Cold heating

Heat pumps are replac­ing heat­ing boil­ers because they use an inex­haustible source of heat- the ener­gy of the sun absorbed by the earth, water and air. They are com­pact, easy to tie, and require only peri­od­ic check­ing and inspec­tion dur­ing oper­a­tion. Requires only a few kilo­watts of elec­tric­i­ty
Mod­ern HP mod­els are equipped with eco­nom­i­cal, low-noise, reli­able scroll com­pres­sors
One of the first domes­tic mod­els of house­hold TN-ATNU-15

23kW of free heat using ground probes with a depth of about 38m sup­plies the HRN unit from CLIMAVENETA
The heat exchang­ers of the evap­o­ra­tor and con­denser in the first mod­els of heat pumps were made of cop­per tubes by sol­der­ing
Robust mod­el45 (THERMIA) uses the col­lect­ed heat almost with­out loss with the help of a sub-cool­er and devel­ops a pow­er of 45kW. FROMwith addi­tion­al cool­ing units in sum­mer it can replace a mul­ti-split sys­tem
Many HP mod­els are equipped with a flow­ing elec­tric water heater
ТНСО2–20 runs on envi­ron­men­tal­ly friend­ly CO refrig­er­ant2Direct­ly from a deep well into the house (through the floor with the help of a heat and water­proof­ing sleeve), at the stage of con­struc­tion of the box, a head of a ver­ti­cal col­lec­tor was intro­duced that col­lects the dis­si­pat­ed heat of the soil
Pump inlet and out­let pip­ing is care­ful­ly insu­lat­ed to reduce heat loss
Wells (diam­e­ter up to 165mm) under the ground probe is placed near the house, tak­ing into account the pos­si­bil­i­ty of access to the drilling rig. They don’t reach arte­sian water
When plan­ning the land­scape of the site, we decid­ed to cov­er the col­lec­tor with a high embank­ment
Hor­i­zon­tal col­lec­tors are some­times made in the form of a spi­ral with a diam­e­ter of about 1m, in incre­ments of 0.3- 0.7m and laid in ditch­es up to a depth of2.5 m
Entrance of a ver­ti­cal col­lec­tor into a well with­out cas­ing

IVT’s Green­line series mod­els are built on a mod­u­lar basis and are eas­i­ly recon­fig­ured to work with water or antifreeze.
Mod­els of the Vito­cal series (VIESSMANN) are avail­able in three types:
“ground-water”, “water-water”, “air-water”; cov­er a range of capac­i­ties up to 106kW; con­trolled by weath­er-com­pen­sat­ed con­troller C60
The WPC unit (STIEBEL ELTRON) “feeds” on the heat of the earth and works for three: in addi­tion to the usu­al duties of heat­ing the house and prepar­ing hot water, it can switch to cool­ing water in fan coil units or radi­a­tors, thus oper­at­ing as a mul­ti-zone air con­di­tion­ing sys­tem
Among the THERMIA units, the Diplo­mat series is designed to sup­ply heat and cold in dif­fer­ent ways- take heat from the earth and water or air (with the Aer block), and togeth­er with the pas­sive cool­ing block- cre­ate cool­ness in the house

one- low-tem­per­a­ture heat sup­ply cir­cuit;
2- evap­o­ra­tor;
3- com­pres­sor;
four- capac­i­tor;
5- high-tem­per­a­ture heat sup­ply cir­cuit;
6- throt­tle valve

ATin a house with large heat loss­es, install a high-pow­er pump (more than 30kW) is unprof­itable. It is bulky, and will work at full capac­i­ty for only aboutmonth. After all, the num­ber of real­ly cold days does not exceed 10–15% of the dura­tion of the heat­ing sea­son. There­fore, often the pow­er of the HP is assigned equal to 70–80% of the cal­cu­lat­ed heat­ing. It will cov­er all the heat needs of the house until the out­side tem­per­a­ture drops below a cer­tain cal­cu­lat­ed lev­el (biva­lence tem­per­a­ture), for exam­ple minus 5–10S.SAt this point, the sec­ond heat gen­er­a­tor is switched on. There are dif­fer­ent ways to use it. Most often, such an assis­tant is a small elec­tric heater, but you can also put a liq­uid fuel boil­er. Choos­ing the best optionis the task of a spe­cial­ist.

