1. Is solar water heating a viable alternative to gas or electricity?
Solar energy should not be regarded as an alternative to gas or electricity, but rather a supplement. It cannot completely replace the need for gas or electric heating as there are days when there is little sunshine. A correctly sized solar water heating system can provide 60%-70% of a household's hot water needs. Providing more than this is unadvisable, as too much heat will be generated in the summer. The solar water heater system can easily be automated so hot water is guaranteed regardless of sunlight levels.
2. How long will the solar collector take to recoup my investment?
Jinyi solar thermal collectors are much more affordable than many other solar water heaters. For a household of four, the price of a full solar water heating system may be similar to that of a new electric or gas system. Depending on your location (solar levels) and current hot water usage, the annual electricity or gas saving will differ. However in a normal household that spends 25% of its electricity bill on solar water heating, the full cost of the purchase may be recouped as quickly as 4 to 5 years in reduced bills. You will definitely make considerable savings during the life of the solar water heater.
3. Can Jinyi solar collectors be used in cold conditions?
Yes. Our evacuated tube collectors can be used in extremely cold temperatures, with solar water heating systems installed in regions of Russia that reach -45oC. Surprisingly even at these temperatures the system can produce hot water with good efficiency due to the vacuum properties of the evacuated tubes.
4. What happens if one of the evacuated tubes is broken?
Jinyi evacuated tubes are very strong and not easily broken, but if the worst should happen, it is very easy to replace the vacuum tubes. Although our solar collectors possess the capacity to operate with several broken tubes, it is recommended that broken tubes be replaced immediately to guarantee efficiency. Replacement tubes are available through your local distributor at a very reasonable price.
5. Will water be heated on a cloudy day?
Yes. Although the heat output of the solar collector is reduced on overcast days, it can still provide significant heating. If it is a heavily clouded day or raining, then more gas or electric boosting may be required to retain the water at the required temperature. This solar water heating system will be automated so you don't have to worry about running out of hot water on a rainy day.
6. Can I use a solar collector with my existing hot water system?
Normally yes. The valves are simply retrofitted and they can often be used to allow solar energy to connect to your existing cold water inlet. If your tank cannot accept the solar input directly, an additional storage tank can be installed to pre-heat the cold water prior to entering the existing tank.
7. Are the solar collectors noticeable on the roof?
If only the collector is installed in the roof, it should be combined with the roof design perfectly. Jinyi solar thermal collectors are very thin and can be flush mounted on a roof. From a distance they look somewhat like a skylight. You may have to check with your local council regarding building restrictions when installing your solar collector.
8. Can Jinyi solar collectors be mounted on a flat surface?
Yes. They may be mounted on a flat roof or on the ground by using an aluminum alloy flat roof frame. The solar thermal collector should be installed at a minimum of 20o angle to guarantee optimal heat pipe operation.
9. How do I protect my solar heating system during subzero temperatures?
If your solar water heating system is operating in areas with subzero temperatures, then freeze protection must be implemented. The easiest means of preventing freezing is to use a solar controller with a low temperature setting, so when the manifold temperature drops below a certain pre-set temperature (5oC/40oF), the pump will circulate and warm the collector with water from the bottom of the storage tank. The pump will run periodically, the frequency of which will depend on the outside temperature. In extremely cold areas, a closed loop using a glycol or water mix may be appropriate.
10. Will the Jinyi solar collector be a fire hazard during hot or dry weather?
No. The components of our solar thermal collectors are all high temperature rated and non-flammable, so even during strong sunlight with the circulation pump turned off, the solar water heating system will not catch alight or ignite dry material. The evacuated tubes are cool to touch even during the summer.
11. Can the Jinyi solar collector heat water to a high enough temperature?
Yes, in good weather the collector can bring water to boiling point. Generally this is not necessary and so the system should be designed to provide a daily temperature rise of around 25-30oC (45-54oF) in the summer. It is not logical to size a domestic solar water heating system that can heat the cold water up to 60oC/141oF in a single day. Because if hot water is not used for one day, the following day the system will be boiling and dumping hot water via the temperature relief valve. This is both a waste of energy and water! Please sensibly size solar water heating system to ensure optimal performance and minimal wastage of water.
12. What maintenance of the solar collector is required?
Under normal circumstances no maintenance is required. Although Jinyi solar collectors can operate with several broken tubes, the heat efficiency will be reduced slightly. The broken one should be replaced as soon as possible.
13. Can Jinyi solar collectors be used for a large scale hot water production?
Yes. Our solar thermal collectors can be connected in series or parallel to provide large scale hot water production for commercial applications such as schools, hotels or office buildings. There is really no limit to the size of the solar water heating system. Jinyi evacuated tube collectors are ideal where high temperatures rang from 60oC/140oF to 120oC/250oF are required.
14. Can I heat my swimming pool or spa using a Jinyi solar collector?
Yes. Jinyi evacuated tube collectors can be used to heat a spa or residential swimming pool. A titanium heat exchanger is normally used to separate the chlorinated water from the solar collector loop, avoiding corrosion damage of the copper piping. For any swimming pool that is to be heated, an insulating blanket should be used to minimize heat loss and evaporation.
