Provide the most efficient and safe heating system


The vacuum hot water boiler works on the principle that water boils at lower temperature and vaporizes when it is under the lower pressure .The inside of the unit forms a sealed and vacuum cavity by vacuum pumping system . The medium water in boiler transmits heat to exchangers through Evaporation and condensation ,which offers hot water.


Correspondence Table of Boiling Point and Vacuum Degree:

Correspondence Table of Boiling Point and Vacuum Degree

Note: 1standard atmospheric pressure=1.01325×105Pa=101.325Kpa

The developing history of vacuum boilers

Zurich Polytechnic University invented the principle of vacuum boiler

TAKUMA in Japan developed vacuum boiler according to the principle

LIJU was established and made the first vacuum hot water boiler in china.

LIJU  become the first brand of vacuum boilers in china

The advantages of vacuum boilers 

  • Simple system, Easy installation

    The built-in exchanger in boiler can directly offer needed water , can offer multi-circuits water with different temperature.

  • Safety, no risk of explosion

    The vacuum boilers operate under nagetive pressure ,Multiple protection,which ensure boiler not explosive.

  • Saving-energy, low operating cost

    The average operating cost can save 30% than steam boiler system and save 15% than ordinary hot water boiler system.

  • It can be installed on roof or underground.

    It’s not necessary to built alone house for vacuum boilers,It can be installed on roof or underground.



Security 100% safety
According to the law, vacuum unit belongs to the type of boiler that is exempted from inspection. The registration or annual inspection at the quality and technical supervision department is not necessary .
The ordinary boiler is required to be registered and inspected annually at the quality and technical supervision department when it is installed and used.
ways The unit (built-in heat exchanger) provides heating directly, and one unit can be used for heats directly and sanitary water at the same time supplying. Ordinary boiler can be used for only one purpose at a time, Because it produces high temperature water and be exchanged into low temperature water by external heat-exchanger .
Efficiency ﹥94%,( persistent ) It's easy to scale inside ordinary boiler ,which results in the efficiency of the heating system is less than 90% and reduce yearly.
Service Life 20 years ( semi-permanent ) 8~10 years
Erosion and Incrustation Scale Inexistent
■ No erosion:
The inside of the unit maintains a state of continuous vacuum, which means ther is no oxygen. This resolves the issue of erosion completely.
■ No scale:
The medium hot water performs closed cycles inside the unit, and the furnace smoke tube only contacts with the medium water.
This eliminates the generation of scale.
■ Corrosion often occurs:
The oxygen in boiler circulating water reacts with the inner steel plate and corrode it when water was heated .
The corrosion thins the steel plate and leads to the scrap of hte boiler.
■ Backwater condensation corrosion:
Occurred in northern heating boilers
■ Easy furring

Comparison of different boiler heating system

1、Steam boiler

  • Boiler efficiency : 85%
  • The discharge loss of condensation water : 15%
  • Steam heat transfer loss : 5%
  • Blowdown heat loss : 3%
  • Integrated heating system efficiency : 65%

2、Hot water boiler

  • Boiler efficiency : 90%
  • Pump power 
     : 3%
  • One heat transfer loss : 5%
  • Blowdown heat loss : 2%
  • Integrated heating system efficiency : 80%

3、Vacuum boiler:

  • Boiler efficiency : 94%
  • One heat transfer loss : 0%
  • Blowdown heat loss : 0%
  • Integrated heating system efficiency : 94%