the house.

All heat col­lec­tors are equipped with an expan­sion tank, an air vent and valves for fill­ing with antifreeze. The main con­di­tion for the coor­di­nat­ed oper­a­tion of the INT cir­cuit with a heat pump- ensur­ing such a flow rate of the coolant, which is indi­cat­ed in the pass­port of the HP.

sun, air and water

A lot of solar ener­gy is stored in air and water. HP, tak­ing heat from the air, are quite effec­tive in the south­ern regions. ATtheir use is lim­it­ed in the mid­dle lane. The fact is that in win­ter they can only work as part of biva­lent sys­tems and at tem­per­a­tures not low­er than 0 … ‑5C. With more severe frosts, their pow­er decreas­es sharply. More­over, the fan is icing up, and you have to stop the pump to thaw the ice.

Scheme for con­vert­ing ener­gy into HP:

a- heat cir­cuit INT; b- ener­gy of fre­on vapors; in- elec­tri­cal ener­gy for the com­pres­sor; G- ther­mal ener­gy at the HP out­put; one- evap­o­ra­tor; 2- com­pres­sor; 3- capac­i­tor; four- throt­tle.

Scheme of air HP oper­a­tion in cool­ing mode:

a- evap­o­ra­tor; b- throt­tling valve; in- reverse valve; G- capac­i­tor; d- com­pres­sor; e- water from INT.

Heat on credit

The edi­tors would like to thank TEPLOSERVICE, TERMOTECH‑M, INSOLAR-INVEST, KORSA, SOLAR TECHNOLOGY EC, GEOTECH‑K, TN-SERVICE for their help in prepar­ing the mate­r­i­al.

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