The following pages will cover all my personal experiance gained since 1991 until 2017 related to solar water heating
On returning to the UK in 1998, with the SUNDA agency and later on establishing Powertech Solar Ltd as the exclusive UK importer/distributor of the Apricus and Suntech solar heat pipe brands ( also exported into Europe as well as supplied direct to UK installer companies) the majority of our sales/installations was as a split pumped system for domestic hot water only or solar central heating with our Thermal Stores.
This picture is of a social housing project in Cornwall
This is a typical solar hot water only system seen across Cyprus and Israel with the option at a higher cost, for the hot and cold water tank located in the basement or garage.During my 5 months in Cyprus, there were always water shortages, so this resulted in large cold water tanks also installed on the roof as well as on the ground, but needed a pump. But in Israel, the solar water tanks made of steel and glass lined were designed to except cold water at mains pressure.
This 20 x 30 tube collector installation on the roof of a care home in Sussex/UK, was plumbed into one of two 1500l vented thermal stores, thus eliminating the issues of lime scale.
After my 5 yrs of my flat plate collector experiances in Cyprus, seeing how they were assembled and installed, I decided on returning to the UK in 1998 that the NEW evacuated tube with a heat pipe as the future, as long as the hot water tank was a vented thermal store as I designed and developed it from 1990.
The majority of failed solar water heating (SWH) systems was caused by lime scale due to the same potable water being in the water tank and the collector.
Both these countries used bore holes and resorvoirs for there water which had heavy lime deposits. As the cold water heated up in the copper exchanger collector, the lime would coat the inner part of the 12mm copper tube behind the glass. Within 2 yrs the water flow through the collectors had almost stoped.
As much as I came up with a solution to solve these through a water conditioner, the local cyprus SWH industry was not interested as they were happy replacing collectors on a regular basis.
One of the most perfect uses for solar thermal all year round is useing the solar heated thermal store in the winter periods when the heating is switched on to use 100% of the day time solar heated water. During the spring-summer months, dump all the solar heated water via the thermal store into the swimming pool. For domestic hot water needs, the back up cost from a oil/gas boiler is minium, when the thermal stores temperature is stable at around 30-40c
This is one of 20 new homes being built by a British property developer in 2003, who asked me to supply an mains pressure thermo-siphon systems with evacuated tubes.
The cold water is pumped from a cold water storage tank located in the garden to the pressure tank. Adding an expansion vessel, limited the water pressure in the solar tank, as the tank heated up. Hot water expands by 10% of the volume in the hot water tank.
The majority of my knowledge and on hands solar water heating installation experiance started in Cyprus from 1993, after selling my luxery bathroom/kitchen and property refurbishement business in 1991.
My research in solar water heating collectors started 1991 after I designed an alternitive to a pressurized hot water tank, we called a Multi Fuel Thermal Store, made of copper sheet and foam sprayed insulatio. After working with a copper smith to produce my design, i started to make some early sales, but as soon as the mains cold water temperture droped to below 8c the thermal store was found to underperform.
The full details of thermal stores can be found under another link.
My decison to set up a new business in Cyprus came about after taking a much needed holiday in 1992, followed by two more visits and finding a British person married to a Cypriot working as a plumber. In 1993, I packed and shipped a 40ft container of a varied mixed range of products to be unloaded into a rented shop in Paphos.
I had planned to be there for 6 weeks setting up the showroom with my own solar collector on the flat roof, with a imported batch water heater with glass tubes on the front of the shop after building an extension to the shop front that represented a UK pitched roof. In those days, there was no digital camera, only film type, which is why I have no early pictures to show, until 2 yrs later.