15. Are evacuated tube collectors more efficient than flat plate collectors?
There is little difference between evacuated tube solar collector and flat plate collector when comparing the peak efficiency. In fact, a flat plate collector may actually be higher, but this is under the conditions of minimal heat loss. When it is averaged over a year, the evacuated tube collector has clear advantages. The key points are as follows:
1)The solar vacuum tubes are able to passively track the sun throughout the day due to the cylindrical shape of the tubes. Flat plate solar collector only provides peak energy output at midday when the sun is perpendicular to the surface of the collector.
2)Air is evacuated from the solar tube to form a vacuum. This greatly reduces 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)Evacuated tubes are strong and long lasting. It is cheap and easy to replace broken one.
4)Due to the various advantages of evacuated tube collector over flat plate collector, 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.
5)Flat plate solar collectors can produce similar heat output to evacuated tube collectors, but generally only during sunny conditions. When averaged over an entire year, the heat output per square meter of the evacuated tube collector is 25% to 40% greater than a flat plate collector.
16. Which collector is the best value for money?
It should consider the installed cost per unit of energy produced, rather than just looking at the peak efficiency levels when comparing solar collectors. For example, collector A may be 20% more efficient than collector B, if collector A is 30% more expensive, then in fact collector B may be a better choice, as per kwh of energy produced per day it is cheaper. Jinyi evacuated tube collectors are particularly easy to install, reducing the installation cost and thus improving $/kWh.
17. What is the solar radiation (insolation) level where I live?
Solar insolation is the amount of electromagnetic energy incident on the surface of the earth. In other words, how much sunlight is shining down on us. Visit http://www.gaisma.com/en for more information.
18. Can Jinyi solar collectors be used in a drainback configuration?
Yes. The end port version of the Jinyi solar thermal collector is very suited to drainback use. The question is often asked if the solar collector will be damaged when the pump turns off and the system stagnates in good sun. No, it won't, as the collectors is designed to withstand stagnation. What must be considered though is the insulation used on the piping close to the collectors, as this must be able to withstand stagnation temperatures.
19. What is a solar water heater?
A solar hot water heater uses the solar energy to pre-heat household water before it enters the conventional gas (or electric) water heater. The solar water heating system could generate up to 90% of your annual water heating needs.
20. How hot can solar heated domestic water get?
Water heated by the sun can reach the temperature exceeding 212º F, but the normal temperature for household use is only 120º to 130º F.
21. Are there different kinds of solar water heaters?
There are two kinds of solar water heating systems: active or passive. Active solar heating systems rely upon moving mechanical parts in order to transport heat, while passive ones simply use the sun to accomplish this action. The bulk of systems installed in EU and US are active because they are considered to be more efficient and attractive. However, most of the solar water heating systems installed worldwide are passive because they are simple and need no auxiliary power (electricity) to operate.
22. How do active solar collectors work?
The water contained within the gas or electric water heater is circulated through the solar collectors in a single-tank system. Or a separate tank is used to pre-heat the water before it enters the conventional water heater in a two-tank system. A two tank system is usually considered to be the best option but if properly managed, a single tank system can provide between 50 and 80% of the household needs for hot water. The water being circulated is gradually heated and the system should be sized to provide between fifteen to twenty-five gallons of hot water per person per day. A reliable automatic control to operate the pump is essential. Fortunately, pumps and electronic controls have evolved and can be expected to provide over twenty years of service.
23. How do passive solar collectors work?
Passive systems can be divided into two types: thermosiphon and integral collector storage(ICS). Passive solar water heaters are popular due to their inherent simplicity and reliability. The storage tank is located on the roof and heating effect of the sun causes warm water to circulate within it. Cold water flows directly to the tank on the roof, and then flows to a conventional water heater located on the ground level. The distance between the solar water heating system and ground level water heater should be as short as possible in order to reduce the amount of cold water sitting in the pipe between the two units. In the case of a thermosiphon system, an insulated tank will prevent the loss of stored heat during the night.
24. Will solar heating affect how much water I have? Will I have to change my bathing and cleaning routine?
You will actually have much more hot water than ever before. If the solar water heating system is sized well for your family, you will no longer need to wait for the water heater to recharge between showers.
Solar water heaters are always installed in addition to your regular water heater, which means that even during bad weather you will still have hot water. In order to maximize your savings, you should try to use the most hot water in the late morning and early afternoon when the solar water heating system is operating at its peak. Also, it helps to spread your cleaning load over the week. This will reduce the amount your regular water heater must operate.
25. Will the solar heating system affect my existing water heater?
Yes. Since the water heater will operate far less frequently, solar water heating system will significantly prolong its service life. Some water heaters retrofitted with solar heating system in 1974 are still in service today, over a quarter of a century later. The using life of an ordinary gas heater without solar system is between five and ten years.
26. How much do I save?
It depends on the size of the solar water heating system, the needs of your family and the way you currently heat your water. The average annual cost for water heating can be over half the expense of a household’s entire annual gas bill, especially in those homes with teenagers or shower hogs. In an average home, a person uses between fifteen and twenty-five gallons of hot water a day, which can cost $5.00 to $25.00 per person every month. A family of four could spend about $384 to $1200 a year just for heating water. A utility bill is sometimes structured to charge for energy at varying rates or tiers, where the most costly level or tier is levied in winter, when you are using the most gas. A solar water heating system can reduce your daily gas consumption. This chopping off or shaving of the highest can have a profound affect on the cost of winter utility expense.
