| 1-What is Evacuated Tubular Collector Solar Water Heater and how it Works? |
Evacuated Tubular Collector Solar Water Heater uses vacuum (evacuated) tubes made of borosilicate glass with selective Al/N-Al coating to high efficiently absorb the solar energy. The vacuum tube is composed of two concentric, borosilicate glass tubes. The outer surface of iner tube is coated with AI-N/AI, able to absorb maximum sunlight and lose minimum energy. Air between the gap of two concentric glass tubes is evacuated to form high level of vacuum, which is best isolative to minimize the heat loss from inner tube. The solar energy absorbed by the black coating on inner tube is then transferred to the water inside the tube. The water inside the Vacuum Tube becomes hot & lighter, and can rise upwards into the storage tank. At the same time heavier cold water from tank comes downward from lower side of the tube. This phenomenon is called as natural thermosyphon circulation, which occurs in every tube. |
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| 2-What is the reliability of Evacuated Tubular Solar Collector? |
| Renowned research institutes from Germany &Australia first invented and successfully experimented on this solar collector with vacuum tube technology. This technology was commercially implemented by some Chinese companies. Now it has been installed all over the country, proved very successful since last 10 years and is widely accepted all over the world including many developed countries like USA, Japan, Germany, Australia, and Spain etc. Every years, countless sets of this solar water heaters are exported from China to overseas. |
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| 3-Is there any possibility of glass tube breakage? Any preventive measures required? |
The vacuum tubes are made from specially developed thick borosilicate glass which can very well withstand the hail stoning even up to 25mm size. So after installation, the chance of tube breakage is almost zero. Only precaution required is not to feed cold water in the empty system during afternoon sunshine hours. The temperature inside dry vacuum tubes may go even up to 250¡æ during bright sunshine. If the cold water enters the tubes under such a condition there is a possibility of cracking of tubes due to thermal shock.
In case of accidental breakage of glass tubes it is very easy to replace the single tube by do-it-yourself. So there is absolutely no need to worry about the glass tube breakage. |
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| 4-How can you select the capacity/model to well suit your family? |
We supply models with tank capacity from 130 to 400 Liters. What model well suit your family uses depends on the average amount of hot water for each person per day in your family. For example, for a family of 4 persons, the daily use of 40L for each person per day, so that is total 160L, ATZ-20/1.5G and ATC-20/1.5G, both equipped with a tank of 160L can meet the daily needs of hot water for the whole family.
You can see the technical specifications including the person numbers for your reference, all are based on the average amount of hot water 30-35L for each person per day.
The way described above is the simplest way to decide on the size of your solar hot water system, which actually depends on more factors, like the type of the system, solar irradiation conditions, orientation and angle of installation, temperarue rise, the daily demand of hot water. This is very complicated and should be consulted with your professional suppliers.
