Economical heating boilers: selection rules, rating of the best models

Back

Published: 06/12/2019

Reading time: 4 min

0

1376

Over the past 30 years, the market price of gas fuel has been constantly growing. Economists explain this trend by two factors. The first is inflation caused by a decrease in the purchasing power of the dollar; since 1975 it has fallen almost 4 times.

The second is the growth of the world population, which over the same period increased from 4.4 billion to 7.2 billion people. At the same time, there are no more energy resources themselves, but on the contrary, there are fewer and fewer of them.

In an era of high gas tariffs, people are not willing to pay a lot for gas fuel for individual heating and therefore they are looking for the most economical gas heating boiler in the retail chain.

There are many types of boilers

A prudent owner will try to figure out on his own which gas boiler is the most economical and reliable, so as not to fall for the trick of dishonest sellers who need to sell stale equipment.

• 1 What affects the efficiency of the boiler
• 2 Rating of the most economical gas boilers

Choosing a gas heating boiler

Let's start with the fact that on the modern market there is a huge variety of heating boilers that run on natural gas. They differ from each other not only in technical and operational characteristics, but also in purely design features. Therefore, we will compare boilers according to different positions, and then provide a rating of gas boilers.

Floor or wall mounted boiler

From the names of the two gas units it is clear that one is installed on the floor, the second is hung on the wall. But this is not the only difference between them.

Firstly, wall-mounted models are low-power compared to floor-mounted ones. Therefore, they are installed in small private houses. Although there is an option when one floor-standing unit is replaced with two or three wall-mounted units, connecting them to different heating circuits. This type of heating system is often used in large houses with several floors. That is, the owner has the opportunity to weakly heat that part of the house where people are rarely present, which leads to significant savings in gas fees.

Gas boiler: floor or wall mounted Source gazblog.ru

Wall-mounted boilers have a small weight - no more than 80 kg. The reason is because they are wall mounted. As for power, it does not exceed 35 kW, and the tank capacity does not exceed 40 liters. That is, this is an excellent option for a house with a total heated area of ​​100-120 m². But wall-mounted models have two more significant advantages:

1. There is no need to organize a separate boiler room for it. Any utility room will do.
2. In this case, all wall-mounted units are equipped with a closed combustion chamber. That is, their design includes a coaxial chimney, which is built into the wall where the boiler itself is located. The chimney simply sticks out on the street from the wall of the house in a horizontal position.

In this regard, floor-standing appliances are heavier. Their minimum weight is 100 kg. They are more powerful in terms of generating thermal energy and are larger in size. Therefore, they can only be installed in premises that meet the requirements of specialized SNiP. That is, such premises must comply with standard dimensions: ceiling height, height of the foundation on which the boiler is installed. A very important parameter is the air exchange rate. That is, there are a lot of problems with the floor-standing unit.

Wall-mounted models powered by gas Source demo.landistore.com

Plus, these models are mainly equipped with open-type combustion chambers. Therefore, it is necessary to install a properly designed chimney for them. And the air flow must be appropriate.

But it should be noted that wall-mounted gas boilers have a thin spot - this is the heat exchanger. It is made of either steel or copper. The second option is expensive, but it will last two or three times longer than steel. Why - because condensation will constantly form on the steel heat exchanger, which leads to corrosion processes. And this is a serious minus.

As for floor-type heat exchangers, they are made of cast iron. After all, the weight of the unit as such does not matter here. There is no need to broadcast it on the wall. And cast iron will serve faithfully for decades. So in this regard, floor-standing models are better.

It is clear that in terms of price, wall-mounted ones are preferable. In addition, it should be added that they are equipped with both a circulation pump and an expansion tank. That is, all this is already included in the cost of heating equipment. For floor-mounted ones, both elements will have to be purchased separately. And this is another additional expense item.

Copper heat exchanger for gas boiler Source static.wixstatic.com

Connecting a gas boiler, both floor-mounted and wall-mounted, is not the easiest process. In this regard they are equal. The main thing is no amateur performance. This should be done by professionals.

Single or double circuit boiler

What is the difference between a double-circuit gas boiler for heating a private house and a single-circuit one? Let's start with the last one. This is a classic heating option. It contains one heat exchanger, which heats the water circulating through the heating system.

Double-circuit gas boilers are designed for heating and hot water supply. They have two circuits, two heat exchangers, hence the name. But it should be noted that heating water for a hot water supply system can be done differently in different models. Manufacturers of gas boilers use three options:

1. A flow-through heating element is used.
2. A separate heating tank is installed in the boiler body.
3. A boiler is installed next to the boiler.

