Which is better, electric water heater or gas water heater?

Now that I'm here, let's list the advantages and disadvantages of various water heaters for your reference ~

Friends who are still worried about buying water heaters, it is enough to read this article ~

It's long, but it's all dry goods. Students who want to be lazy can go straight to the end to see the summary, and give me a compliment by the way. ( ? )

The following content comes from the design of APP User @ Zero Space, and some pictures come from the network.

Although water heaters are common household appliances, they are often difficult to choose. Coincidentally, LEON's family recently had a water heater that had been in service for six or seven years, and just bought a new one, so I also did some homework properly. The topic has been answered before, but the word 1000 is obviously not enough. I will introduce the mainstream water heaters in detail from all aspects.

The mainstream water heaters in the market can be divided into four types: gas water heaters, electric water heaters, solar water heaters and air energy water heaters. Gas water heaters and electric water heaters are the most mature water heaters with the highest market share. It is worth mentioning that there is also a kind of water heater called speed magnetic water heater in gas water heater, which is to add a magnetizer at the inlet end. It is said that magnetized water can protect skin and purify water. X is too focused on this kind of water heater. As for whether it is really effective, residents can go online to see other people's comments, and the price is higher than that of ordinary water heaters. Because of the high cost and large volume, air energy water heaters are generally big houses, and villas are used more. Sumitomo who are interested in feelings can take one last look.

First, electric water heaters

1. Xiaobai Literacy:

According to the heating power, electric water heaters can be divided into three types: water storage type, instant heating type and fast heating type (also called semi-water storage type). Although the common quick-heating electric water heater and dual-mode electric water heater are similar in size, their internal structures are quite different. Compared with the water storage electric water heater, the quick-heating electric water heater is only smaller in size and more powerful, so the heating speed is indeed faster than that of the water storage electric water heater. However, it can't be hot in spring and autumn, so it needs to be preheated, that is, it needs to wait. However, dual-mode electric water heaters can be used in the instant heating mode in spring, summer and autumn, which is of course.

Diagram of water storage electric water heater Internal structure diagram of water storage electric water heater

Electric water heaters have developed into very mature products today, and the technology is actually nothing new. The inside of the electric water heater is powered by an electric heating rod, and a large area of electric heating tube directly contacts the water in the heating water storage tank.

60L parameters of a brand

That is, the schematic diagram of the hot electric water heater (it looks very valuable, even smaller than the gas water heater, depending on whether you can eat it. )

Kitchen treasure map of internal structure of instant electric water heater

2. Comparison of advantages and disadvantages

Advantages:

The biggest advantage of electric water heater is that it is easy to install and can be installed in commercial houses without gas.

② The installation location is not limited, and it can be installed separately in the space that needs hot water, such as the bathroom, unlike the gas water heater that must be installed near the gas pipeline (but it should be noted that the water storage type water heater needs to clean the water storage tank regularly, and it is best to set it in a place that can drain water).

(3) Hot water is hot, because general electric water heaters are directly installed in the bathroom, and the hot water pipe is almost zero distance from the faucet. Of course, the premise must be the use of instant electric water heaters, and the storage type needs to be preheated in advance.

Disadvantages:

① Because the water storage electric water heater needs a water storage bucket, its volume is much larger than that of the gas water heater, which takes up more space and affects the appearance. Of course, it can also be hidden in cabinets. For example, some attic designs often put electric water heaters in lockers under stairs.

(2) The water quantity of the storage electric water heater is limited, and it needs to be burned after use. Of course, there are also frequency conversion quick-heating water storage electric water heaters now. If you burn while using them, it depends on whether there is enough electricity. Of course, high power consumption is certain.

(3) The cost is higher than that of gas water heaters, and the electricity fee is now about 0.5-0.6 yuan per kilowatt hour. For a family of three, the annual electricity bill is estimated to be around 1.300 yuan, which is higher than the gas water heater. Although there will be no gas poisoning, some electric water heaters will leak electricity and hit the wall when running in humid environment, which has certain safety hazards. Of course, many brands have also issued related patents.