Today we have oppor­tu­ni­ties to ful­ly use the advan­tages of heat pumps. Andalthough hard­ly a third of the world’s HP man­u­fac­tur­ers sup­ply us with their prod­ucts, their deal­ers are ready to install equip­ment any­where in the coun­try. Small busi­ness- for the desire of the Euro­pean to bend down and take the heat from under their feet.

On the mar­ket you can find heat pumps from IVT, MECMASTER, THERMIA (all- Swe­den), OCHSNER (Aus­tria), VAILLANT, VIESSMANN, STIEBEL ELTRON (all- Ger­many), CLIMAVENETA (Italy), CARRIER, AERTEC (both- USA), PZP KOMPLET, G‑MAR (both- Czech). In addi­tion, in the off-sea­son, we have long used air con­di­tion­ers and chillers with the “heat­ing” mode from such well-known man­u­fac­tur­ers of refrig­er­a­tion equip­ment as HITACHI, Daikin (both- Japan), CARRIER, YORK (both - USA), CLIVET (Italy) andetc. There are still few domes­tic man­u­fac­tur­ers of house­hold HPs (the change of own­ers and the pro­file of enter­pris­es affects). Among them- “EKIP”, “NPF TRITON”, RZP, “ENERGY”. The prod­ucts are sim­ple in design, but reli­able and cheap­er than import­ed ones. ToIn addi­tion, devel­op­ers are look­ing for solu­tions that are more suit­able for Euro­pean con­di­tions. So, the AVTN-28g mod­el (“NPF TRITON”) heats water in the heat­ing sys­tem up to 70C, and this is with good econ­o­my (=3.3). Import­ed instal­la­tions do not give such results. The com­pa­ny “EKIP” has cre­at­ed a pump TNSO2-20, oper­at­ing on car­bon diox­ide (CO2)- an envi­ron­men­tal­ly friend­ly refrig­er­ant that allows you to heat water up to a record high of 85C at =3.28.

A wide range of HP mod­els with pow­er from 2 to 130kW is able to sat­is­fy any requests of the inhab­i­tants of both small cot­tages and large man­sions. It is only nec­es­sary not to make a mis­take with the choice of the type of instal­la­tion.

Ground-water installations

Prim­ingis per­haps the most ver­sa­tile source of dis­si­pat­ed heat. It accu­mu­lates solar ener­gy and is heat­ed from the earth­’s core all year round. At the same time, it is always “under­foot” and is able to give off heat regard­less of the weath­er. After all, at a depth of 5–7m tem­per­a­ture is almost con­stant through­out the year. For cen­tral Europe, it is 5–8C. These are very suit­able con­di­tions for the oper­a­tion of the HP. More­over, in the upper lay­ers of the earth, the min­i­mum tem­per­a­ture is reached by steammonths after peak frost- the need for inten­sive heat­ing by this time decreas­es. ATIn gen­er­al, the soil sup­plies calo­ries quite reli­ably. The required ener­gy is col­lect­ed by a heat exchang­er buried in the ground and accu­mu­lat­ed in the car­ri­er, which is then pumped to the HP evap­o­ra­tor and returned back for a new por­tion of heat. ATas such an ener­gy car­ri­er, a non-freez­ing, envi­ron­men­tal­ly friend­ly liq­uid is used (it is also called “brine” or antifreeze). It can be a thir­ty per­cent aque­ous solu­tion of eth­yl­ene gly­col or propy­lene gly­col.

There is anoth­er scheme for col­lect­ing heat, when instead of “brine” fre­on cir­cu­lates in the cir­cuit, which turns into steam right in the pipes of the heat col­lec­tor. This is how, for exam­ple, the pump ATNU-10 (RZP) or Golf-GMDW (OCHSNER) can work. But although this scheme improves effi­cien­cy, its oper­a­tion is dif­fi­cult. Today the most pop­u­lar sys­tems with “pick­le”. ATThey use two types of heat exchang­ers: ground col­lec­tor and ground probe. Both are made of poly­eth­yl­ene pipes with a diam­e­ter of 25, 32 or 40mm (the more- the bet­ter the heat extrac­tion, but the more expen­sive the sys­tem).

