Eco Hi Solar Thermal FAQs

Is my roof suitable?
Ideally, at this latitude, your roof would be oriented south and have a pitch of 35 degrees. However, it is possible to install solar systems onto many surface types (pitched and flat roofs, walls, gardens, pergolas etc) with orientations from west to east and pitches from 0 to 90 degrees with varying levels of efficiency loss. However it is preferable for pipe runs to be short.

Is Planning Permission needed?
In England and Scotland, changes to permitted developments rights for renewable technologies introduced on 6th April 2008 and 12th March 2009 respectively, have lifted the requirements for planning permission for most domestic microgeneration technologies. Always check with your local planning authority whether you require planning permission or not.

Permitted developments:

What is MCS?
The Microgeneration Cerification Scheme is an independent scheme that certificates microgeneration products under 50kW and installers in accordance with consistent standards.

How do I determine the size of the system?
Solar thermal systems are most efficiently sized by understanding the daily hot water requirements of the household.  Generally the goal is to design a system that covers the hot water requirement entirely in the peak summer months.  For example, an average 4-person household will require 2m² of evacuated tubes and a solar cylinder of approximately 200 litres.

Do solar thermal systems work with combi boilers?
Yes they do. Combi boilers take water direct from the mains and heat it as required. The engineering to install solar thermal systems with combi boilers is more complex, but here at Eco Hi Solar our engineers can design such solar systems. A new cylinder will need to be installed in order to store the solar energy (heat).

Can solar thermal systems be integrated with ground source heat pumps or air source heat pumps?
Yes, and the various technologies often link up with a thermal store.

Can solar thermal systems be used to heat a swimming pool?
Yes, we can take the heat from solar collectors and use it to heat the pool. The solar collector area varies from 50% - 100% that of the pool. Heat exchangers may be used depending on the solution chosen.

Can solar thermal systems be used for space heating?
Yes, usually we combine the solar system with a large thermal store and integrate with under-floor heating. A greater area of solar collector is normally required.

How long does it take to install a solar thermal system?
A straightforward installation usually takes 2 days to complete and this involves installing the collector, changing the cylinder and doing the associated pipework including insulating the pipework to a high standard.  Many retrofit projects or new builds require installation of components at varying times and therefore the project can take longer.

What maintenance is required?
Provided some simple maintenance is carried out, the expected life of a solar water heating system is in excess of 20 years and we have seen many examples to prove this.

Five-yearly checks
It is recommended that the system should be completely drained and flushed, then refilled with new antifreeze/inhibitor.  At the same time all insulation, pipe work and correct operation of components should be checked.

What happens if I go on holiday?
If you are not going to be using hot water for 2 days or more between March and September we suggest switching off your backup heating altogether until you return. This will save energy and control overheating. It is good practice to leave the airing cupboard door open. Upon your return switch the boiler back on and heat the water to at least 60C for an hour before using it.

What is the significance of Legionella Bacteria?
Legionella bacteria grow in water at temperatures between 20°C to 46°C. They are killed quickly at 60°C. It is therefore important to ensure that solar pre-heated water (which can vary in temperature from 5°C in winter to 85°C in summer) passes through an auxilliary heat source capable of heating to at least 60°C before distribution to the domestic hot water system.

What is a heat dump–radiator?
If the property is to be unoccupied for long periods of time it is possible to install a radiator which connects to the solar system pipework to divert excess heat. This is not necessary with many solar systems.

What is a drain-back system?

 This is a solar system in which the solar transfer fluid drains back out of the collector when the solar pump switches OFF. This may be appropriate if there is an issue of too much solar-generated heat during times of low hot water demand (e.g. a holiday home or a school). Our engineers will assess your situation and advise whether this system is suitable.