3. Key points of purchasing electric water heaters

Capacity selection

Generally, adult men need about 50L-60L water for shower, while adult women generally use more, which means that a family of three usually needs about 150L- 180L water. All electric water heaters work in the mode of mixing hot and cold water, and 1L hot water can produce warm water of about1.6-1.7l. Therefore, an electric water heater of 80L or 100L for a family of three is definitely enough.

lining

The inner container is one of the most important parts of the water storage electric water heater, and the material of the inner container directly determines the service life of the water heater. There are two kinds of mainstream liners: stainless steel liners and enamel liners. Others include Jingui liner, titanium liner and timely porcelain glaze, which are mainly the fancy names of some liner technologies of various manufacturers. Considering corrosion resistance, heat preservation and service life, Jingui liner is the best scheme at present. Of course, many brands now have a long warranty period for the liner and can even replace it for free, so choosing after-sales warranty is also an important reference index.

Here's a simple literacy about the difference between liner materials.

① Let's talk about enamel liner first. In fact, most domestic brands use enamel liners. There is a layer of enamel on the surface of the enamel liner, which has the advantage of not rusting. However, the low-grade carbon steel plate used in general enamel liners has only two layers of liners, which has many problems such as fish scale explosion, acid corrosion, rapid dissolution and so on, and its service life is short. Therefore, when choosing enamel liner, we should also pay attention to the quality of enamel liner mainly depends on the processing technology. As for the so-called enamel powder formula, it's just a mystery. As we all know, as long as you apply for a patent, the formula is open. King Kong three-layer gallbladder is a better one on the market at present.

Brands that adopt diamond three-layer liner technology include Midea Blue Diamond Liner, Haier Diamond Three-layer Liner and Shuaikang Sapphire Liner. In fact, the materials and technology are similar. The technology adopts dry-lined enamel special superfine powder and is sintered at 890 degrees, finally forming a dense three-layer liner, including enamel layer, dense layer and decarburized steel plate layer, which greatly improves the dissolution resistance, explosion resistance and acid resistance, and prolongs the service life of the product. As for the name, it's just different cool names that merchants come up with when doing copywriting in order to reflect product differences when promoting brands.

Schematic diagram of enamel layer process

The advantages of stainless steel liner are high temperature resistance, corrosion resistance, stable performance and not easy to rust. However, it is difficult to weld and it is easy to leave a weld. After a long time, the weld is easy to rust, leading to water leakage. In order to reduce the cost, some enterprises use thin stainless steel, which reduces the pressure on the inner container and affects the service life. So there are few pure stainless steel liners on the market now, and most of them are coated.

③ Jingui water tank is a unique patent of AO Smith electric water heater. After all, it is the leader of water heaters, and it is normal to open the gap with other brands in patents. The tank adopts the latest technology on the basis of steel plate. Silicide is baked at 850℃ and attached to the inner and outer walls of the tank, which can isolate water from the tank and avoid direct contact between water and steel plate. It has the advantages of no rust and high strength. As for whether it can be washed for half a century, you have to buy it yourself to try, but AO has been changed for 8 years, and you are still very confident in your products.

④ Titanium liner is a unique liner in ariston, made of rare metal titanium. We all know that titanium has much stronger corrosion resistance than stainless steel. The titanium lining has four layers, and the outermost layer is titanium steel plate. Titanium is added to the steel plate to enhance affinity and increase corrosion resistance, followed by an adhesive layer and then an enamel layer. The innermost layer of the enamel layer is a titanium protective layer. Moreover, the electric water heater in ariston has a characteristic, and the heating tube is also titanium-plated, so the corrosion resistance is much stronger.

It should be noted that with the continuous increase of service life, the probability of accidents such as leakage and bursting of the inner container is also increasing. Therefore, when choosing an electric water heater, we should pay special attention to the following two aspects. The water quality in China is very complicated and the water pressure fluctuates greatly. The impact resistance of liner is directly related to product quality and service life. Therefore, when shopping, we must choose a liner product with good impact resistance. Domestic brands generally have a compression test of 654.38+0.6 million, which is more reliable. Other technologies for protecting the liner, such as anode rod technology, can be seen in the figure, so I won't introduce them much.

safe

No matter what kind of water heater it is, safety must be the primary consideration. After all, life is precious. The article mentioned earlier that the water heater may leak electricity in a complex working environment. At present, the leak-proof wall technology is a reliable leak-proof protection measure, which has been included in the new national standard of electric water heaters. When purchasing, you can check whether the product has safety technologies such as anti-electricity wall (Haier electric water heaters basically have corresponding patents).