Now about the choice. It would seem that the optimal solution is to choose a double-circuit gas boiler for heating for a large house, and a single-circuit gas boiler for a small house. But it's not that simple.

Double-circuit gas boiler with two heat exchangers Source koffkindom.ru

The operating principle of a double-circuit gas boiler is as follows: two circuits cannot operate simultaneously. That is, when the hot water supply system is turned on for consumption, the circuit to the heating system is turned off. This is done in order to increase the efficiency of water heating in the DHW system. It turns out that while you are bathing in the bath or taking a shower, the heating radiators in your house are gradually cooling down.

Another situation often happens. You are taking a shower, and your wife decided to wash the dishes. The result is that you get a contrast shower, when either hot or cold water flows from the watering can. It may not be possible to solve the problem by purchasing a more powerful double-circuit gas boiler. An accurate calculation of both the heating system and hot water supply will be required regarding hot water consumption.

There is a way out - install one or more single-circuit gas boilers for heating, and use a boiler for the hot water system. The latter is selected by volume. For example, if this parameter is 200 liters, then it is enough for a family of 5-6 people. The boiler itself is a heat-insulated steel container in which a coil is installed that acts as a heat exchanger. It is connected to the heating system, so there will always be hot water in the house.

Single-circuit wall-mounted gas boiler with boiler Source oteple.com

But compared to double-circuit gas boilers for heating and hot water, this combination will be more expensive. In addition, you will have to organize a separate room for it.

And one more drawback. The practice of operating double-circuit boilers shows that often, due to increased water hardness, the DHW heat exchanger quickly fails. And its repair is almost 50% of the cost of the entire boiler.

If we think sensibly, then the optimal solution for installing double-circuit floor and wall-mounted gas boilers for heating and hot water would be a small private house.

See also: Catalog of popular house designs for year-round use

Convection or condensation boiler

Scientific and technological progress has recently presented a large number of technologies and materials. He did not bypass heating units either. Therefore, today there are two types of gas boilers on the market, which are based on different heating methods. This is the traditional option, also known as convection and condensation.

How does a regular gas boiler work? Natural gas burns in the firebox, which heats the heat exchanger, inside which water moves. In this case, the burned fuel releases a certain amount of thermal energy, which is not completely used by the boiler. She simply flies out into the street through the chimney. Hence the efficiency of such devices is no higher than 90%.

Gas condensing boiler Source www.vaillant.info

Condensation models differ in design in that they have two chambers. In one, fuel burns, in the other, carbon monoxide and excess heat condense on the surface of the heat exchanger. The condensation process is accompanied by the release of thermal energy, which increases the heating temperature of the heating water.

It should be noted that condensing units are economical. And it would seem that replacing convection heating devices with condensing ones will lead to significant savings in natural gas. But here, too, not everything is so simple.

Condensate from burnt gas is a chemically active liquid. Not any material can withstand it. This means that both the heat exchanger and the chimney must be made of appropriate materials. And this leads to higher prices for heating equipment. In addition, the condensate will need to be drained somewhere. Problems can arise here too.

For example, active liquid cannot be drained into a septic tank or sewer. This means that additional equipment will be needed to neutralize the condensate. Plus, you can’t do without consumables here either.

Operating principle of a condensing boiler Source teploknam.ru

There is one more nuance that will have to be taken into account when purchasing a condensing gas boiler. It does not work well in high temperature heating systems. Usually this is a radiator option. The thing is that the outlet water temperature is +50C. In contact with the heat exchanger, where the water is not lower than the indicated value, condensation occurs weakly. This means that thermal energy will be released weakly. That is, the efficiency of the unit will decrease. It will be good, but not maximum.

But if the system has a heated floor, then condensation models here will show themselves in the best possible way. Because this type of heating requires water with a temperature of no more than 30-35C. Therefore, the condensation process on the heat exchanger will occur more efficiently.

That is why manufacturers of condensing boilers indicate two efficiencies in their data sheets: for a system with a temperature of 30-50C and for a system with a temperature of 30-50C and for 50-80C. That is, it turns out that if the question is which type to choose from the two indicated above, then everything will depend on what type of heating is installed or planned to be installed in the house.

Which boiler is more economical: evaluation of different heaters

Gas, electric, solid fuel series - each of them contains conditions that reduce the degree of efficiency in terms of associated costs. In this same aspect, alternative heat sources should be cited - not all of them are as convenient as manufacturers claim.

