deepeedeepee wrote:Whaler,
typically most solar systems have a "closed loop"collector panel with the heated liquid(vegetable oil is commonly used) then being piped thru a coiled pipe inside a water supply tank. The absorbed heat is given off into that water . This water supply can be pressurized ie what ever pressure your normal water supply comes in at or simply gravity fed down from the supply tank if roof mounted.
Sorry you misunderstood
I was refering to the normal hot water tank inside (used for cold during the summer) which is usual heated by an electric element, will have to withstand normal domestic water pressure.As you note the solar tank direct or indirect can be both a simple open tank or a closed presurised one. With an open system it will have to be mounted up high to produce a static head of water. With indirect using a closed coiled piping if not pumped to the storage tank it will have to be reasonable close to allow natural convection to circulate the heated water via the coil to the storage tank. The advantage of the closed indirect system is it allows the storage tank to be insulated to over come heat loss during the night if the circulating pump is temprature controlled.
The problem comes on how your house is configured with the small instantaneous electric heaters used in Thailand. If you have only one main one then there is dual pipework but if you have individual ones in each bathroom then not only the cost of the solar unit but more additional pipework.
As for savings if you run washing machines and dishwashers daily then your in with a chance
