Gas boiler: tips for choosing and installing

Gas boilers are economical and easy to use. They are installed in buildings with a small area, and in large multi-storey buildings. Heating large cottages is not an easy task. It becomes more complicated in cases where the owners do not want to sacrifice precious meters for the arrangement of a separate room — a boiler room. The power of the wall appliance may not be enough. Especially if you use it to prepare hot water. Floor is allowed to be mounted only in a boiler room, isolated from other rooms. There are other important nuances that must be taken into account in order to choose the right gas boiler for heating your home.

Choosing a gas boiler and installation rules

Which type is better
Specifications
What is better to choose for the HVO system
Condensation problems and solutions
Safe Installation

Instrument design

According to the design of the device, there are two types.

convection

Convection appliances — consist of one heat exchanger, burner and electronics necessary for control.

Condensing

Condensing boilers have three heat exchangers. They make it possible to mix cold and hot water. As a result of this displacement, a condensation process occurs, in which useful energy is released.

What to look for when choosing a gas boiler

Efficiency and comfort level

Pay attention to how quickly the device heats up water and what is the level of noise produced by the equipment during operation.

economy

Perhaps every cottage owner seeks to reduce the cost of monthly maintenance and housekeeping. Therefore, we recommend paying attention to the design features of the equipment that contribute to savings. For example, for cooling in condensing circuits, a coolant returning from the heating system is used. Its temperature must be below 55 ° C — otherwise there will be no necessary cooling. Therefore, such equipment is effective only in low-temperature systems, and in conventional systems with a 90/70 mode, they are only 3-5% more economical.

For cooling, heat exchangers of improved design made of acid-resistant materials should be used. The condensate contains acids and other aggressive chemical compounds. This hot solution acts on the metal surface for years. The most commonly used materials are plastic, stainless steel, or an alloy of aluminum and silicon.

The maximum energy savings when using the heat of condensation is:

• during the combustion of natural gas is 11%;
• liquefied gas (propane-butane) — 9%;
• diesel fuel — 6%.

Equipment reliability

Be sure to specify what materials the main components are made of and what is their warranty period from the manufacturer.

For the reliability of the target, automation is also installed that accurately maintains the combustion mode, the temperature of the exhaust gases, water in the return line and other operating parameters.

Environmental friendliness

Learn how environmentally friendly the device is if you care about the ecology of your home and are aware of the importance of protecting the environment.

Ease of installation

The manufacturer is obliged to ensure that the installation does not cause difficulties.

When installing or replacing the device, it will be necessary to agree on a certain list of documents. When replacing with a similar one, there should be no problems associated with the coordination and proper operation of the system. In the case of its modernization, technical calculations will be required.

Outdated equipment can be replaced with a modern model with minimal material costs, since the hydraulic and gas connections are similar in location. The chimney may need to be replaced. In general, the design of the chimneys in both cases does not differ much. There are also features. In the first case, the material must be acid-resistant. The equipment is more expensive, but it is more economical.

Ease of controls

Management should be convenient, intuitive and not cause difficulties for the user.

How to choose a gas boiler for the home based on the characteristics?

The choice of model is primarily determined by the required power. Many manufacturers use built-in secondary heat exchangers and boilers for hot water preparation. In wall-mounted devices, the boiler is small. The volume of its tank is usually 30-40 liters. In outdoor appliances, it has a volume of 150-100 liters.

Need to figure out how to use water. Double-circuit models, unlike single-circuit ones, are completely universal. Single-circuit ones can also be used for HVO, but only if there is an additional boiler, which can be purchased separately.

Modern automation can greatly simplify the process of controlling equipment, including remotely. Electronics allows you to integrate devices into multi-component systems, consisting of the main and several auxiliary heat sources. Automation can control up to four heating circuits and two circuits for the preparation of hot water and a solar system.

For remote control, wall panels can be used, such as the Logamatic TC100 electronic thermostat (Buderus) or the Diematic VM ISystem control panel (De Dietrich). Communication with the regulator takes place using a low-voltage wire connection. The rest of the communications are carried out over the Wi-Fi network. To do this, the house must be equipped with a Wi-Fi router. It becomes possible to program operating modes depending on the time of day and days of the week, to correct the functioning of certain system components. Similar programs can be installed on a tablet computer or smartphone and control all home climate equipment via the Internet.

