The Solar Basics: Q & A
Q: So how does it work?
A: A solar heating system uses a hot water storage tank and solar heat collector panels. The hot water moves between the collectors and the tank while the sun is shining and is stored at the end of the day in an insulated storage tank. The system is equipped with an electrical heating element as a back-up, which is controlled by a thermostat for when the sun’s energy is insufficient for heating water.
Q: What type of temperature can I expect on a hot day?
A: Over 50 degrees. According to studies, the hottest bath a man can tolerate is 41 degrees and a woman, 43 degrees.
Q: Will my system be damaged if I go away for 3 weeks in mid-summer?
A: No, it won’t be damaged. Solar Beam systems are designed not to generate excessive, stagnant heat, so your system will not exceed 65 – 70 degrees, stagnating in mid-summer. We are very aware of the hazards of high temperature delivered water. Whilst this is possible using solar water heaters, it is definitely not the goal of a good solar system to get excessively hot. Now this might sound contradictory, but remember, along with possible safety hazards, it is a plain and simple fact that the higher the temperature, the less efficient the system!
Q: Will I have hot water at night?
A: The system is designed to supply hot water 24 hours a day and that is why it is so important that the solar system is well insulated and is sized correctly for the hot water requirements of the whole family. (See question below). Hot water collected during the day is stored in the storage tank, which is very well insulated and designed to keep the water hot overnight.
Q: What size system will my family need?
A: Calculate how much hot water your family uses in a day. If a family of four is frugal with the hot water and uses a shower instead of a bath, then a 200 litre system will suffice. However, if you enjoy long, leisurely showers, or one of the four has a bath, then a 300 litre system is your minimum starting point. Always remember that the larger the solar system, the higher the savings.
Q: Why is my solar system so much bigger than my existing geyser?
A: The heating element in the electric geyser can heat the contents of that geyser in a short period of time. Therefore, it is not necessary to have a normal geyser with a large volume. In a solar geyser, the sun has 6 hours on average to heat ALL the water your family is going to use in 24 hours. This is why the volume of the solar geyser must be much bigger than that of a normal geyser.
Q: Why do you use flat plate collectors and not the ‘new’ evacuated (glass) tube technology?
A: Quite simply because flat plate collectors are better for our application in Africa. The history of glass tubes is that they were invented and developed by the Swiss for Swiss conditions – a far cry from our African climate! Glass tubes have advantages ONLY when temperature above 70 degrees is required. As per the above answer, high temperatures in a domestic situation are not ‘clever’ at all; in fact it is downright dangerous!
Q: What happens on a cloudy day? Will we get any solar contribution at all?
A: On a cloudy day, there will still be solar radiation. To give you an example: If your car has been parked with the windows closed on a cloudy day, feel the dashboard. You will see that it is warm and sometimes even hot. This is an indication of what you can expect from your solar heating system. Therefore the element will not have to work too hard on a cloudy day and will generate heat as per normal.
Q: What about maintenance?
A: Maintenance is negligible and merely entails hosing down the panels (flat plate collectors) once or twice a year to remove excess dust (DO NOT hose down the panels in the heat of the day – this is very important!). The system will work uninterrupted for years.
Q: What is the guarantee period?
A: The Manufacturer carries a 5 year warranty on the collectors and storage tank. There is equipment that has been in use for over 30 years, and the average life expectancy is between 15 – 20 years.