The con­trol of humid­i­ty and tem­per­a­ture in the room is of great impor­tance for human health and life. At the same time, the humid­i­fi­ca­tion process plays an impor­tant role in many indus­tri­al areas. For exam­ple, the reduc­tion of elec­tro­sta­t­ic sur­face charge in the “clean rooms” of instru­ment-mak­ing enter­pris­es, where work is car­ried out with elec­tron­ic com­po­nents and semi­con­duc­tors, or the sup­pres­sion of dust by water mist in sawmills and wood­work­ing plants, while at the same time ensur­ing the required lev­el of wood mois­ture for sub­se­quent pro­cess­ing. An equal­ly impor­tant prob­lem is main­tain­ing the tem­per­a­ture and humid­i­ty con­di­tions in ware­hous­es, veg­etable stores, green­house com­plex­es and the so-called fresh zones of food dis­tri­b­u­tion cen­ters.

Every year the prob­lem of envi­ron­men­tal pro­tec­tion becomes more and more urgent, there­fore, water, as a nat­ur­al com­po­nent, sprayed under high pres­sure, in the form of a fine mist, turns into one of the most cost-effec­tive ways to achieve a good and nat­ur­al micro­cli­mate com­pared to tra­di­tion­al refrig­er­ant-based air con­di­tion­ing sys­tems. . In this regard, water mist tech­nol­o­gy is rapid­ly gain­ing ground in the mar­ket as a reli­able and extreme­ly ener­gy effi­cient alter­na­tive.


The main com­po­nent of the high pres­sure humid­i­fi­ca­tion sys­tem is the pump. More than 30 years ago, Dan­foss pio­neered the devel­op­ment of axi­al pis­ton pumps for water hydraulics. The main advan­tages of Dan­foss high pres­sure pumps are the absence of lubri­cants in the design, a min­i­mum num­ber of mov­ing parts and an extend­ed ser­vice inter­val at a min­i­mum lev­el of cost.. Struc­tural­ly, these pumps are self-lubri­cat­ing, i.e. do not require the use of lubri­cants. The water envi­ron­ment itself in the work­ing cav­i­ty of the pump pro­vides a suf­fi­cient lev­el of sur­face slid­ing of the mov­ing parts of the pump, pis­tons and swash plate. Today, Dan­foss is the world leader in oil-free or self-lubri­cat­ing high pres­sure pumps that bring all the ben­e­fits of axi­al pis­ton tech­nol­o­gy to humid­i­fi­ca­tion appli­ca­tions.

Com­pared to plunger pumps found in humid­i­fi­ca­tion sys­tems, Dan­foss axi­al pis­ton pumps pro­vide reli­able oper­a­tion and longer life due to few­er mov­ing parts in the pump cham­ber, as well as an 8000 hour ser­vice inter­val. The vol­u­met­ric effi­cien­cy of some pump mod­els is up to 95% and the ener­gy con­sump­tion is extreme­ly low (approx­i­mate­ly 4 W per liter of water), which makes the axi­al pis­ton tech­nol­o­gy ener­gy effi­cient when eval­u­at­ing the return on invest­ment and cost of own­er­ship (TCO) of the entire humid­i­fi­ca­tion sys­tem at the cus­tomer’s site.

Thanks to their unique tech­nol­o­gy, name­ly the loca­tion of the plungers along the axis of rota­tion of the pump, axi­al pis­ton pumps have the low­est noise lev­els (below 85 dB) and vibra­tions on the mar­ket. The low pul­sa­tion fre­quen­cy dur­ing the oper­at­ing cycle of all 5 or 9 pump plungers simul­ta­ne­ous­ly elim­i­nates the need for shock-absorb­ing mate­ri­als and damp­ing devices in the frame struc­ture of the pump­ing sta­tion. Giv­en the rel­a­tive­ly small over­all dimen­sions, the axi­al pis­ton pump is ide­al for design­ing a mobile humid­i­fi­ca­tion sys­tem, for exam­ple, a pri­vate house or cot­tage, a hotel com­plex or any res­i­den­tial build­ing where the own­er can enjoy peace and fresh air with the humid­i­ty lev­el nec­es­sary for com­fort­able liv­ing.

Dan­foss pumps will serve you for a long time, as the parts are made of AISI 304/316 stain­less steel, and the fric­tion parts of the pump inter­nal parts are made of semi-crys­talline high per­for­mance ther­mo­plas­tic (PEEK). The wide range of per­for­mance of Dan­foss axi­al pis­ton pumps will sat­is­fy the need to ensure the tem­per­a­ture and humid­i­ty con­di­tions both in a small green­house and in the largest green­house com­plex, or in an indus­tri­al and logis­tics cen­ter with a large cov­er­age area.