Gas boilers

Cheap gas-air systems are rightfully considered the most profitable heating option, but only if the gas pipeline is located in close proximity. The further the highway is, the more expensive the installation work will be.

Wall-mounted double-circuit gas boiler

In the context of a steady decrease in natural fuel reserves, a continuous increase in tariffs is predicted, so there is no guarantee that in the near future the rationality of this method will not be called into question.

Electrical equipment

Thanks to the efforts of marketers, electric boilers are becoming significant competitors to gas boilers in the niche of economical heat sources. But this alternative is also systematically becoming more expensive, which causes healthy skepticism among consumers.

The introduction of an electric boiler into a boiler room can still be justified in special cases: when there are subsidies and benefits, in villages where reduced electricity tariffs are used. The main advantage of the solution is comfortable conditions of use at a relatively low cost of the unit; it does not require constant maintenance. The downside is complete energy dependence, which is undesirable for populated areas with frequent power outages.

Solid fuel boilers

Unlike the two previous options, this method can be completely autonomous. But here, too, fuel becomes more expensive every year - due to the depletion of coal mines and intensive deforestation, high demand for raw materials in light of rising tariffs for gas and electricity. The use of classic wood and coal boilers is justified only in regions rich in wood.

Unlike traditional variations with high consumption of raw materials and low efficiency, long-burning boilers and pyrolysis models do not require constant replenishment of the firebox. They are 3-4 times more economical than gas heating systems; they operate on traditional fuel, pellets and briquettes; one stack can burn for 3-5 days.

Various solid fuel boilers

Recycling heating boilers also perform well - they are “omnivorous”, recycling plastic, industrial waste, rubber, and ordinary garbage. They will help you survive even in conditions of complete absence of usual energy sources, and will function fully if there is a landfill or tire waste nearby. But they are not safe from an environmental point of view - the resulting smoke will contain toxic compounds.

Alternative heat sources

Options in which you do not need to spend money on fuel to maintain a healthy microclimate in your home are associated by many as the most economical. In fact, the degree of efficiency is determined by the type of equipment.

Fashionable solar collectors in domestic latitudes can only be considered as additional sources of energy. In winter they are not as productive due to worsening weather.

Heat pumps are another expensive innovative technology; it is based on the use of heat from water, soil, and the bowels of the earth. Such systems fully pay for themselves after 10-12 years of operation. In this case, functional pipes are installed on a large plot of land where it is impossible to set up a garden or build on it.

Rating of gas boilers

So, let's move on to the rating of the best gas boilers for heating a private home. Let's start with the wall ones.

Wall mounted

Which is the best wall-mounted double-circuit gas boiler is a difficult question, because there are a huge number of manufacturers working in this area who have long proven themselves on the positive side. And yet we will try.

See also: Catalog of companies that specialize in autonomous gasification

Bosch Gaz 7000 W MFA

The German manufacturer offers a unique unit that can operate on both natural and liquefied gas. The line also includes single-circuit models. Boiler power is from 24 to 33 kW.

Design features:

• ceramic monothermal heat exchanger;
• stainless steel burner;
• electronic ignition;
• two water heating modes: “eco” – when water is needed as needed, “comfort” – maximum heating;
• you can connect the boiler through a three-way valve;
• automatic system, with which you don’t have to worry about thermal inertia;
• Efficiency – 91%.

Gas boilers from BOSCH Source stroy-podskazka.ru

Baxi Eco Four

This is a representative of Italian production. It can also run on both liquefied and natural gas. The manufacturer produces two power models: 14 and 24 kW.

Design features:

• copper heat exchanger;
• heat exchanger for domestic hot water made of stainless steel;
• The burner is made of the same material;
• there is an automatic system that protects the boiler from freezing and blocking;
• sensor responsible for water movement;
• automatic bypass;
• weather-compensated automation;
• electronic self-diagnosis;
• flame modulation – electronic.

Gas boiler Baxi Source krayinatepla.com

Vaillant turboTEC plus VU INT

This is another German whose power varies in the range of 12-36 kW. These are single-circuit models with a closed fuel combustion chamber.

Design differences:

• copper heat exchanger;
• chromium-nickel steel burner;
• step circulation pump;
• automatic air vent;
• equipment freeze protection system;
• electronic ignition;
• Efficiency is above 91%.

Boiler from the Vaillant company Source kak.znate.ru

Rating of the most economical models

Let's look at the 5 most economical models of heating boilers.