Ground col­lec­tor (hor­i­zon­tal) is a long pipe laid hor­i­zon­tal­ly under a lay­er of soil. Main advan­tage- ver­sa­til­i­ty and ease of instal­la­tion. Found a free space- dig grooves and stack. Flaw- large required area under the col­lec­tor- 25–50m2 per 1 kW of pow­er (more­over, the site can only be used for a lawn or annu­al flow­ers). There are dif­fer­ent pipe lay­out schemes: loop, snake, zigzag, flat and heli­cal spi­rals of var­i­ous shapes andt.n. The choice is deter­mined by the ther­mal con­duc­tiv­i­ty of the soil and the geom­e­try of the site. The heat col­lec­tion capac­i­ty is high­er in moist loams and low­er in dry sandy areas. ATaver­age 1m2 ground sur­face can pro­vide “sup­ply” 10–35W of pow­er. The length of the pipe in one loop, and one-piece, with­out con­nec­tors, tends to be lim­it­ed (no more than 600m), oth­er­wise the ener­gy con­sump­tion of the cir­cu­la­tion pump increas­es marked­ly. If more pow­er is need­ed, sev­er­al loops are made.

Atcol­lec­tors have a fea­ture that gives a lot of trou­ble to builders. It turns out that the tem­per­a­ture of the soil lay­er around the pipes grad­u­al­ly decreas­es, and the stronger, the high­er the per­for­mance of the HP. It can fall below zero, and the array can even freeze. There­fore, the main con­cern of heat col­lec­tor builders- to make it for a rea­son­able price so that the soil has time to gain “ther­mal fat” over the sum­mer and at the same time con­tin­ues to sup­ply ener­gy for the prepa­ra­tion of hot water. There are no uni­form norms here, because soils and cli­mat­ic con­di­tions are zoned. So, in the world region, the TN-SERVICE com­pa­ny has been suc­cess­ful­ly prac­tic­ing pipe lay­ing just below the freez­ing depth (1.5m) with a step cal­cu­lat­ed from the con­di­tion of 2 run­ning meters. m pipe per 1m2 heat­ed area of ​​the house. BUThere, near , spe­cial­ists from the com­pa­ny “TEPLOSERVICE” deep­en pipes by only 1.2m, which is high­er than the freez­ing depth, and in incre­ments of 1m. In the spring, when heat reserves run out, the upper lay­er of the earth warms up faster with the ener­gy of the sun and melt water. Izhevsk com­pa­ny “ECOSERVICE” uses a step of 0.6m and depth 1.5On the con­trary, spe­cial­ists from the Bel­go­rod orga­ni­za­tion “GROUND CONSTRUCTION” aban­doned ground col­lec­tors because of their low­er effi­cien­cy com­pared to ground probes or pumps “air- water.

Ground probes (ver­ti­cal col­lec­tors)is a sys­tem of long pipes low­ered into a deep well (50–150m). Here you need only a patch of land, but expen­sive drilling work is required (from $20 for 1 line m). The tem­per­a­ture is always the same at depth- about 10C, so the probes are more pow­er­ful than hor­i­zon­tal col­lec­tors. A meter of their length sup­plies from 30 to 100W of ther­mal pow­er, depend­ing on the soil.

A dozen dif­fer­ent designs of probes are known, some­times very unusu­al (for exam­ple, in the form of pipes immured in the piles of the foun­da­tion of a house). But the most applic­a­ble are two: pipe in pipe and U‑shaped. On one line, the “brine” is fed down by the cir­cu­la­tion pump, on the oth­er it ris­es up to the evap­o­ra­tor. ATin deep wells, the assem­bly is always pro­tect­ed by a cas­ing pipe, in shal­low wells it is not always.

To improve heat trans­fer and increase the strength of the probe, the gap between the ground or cas­ing and work­ing pipes is filled with ben­tonite or con­crete. If you need to get more pow­er, there are sev­er­al such heat col­lec­tors. Dis­tances between them- 5–7m.

Atver­ti­cal col­lec­tors, in addi­tion to high cost, there is anoth­er weak point, which is not men­tioned in com­pa­ny brochures. As shown by stud­ies con­duct­ed by one of the pio­neers of the intro­duc­tion of HP- by INSOLAR-INVEST, the bal­ance between the process­es of heat extrac­tion and restora­tion of the “feed­ing” capac­i­ty of the soil (the earth around the probe becomes cold) occurs only after 4–5 years of oper­a­tion. There­fore, the pump in the project must be laid more pow­er­ful­ly. How much- only experts can say.