Patent Description of Anti-electricity Wall and Alarm Technology

energy consumption

The biggest indicator to measure electric water heaters is the energy consumption label. Nowadays, electrical appliances basically have energy consumption grade labels. The new standard is divided into three levels, and the first level has the highest energy efficiency. Just look at the label and buy it directly, which is more intuitive.

Energy consumption identification chart

Second, the solar water heater

1. Xiaobai culture

Solar water heater is a kind of heating device that converts solar energy into heat energy and heats water from low temperature to high temperature to meet the needs of hot water in people's life and production. Solar water heaters are divided into vacuum tube solar water heaters and flat plate solar water heaters according to their structural forms, with vacuum tube solar water heaters as the main one, accounting for 95% of the domestic market share. Vacuum tube household solar water heater consists of collector tube, water storage tank, bracket and other related parts. The conversion of solar energy into heat energy mainly depends on the vacuum collector tube. By using the principle that hot water floats and cold water sinks, the water generates microcirculation and the required hot water is obtained.

Description of real-life structure of solar water heater Working principle of vacuum collector tube of solar water heater Schematic diagram of hydropower wiring

2. Comparison of advantages and disadvantages

Advantages:

The biggest benefit is definitely energy saving, which greatly reduces the cost compared with electric water heaters and gas water heaters.

(2) The technology is mature, both north and south are basically popular now, and the cost is relatively cheap.

(3) If you can consider installing two water heaters in a duplex building, using solar energy in summer and gas in winter is definitely the best choice to save money.

Disadvantages:

① Under the influence of weather, temperature and seasonal light duration, the utilization of sunlight is reduced in winter, and if it is placed outdoors, the energy efficiency will definitely be weak.

(2) Vacuum tube solar water heaters are generally installed on the roof only by people at the top of multi-storey houses, so there are installation restrictions. Of course, with the progress of technology, balcony solar products have gradually entered the market.

③ Because it is installed outdoors, there will definitely be maintenance problems, and the dirt in the water tank needs to be cleaned regularly.

3. Connection mode with gas water heater.

Many sumitomo will consider the scheme of gas water heater and solar water heater when they live in duplex houses, but they don't know how to take over to make the use of the two water heaters switch freely. Let's use a picture to illustrate.

Description: First, add a three-way L-shaped valve at the cold water inlet of the gas water heater and the hot water outlet of the solar water heater and link them with water pipes (mark the position of the five-pointed star). In this way, if you want to use the gas water heater in winter, you can open the valve to let the cold water preheated by the solar water heater enter the cold water pipeline of the gas water heater, and close the valve of the gas water heater in summer when the light is good, so that the cold water can directly go to the solar water heater without going through the gas water heater to make it run independently.

Valve diagram for those who need to insert an additional heating diagram combining solar energy and electric boiler.

4. Precautions for purchase

Although solar water heaters are mature products, there are many brands, low threshold and uneven quality level. In addition to choosing mature brands with guaranteed after-sales quality, we should also pay attention to the following points:

① Select the volume. As mentioned above, the amount of hot water for adult showers is about 40-50L. Because solar energy is an unconventional energy source, it can't produce hot water in rainy days, so we should choose a water heater with twice the daily water consumption to store the hot water in sunny days for rainy days. In case of two consecutive days, you can choose the photoelectric dual-purpose type to ensure the use of hot water all day long.

(2) Pay attention to whether the building structure is allowed, and choose products with appropriate functions and forms according to the building form.

(3) Because the water heater is often placed on the roof, there is a certain pressure in the house. In summer, the hot water temperature is high (up to about 90℃) and the outdoor environment temperature is low. It is best to choose cross-linked pipe, aluminum-plastic composite pipe or reinforced plastic hose. It has the characteristics of pressure resistance, high temperature resistance, low temperature resistance, non-toxic, tasteless, small heat capacity, small heat loss and not easy to freeze in winter. Therefore, when purchasing, we should also pay attention to whether the products have been tested for withstand voltage and leakage and performance parameters before leaving the factory.