PAHT High Pres­sure Pumps for Ultra­pure Water

The Dan­foss PAHT pumps are pos­i­tive dis­place­ment pumps and move a con­stant vol­ume of water per cycle. The flow rate of the work­ing medi­um is pro­por­tion­al to the num­ber of rev­o­lu­tions of the pump shaft (rota­tion speed) and does not depend on the out­let pres­sure. All prod­ucts com­ply with the strict Euro­pean hygiene stan­dards VDI 6022 and HACCP and are cer­ti­fied accord­ing to ISO 9001 and ISO 14001. ATEX cer­ti­fi­ca­tion and API cer­ti­fi­ca­tion are avail­able upon request.

Danfoss PAHT pumps

High pres­sure valves for use in humid­i­fi­ca­tion and adi­a­bat­ic cool­ing sys­tems

Dan­foss man­u­fac­tures a wide range of AISI 304/316 stain­less steel valves which are used as sec­tion­al valves for water flow con­trol in humid­i­fi­ca­tion sys­tems. The valves are con­trolled by sole­noid coils, but if nec­es­sary, have a man­u­al reset func­tion. All valves are dirt resis­tant, pit­ting resis­tant and easy to main­tain. Degree of pro­tec­tion IP 67 [NEMA 4X]Danfoss stainless steel valves

Noz­zles with anti-drip valve

To obtain a water mist or a cloud, stain­less steel noz­zles are used with low (3–25 l/h) and high flow rates (25.2–344 l/h) depend­ing on the angle and spray area. The noz­zle has a built-in anti-drip valve. When the oper­at­ing pres­sure drops to 5 bar, the valve clos­es, pre­vent­ing the for­ma­tion of large drops and their sub­se­quent fall down. For opti­mal per­for­mance, sup­ply line pres­sure must be quick­ly relieved at the moment the noz­zle clos­es. This is ensured by the use of Dan­foss 3/2‑way high pres­sure valves, which imme­di­ate­ly relieve pres­sure to the drain.

Danfoss nozzles

Imple­men­ta­tion exam­ples of humid­i­fi­ca­tion and adi­a­bat­ic cool­ing sys­tems on Dan­foss pumps and valves

To date, Dan­foss pumps and valves have been installed in a large num­ber of imple­ment­ed humid­i­fi­ca­tion sys­tems around the world. For exam­ple, low oper­at­ing costs and long ser­vice inter­vals were deci­sive for the cus­tomer’s deci­sion to use 26 PAHT pumps for an adi­a­bat­ic cool­ing sys­tem at Face­book’s first Euro­pean data cen­ter (DPC) in Lulela, Swe­den. On a total area of ​​28,000 m², the pump­ing group sup­plies and dis­trib­utes 13,000 liters of water per hour. The main require­ments of the cus­tomer were trou­ble-free oper­a­tion with min­i­mum ser­vice inter­vals and the use of an oil-free pump to elim­i­nate the risk of con­t­a­m­i­na­tion of the dehu­mid­i­fi­er area with lubri­cants accord­ing to ISO 22000 stan­dards. Using its advanced tech­nolo­gies in the field of humid­i­fi­ca­tion and air purifi­ca­tion, Condair used Dan­foss axi­al pis­ton pumps, which made it pos­si­ble to achieve reduce ener­gy costs by 50% com­pared to tra­di­tion­al cool­ing meth­ods. The ener­gy con­sump­tion at the facil­i­ty has been increased to 0.005 kWh per kW of cool­ing. In addi­tion to pro­vid­ing pol­lu­tion-free humid­i­ty, Condair’s adi­a­bat­ic cool­ing sys­tem main­tains humid­i­ty lev­els at opti­mal lev­els to neu­tral­ize elec­tro­sta­t­ic charge and pre­vent dam­age to serv­er hard­ware and worse, data loss. Dan­foss pumps oper­ate con­tin­u­ous­ly and reli­ably in one of the most mod­ern and ener­gy effi­cient data cen­ters in the world. In Rus­sia, adi­a­bat­ic cool­ing sys­tems for data cen­ters are not yet very pop­u­lar, but experts believe that in the com­ing years, data cen­ter design­ers will show increas­ing inter­est in them. The rea­son is the Fed­er­al Law FZ-261, which sets strict lim­its for ener­gy con­sump­tion and requires a 40% increase in ener­gy effi­cien­cy by 2022.

