Why our solar heating?

The Radiant Solar Hot Water system is stylish, powerful and can be used for just hot water or as part of a complete heating system.

  1. The Radiant Solar Hot Water System
  2. Solar for Swimming Pools
Radiant Solar Collectors

Radiant solar collectors are made by the German ‘Ritter’ solar organisation, a leading name in the world of solar heating.

We have three different modules (width sizes of collector), 6 tube, 12 tube and 18 tube. All our collectors come fully assembled and ready to fit on the roof or mounting frame.

The different widths of the collector modules offer considerable flexibility in the design of tailor-made collector arrays. Short installation times are guaranteed thanks to off-the-shelf collector units and simple technology for connecting several collectors in together. The use of high quality materials guarantees considerable operational security and a long service life. Thanks to the CPC reflector, it is ensured that each individual tube is always optimally oriented to the sun.

The CPC evacuated solar collectors provide high energy yield and long life expectancy. Produced from quality materials and components, the solar collectors are corrosion resistant and easy to install and maintain. Hailstone impact tests, in accordance to EN12975-2 and thermal shock tests by ITW ranks this collector amongst the finest solar system in the market place.

The CPC evacuated solar collectors are the most advanced technology solar collector available today. Designed specifically to perform efficiently in climates similar to the UK, the vacuum insulation and the CPC reflector produces a remarkable “all weather, all year round” performance.

The ‘CPC’ Reflector

To increase the performance efficiency of evacuated tube collectors, a highly reflective, weather-proof CPC reflector (Compound Parabolic Concentrator) is fitted behind the evacuated tubes. The special, improved geometry of the reflector ensures that direct and diffused solar radiation falls on the absorber even when the angle of incidence is not ideal. This considerably improves the energy yield of the solar collector.

Performance Benefits

  1. Vacuum Insulation
    A high level of vacuum makes the solar tube collector light reactive, rather than heat reactive. The collector works even on cold and overcast days, giving exceptional performance no matter what the weather is.
  2. Reflector
    The CPC collector has an external reflector which concentrates radiation into the absorber, thus increasing the effective capture area. This effectively means that the Radiant collector can absorb the same amount of solar irradiation of a larger traditional flat panel design, more power, less expense.
  3. Absorber
    A 360° glass absorber allows the effective capture of sunlight and makes the angle of the sun less of a problem.
  4. Aperture Area
    Due to its unique design, the collector has a very high aperture area when compared to its overall size. This allows a greater output per m2 when compared other types of panel.

Equipment Benefits

  1. Costs
    Radiant CPC Collector Solar Systems are a similar price to a standard Flat Panel system = more performance for the same money.
  2. Quality
    All the components of the Radiant Solar system are from leading industry suppliers such as Watts Industries and RWC = proven technology with international support.

Consumer Benefits

  1. Performance
    High outputs even on cloudy and cold days = more hot water during the winter.
  2. Set & Forget
    Simple to use controls look after the installation all year long, even recording the amount of energy generated.
  3. Piece of mind
    Once installed your Radiant Solar system will continue to produce hot water for years to come. Our collectors have a 5 year warranty.

Pumps and Controls

The solar pump station is a one piece module allowing quick assembly and precise control. pump stationConnected to this is the solar expansion vessel, sized by Radiant to match the total fluid capacity of the system.

Download pump information pdf (2MB)

We offer three types of controllers, basic, advanced and integrated.

basic controllerBasic
Used for simple systems of collector and cylinder only with added safety features.

advanced controller

Used when there are variations in the system such as two tanks or east/west collectors with additional safety features.

intergrated controller

Used when the solar system forms part of a larger integrated design requiring advanced energy management controls.


To complete the system we have:

  1. Twin pre-insulated flexible stainless steel hoses with sensor cable and connection adaptors.
  2. Solar rated expansion vessels.
  3. Single or twin entry roof flashings in either lead or coated alloy.
  4. Ready to use Solar fluid in handy 5 litre containers.
  5. 3 port diverting valves and actuator.
  6. In line heat exchanger for swimming pools and GSHP ground collector.
Solar for Swimming Pools

There are two ways of heating a swimming pool with solar warmth. The first is a direct type whereby the pool water is pumped through the solar collector. These collectors are mostly just coils of plastic pipe mounted on a nearby roof. They perform particularly well in hot climates but are not best suited to the UK climate. Radiant do not supply this type of solar equipment.

The second way is to use a standard solar collector and through a heat exchanger indirectly heat the pool water.

The Radiant Solar collector can be used to solely heat the pool or as part of some system integration schemes.

solar collection for swimming pools

When used as an addition to heating the hot water cylinder a special pool heat exchanger is used. This fits in to the pool filtration circuit in the same way as any pool heat exchanger does. Using the Radiant advanced solar controller surplus solar warmth is diverted into the special heat exchanger. The system design has to be such that large collector areas do not overpower the hot water cylinder or any other part of the system.

It is advisable to use the Radiant system design service when considering heating your pool with solar warmth.

Advantages of the Radiant Solar system:

  1. Less panels (collectors) required than for standard plate panel systems
  2. Better year round performance, ideal for indoor pools and spa’s
  3. Can be integrated into the main heating system
  4. Can supplement the existing pool heating
  5. Good all year round performance thanks to the CPC technology

An alternative to solar is a dedicated swimming pool air source heat pump. For information on these see our Pool ASHP page.

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  • design service

The term CPC stands for Compound Parabolic Concentrator and refers to the special mirror behind the evacuated tubes. This mirror greatly improves the energy absorption of the tube resulting in more energy generation.
For anything other than a simple basic solar system it is strongly advised using the Radiant design service. With high performance solar systems such as the ones supplied by Radiant it is imperative to size all parts of the system correctly. Failure to do this would invalidate any warranty and could be dangerous.
A mixture of propylene glycol, water and corrosion inhibitors that is able to withstand extremes of temperatures. This fluid should be inspected periodically and replaced when necessary.
A method of system control utilising temperature sensing inputs to accurately establish real time heat requirements. This can be a simple room control to optimise the rate at which heat input is delivered. It does this by checking how quick the room temperature rises and controlling it to make sure it does not overshoot the set level. More complex controls monitor the outside temperature as well as the internal temperature. These devices can calculate the minimum amount of heat required and control its delivery in to the building. This precise control saves unnecessary fluctuations in room temperature that result in wasted energy.
The solar fluid is contained in the sealed unvented circuit of the solar system. Because of the extremely high temperatures involved this fluid must be allowed to expand. The expansion vessel is a sealed tank with a special membrane across the middle. Solar fluid is on one side of the membrane and an inert gas on the other. The expanding fluid pushes against the membrane and compresses the gas. It very important that these vessel are sized correctly by a professional. Using the design service from Radiant will ensure the correct sized vessel is specified.
The advanced solar controller displays the current energy being generated by the collector. The running total of which is recorded for reference and can be viewed at any time.