④ The service life and thermal insulation performance depend on the liner material, liner thickness and thermal insulation layer thickness. The thickness of the liner is generally 0.6mm, and the polyurethane foam of the insulation layer is better, generally 4-5CM thick. It should be noted that the thickness of the northern region should reach more than 6CM.

⑤ The most important technical indicators are thermal efficiency > 40% and heat loss coefficient < 2/m, so remember to pay attention when buying.

Third, gas water heaters.

1. Xiaobai culture

As the name implies, gas-fired water heaters use gas as fuel, and heat is transferred to the cold water flowing through the heat exchanger through combustion heating, so as to achieve the purpose of making hot water.

Gas water heater is mainly composed of valve body assembly, main burner, small fire burner, heat exchanger and safety device. It also includes the flue of the flue water heater and the forced exhaust device of the forced exhaust water heater. The valve body assembly controls the working procedure of the whole water heater, including water valve, air valve, microswitch and igniter. When installing the water heater, valves should be installed on the water inlet pipe, water outlet pipe and gas pipe.

According to the working mode, gas water heaters can be divided into three types: direct row type, flue type, forced row type, balanced type, outdoor type, direct row type and flue type. Because of safety problems, they have been forced out by the state, so I won't say much. Forced exhaust type is the most widely used gas water heater at present. The garbage is forced out of the room by fans, but there are also safety hazards when it is used in narrow indoor spaces. But at present, major manufacturers have produced balanced products with better performance and safety.

Real-life map of common forced water heater

Schematic diagram of internal structure of common gas water heaters

2. Comparison of advantages and disadvantages

Advantages:

(1) can be used immediately, without water storage, and the continuous combustion time is long.

② The daily use cost is lower than that of electric water heater, and the annual gas cost is about 500 yuan.

(3) Small size, saving space compared with the water storage electric water heater.

PS: Calculation method of gas water heater and electric water heater. If you are bored, just skip it.

At present, the natural gas fee is 0.52 yuan per cubic meter of 2.2 yuan and the electricity fee is 0.52 yuan per kilowatt hour. Because both of them are used to heat water, compared with heat, the cost of natural gas per kilowatt-hour is 0.22 yuan, and electricity is 0.52 yuan. Therefore, the cost of electric water heater is 2~3 times that of gas water heater. Suppose the family is a family of four, and each person uses 50L bath water, with an average of 150L hot water every day and 54500L a year. When the hot pressing is increased from 15 degrees to 40 degrees and the temperature is increased by 25 degrees.

The formula q = 54500l× (40℃-15℃ )× 4.2×10? 3; J/(㎏ ℃)= 5722.5MJ .

And the price of natural gas per cubic meter: the heat conversion rate of natural gas in 2.2 yuan is 70%, and the maximum heat per cubic meter of natural gas Q = 8,500 kcal/cubic meter x 70% = 5,950 kcal/cubic meter;

65,438+0 kcal/65,438+0 kcal/65,438+0,000 kcal = 4.65,438+0.868 kJ. The actual calorific value of natural gas per cubic meter is about 24.9 1. 1.46 mj.

Natural gas cost for a family of four: 229.438+036× 2.2 yuan ≈505.36 yuan. The cost of electric water heater is about 2.3 times that of gas. The cost of electric water heater is 367.54×2.5= 1263.4 yuan.

Disadvantages:

(1) part of the cold water should be discharged from the remote outlet (it needs to be solved by adding a circulating pump, or the water heater comes with a circulating pump, which is more expensive).

② When it is used indoors, the high temperature of combustion, the consumption of waste gas and oxygen may become hazards, and there is a risk of carbon monoxide poisoning. (Now the CO alarm is also standard for balanced gas water heaters, and high-end products can even burn without producing CO)

(3) The temperature of hot water is affected by many factors, such as water velocity, water pressure, heat exchange efficiency, gas flow rate, etc., and the water temperature may be unstable. (The water server of constant temperature water heater can solve the problem, and the temperature can be stabilized at 0.5℃- 1℃. )

④ The purchase cost of the machine itself is higher than that of the electric water heater.

3. Key points of gas water heater purchase

① Gas types

Before choosing a water heater, be sure to determine what kind of gas is used at home, because natural gas, gas and liquefied gas tanks all correspond to different products or different types of nozzles. It can be distinguished from the models of gas water heaters: "T" stands for natural gas, "R" stands for artificial gas and "Y" stands for liquefied gas.