ARISTON

The Italian ARISTON GENUS PREMIUM EVO 24 FF is the most economical gas boiler. The double-circuit condensing-type unit consumes less fuel compared to its competitors, while its efficiency reaches 108%. The wall-mounted model is efficient, compact, and has high power. Innovative automation is responsible for optimizing the operation of the heating system. The downside is the high cost of the boiler.

NAVIEN

The South Korean NAVIEN GA 35KN will cost almost twice as much. The double-circuit convection boiler is designed to serve buildings whose area does not exceed 350 square meters. m, it is actively used for heating and providing hot water supply in offices, homes and retail outlets. The efficiency of the floor-standing device is just over 91%; per hour it consumes about 3.4 cubic meters. m of gas. The automation is powered from a single-phase power supply.

Vaillant

In third place is a single-circuit electric boiler from the middle price segment - Vaillant eloBLOCK VE 12. The device with an efficiency of 99% operates from a three-phase network, the serviced area is within 120 square meters. m. Economical energy consumption is ensured by such processes as a smooth increase in power, a summer operating scenario, an anti-freeze option, weather-dependent and remote control.

Lemax

The fourth place is occupied by the domestic Lemax Premium-10, sold in the budget segment. A single-circuit gas boiler allows you to fully heat houses of 100 square meters. m, hourly gas consumption does not exceed 0.6 cubic meters. m, one cannot fail to note the high efficiency for this class - 90%. The device is independent of the electrical network, it is compact and safe, and Italian gas burner components are responsible for optimizing its operation.

ACV

In fifth place is the ACV E-Tech S 240 - a premium Belgian double-circuit electric boiler with an efficiency of 99%. A powerful unit will take care of heating a large house and supplying hot water, and built-in electronics will minimize energy consumption. The equipment operates almost silently and attracts users with its versatility.

In order to make full use of the presented equipment and not overpay for resources, you need, in addition to choosing an economical boiler, to take care in advance of the competent design of the heating system. Professional installation of equipment and complete insulation of the building will help minimize heat loss, rationalize boiler room management and maintain an optimal microclimate.

Video description

In the video, a specialist talks about the Protherm Panther KTV wall-mounted boiler:

Floor standing gas boilers

They are presented on the market from the same manufacturers, so the range is wide. And yet we have to choose the best floor-standing double-circuit gas boiler.

Vaillant atmoVIT VK INT

First place again goes to German equipment. There are several types in the model range of this unit, differing from each other in power. This figure varies in the range of 16-56 kW. Basically, a boiler is required to heat hot water, but one model has an instantaneous heater installed inside.

Boiler features:

• atmospheric injection burner without fan;
• cast iron heat exchanger;
• Efficiency 92%;
• flame, temperature and draft control sensors.

Boiler Vaillant atmoVIT VK INT Source mostszh.ru

Viessmann Vitogas 100-F 29-60

This brand is one of the most extensive in terms of model range. It contains 15 models with a power from 29 to 60 kW, which is very convenient if you need to select the required unit. Experts say that if the consumer is faced with the task of choosing an economical gas boiler, then this is it.

Moreover, all models easily cope with gas pressure differences in the main pipeline. That is, it is not a problem for them.

Design features:

• the burner is made of stainless steel, it is rod type;
• heat exchanger made of gray cast iron;
• full automation of equipment;
• gas control relay.

Viessmann Vitogas floor standing boilers Source static.wixstatic.com

Gas consumption calculation method

Let us calculate the gas consumption for heating a house with an area of ​​approximately 100-140 m2. The main parameter is the minimum permissible gas pressure in the boiler.

Direct calculation of liquefied gas consumption

Since the cylinder (depending on the refiller and the season) contains from 35 to 42 liters. gas (on average 22 kg), then refilling will cost you approximately 12 - 20 rubles. per liter, which will be 420 - 840 rubles. per cylinder.

Conventional liquefied gas cylinders

With an average boiler consumption of 0.12 kg of gas/hour per 1 kW of heat for a 12-15 kW boiler, the gas consumption rate for heating will be about 1.2-1.7 kg/hour.

This power is quite enough to heat a room with an area of ​​100-140 m2.

If our boiler functioned at maximum all the time, the consumption would be:

1.7*24=40.8 kg of gas, or almost 2 cylinders per day

The amount will be

(420 – 840)*2 = 840 – 1680 RUR,

And this is naturally not beneficial for the owner.

But since gas heating boilers, with proper settings, selection of all components of the system and the absence of large heat leaks, consume many times less gas (about 3-4 times), then to maintain an acceptable temperature throughout the house, gas costs are significantly reduced.