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| 5-Is solar water heating a viable alternative to gas or electricity? |
| Yes. Solar Water Heaters can be used all year round in many regions and can provide all of your hot waters on clear or intermittently overcast days. If it is particularly overcast or raining, electric or gas backup booster may be required. |
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| 6-Can Solar Water Heaters be used in cold conditions? |
| Yes. Solar water heater can be used in temperature as low as -18¡æ and there is no need for adding antifreeze, although performance is reduced in such extreme conditions. Good heat output is still achieved in mild sub-zero conditions. |
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| 7-Can the Evacuated Tube Solar Heater be mounted on a flat or inclined roof? |
| Yes. it can be mounted on both flat and inclined roof. |
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| 8-Can the solar water heater bring you hot water of high enough temperature? |
| For daily use, the heat rise of tank water can reach up to 30-40 ¡æ, this is hot enough for family use like shower, washing. |
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| 9-Can the Solar Collectors be used for a large scale hot water production? |
| Definitely Solar collectors can be connected in series to provide large scale hot water production for a commercial settings such as school, hotel, swimming pool etc. There is really no limit to the size of the system! |
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| 10-What maintenance & servicing is required for the solar water heaters? |
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Under normal circumstances no maintenance of the system is required. Due to the shape of the tubes, regular rainfall and wind should keep the tubes clean. Should a tube become broken it can be replaced. This, however, is an inexpensive and easy job. A simple do-it-yourself work can finish it. Generally the water supplied through local municipal authorities is always of good quality with hardness of below 100 PPM if such water is used, the maintenance and service required will be almost negligible When the water hardness is higher or when the suspended dirt & impurities are present in the water, there is a possibility of stains dirt accumulation inside the vacuum tube. This is easily removable by removing the vacuum tube and cleaning them properly. Certainly we suggest the use of softners and magnesium anod to prevent against the formation of scale where the supply water exceeds 100PPM in hardness. |
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11-What is the lifetime for a solar system like this? and how long you warrant your solar heaters? |
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It can work 10 to 15 years under right use and maintenance. Normally, we warrant inner tank for 3 years against leakage. the vacuum tube is composed of two concentric borosilicate glass tubes, very strong, the typical stagnation temperature is over 260 C degrees, able to withstand hailstone of 25 mm in diameter, theoretically it can work 5 year
We warrant water tank and vacuum tubes for 3 years and all electric parts (like intelligent controller, heating element, pump, valves etc.) for 1 year.
Besides, we provide free vacuum tubes at the percentage of 5 in thousand per order.
The warranty is based on the condition that all parts are under right use.
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| 12-what is heat pipe? |
| The heat pipe evacuated tube consists of the glass evacuated tube described above. In addition, a copper heat pipe is installed within the tube. The copper heat pipe transfers from within the evacuated tube to its tip (condenser) which is plugged into the header pipe contained in the manifold. As water runs through the heat pipe, heat is transferred from the copper heat pipe to the water. The copper heat pipe is hollow and contains heat-transfer liquid. The hollow centre of the heat pipe is a vacuum (about 4 x 10-6 Pa), which allows the heat transfer compound to vaporize at low temperatures of 20-25C degrees. When heated, the vapor rises to the tip (condenser) of the heat pipe where the heat is transferred to the water flowing through the manifold. The loss of heat causes the vapor to condense and flow back down the heat pipe where the process is once again repeated. Using heat pipes, heat is very efficiently transferred from the glass evacuated tube to the water. |
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| 13-Can a solar water heater replace an electric or gas water heater? |
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Not completely. Conventional electric or gas water heating systems are still necessary as a supplement to the solar water heating system, largely because the sun might not shine in a particular area for several days at a time. However, because solar water heaters are designed to provide hot water directly to the tank of a gas or electric water heater, they reduce the need for the water heater to run on conventional fuels. And this in turn reduces your gas or electric bill. Depending on where you live, solar water heaters can provide up to 80% of your home's annual water-heating needs.
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| 14-Can solar water heaters be used in northern places and other colder climates? |
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Yes. Solar water heating technology is effective regardless of the outside temperature. In colder climates, more energy is required to heat cold incoming ground water, so using solar energy in such conditions could dramatically lower a consumer's utility bills. In addition, colder incoming ground water helps solar water heaters to operate at higher efficiencies. |
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| 15-What about heating my swimming pool with solar? |
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Solar swimming pool heating is the most common way that people in rich countries like the United States utilize solar energy today. Solar pool-heating systems increase water temperature by 10 degrees or more over an unheated pool, and can extend the swimming season by two to three months. System prices range from $2,500 to more than $5,000 (in USA), depending on the size of your pool and on other conditions such as shading and proximity to the ocean. When systems are installed to replace a conventional gas or electric swimming pool heater, the initial investment can usually be recovered in approximately three years, sometimes less.