BUTwhat can real­ly cause a lot of trou­ble is get­ting per­mis­sion from the water super­vi­sion ser­vice to drill a deep well for a probe. For the prob­a­ble freez­ing of the soil can dis­rupt the behav­ior of aquifers. There­fore, for small cot­tages, spe­cial­ists from INSOLAR-INVEST advise lay­ing sev­er­al small­er ones instead of one deep one (25–35m) wells, since they do not require the approval of an offi­cial. Idea test­ed. FROMWith the help of eight short­ened probes and the heat of the exhaust air, a plant for sup­ply­ing hot water to a sev­en­teen-sto­ry build­ing in the world was assem­bled, the res­i­dents of which are 45% cheap­er than those in neigh­bor­ing hous­es.

Scheme of instal­la­tion of TN type “soil-water”:

STIEBEL ELTRON1- ground probe;
2- TN;
3- heat­ing sys­tem;
four- DHW net­work

Water-to-water installations

The source of heat can be sur­face water (rivers, lakes) or soil water (wells), as well as waste water from tech­no­log­i­cal instal­la­tions. The pumps them­selves are almost the same as those that work with the “brine”. But due to the high­er tem­per­a­ture of the coolant in win­ter, the annu­al effi­cien­cy of using water-to-water devices is the high­est. It is a pity that this tech­nique is good main­ly only for indus­tri­al appli­ca­tions. Too rarely there are suit­able con­di­tions for a pri­vate trad­er. But if a non-freez­ing riv­er flows near­by, you can lay a loop of pipe with antifreeze on the bot­tom (by drown­ing it with loads) and heat up almost for noth­ing. Of course, if the water pro­tec­tion ser­vice gives the go-ahead.

The well is more dif­fi­cult. Water from it (at the rate of about 0.25m3/h per 1kW of ther­mal pow­er) is sup­plied by a bore­hole pump direct­ly to the evap­o­ra­tor, and drained … into a sec­ond well, remote from the first down­stream water in the under­ground lay­er by 15–20m. In this case, the aquifer must accept and divert the drained water, oth­er­wise a small flood is pro­vid­ed to you. It is clear that such for­ma­tions at shal­low depths are not found every­where, and for arte­sian wells it is not easy to get per­mis­sion from us. AndIt is also nec­es­sary to pro­tect the evap­o­ra­tor from con­t­a­m­i­na­tion and cor­ro­sion. Fil­tra­tion and water analy­sis are required. If there are too many salts in it, it will be nec­es­sary to equip an inter­me­di­ate heat exchang­er, deaer­at­ed clean water will cir­cu­late between it and the HP.

Air-to-water installations

In terms of ver­sa­til­i­ty of appli­ca­tion in Euro­pean con­di­tions, this type of pumps is still in sec­ond place. Andthe pumps them­selves are cheap­er, and pipes (with the same earth­works) are not required. There is only one draw­back, but a sig­nif­i­cant one: you can’t take much heat from the frosty air. Steadi­ly, albeit with reduced pow­er, these devices oper­ate down to ‑15 C, and then you need to turn on anoth­er boil­er. ATsome mod­els, such as Green­line (IVT), TCLM-Kom­plet (PZP KOMPLET) and Duo (THERMIA), heaters with pow­er from 3 to 12 kW are already built into the design. In addi­tion, firms are work­ing hard to low­er oper­at­ing tem­per­a­tures even fur­ther. Let’s say pumps of the WPL series from STIEBEL ELTRON work up to ‑20C, and the HP-40 mod­el from G‑MAR and at ‑25FROM.

When it comes to the choice of “air” units, it is use­ful to take into account two impor­tant cir­cum­stances that are usu­al­ly silent in arti­cles. First­ly, the val­ue of the rat­ed pow­er giv­en in the pass­port refers to a cer­tain tem­per­a­ture of the out­door air. Ateach com­pa­ny has its own. It can be 0 or 2 or 10 or even 25C. So, in terms of effi­cien­cy, all machines must be com­pared at the same out­door tem­per­a­ture. Sec­ond­ly, with the inten­si­fi­ca­tion of cold weath­er, the HP devel­ops notice­ably less (some­times three times) pow­er, so an addi­tion­al heater is required.