② capacity

Common gas water heaters in the market are 10L, 1 10L, 12L, 13L, 16, 20L, etc. 1 kitchen suggestion10. 1 Water heaters are recommended for kitchens with three dimensions (duplex buildings) or above 16L or above. Of course, Sumitomo who likes to take a bath should choose a larger water heater than usual, but it should be noted that the liter index of the water heater refers to the hot water output, that is, the number of liters of hot water can be increased by 25℃ per minute. Obviously, this index is also related to the water pressure of municipal water intake. If the water pressure itself is not enough, you can buy a big water heater.

③ Safety

Do literacy here. After all, this is a matter of life and death. Many people may have a misunderstanding about natural gas. They think that natural gas will not be poisoned. Actually, methane is not. It is the main component of natural gas and biogas. Methane is basically non-toxic to people, but when the concentration is too high, the oxygen content in the air will be significantly reduced and people will suffocate. When the methane content in the air reaches 25%-30%, it can cause headache, dizziness, fatigue, inattention, accelerated breathing and heartbeat, and ataxia. If you don't stay away in time, it will lead to suffocation and death.

The main COmponents of gas are CO and co, which is familiar to everyone. The affinity between carbon monoxide and hemoglobin is 200 ~ 300 times higher than that between oxygen and hemoglobin, so carbon monoxide can easily combine with hemoglobin to form carboxyhemoglobin, which makes hemoglobin lose its oxygen-carrying ability and function and causes tissue suffocation. It is toxic to tissues and cells all over the body, especially to the cerebral cortex.

If it is three rooms or two rooms, because the space is better, the safety of the general forced row water heater in the kitchen or balcony space is actually guaranteed, mainly for the small space of 1 room, the kitchen is close to the bedroom, and the safety needs special ideas. Choose a water heater with alarm detection. (It is worth mentioning that Haier's dual gas detection and alarm technology is still a very reliable patent, which can monitor two gases, alarm when the concentration exceeds the standard, and then turn on the exhaust. )

Gas water heater with carbon monoxide safety system

④ Energy consumption

The energy consumption of gas water heaters is mainly electricity and gas. Ordinary gas water heaters are basically in the second level of energy consumption, and only condensing gas water heaters can reach the first level of energy consumption. The main principle is to add a primary condensation heat exchanger to preheat cold water by absorbing high temperature flue gas. Thereby improving the heat conversion efficiency and saving the fuel gas cost. Of course, the more functions, the higher the cost, and the more demand for condensate drainage.

⑤ Brand

Brand selection is definitely an unavoidable topic. China's mid-to-high-end market is basically monopolized by two Japanese brands, Lini and Nengli. As we all know, many times, the principle of choosing electrical appliances always depends on the brand first to see if it is this category. The main product of their products is the original Japanese chip. In fact, their water heaters are estimated to be made in China, but some parts such as chips are imported. It is worth mentioning that these two brands only provide 1 year warranty. LEON has always believed that water heaters are not high-tech products, and domestic brands such as Haier dare to guarantee them for 6 or even 8 years. I believe that if the product is not too hard, I dare not boast, so it is different to choose domestic or foreign brands. Personally, I will pay due attention to domestic brands with R&D capabilities and patented technology.

⑥ Analysis of other patented technical terms.

Phosphorus deoxidized copper heat exchanger: Compared with pure copper heat exchanger, the heat exchange rate is higher, and the phosphorus coating is antioxidant.

Double electromagnetic proportional valve: accurately control the gas proportion.

Blue flame technology: By accurately controlling the gas, a more energy-saving blue flame is produced.

Memory metal: adjust the water output by sensing the water temperature. (Low-end machine controls water temperature fittings)

Water quantity server: accurately control the water quantity according to the outlet temperature. (Price above 3000)

Circulating pump: farthest hot water pipe plus return pipe. Through the circulating pump, the hot water in the hot water pipe can be heated circularly to realize hotel-style zero cold water. Of course, it takes time. (high-end model)

Electromagnetic remote controller: A control panel can control the temperature of the water heater directly by plugging it into the socket without wiring.

