Choosing a gas column for heating water

The gas water heater is a flow-through water heater operating on natural gas. If you do not have hot water supply, but gas is supplied, this equipment will increase the comfort of your life. You just open the tap, hot water runs out of it, and its temperature is regulated by you yourself. Even if you have a centralized hot water supply in your house or apartment, but you are not satisfied with the price you have to pay for heating, or, perhaps, you are not happy with the temperature, installing a gas water heater will also solve these problems. Heating water costs much less than it is provided centrally - this is a significant saving on utility bills. To understand which gas water heater is better, you will have to study the structure of the equipment and its types. Then the choice for you will be simple and deliberate.

Which gas water heater is better depends on your requirements

The structure of the gas column

Flow-through gas water heaters consist of three main units:

• gas burner device and gas evacuation system;
• heat exchanger;
• ignition and control module.

The structure of a water heating column with piezo ignition

All these nodes have several modifications and their layout gives different models with different characteristics. All this allows you to choose a unit for your own requirements, because to say which gas water heater is better can only be tied to a specific situation.

Type of ignition

In order for the column to start its work, it is necessary to ignite the gas. Old models were lit by hand, holding a burning match to the igniter. Today, such units are no longer on sale, they are a thing of the past. They were replaced by others who work in automatic or semi-automatic mode.

Piezo ignition

In geysers with a piezoelectric element, ignition occurs in a semi-automatic mode. There are two burners - main and pilot. A pilot burner is a small wick that burns continuously, whether hot water is flowing or not. The main burner only turns on when the tap opens. The rest of the time it is off.

The procedure for starting a gas water heater with piezo ignition is simple: press the button displayed on the front panel, a spark appears on the candles, which ignites the pilot burner. When the hot water tap opens, gas is supplied to the main burner, ignition occurs from the pilot. While the water is running, both burners are on. The valve was closed, the gas supply to the main one was stopped, only the pilot one is on again.

Piezo ignition device for gas water heaters - a simple and inexpensive device

What are the advantages of geysers with piezoelectric elements? These are the cheapest models, they usually have mechanical control - a regulator that allows you to change the height of the flame, thereby regulating the temperature of hot water. These models are non-volatile, which can be important for a summer residence.

There are more disadvantages and they are more serious. The wick burns (should burn) constantly while you use the column, and this is the gas consumption. Let it be small, but constant, as a result, quite a decent amount accumulates in a month. So this is far from the most economical way to heat water. The second minus is also associated with the burning of the wick. If it goes out, you will not be able to light the column. The wick goes out because it does not have enough oxygen for combustion, or because a back draft periodically occurs in the chimney, which blows out the flame. Since there is a flame controller, this is not a big deal - the gas is cut off automatically, but having to re-ignite the pilot burner is unpleasant.

Electric ignition

Automatic gas water heaters have electric ignition.This is an electric spark generator that is activated when the tap is opened. The rest of the time the gas does not burn, which significantly saves fuel. There is an electric ignition that runs on batteries, there is - from a 220 V network. Which gas water heater is better for this parameter should be chosen according to the circumstances.

If your lights are often turned off, it makes sense to choose a model that runs on batteries. As you can imagine, in this case you have to make sure that they do not "sit down." If there are no problems with electricity or there is a backup power source, it is better to choose a gas water heater operating from a 220 V network. Once they plugged the cord into the outlet and forgot about it. Electricity consumption is scanty, so they have almost no effect on bills.

Electric firing is controlled by a microprocessor

Automatic geysers are electronically controlled. A board with a microprocessor is installed in the case, the desired temperature is set from a small control panel (push-button or touch) A small liquid crystal screen is often installed right there, which displays the current state of the equipment, the temperature of the water, if it is heated. This type of gas water heater is the best if you value ease of use.

Disadvantages - higher price and power requirements. Electronics needs a stable voltage of 220 V with small deviations of the order of 2 * 3 V. We do not maintain such parameters, so in order for the automatic gas water heater to work for a long time, a stabilizer is required, and it is better not a relay, but an electronic one. It not only stabilizes the voltage, but also equalizes the shape of the impulses, which is also very important for imported water heating columns.

Burner, combustion chamber, chimney

The heating of water in the gas column occurs due to the heat released during the combustion of gas. The combustion itself takes place in the burner, and it is "packed" into the combustion chamber. Unburned gases that remain in the chamber are discharged through the chimney. Let's consider all these devices in more detail.

Burner - main unit

Burner

The heat source in the gas column is a gas burner. There are three types of them: one-stage, two-stage, modulating. The first two types have almost never been found recently - they do not allow maintaining the set temperature, therefore it makes no sense to consider them - all columns have a modulating burner.

It looks like a gas burner for a column in the installed form

Modulated burners can be controlled manually - with a special handle installed on the body - or through a microprocessor that maintains the set water temperature. Burners are made mainly of galvanized steel, as this material is optimal for the performance of the tasks. It is inexpensive, durable, has a high melting point, and tolerates frequent heating.

Types of combustion chamber and chimney

Combustion chambers in gas columns are of two types - open and closed. Their name reflects the essence:

• closed (turbocharged, ventilated) is a metal box into which a burner is inserted with a bell at the top for installing a chimney;
• open (atmospheric) - this is actually the entire column body, since there is no isolated space, just a burner is installed in a certain place, there is a cover with a bell on top, to which the chimney is connected.

Different types of combustion chambers require a different chimney. In an open chamber, air is drawn from the room, therefore, an effective ventilation system, a normal air flow and an atmospheric chimney that goes into the ventilation duct are needed. The closed chamber is equipped with a coaxial chimney (two pipes of different diameters, inserted one into the other), which is led out through the wall to the street. In this case, the combustion products are discharged forcibly, with the help of a fan, through the inner pipe, and oxygen flows directly to the burner through the outer pipe.

