Gas boilers are essential for maintaining a warm and comfortable environment in our homes. However, not every boiler is made equally. Open and closed system gas boilers are the two most common types that you may encounter. It’s critical to comprehend their distinctions in order to make well-informed decisions regarding the effective and efficient heating of your house.
Let’s begin with the fundamentals. Gas boilers with open or closed systems are made to heat water, which is then distributed throughout your house to create warmth. Their approaches to the procedure, though, are very different.
The feed and expansion tanks of open system gas boilers, commonly referred to as conventional or regular boilers, are typically found in the loft. When needed, these boilers can be used to heat water from the mains supply and store it in a hot water cylinder. The system can function safely because the open vent pipe lets go of extra pressure.
Closed system gas boilers, on the other hand, function without the requirement for a feed and expansion tank. Rather, they employ a sealed system in which heated water is pumped straight through underfloor heating systems or radiators. This closed-loop design does away with the requirement for a loft tank and reduces the chance of contaminated water.
The efficiency and performance of open and closed system gas boilers are two important distinctions between them. Because they retain water pressure better and lose less heat, closed system boilers are generally more energy-efficient. Lower energy costs and a cozier home are possible outcomes of this.
Installation and maintenance are additional crucial factors to take into account. The feed and expansion tanks for open system boilers need more room, and they also need to be checked frequently to make sure the system is operating properly and the tank is correctly topped off. On the other hand, because of their sealed system and compact design, closed system boilers are usually simpler to install and maintain.
Your unique heating requirements, your available space, and your budget will ultimately determine which type of gas boiler—an open or closed system—is best for you. Knowing the primary distinctions between these two kinds of boilers will help you make an informed choice that will guarantee your house remains warm and cozy throughout the entire year.
| Open Type Gas Boilers | Closed Type Gas Boilers |
| Exhaust gases are released directly into the atmosphere | Exhaust gases are expelled through a flue or chimney |
| Less efficient due to heat loss through the flue | More efficient as heat is retained within the system |
| Suitable for well-ventilated areas | Can be installed in areas with limited ventilation |
| Require more frequent maintenance | Generally require less maintenance |
| Lower initial cost | Higher initial cost |
Boiler with an open combustion chamber
An open-chamber gas boiler is a very basic apparatus. Its structural components are as follows:
- burner heating coil;
- coil, through the thin tubes of which the coolant flows;
- channels for collecting air from the street;
- no chimney to discharge the combustion products.
Certain models have the ability to include sensors, programmers, valves, and a circulation pump.
The coil is beneath the burner. The heating pipes receive heated water that is pumped there. In the event that the pump is not included in the design, the coolant moves through the system naturally. Fuel efficiency is increased while the heating rate is decreased.
The boiler’s operation can be managed by you thanks to automation. When the gas stops flowing or it reaches a certain temperature, it turns off.
In terms of operation, atmospheric boilers are similar to gas burners. They can only function when there is a natural draught. The room provides oxygen, and the chimney allows the combustion products to be released outside. A lack of air will result from inadequate draught, and there is a chance that fumes that enter the room could poison you. The following are some benefits of an open gas boiler:
- Models with a cast iron coil are very powerful and will last a long time;
- There is no dependence on electricity;
- reliable operation has been proven for decades;
- silent operation;
- does not require frequent maintenance;
- the price is many times lower than for a gas boiler with a closed chamber.
It is hard to avoid discussing the drawbacks of atmospheric boilers, particularly since for many people they can be the deciding factor when selecting heating equipment:
- large dimensions of boilers imply a separate, specially equipped room for installation;
- without good ventilation installation of boilers with an open chamber is impossible;
- Gas consumption is not as economical as with other devices;
- the boiler requires a chimney with a height of 6 meters or more, which complies with the necessary requirements of gas services.
The inability to install the open boiler in the apartment is its primary drawback. It is exclusively intended for use by private residences and companies, and it has a room just for them.
Boiler with closed combustion chamber
Closed boilers are an option for apartments and rooms lacking air circulation. These are relatively small devices that are made up of the following components:
- enclosures with a control panel;
- gas burner;
- heat exchanger;
- pump;
- temperature sensor and regulator;
- expansion tank;
- security systems;
- forced outlet for combustion products.
