What are hybrid boilers, their types, and their functions?

What are hybrid boilers, their types, and their functions?

What are hybrid boilers, their types, and their functions?

1) Introduction to Boilers

  • What is a boiler?

A boiler is an enclosed system that is designed to provide means for combustion and transfers heat to water until it becomes hot water then steam. Under pressure, the steam is then used for transferring the heat to a process. The boiler system is made out of three different systems:

  1. Feed Water System: this system is responsible for providing water to the boiler and regulating it automatically to meet the steam demand.
  2. Steam system: this system is responsible for collecting and controlling the steam that is produced in the boiler.
  3. Fuel system: the fuel system, is the combination of equipment necessary for generating Heat.


  • Types of Boilers:

Boilers can be divided and classified into two large general categories, these two categories are fire tube boilers and water tube boilers:

  • Fire Tube Boilers: combustion gas passes through the inside of the tubes while the water is surrounding the outside of the tubes. Their advantages are its simplicity in order to construct it and less rigid water treatment requirements. Their disadvantages are the excessive weight-per-pound of steam generated and the excessive time required in order to raise steam pressure. Fire tube boiler is usually used in the facilities of heating applications.

Fire Tube Boilers

  • Water-tube Boilers: unlike Fire Tube Boilers, in the water tube boilers the water flows inside the tubes and combustion gas passes around the outside of the tubes. Their advantages are a lower unit weight-per-pound of steam generated and less time required to raise steam pressure; however, their disadvantages are High initial capital cost and their cleaning process. Water tube Boiler is used in facilities that use large steam.

Water Tube Boiler

2) Introduction to Hybrid Boilers

  • What is a Hybrid Boiler?

The term hybrid stands for a mixed character or the composition of different elements (more than two). A Hybrid Boiler System is a combination of two types of boilers condensing and noncondensing Boilers. The hybrid system is designed to take advantage of the best properties of both boilers.

Hybrid Boilers

  • Components of Hybrid Boiler

As stated before a Hybrid Boiler is the combination of two different types of Boilers, Condensing boiler and non-Condensing Boiler

  • Non-condensing Boiler: A non-condensing Boiler is composed of a Single combustion chamber and a single heat exchanger its temperature of combustion can reach up to 180°c with a high carbon emission.
  • Condensing Boiler: a condensing Boiler is a water heater that is fueled by either gas or oil, these types of Boilers condense water vapor in the exhaust gases and recover its latent heat of vaporization that in other types of boilers and heaters would have been wasted. This condensed vapor leaves the system in a liquid form, via a drain. This technique is a key to achieving a high-efficiency rate greater even than 90%. There are lots of advantages related to using a condensing boiler such as:
  • Increase in energy efficiency: Condensing Boilers use waste heat in flue gas to preheat the cold water entering the boiler, meaning that they capture more heat from the outside rather than the inside, this way condensing boilers can achieve a stunning high-efficiency rate reaching up to 99% efficiency.
  • Safe to use in Homes: the fact that condensing boilers are perfectly sealed eliminates the possibility of anything being sucked into the boiler. Not to mention their low carbon emissions which makes them perfectly safe for users.

Condensing Boilers may suffer from few disadvantages and challenges such as:

  • Complex Systems: Condensing boilers are complex systems, their constructing and installation is not a simple task, on top of that in very cold weathers, the system may shut down in some cases.
  • Expensive to Maintain: being a complex system, a condensing boiler is obviously expensive to maintain and fix.

3) Hybrid Boilers Applications and Costs

  • Advantages and Applications

A combination of condensing and noncondensing Boilers can lead to up to 40% of reducing of fuel consumption by basically controlling and reducing of the boiler cycling. This makes the hybrid boiler a perfect solution for heating and domestic hot water to any home. Also, Hybrid Boilers work perfectly fine regardless of the outdoor temperature, this makes the hybrid boiler Suitable for any type of installation. They also have a high-efficiency rate and an Instant production by means of an external accumulator. Hybrid boilers can also be utilized in already existing plants or new designs. Other advantages of using a hybrid boiler:

  • Less Maintenance: hybrid boilers require less maintenance than regular boilers
  • Long Life-Span: The life-span of hybrid boilers is relatively long, reaching up to 50 years,
  • Costs

Gas prices are expected to continue to rise, however using a hybrid boiler may reduce the total reliance on extortionately priced fuel from energy companies. Users can expect to save up to 35% on main gas usage and up to 60% on liquefied petroleum gas. This makes hybrid boilers perfect for average families that wish to save money.

  • Disadvantages

  • High Upfront Cost: Hybrid Boilers have a large upfront cost however their oil saving and efficiency may cover their upfront costs in the long run.
  • Difficult to Install: Hybrid Boilers are fairly difficult to install considering them as being systems composed of two other sub-systems.
  • Significant Work: The installation process requires significant work and disruption to user’s house. Also, their maintenance is no easy task.

4) Conclusion

Just like any technology Hybrid Boilers may have their own disadvantages and drawbacks however their pros and benefits are far greater, making them hands down the best type of boiler out there. Environmentally friendly, economically, and safe to use in homes or any other place for that matter. That’s why possibly in the near future the replacement if older boilers by hybrid boilers will probably be mandatory in order to have a safer and healthier environment.

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