Open and closed combustion chambers near gas columns require the installation of a different type of chimney

A geyser with a closed combustion chamber works more stably under normal conditions, but it has drawbacks. The chimney can become covered with frost in winter, because of which the column goes out (it is extinguished by the automation that controls the removal of combustion products). The second point - with a strong crosswind, the air stream can blow out the flame. The gas supply is turned off by the same automatic equipment, but the situation is unpleasant. The third circumstance is that not all city authorities allow holes in the walls of houses and pipes.

So in this case it is difficult to say for sure which gas water heater is better - it depends on many factors.

Heat exchanger

The water is heated while it flows through the heat exchanger. It is a metal pipe installed above the burner. The shape of the heat exchanger in the gas column is special - in the lower part a pipe with ribbing is laid in a snake, then a sheet of metal is installed around it, on top of which the pipe is wound with a spiral. Water flowing through this long path is heated by the heated metal.

It looks like a heat exchanger for a gas column

Heat exchangers are made of galvanized steel (the cheapest option), stainless steel and copper. The best ones in terms of efficient heat transfer are copper. They are the most economical, but also expensive. The most durable ones are stainless, but they have much worse heat transfer. Which gas water heater is better in this case is up to you. Choose the quality that is more important to you.

If you decide to buy a gas water heater with a copper heat exchanger, do not try to find a cheap model. In order to reduce the price, manufacturers use low-quality copper, and even tubes are made with thin walls. Such a heat exchanger will serve the warranty period, and then problems begin - a leak will appear.

If you remove the cover, you will see fistulas in the tubes through which water drips. They are located mostly on the outside of the pipe, just in the place where condensation forms. With normal pipe thickness, this is not terrible, but thin walls quickly corrode. Such a heat exchanger with a leak does not have to be replaced (it costs about 1/3 of the total price), it can be soldered. You will need a refractory solder with a melting point of about 200 ° C, a powerful soldering iron and a soldering flux. The technology of work is usual - clean the damaged area to clean metal, degrease, tin, solder.

How to determine power

First of all, you need to decide on the power or performance of the gas column. These are two interrelated characteristics, simply reflecting different characteristics of the unit. Productivity is how many liters of water per minute the column can heat, and power is how much heat it can generate. Some manufacturers indicate power, others - performance, so you need to understand exactly what you need.

Let's first figure out what kind of performance you need a gas water heater. It depends on the number of consumers that need to be provided with warm water. There are consumption rates for different types of equipment:

• kitchen sink, washbasin - 4 l / min;
• shower - 7-10 l / min.
  

  The higher the power, the larger the dimensions

If you have a kitchen sink, shower and washbasin connected to hot water, so that all three points work simultaneously and the water temperature does not drop, you need a capacity of 4 + 4 + 10 = 18 l / min. This is a lot, the price tag will be solid. If you think about it, you will realize that all three devices almost never turn on at the same time. There are situations when a shower and one of the taps work together. To provide them with hot water, the capacity should be 14 l / min. This is already a little more modest, but quite enough for a comfortable stay. Look for the found value in the technical specifications, it should not be less.

Now let's figure out the power. Geysers can generate from 6 kW to 40 kW of heat for water heating. Here the division is:

• a gas water heater with a capacity of up to 19 kW is suitable for heating water for one tap;
• for two points, the power should be from 20 kW to 28 kW;
• three require more than 29 kW.

Now, you can say for sure which gas water heater is better in terms of power in relation to your needs.

What else to look for when choosing

There are several more lines in the technical characteristics of gas water heaters that are worth paying attention to. First, see the minimum water and gas pressure that this model can handle. Imported gas water heaters of European manufacturers are more capricious in this regard - they are designed for stable pressure, they do not tolerate changes well. But under normal conditions, they work stably and without breakdowns.

Some manufacturers, in order to adapt their equipment to our conditions, put gearboxes that compensate for surges. If the model you like does not have such a device, and your water and / or gas pressure jumps, you can install the reducer on before entering the column. The device is simply put into a pipe rupture, the installation is standard. At the same time, other consumers will be protected with you.

Operation parameters must be monitored

It is also helpful to review the list of utilities and protection levels. The safety and comfort of the equipment depends on them. It is highly desirable to have the following functionality:

• Gas control. Monitors the presence of a flame on the burner, if it goes out, cuts off the gas supply.
• Traction control. The presence of draft in the chimney is monitored. If no combustion products are discharged, the gas supply is shut off.
• Flow control or hydraulic valve. Turns off the column if the water pressure is too weak or not at all.
• Overheat protection. The temperature sensor controls the temperature of the water in the heat exchanger; when it approaches the critical point (boiling), it turns off the column. This prolongs the life of the equipment (when boiling, the heat exchanger can burst, like pipes).

These functions are necessary for the safe operation of the gas water heater. This is almost the standard set found in all good gas water heaters. All others are optional. They, as a rule, are no longer so critical (for example, the remote control).

Dimensions of gas columns and prices

The overall dimensions of gas water heaters are small - they are commensurate with a small hinged kitchen cabinet. Average height - 550-650 mm, width 300-400 mm, depth 200-300 mm. But if you wish, you can find models that are wide and flat, or vice versa, narrow and deep. Which gas water heater is better for this parameter can be said only by being tied to the installation site, so there is no definite answer here either.

Colors may be different

Gas heater prices vary widely. Simple models with piezo ignition and a galvanized burner start at $ 110. Equipment with electric ignition and a bunch of service functions - up to $ 450. So there is where to roam.