Basic Information

System Capacities Available for non-pressurized ETC solar hot water systems – 100, 150, 200, 250, 300, 400, 500, 750 & 2500 Liters Per Day (LPD)

Pre-Purchase Information

Following points should be considered prior to purchase of solar water heater:

ParametersPoints to be noted
Water QualityDurability of solar water heater depends on quality (TDS level) of cold water supplied to hot water tank. Customer should make the arrangement of supplying minimum ppm water/lower TDS level water.
Using PointsNumber of hot water outlets, Bathrooms
Cold Water HeadSystem requires cold water supply from the level above the solar storage tank, which is ideal method of solar water heater installation
Shadow Free PlaceThe selected system should be shadow free so as to receive clear sun shine from morning 9 AM to evening 4 PM in any season throughout the year
Water QuantityCold water supply tank capacity should be at least double than system capacity
System OrientationSystem should face towards south direction; if there is some site limitation variation of + 10 0 from south can be allowed. As it has very less effect on system Performance
Minimum Hot Water lineThe selected place should be as near as possible to hot water using points. This is very important because heat loss takes place from hot water inside the pipe if pipeline is very long. In which case, solar water heater capacity should be selected more than actual hot water requirement taking in consideration hot water pipeline heat losses. Its better that solar water heater system be installed nearest to the point of hot water usage to avoid longer pipeline & higher heat losses
Place of InstallationSystem can be installed directly on RCC slab or on taper roof facing towards south or on open ground with proper foundation. Customer scope of work includes Solar Water Heater System installed in high windy area should be well grouted/ clamped with collectors installed in a way that it is able to sustain the highest wind pressure of that area. This is necessary step for protection of solar water heater from strong wind velocities

Capacity Selection Criteria:

Place of UsingPoints to be notedApprox. Hot Water Requirements
In House for Tanking BathUsing Bucket
Using Hot & Cold Mixer & Shower
20 to 25 Ltrs per Person
30 to 35 Ltrs per Person
Apartments / Multi Storied Residential Building1 BHK- using Bucket / Mixer Shower
2 BHK- using Bucket / Mixer Shower
Luxurious Flat – Using Mixer Shower
150 Ltrs per Flat
200 Ltrs per Flat
250 Ltrs per Flat
In lodge, Hospital, Hostel & Rest. House of Taking BathHot Water Common tap outside bathroom
Hot Water tap inside bathroom
20 to 25 Ltrs per person30 to 35 Ltrs per person
In hotel
Low or Medium Grade
High Grade with Deluxe Room
Star Category
Hot Water tap inside bathroom
With Mixer & Shower without tub bath
With Mixer & Shower with tub bath etc
30 to 35 Ltrs per person
40 to 60 Ltrs per person
150 to 200 Ltrs per person
In Restaurant & CanteensOily dish washing under hot water tap15 Ltrs per dish
For Industrial RequirementsQty. of hot water required in 24 Hrs. i.e. per day is to be observed at actual.System rating to be decided as per actual daily observations

Post purchase Advices for Redsun ETC Non-pressurised Solar Water Heaters:

Do not supply cold water in empty system during afternoon hours:
Its dangerous to supply cold water to solar water heater during afternoon hours if the system is empty, due to sudden temperature changes into ETC, Tube may break, if cold water abruptly enters the hot glass tubes. However the tubes are designed to take such impact to great extent.

Cleaning of Vacuum Tubes:
Outer surface of glass tubes must be kept clean by frequent removal of dust whenever accumulated. Dust cleaning on vacuum glass tubes is necessary in winter as dew in early morning will help the dust accumulated on vacuum glass tubes to make thick layer of dust day by day on vacuum tubes. Regular cleaning of dust on vacuum tubes every 20 days will help you to get maximum hot water output during chilly winter days.

Covering of Vacuum Tubes during Hot Summer Days:
Its advisable to cover vacuum glass tubes with thick cloth or suitable obstruction so that water don’t get excessively hot during hot summer days.

Shadow free Place :
Remove any of the objects obstructing the sun-rays while reaching the absorber panel by forming shadows. Consider such obstructions while installing the system.