PS: The technology of gas water heater is varied, which is the easiest to see. In fact, gas water heaters are the most common household appliances, such as intelligent temperature control to wash some things, the constant temperature is accurate to 0.3℃, and the power is high. These may be redundant functions, and the actual experience is irrelevant at all, because many houses have limited water pressure and the same water output, which can not give full play to the full efficiency of water heaters. Therefore, LEON suggested buying a gas water heater.

Description of internal structural components

Different temperature requirements can be controlled by controlling the size and ignition times of the ignition row.

Schematic diagram of water pipe connection of water heater with circulating pump. If you want to use this kind of water heater later, you can only connect a one-way valve to the hot water pipe at the farthest cold water outlet, that is, after the hot water of the water heater is output, it goes to the farthest cold water pipe and then returns to the cold water inlet of the water heater through the supercooled water pipe. The disadvantage of this is that all cold water faucets can put hot water, including toilets, and hot water managed by cold water will reduce the effect of hot water. If someone takes a bath, it can't be done at the same time.

Dream of transforming the electromagnetic remote control used at home, which can remotely adjust the temperature of the water heater, and the duplex room may be useful.

Fourth, air energy water heaters.

1. Xiaobai culture

Air energy water heater, also known as "air source heat pump water heater". The "air energy water heater" absorbs the low-temperature heat in the air, gasifies it through fluorine medium, then pressurizes and heats it through a compressor, and then converts it into water for heating through a heat exchanger. The compressed high-temperature heat energy is used to heat the water temperature. Air energy water heater has the characteristics of high efficiency and energy saving. It produces the same amount of hot water, which is 4-6 times that of ordinary electric water heaters, and its annual average thermal efficiency ratio is 4 times that of electric heating, so it has high utilization efficiency.

This product overcomes the disadvantage that the solar water heater relies on sunlight to collect heat and is inconvenient to install. As the work of air energy water heater is heat exchange through medium, there is no need for direct contact between electric heating elements and water, thus avoiding the danger of electric leakage of electric water heater, preventing the danger of explosion and poisoning of gas water heater, and more effectively controlling the air pollution caused by exhaust gas discharged from gas water heater. Air energy water heaters do not need sunlight, and can be placed at home or outdoors. It is difficult to produce hot water immediately after the water stored in the solar water heater is used up. If the electric heating time is long, the air can heat the water to above minus 20 degrees Celsius, and it can run under pressure for 24 hours. In this way, even if a box of water is used up, the air energy water heater will generate another box of hot water in an hour or so or even less.

At the same time, it can also fundamentally eliminate potential safety hazards such as electric water heater leakage, dry burning, harmful gas generated when gas water heater is used. As the name implies, the air source heat pump water heater transports the heat in the air to the water through the refrigerant. Traditional electric water heaters and gas water heaters obtain heat energy by consuming gas and electric energy, while air energy water heaters achieve the purpose of heating water by absorbing heat in the air. Consumption of the same electric energy can absorb heat energy equivalent to about three times of electric energy.

Real map of air energy water heater

Schematic diagram of air energy water heater.

2. Comparison of advantages and disadvantages

Advantages:

① Compared with the electric water heater, it is energy-saving and environment-friendly, with higher energy efficiency.

② Compared with electric water heater, the heating speed is faster.

(3) Compared with the leakage phenomenon of electric water heaters and the possible air leakage phenomenon of gas water heaters, it is safer and more environmentally friendly than waste gas pollution.

④ The water storage capacity is large, generally 150L or 200L is optional.

Disadvantages:

(1) The water storage tank is large, and the external machine takes up more space.

(2) The water storage tank produces scale and needs to be cleaned regularly.

③ The purchase cost of machines is higher than that of electric water heaters (starting from 5000+).

④ Product pedigree and maturity are inferior to gas water heaters and electric water heaters.

abstract

Finally, according to the content of the above article, make an intuitive comparison of several parameters that must be seen when buying a water heater.

Convenient installation: electric water heater > gas water heater > air energy water heater > solar water heater.

Volume: air energy water heater > solar water heater > electric water heater > gas water heater

Energy efficiency: air water heater > solar water heater > gas water heater > electric water heater.

Save money: solar water heater > air water heater > gas water heater > electric water heater.

Cost: air energy water heater > gas water heater > electric water heater > solar water heater.