For rooms where people are often present, low noise level during operation is also important. For such rooms, it is recommended to choose appliances equipped with low-noise catalytic burners. They produce less noise than, for example, an extractor hood or a boiling kettle, which is very important for everyday comfort.

What to do with condensate

Condensate can have a damaging effect not only on the heat exchanger, but also on the inner surface of the chimney pipe. Therefore, when replacing a convection boiler with a condensing one, you will also have to redo the chimney, which is made of special materials. Modern technologies can significantly speed up and reduce the cost of the process. For example, a flexible sleeve is lowered into the chimney, which then fills the entire space under the action of hot air and hardens.

Against the use of such equipment, the argument is sometimes put forward that it is poorly compatible with radiator heating systems. Actually it is not. It works efficiently at coolant temperatures below 55 °C.

Even in radiator systems, it is far from always necessary to additionally heat the coolant. When outside the window is a cool autumn day and the first frosts, the coolant can be cooled to 55 ° C. In frost, it is better to warm it up to 90 ° C, but condensation in this case will no longer be possible. Even under these conditions, condensing technology is 1-3% more efficient than traditional technology.

The amount of moisture falling out is calculated according to the formula 0.14 kg per 1 kW / h. Thus, a 24 kW appliance produces approximately 40 liters at low temperature. To drain moisture containing chemically active components into the sewer, you will need to dilute it with water. The ideal ratio is 25:1, but 10:1 is acceptable. If there is a septic tank or the power of the equipment is high, it is necessary to neutralize the resulting solution. For this, a container with marble chips with a capacity of 5 to 40 kg is used. It is usually necessary to change the marble chips every few months. Devices are of two types: with a pump that creates pressure to raise the solution into the sewer system, and without a pump. The filler is changed only manually.

Safety during installation and operation

In addition to the process of choosing a gas boiler for heating a private house, conditions should be provided for its safe operation.

How to equip the installation site

The place of installation is regulated by the rules and regulations. A boiler room cannot be equipped in a house basement or a dark closet, since, according to the same standards, natural light and a window with a window of at least 0.5 m2 are required². According to fire regulations, a separate room with a total area of ​​at least 6 m is required². The ceiling height must be at least 2.5 m. The distance between the side wall of the housing and the wall must be at least 20 cm. This is required, first of all, for convenience during service.

It is not allowed to make a doorway less than 80 cm wide. To ensure its effective ventilation, the device is installed opposite the entrance opening at a short distance (usually no more than 2-3 m).

The ceiling should be sheathed with non-combustible material. It can be asbestos sheets or plaster based on gypsum mixtures.

The wall device is hung on a solid and blank wall without windows and doors. A solid wall is needed, because the weight of the equipment is at least several tens of kilograms. If the structure is made of foam concrete, it is better to choose the appropriate dowels for fasteners (for example, for cellular concrete). If the thickness of the bearing wall is insufficient, we can recommend anchor fasteners or through fastening. And when the internal partitions are mounted from plasterboard, it is better not to take risks and choose a model for floor mounting.

Ventilation holes must be provided for the atmospheric burner. When using it, special holes for ventilation are required. Their cross-sectional area must be at least 50 cm² for a device with a power of 23 kW and at least 100 cm3² at a power of 35-50 kW.

For floor models, a non-combustible base is required. It can be a concrete platform or a podium made of refractory plates. The podium is more convenient, since when using it, less dust enters the air intake. In this case, the device is installed at a distance of at least 100 mm from the wall.

Can it be installed in the kitchen

The kitchen needs a powerful extractor fan. It is better to hang the case as far as possible from the stove, especially if it is a model with an atmospheric burner. It consumes air directly from the room and it is desirable that grease and soot that are harmful to equipment do not get into it.

Is it allowed to build a boiler

It is forbidden to embed heating equipment in furniture sets. They cannot be decorated with panels and shields made of combustible materials. To finally figure out how to choose a gas boiler for your home, you need to decide on its appearance. It should become an organic part of the interior. Manufacturers pay a lot of attention to this aspect. There are models with a front panel made of shock-resistant glass in white or black.

• Source: Ideas for Your Home Magazine#205