302J Roof Top Solar: Key Attributes
The Solahart J Series is a roof mounted, closed circuit solar water heater specifically designed to provide economical service in medium to high solar gain areas. It is recommended for use in frost or poor water chemistry areas.
The J Series features Solahart's revolutionary multi-flow collector to extract the maximum amount of energy from the sun. This is used to heat the Hartgard fluid in the collector which rises into the heat exchanger where the heat is transferred to the water inside of the tank. The ceramic lined tank has a protective anode and the SP Free Heat series features additional protection.
- Space saving roof mount design
- Reliable, low maintenance operation
- Energy Efficient – cuts water heating energy use by up to 89%^
- Reduces household greenhouse emisions
† Solahart Warranty Details: 5/5/5 warranty; 5 year cylinder and collectors supply, 5 year parts, 5 year labour. 10/5/5 warranty, 10 year cylinder and collectors supply, 5 year parts, 5 year labour.
302J Solar Specifications
|Thermosiphon J Closed Circuit Systems|
|Tank Model||J - 300J
Free Heat - 300F
|Storage Capacity||300 litres|
|Boost Capacity||150 litres|
|Weight Empty Tank Only||107 kg|
|Weight Full Tank Only||407 kg|
|A-Width* Tank Only||2.43 m|
|Weight Empty System||202 kg|
|Weight Full System||521 kg|
|A-Width* System||2.43 m|
* For safe access and servicing, a space equal to the tank length should be left on the water connection end of the system and 1m (40in) should be left on the three other sides of the installation. ‡HartStat OTP is optional on these models in Australia and New Zealand. Systems (if installed with a HartStat OTP system) can be installed as a solar preheater with an inline Solahart gas booster water heater. Refer to the Solahart gas booster specification sheet for further details on the gas booster.
|Aperture Area||1.8 m2|
|Weight Empty||45 kg|
|Weight Full||49 kg|
|No OTP||80 kPa|
|With OTP||170 kPa|
|Absorber Surface||Black polyester powder coat|
|Number of Risers||35|
|Insulation Material (Base)||38 mm glass wool blanket|
|Glass||3.2 mm tempered low iron
|TPR Valve Setting||1000 kPa|
|ECV* Setting||850 kPa|
|Maximum Supply Pressure|
|With ECV||680 kPa|
|Without ECV||800 kPa|
*Expansion Control Valve.
|Electric Boost Specifications|
|Heating Unit Type||Copper sheath immersion element|
|Supply Voltage||220 V - 250 V|
|Recovery Rate @ 240 V and Temperature Rise Of:|
How Roof Top Solar Systems Work
The 302J solar system has its vitreous enamel lined solar storage tank installed on the roof directly coupled to the solar collectors. In the Closed Circuit Series, heat is absorbed by the collector and passed to the ‘Hartgard’ heat transfer liquid inside the collector. As the temperature of the ‘Hartgard’ increases, the hot fluid rises up through the collector by the Natural Thermosiphon Principle, into the heat exchanger jacket around the potable water storage tank. Here, the heat is transferred to the potable water, cooling the ‘Hartgard’ fluid. The cooler fluid is then forced back down into the collectors through the displacement action of further hot fluid rising up into the heat exchanger jacket.
Orientation of Solar Collectors
To help maximise system performance, solar collectors should be installed with an optimum orientation facing true north (in the southern hemisphere) or true south (in the northern hemisphere). Always check for true north or true south using a compass or other suitable device.
To help maximise system performance, solar collectors should be installed with an optimum inclination. This is equal to 90% to 100% of the local latitude angle when collectors are oriented within 60° of true north or true south, and between 10° and 20° if the collectors are oriented between 60° and 90° from the optimum orientation. Generally, improved summer performance is obtained from an angle of inclination less than the optimum angle and improved winter performance is obtained by an angle of inclination greater than the optimum angle. If the angle of inclination varies by 20° from the optimum angle, the solar collectors will receive about 10% less total annual solar radiation.
Solahart Closed Circuit Systems are protected against freezing or harsh water conditions by our exclusive ‘Hartgard’ fluid. ‘Hartgard’ is a blue, non-toxic, propylene glycol fluid which, when mixed with water, provides the Heat Transfer Fluid contained in the solar collectors and the heat exchanger jacket around the tank. ‘Hartgard’ is used to lower the freezing temperature of the Heat Transfer Fluid and so provides protection against freezing (Note: for the correct % of Hartgard in the Heat Transfer Fluid, refer to the section on Frost / Freeze Protection). ‘Hartgard’ is a special food grade solution and is the only solution permitted to be used in the closed circuit systems. Hartgard has been approved by the National Health and Medical Research Council of Australia.
An isolating switch is installed in the electrical meter box for an electrically in-tank boosted model. This should be left switched on to allow the booster heating unit to operate if required. The booster heating unit is for heating the water at times of low solar energy gain, such as during very cloudy or rainy weather, or during the colder months. The booster heating unit will only activate if heating is required and power is available from the switchboard. When the water is below the thermostat setting, the booster heating unit will turn on and heat the water. The booster heating unit will automatically turn off when the temperature of the water reaches the thermostat setting. If the water temperature drops below the setting again the booster will re-activate.
In-Series Gas Boosting
An in-series gas booster (also known as a continuous flow gas booster) can be installed between the solar water heater and the hot outlets in the house. This booster should be permanently active. The booster senses the temperature of the water passing through it: if the water temperature is above its temperature setting it does nothing; if below it will automatically heat the water up to the preset outlet temperature setting. This gas booster ensures hot water delivery for a variety of hot water demands without the need for user intervention while enabling maximum solar energy contribution to the water heating. For more information on this booster, consult the owner’s manual for the product.
Over-Temperature Protection System
The Closed Circuit Series solar water heaters have a means of controlling the maximum temperature of the water in the storage tank. These systems may be installed with a ‘HartStat’ valve located between the hot outlet of the collectors and the inlet to the tank heat exchanger. This valve closes when the tank has reached a sufficiently high temperature, thereby preventing further heat transfer to the tank, and thus limiting its temperature.
Why Solahart Solar Hot Water Systems: Download
Solahart 302J Solar Hot Water System Brochure: Download
Solahart In-Line Gas Booster Brochure: Download
Solahart On-Roof Solar Hot Water System Owner's Guide and Installation Manual: Download
Solahart In-line Gas Booster Owner's Guide and Installation Manual: Download