Calculation results for the week

Therefore, in a house with an area of ​​100-140 m2, normally insulated, with windows of good quality, without obvious cracks and cracks, at an outside temperature of -18 -23 degrees, and inside the house about 21-23 degrees, the average gas consumption for heating the house will be about 10-13 kg in one day (half a regular cylinder).

Gas holder - an alternative to conventional cylinders

This means that gas consumption for heating is 1 standard cylinder for 2 days. From the experience of those who have been using such a heating system for a long time, it is clear that at 21-23 degrees in the house and the presence of hot water in the bathroom and kitchen, you will use only 3-4 gas cylinders per week (1700-3300 rubles).

Methods and ways to reduce costs

There are instructions and many videos on the Internet on how to reduce costs. As the calculation of gas consumption for heating shows, the total cost reaches 3000 rubles.

But it can be significantly reduced. To do this, you can install an automatic system that reduces the temperature at night, during your sleep (naturally, the amount of gas burned is also reduced).

Those who have already acquired such systems confirm that if from 12-00 at night to 8 a.m. the temperature is lowered by 6-7 degrees, this will reduce gas costs by about one third.

This means that you will consume only two cylinders of gas per week (RUB 840-1,700).

But this is not the limit. You don’t have to buy automatic equipment and regulate the gas supply yourself at night.

This will reduce the cost of wiring hoses, and you can make a box for cylinders yourself or order it. Two options for cylinder locations are shown in the photo

Calculation of gas consumption and costs for the heating season

As can be seen from the previous calculation and based on ways to reduce the cost of heating a house with automation, it takes about 10 cylinders per month.

For example, if you go to the dacha only on weekends and holidays, then over the entire heating season (from October to April) there are 30-35 days - a little more than a month.

Valliant LPG boiler

Let's calculate the consumption of liquefied gas for heating the house for the entire season.

1. Calculation without the use of automation (temperature +22, does not decrease at night)

(З0-35)/2=15-17 cylinders per season

(15-17)*840=12600-14280 per season

2. Calculation with an automatic timer (night temperature drops to 12-15 degrees)

(10-11)*840=8400-9240 per season

The difference is over $100.

Condensing units

I would like to indicate the rating of condensing boilers. In today's market, their range is increasing. All manufacturers try not to miss the opportunity to prove that they remain in trend. But even the most famous companies do not always manage to create the best boiler. That's why you won't see many of them in our ranking.

De Dietrich Innovens PRO MCA

Oddly enough, the French take first place. The reasons are that their boilers are the best in terms of operating efficiency, safe operation requirements, productivity, and energy saving. The power of the units varies from 43 to 114 kW. All models belong to the “wall-mounted” category.

Design features:

• the heat exchanger is made of an alloy of aluminum and silicon, and it has a monoblock design;
• steel burner;
• composite body insulation;
• self-diagnosis system;
• full automation;
• condensate is collected in a special siphon;
• There is a backlight inside, which is very convenient when servicing the boiler;
• sensor showing the temperature of the exhaust gases;
• Efficiency 102.5%.

Wall-mounted condensing boilers from De Dietrich Source sanitech-instalacje.pl

Viessmann Vitodens 100-W

In the model line of this brand there are both single- and double-circuit heating devices with a power of 19-35 kW. An interesting fact is that in the category of gas-fired condensing boilers, these are the cheapest.

Design Features:

• heat exchanger made of stainless steel;
• the burner is steel, it is cylindrical in shape;
• the air is driven into the firebox by a fan, and if you correctly configure it in terms of rotation speed, you can save a lot on fuel consumption;
• the exhaust gases have a very low content of harmful substances;
• protective systems against freezing and overheating;
• convenient arrangement of parts and assemblies in the body;
• Efficiency 108%.

Gas boiler Viessmann Vitodens 100-W: appearance and inside Source www.v-store.ro

Vailliant ecoTEC plus VU OE

This manufacturer has only two models with a power of either 45 or 65 kW. Advantages: high environmental friendliness and cost-effectiveness. Both models are single-circuit, but it is possible to connect a boiler to them. Boilers can only be used in low-temperature heating systems. In Germany they are installed on the roofs of private houses.

Peculiarities:

• Efficiency – 109%, that is, the highest efficiency;
• burner adjustable in power within 28-100%;
• full automatic;
• circulation pump – two-stage with the possibility of manual or automatic switching;
• fan with adjustable rotation speed.