Mer­lin Tech­nol­o­gy’s man­u­fac­tures humid­i­fi­ca­tion sys­tems for crit­i­cal appli­ca­tions such as the phar­ma­ceu­ti­cal and food indus­tries, auto­mo­tive plants, and micro­elec­tron­ics assem­bly plants (“clean rooms”). The humid­i­fi­ca­tion sys­tem of these plants requires the use of only dem­iner­al­ized water, with­out the pos­si­bil­i­ty of spread­ing par­ti­cles or salts of min­er­als, bac­te­ria or oth­er organ­ic mat­ter. There­fore, the sys­tems must be com­plete­ly made of stain­less steel. The use of pumps with a min­er­al oil lubri­ca­tion sys­tem is strict­ly unac­cept­able. And for more than 20 years, Dan­foss has been using PAHT pumps in its humid­i­fi­ca­tion sys­tems. “When we start­ed,” com­pa­ny founder Johan Reisinger recalled, “peo­ple were still using steam to humid­i­fy. But for large areas, the cost of elec­tric­i­ty costs was 700–800 W per liter of water. By using Dan­foss PAHT pumps, we have been able to reduce our ener­gy con­sump­tion to just 3 W per liter! Main­te­nance is anoth­er impor­tant expense item. Espe­cial­ly when humid­i­fi­ca­tion sys­tems are installed all over the world and an entire ser­vice infra­struc­ture is required. “Dan­foss promised us,” said Johan Reisinger, “that PAHT pumps typ­i­cal­ly run at least 8,000 hours before they need ser­vice, but field expe­ri­ence has shown that at least 80% of installed pumps actu­al­ly last twice as long as adver­tised. We even have pumps that have run 25,000 hours with­out main­te­nance! With Dan­foss PAHT pumps, installing our humid­i­fiers returns cus­tomers on their invest­ment with­in the first year of oper­a­tion.” Thanks to the inno­v­a­tive approach of Mer­lin Tech­nol­o­gy’s engi­neers, Dan­foss axi­al pis­ton pumps as part of humid­i­fi­ca­tion sys­tems pro­vide tem­per­a­ture and humid­i­ty con­trol in fac­to­ries of com­pa­nies such as Mer­cedes, Audi and VW, Bosch and IKEA, such as Velux, Canon, Hipp and Nes­tle.

Not only in Europe, but also in Rus­sia, Dan­foss pumps have proven them­selves since 2011 as reli­able and prac­ti­cal com­po­nents for humid­i­fi­ca­tion sys­tems. The project on the basis of a green­house facil­i­ty with an area of ​​70,000 m² in the Leningrad region was imple­ment­ed by the Dutch com­pa­ny Van der Ende Pom­pen. The cus­tomer was tasked with gen­er­at­ing enough water mist from dem­iner­al­ized water to con­trol tem­per­a­ture and humid­i­ty for such an ambi­tious green­house busi­ness at the time. Cre­at­ing a reli­able fog­ging device that can reg­u­late tem­per­a­ture and humid­i­ty on sev­en hectares under glass is not an easy task. The aver­age tem­per­a­ture in the Leningrad region ranges from ‑10°C in win­ter to +23°C in sum­mer. Accord­ing to Paul van den Bos, Design Engi­neer for Van der Ende Pom­pen, the main cri­te­ria for select­ing a pump for the sys­tem were reli­a­bil­i­ty, ease of main­te­nance and main­te­nance costs in order to vis­it the site as lit­tle as pos­si­ble, locat­ed at a dis­tance of 2500 km from the near­est ser­vice part­ner. Van der Ende Pom­pen used Dan­foss high-pres­sure axi­al pis­ton pumps to cal­cu­late the duty point for pump and motor units. The result was the fol­low­ing solu­tion — a par­al­lel bun­dle of five pumps of the PAHT 90 series. Each pump is capa­ble of deliv­er­ing up to 120 liters per minute at a max­i­mum pres­sure of 129 bar, and they are all con­nect­ed to a col­lec­tor that sup­plies water mist to the entire green­house through a com­mon line. The max­i­mum capac­i­ty of the entire humid­i­fi­ca­tion or mist­ing sys­tem is 581 liters per minute. Also at this facil­i­ty, Dan­foss high-pres­sure valves are used in each sec­tion. The con­struc­tion of the green­house com­plex and the instal­la­tion of equip­ment and aux­il­iary sys­tems was com­plet­ed in the 3rd quar­ter of 2013, and the res­i­dents of St. Peters­burg received the first har­vest of toma­toes and cucum­bers in the win­ter of the same year.

In Rus­sia, Dan­foss is a part­ner of OOO ES Engi­neer­ing (St. Peters­burg), a leader in the design and man­u­fac­ture of humid­i­fi­ca­tion and adi­a­bat­ic cool­ing sys­tems based on Dan­foss high-pres­sure pumps and valves. The com­pa­ny “ES Engi­neer­ing” pro­vides a full range of ser­vices for the instal­la­tion, main­te­nance and mon­i­tor­ing of humid­i­fi­ca­tion sys­tems, as well as for the train­ing and edu­ca­tion of per­son­nel.

Dan­foss LLC, the Russ­ian rep­re­sen­ta­tive office of Dan­foss A/S, and EC Engi­neer­ing LLC will be hap­py to assist in the selec­tion of an effi­cient humid­i­fi­ca­tion sys­tem and its imple­men­ta­tion at any cus­tomer site.

We look for­ward to work­ing with you, Dan­foss.

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