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| 16- How do I protect my solar system during subzero temperatures? |
| If you have a system that is operating in areas with subzero temperatures then freeze protection must be implemented. The easiest means of preventing freezing is to use a controller with a low temperatures setting, therefore when the manifold temperature drops below a certain pre-set temperature (5oC / 40oF), the pump will circulate, warming the collector with water from the bottom of the storage tank. The pump will not run continually, just periodically, the frequency of which will depend on the outside temperature. In extremely cold areas, a closed loop using a glycol/water mix may be appropriate. |
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| 17- Are solar tube collectors more efficient than flat plate collectors? |
| 1. Due to the cylindrical shape of the evacuated tube, the solar tubes are able to passively track the sun throughout the day. Flat plate collector only provides peak energy output at midday when the sun is perpendicular to the collector's surface.
2. Air is evacuated from the solar tube to form a vacuum. This greatly reduces conductive and convective heat loss from the interior of the tube. As a result wind and cold temperatures have less effect on the efficiency of the evacuated tube collector.
3. Evacuate tub solar collectors can often be used in subzero temperatures without the system sustaining damage. Flat plate systems often require expensive and complicated "antifreeze" systems to be installed.
4. Evacuated tubes are strong, long lasting, and should not be broken, inexpensive and easy to replace. If a flat plate collector panel is damaged the whole panel must be replaced.
5. Due to the high efficient absorption of solar radiation even during overcast conditions, combined with excellent insulative properties of the solar tube, solar tube collectors can heat water all year round (backup from gas and electricity is still required).
6. Due to the various advantages of evacuated tube collector over flat plate collectors, a smaller collector can be used to provide the same heating performance. For example, a standard household of 4-5 people would usually require a 250-300L water storage tank. Depending on your location, only 30 evacuated tubes would be required to provide all summer hot water needs and a large percentage in other seasons, while Flat plate solar collectors can produce similar heat output to evacuated tube collectors, but generally only under warm and sunny conditions. When averaged over an entire year, evacuated tube collector heat output per net m2 of absorber area, is between 25% to 40% greater that a flat plate collector.
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| 18- Can the ATZ series install with reservoir mounted on the top of buildings? |
| Yes, ATZ series solar water heaters can install with reservoir (which acts as a water supply for the solar water heater), however, the reservoir must be higher than the solar water heaters, the height has no special requirement, otherwise the water inside the reservoir can not naturally flow into the water heaters, in this case a pump must be used. |
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| 19- How to size your swimming pool solar heater? |
It is really hard to size the swimming pool solar collector area. However, there are some general guidelines you can follow:
• 90% of the heat loss on most pools is from the water surface.
Therefore, the surface area of the swimming pool determines the total area of the solar collectors needed to heat the pool.
For every square ft. of pool surface area, you need at least 50% in solar square footage. This is a suggested minimum size based on typical heating performance and past customer satisfaction. Larger solar systems can be used to gain even higher temperatures and longer swim seasons. For most applications 80% coverage is optimum for comfortable swimming temperatures and a maximum swim season.
So you must measure your pool, multiply the average length by the average width of your pool to
determine the total surface area of your pool. For example, if your pool is 20 ft. x 30 ft this
equals a 600 sq. ft pool.
• For south-east and south-westerly facing positions in cooler climates the collector area should be increased by 35-40%.
• If the pool is shaded all day, increase the collector area by 50 percent of the percentage shaded. For example, if the pool is shaded 50 percent of the day, add 25 percent collector area. If the pool is inside an insect screen room, increase the collector area by 25 percent.
• In locations where the average wind speed exceeds 10 miles per hour, add 25 percent to the collector area for each 5 miles per hour over 10. |
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| 20- You provide split pressure SWH systems with single coil and double coils cylinder, like TFC-280RI and TFC-280RII, what does single/double coil(s) means? |
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TFC-280RI means 280L heat pipe split pressure SWH system with single coil in cylinder, while TFC-280RII means 280L heat pipe split pressure SWH system with dobule coils in cylinder.
Single coil means only one copper coil included in the cylinder for heat exchange with hot water from the solar collectors, double coils mean two coils included in the cylinder, one for solar collectors, one for backup heaters like boiler, gas water heater etc.
We also provide TFC-280UI and TFC-280UII, here U represents U-pipe. |
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