FAQ

1. Can a solar water heating system be used in place of a traditional gas or electric heating system?
In order to ensure proper efficiency of your water heating system, a solar energy system must be used in conjunction with a traditional gas or electric heating system, rather than as an alternative to a traditional system.

2. Do solar systems produce hot water in the winter?
Erjin  solar systems will operate and produce hot water during the winter months but may require anti-freeze protection where applicable.

3. Do solar systems produce hot water on a cloudy/overcast day?
Erjin solar systems will be able to provide heating during cloudy or overcast days, but may require the use of traditional gas or electric heating system to produce required temperatures.

4. Can I use a solar collector with my existing hot water system?
Most often times solar collectors can be used with an existing system by utilizing a simplistic solar conversion valve that connects to your existing water tank.

5. What happens if one of the solar tubes is broken?
The tubes are very strong and not easily broken, but can be replaced very easily.  They are inexpensive and available.

6. What is the payback/ROI of the system?
Depending on factors including geographic location of the system, insolation levels (amount of solar radiation) in that area and annual usage of the system, an average household of 4 persons can expect to recover the cost of a solar system within 4 to 6 years.

7. What is the life of the solar collector systems?
Erjin solar systems have a life expectancy of greater than 20 years with a manufacturer's warranty of 3-5 years.

8. Do Erjin solar heating systems require any maintenance?
Maintenance of the system is negligible; however, an annual assessment of the solar system is recommended to help to maintain efficiency levels and to help avoid potential long term problems.

9. Can evacuated tube solar collector be used for swimming pools?
Due to the enormous amount of energy required to heat a swimming pool, normally the answer is no, as there is not enough space to put a number of collectors required to contribute significantly to the pool heating. That is to say, if you have the space and money to devote to a solar thermal heating system for your pool, there is no reason why it cannot be done.
Thus, we designed a patented project collector to realize this. The collector is about 2 m2 in size and can provide 200 liters hot water daily.

10. How to calculate hot water usage?
When choosing a solar system for hot water, we must first determine our need for hot water, in quantity as well as in preferred temperature. The typical temperature used for calculation is 45°C, but the required quantity must be calculated according to specific daily needs.
Hot water usage calculation

1) ResidencesIn family residences, the needs for hot water remain stable during the whole year. An indication for the needs is given by the number of individuals living in the building (or apartment). Usually, the per capita daily consumption of hot water at 45°C is calculated taking into consideration of the following:Low consumption: 35 liters per capita / dayMedium consumption: 60 liters per capita / dayHigh consumption: 80 liters per capita / dayIn the case where we want to connect the solar installation to the washing machine and the dishwasher, we would have to increase the calculated daily needs of consumption as follows:Washing Machine: 20 liters / day (1 wash per day)Dishwasher:  20 liters / day (1 wash per day)Example:A family of 4 needs around 240 liters of hot water daily in order to have a medium daily consumption. (60 liters per capita x 4 persons) If we include a washing machine and a dishwasher, then we must calculate a consumption of 280 liters per day.

2) Hotels - HostelsIn buildings such as hotels, hostels, etc..., the needs for hot water are related to the number of guests. In this case, the daily consumption is calculated by the average occupancy of the rooms, from the period of May until August. Using this basis, the size of the proposed installation is determined. Here below we indicate the per capita daily need for hot water at 45°C.Hostels with shared bath: 35 liters / person / dayHotels: 40 liters / person / day2 Star Hotels: 50 liters / person / day3 Star Hotels: 80 liters / person / day