Scheme of appli­ca­tion of HP “air-to-water” and solar water heater:

2- heater pan­els;
3- heat accu­mu­la­tor;
four- boil­er

Struc­tural­ly, air-to-water devices are made accord­ing to two lay­out schemes: split and mono. ATIn the first case, the instal­la­tion con­sists of two blocks con­nect­ed by com­mu­ni­ca­tions. One, out­door, includes a pow­er­ful fan and evap­o­ra­tor (mount­ed on a site near the house). The sec­ond, inter­nal, con­tains a capac­i­tor and automa­tion and is installed indoors. The com­pres­sor can be locat­ed either out­side, so as not to make noise in the house, as, for exam­ple, in the HP-40 (G‑MAR) mod­el, or in the indoor unit, as in TCLM (PZP). ATmonoblocks, all ele­ments are assem­bled in a com­mon hous­ing and mount­ed in the house, and con­nect­ed to the street by a flex­i­ble duct. They are sup­plied by most com­pa­nies, but have lim­it­ed capac­i­ty.- usu­al­ly 3–16kW. There are monoblocks that allow both exter­nal and inter­nal instal­la­tion, for exam­ple WPL (STIEBEL ELTRON). New­ly devel­oped, monobloc for out­door instal­la­tion with a record low oper­at­ing tem­per­a­ture (-25C), offered to con­sumers by G‑MAR.

ATIn recent years, due to the dete­ri­o­ra­tion of hous­ing ven­ti­la­tion due to the wide­spread use of new sealed win­dows with dou­ble-glazed win­dows, air-to-water heat pumps have received addi­tion­al devel­op­ment. In addi­tion to heat­ing and hot water prepa­ra­tion, some mod­els “learned” not only to work in ven­ti­la­tion sys­tems, but also to use the heat of the exhaust (exhaust) air of the premis­es. These are, for exam­ple, Europa and Com­bi from OCHSNER, IVT490 and 495 from IVT, Com­fort­Zone from MECMASTER, Solvik from THERMIA.

Ocoor­di­na­tion of the oper­a­tion of the pump with con­nect­ed cir­cuits (for exam­ple, heat­ing) and we will talk about the fea­tures of these cir­cuits in a sep­a­rate arti­cle.

Characteristics of heat pumps for houses up to 200m2

Man­u­fac­tur­er (num­ber of house­hold mod­els) Mod­el Ther­mal pow­er, kW Pow­er con­sump­tion, kW Type of Dimen­sions (lengthwidth
height), mm
THERMIA (21) diplo­mat 10 10.0 3.6 G‑V, V‑V 5966901705 9020
Robust 28UM 27.1 10.1 G‑V, V‑V 7658901150 ten790
VIESSMANN (30) Vito­call 300-AW116 14.6 4.6 Woz‑B 76012001510 eleven200
Vito­call 300-BW110 10.8 2.4 G‑V 650600945 6390
OCHSNER (41) Golf Maxi-GMSW15 11.0 2.45 G‑V 6506001150 6195
Europa 122 LHK 3.6 0.54 Woz‑B 640900695 3980
STIEBEL ELTRON (28) WPF 13 16.8 3.0 Woz‑V, G‑V 510680960 8652
WPL 18 11.6 3.4 Woz‑B 78411821116 ten130
IVT(25) Green­line E11 Plus 10.7 2.2 V‑V, G‑V 6006001770 7866
IVT-495Twin 4.0 1.4 G‑V, V‑V, Voz‑V 6156002090 9080
PZP KOMPLET (23) TCLM Kit‑5.3 5.8 1.6 Woz‑B 8707751710 8990
TCMM-15.5G 15.5 3.6 G‑V 6704481236 6790
MECMASTER (12) MEC 6TB 10.0 3.4 G‑V, V‑V 600600850 5300
HVP 6TB 8.0 2.8 G‑V, V‑V 6006001650 5960
CLIMAVENETA (7) HRN-0101 34.0 11.0 G‑V, V‑V 650600850 8500
CARRIER (20) 30 RYH-017B 18.3 9.78 Woz‑B 20718701329 four­teen048
AERMEC (14) NRW-47H 12.0 4.4 B‑B 4504501140 6400
G‑MAR (4) HP 40–065 20.0 5.0 Woz‑B 718718945
(out­door unit)
RZP (3) ATNU-15 15.0 5.0 B‑B 9666161590 4500
“NPF TRITON” (2) AVTN-28G 17.0 9.0 B‑B 400400600 8500
“EKIP” (2) TNU-10 10.0 2.36 B‑B 4004001500 3000
Note. G‑V- “soil-water”; B‑B- “water-water”; Woz‑B- “air-water”


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