Additional coils, shut-off valves, and fans can be added to the boiler, depending on how many circuits it has.
The forced draught into the combustion zone is the reason closed-type devices function. A specialized fan is used to inject it. Since air is drawn from the street, a chimney and additional ventilation are not required. Coaxial pipes that exit to the street through a hole in the wall are used to remove smoke from the boiler.
Installing a coaxial chimney is less complicated than a traditional chimney. It’s built like a "pipe-in-pipe." It is led outside and laid through the wall. Air can circulate in two directions with this boiler design: it enters the boiler through the top and exits the room through the internal horizontal pipe. A coaxial chimney and a conventional chimney differ significantly. The following are the latter’s primary benefits:
- absolutely safe. The exhaust gases pass through a tube which is continuously cooled on all sides by cold air;
- environmental safety. Contributes to a more efficient combustion of fuel and increases the efficiency of the entire heating system;
- complete isolation of the system from the user. The exhaust gases, as well as the air itself, are not in any way in contact with the living space.
In terms of comparison, the closed-type gas boilers perform better than the open design:
- Do not require a separate room for installation and arrangement of a vertical chimney;
- compact size allows you to place them in the bathroom, toilet or kitchen;
- there is no need to constantly ventilate the room, thus releasing warm air to the outside;
- there is a choice between wall and floor models, the design of which will fit perfectly into any interior;
- it is possible to set the required temperature parameters;
- no resources are wasted, all fuel is burned to completion;
- operation is powered by electricity and does not depend on the presence of oxygen.
The following are some drawbacks of closed boilers:
- high cost compared to open heating devices;
- periodic maintenance, lubrication of the fan blades, inspection of the turbine;
- to avoid freezing of the combustion area it is necessary to equip the system with automatic gate valves and a temperature controller;
- operation of the turbine creates noise, which increases with the wear of the bushings and contamination of the fan blades;
It is up to each individual whether or not to favor a closed device because substantial fuel savings raise the price of electricity needed to keep the boiler running.
Knowing the differences between open and closed type gas boilers is essential for efficiently heating your home. Although simpler and less expensive, open type boilers require the room’s air to be burned, which may have an impact on the quality of the air inside. Closed type boilers, on the other hand, provide greater safety and efficiency because they have a sealed system that draws air from the outside and expels exhaust outside.
Their needs for ventilation are one of the primary differences. Since open-type boilers depend on natural ventilation, the space in which they are installed must always be supplied with air. If the room is not adequately ventilated, this may result in heat loss and possible safety risks. On the other hand, closed type boilers have a sealed combustion chamber, which lowers the possibility of carbon monoxide leaks and increases energy efficiency.
Furthermore, compared to their open counterparts, closed type boilers frequently have higher energy efficiency. They can maintain a more steady combustion process and ultimately achieve higher efficiency and lower energy costs by drawing air from the outside. Because of this, they are a popular option among homeowners who want to lower their energy expenses and their carbon footprint.
Furthermore, there is more installation location flexibility with closed type boilers. They can be installed in a larger range of spaces, including utility rooms and basements, without sacrificing safety or efficiency because they don’t rely on room air for combustion. For homeowners with specific installation requirements or limited space, this flexibility can be especially helpful.
In summary, although the function of both open and closed type gas boilers is to heat your home, performance, safety, and energy efficiency can all be greatly impacted by the variations in their construction and use. With their unique benefits in energy efficiency, installation flexibility, and ventilation, closed type boilers are the boiler of choice for many homeowners looking for dependable and effective heating solutions.
Gaining an understanding of the basic differences between open and closed-type gas boilers for your home is essential. Because open-type boilers use the surrounding air to fuel their combustion, they require adequate ventilation and may lose some heat. Closed-type boilers, on the other hand, draw air from the outside and release exhaust through a flue because they have a sealed combustion chamber. Closed-type boilers are safer and more efficient because of their design, which reduces the possibility of carbon monoxide leaks. Closed-type boilers also save energy and create a more comfortable home environment because they are generally quieter and more adept at holding onto heat.
