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High efficiency vacuum hot water boiler

KDNV-G2HEX series

The KDNV vacuum hot water boiler encloses a fixed amount of heating medium water and keeps it in a vacuum (negative pressure) state in the boiler body. When the medium water is heated, it immediately evaporates into decompressed steam to indirectly heat the heat exchanger to provide hygienic water

Main specifications

Full specification table
ModelKDNV-20G2HEX ~ KDNV-200G2HEX · 16 models
Rated heat output0.23 – 2.33 MW (200,000 – 2,000,000 kcal/h)
Efficiency98.3%
Control methodON - OFF · HI - LOW - OFF · HI - MIDDLE - LOW - OFF
Power consumption0.47 – 11.10 kW
Power220V x 1ø x 60Hz · 380V x 3ø x 60Hz
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Operating principle and features

  • Multi-purpose heat exchangers

    Heat exchangers can be used for heating, hot water supply and circulation heating in 1~3 circuits depending on the user’s demand. Each heat exchanger is independently installed and provides hygienic water without water mixing.

  • Low NOx burner attached as default

    Fuel saving low NOx burner is attached as default and guarantees 40ppm or less when operating under 4% of O2

  • Absolutely safe design

    Unlike pressure boilers, the KDNV vacuum hot water boiler operates under negative pressure (pressure below atmospheric pressure) and has no risk of explosion. 4-level safety devices (Vacuum pressure, over heat prevention, boiler body thermistor and low water level switches) further ensures the reliability of the product.

  • Semi-permanent life

    As the boiler water (heating medium water) of the vacuum hot water boiler is always kept in a fixed amount under vacuum condition without moving, there are no risks of corrosion or scale accumulation caused by dissolved oxygen. In addition with hygienic high corrosion resistant stainless steel heat exchangers, the boiler body is semi-permanent.

  • Fuel cost reduction with high efficiency furnace design

    The high efficiency body design, which adopts once-through characteristics of the water tube boiler, forms the water cooling wall structure and heat absorbing 3-pass structure, greatly reduces fuel costs.

  • High efficiency economizer

    Condensing economizer can be attached to the flue to drastically reduce fuel cost (Option)

Helium gas leak detector

Check any leakage after processing the boiler body → Check any leakage after assembling the heat exchanger→ Check any leakage after assembling the finished product

High efficiency vacuum hot water boiler Helium gas leak detector figure
High efficiency vacuum hot water boiler Helium gas leak detector figure

Standard specifications

KDNV-G2HEX series

tandard specifications for low NOx high-efficiency vacuum hot water boiler G2HEX series

Category Unit KDNV-G2HEX series
Hot water generator mounted type
KDNV- 20G2HEX KDNV- 25G2HEX KDNV- 30G2HEX KDNV- 35G2HEX KDNV- 40G2HEX KDNV- 45G2HEX KDNV- 50G2HEX KDNV- 60G2HEX KDNV- 80G2HEX KDNV- 100G2HEX KDNV- 120G2HEX KDNV- 130G2HEX KDNV- 150G2HEX KDNV- 160G2HEX KDNV- 180G2HEX KDNV- 200G2HEX
Boiler specifications Rated heat output MW 0.23 0.29 0.35 0.41 0.47 0.52 0.58 0.70 0.93 1.16 1.40 1.51 1.74 1.86 2.09 2.33
kcal/h 200,000 250,000 300,000 350,000 400,000 450,000 500,000 600,000 800,000 1,000,000 1,200,000 1,300,000 1,500,000 1,600,000 1,800,000 2,000,000
Efficiency % 98.3%
Heating area ㎡ 10.1 10.1 10.1 11.0 11.0 12.2 12.2 14.5 18.2 19.9 22.0 22.0 25.0 25.0 28.0 31.0
Burner - MAXI 25(LX) MAXI 32(LX) P4M (LX) P5M (LX) P60M (LX) P72M (LX) P9M(LX) S-4TG(LX)
Burner capacity (MAX) kcal/h 295,000 411,000 550,000 650,000 800,000 1,500,000 2,000,000 3,200,000
Control method - ON - OFF HI - LOW - OFF HI - MIDDLE - LOW - OFF
Blower capacity kW 0.37 0.37 0.75 0.75 1.50 1.50 1.50 1.50 3.00 4.00 5.50 5.50 7.50 7.50 11.00 11.00
Total power consumption kW 0.47 0.47 0.85 0.85 1.60 1.60 1.60 1.60 3.10 4.10 5.60 5.60 7.60 7.60 11.10 11.10
Power V 220V x 1ø x 60Hz 380V x 3ø x 60Hz
Fuel consumption LNG N㎥/h 20.3 25.4 30.5 35.6 40.7 45.8 50.9 61.0 81.4 101.7 122.1 132.2 152.6 162.8 183.1 203.5
Propane(LPG) N㎥/h 9.1 11.4 13.6 15.9 18.2 20.4 22.7 27.2 36.3 45.4 54.5 59.0 68.1 72.7 81.7 90.8
Diameter Gas inlet A 25 40 40 40 50 50 50 50 50 50 65 65 65 65 65 65
Flue ømm 200 250 250 250 250 250 300 300 350 350 400 400 450 450 450 500
External size Width(W) mm 1,060 1,060 1,060 1,310 1,310 1,310 1,310 1,310 1,530 1,530 1,660 1,660 1,700 1,700 1,700 1,700
Length(L) 2,750 2,880 2,980 3,130 3,230 3,360 3,360 3,490 4,120 4,320 3,580 3,580 3,830 3,830 3,960 4,210
Height(H) 1,810 1,810 1,810 1,900 1,900 1,900 1,900 1,910 2,070 2,190 2,670 2,670 2,740 2,740 2,790 2,790
Product weight kg 1,600 1,700 1,750 2,070 2,120 2,200 2,250 2,400 3,100 3,300 3,600 3,750 4,200 4,500 4,850 5,100

