Vaillant offers its customers a variety of solar thermal options to harness the energy from the sun for domestic solar water heating. In general, hot water consumption can be met up to 90% with the right Solar Water Heating system design. In average and common residential situations, one person may require around 50 liters of hot water per day. Vaillant’s Solar Water Heating systems are designed to meet all of the diverse hot water requirements of your family and house in the most efficient way possible.
Among the Drainback, Pressurized and Thermosyphon solar water heating systems that Vaillant offers, let us take the Drainback system as an example for this matter. This Solar Water Heating system utilizes Vaillant’s high efficiency flat plate solar collectors VFK 135 D that ensures high heating capabilities compared to the other conventional ones, which helps the end-user to utilize less area for the panels. On the other hand the following “generic sizing approaches” can be kept in mind while deciding the best solar water heating system size for you:
When sizing the Drain Back System, 50 liters of hot water per person in a regular town house or villa can be considered as a rule of thumb.
The storage usually matches the daily hot water requirement, so for every person 50 liters of storage capacity is also needed. - If there are any washing machines (clothes or dishes) connected to a hot water supply line, another 20 liters should be added to every machine.
1 collector is usually enough for a family of two persons or two adults up to three in total, while 2 collectors can cover the hot water requirement for a family of 5 up to 6 members. Hot water for a bigger family can be covered by 3 collectors of VFK type (e.g. VFK 135D)
The right system sizing and selection makes all the difference in reducing the initial investment and optimizing system performance with what suits the hot water requirement.