For heating and hot water circulation (333K → 343K) {60℃ → 70℃}

Category Unit KDNV- 20G2HEX KDNV- 25G2HEX KDNV- 30G2HEX KDNV- 35G2HEX KDNV- 40G2HEX KDNV- 45G2HEX KDNV- 50G2HEX KDNV- 60G2HEX KDNV- 80G2HEX KDNV- 100G2HEX KDNV- 120G2HEX KDNV- 130G2HEX KDNV- 150G2HEX KDNV- 160G2HEX KDNV- 180G2HEX KDNV- 200G2HEX
For heating and hot water circulation Rated heat output MW 0.23 0.29 0.35 0.41 0.47 0.52 0.58 0.70 0.93 1.16 1.40 1.51 1.74 1.86 2.09 2.33
kcal/h 200,000 250,000 300,000 350,000 400,000 450,000 500,000 600,000 800,000 1,000,000 1,200,000 1,300,000 1,500,000 1,600,000 1,800,000 2,000,000
Circulation volume ℓ 20,000 25,000 30,000 35,000 40,000 45,000 50,000 60,000 80,000 100,000 120,000 130,000 150,000 160,000 180,000 200,000
Maximum operating pressure MPa{kgf/㎠} 1{10}
Head pressure loss MPa{mH2O} 0.017{0.17} 0.02{0.2} 0.018{0.18} 0.022{0.22} 0.02{0.2} 0.022{0.22} 0.03{0.3} 0.033{0.33} 0.02{0.2} 0.022{0.22} 0.033{0.33} 0.03{0.3} 0.02{0.2} 0.022{0.22}
Material - Stainless steel pipe
Connection diameter A 50 50 65 65 65 80 80 100 100 100 125 125 125 125 150 150

For hot water supply (298K → 338K) {25℃ → 65℃}

Category Unit KDNV- 20G2HEX KDNV- 25G2HEX KDNV- 30G2HEX KDNV- 35G2HEX KDNV- 40G2HEX KDNV- 45G2HEX KDNV- 50G2HEX KDNV- 60G2HEX KDNV- 80G2HEX KDNV- 100G2HEX KDNV- 120G2HEX KDNV- 130G2HEX KDNV- 150G2HEX KDNV- 160G2HEX KDNV- 180G2HEX KDNV- 200G2HEX
For hot water supply Rated heat output MW 0.23 0.29 0.35 0.41 0.47 0.52 0.58 0.70 0.93 1.16 1.40 1.51 1.74 1.86 2.09 2.33
kcal/h 200,000 250,000 300,000 350,000 400,000 450,000 500,000 600,000 800,000 1,000,000 1,200,000 1,300,000 1,500,000 1,600,000 1,800,000 2,000,000
Circulation volume ℓ 5,000 6,250 7,500 8,750 10,000 11,250 12,500 15,000 20,000 25,000 30,000 32,500 37,500 40,000 45,000 50,000
Maximum operating pressure MPa{kgf/㎠} 1{10}
Head pressure loss MPa{mH2O} 0.017{0.17} 0.02{0.2} 0.018{0.18} 0.022{0.22} 0.02{0.2} 0.022{0.22} 0.03{0.3} 0.033{0.33} 0.02{0.2} 0.022{0.22} 0.033{0.33} 0.03{0.3} 0.02{0.2} 0.022{0.22}
Material - Stainless steel pipe
Connection diameter A 40 40 50 50 50 50 50 50 65 65 100 100 100 100 100 100

For hot water supply (278K → 338K) {5℃ → 65℃}

Category Unit KDNV- 20G2HEX KDNV- 25G2HEX KDNV- 30G2HEX KDNV- 35G2HEX KDNV- 40G2HEX KDNV- 45G2HEX KDNV- 50G2HEX KDNV- 60G2HEX KDNV- 80G2HEX KDNV- 100G2HEX KDNV- 120G2HEX KDNV- 130G2HEX KDNV- 150G2HEX KDNV- 160G2HEX KDNV- 180G2HEX KDNV- 200G2HEX
For hot water supply Rated heat output MW 0.23 0.29 0.35 0.41 0.47 0.52 0.58 0.70 0.93 1.16 1.40 1.51 1.74 1.86 2.09 2.33
kcal/h 200,000 250,000 300,000 350,000 400,000 450,000 500,000 600,000 800,000 1,000,000 1,200,000 1,300,000 1,500,000 1,600,000 1,800,000 2,000,000
Circulation volume ℓ 3,333 4,167 5,000 5,833 6,667 7,500 8,333 10,000 13,333 16,667 20,000 21,667 25,000 26,667 30,000 33,333
Maximum operating pressure MPa{kgf/㎠} 1{10}
Head pressure loss MPa{mH2O} 0.015{0.15} 0.018{0.18} 0.015{0.15} 0.02{0.2} 0.018{0.18} 0.02{0.2} 0.024{0.24} 0.033{0.33} 0.02{0.2} 0.022{0.22} 0.033{0.33} 0.03{0.3} 0.02{0.2} 0.022{0.22}
Material - Stainless steel pipe
Connection diameter A 40 40 40 40 40 50 50 50 65 65 100 100 100 100 100 100

Consultation and quotes

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