Andrews Water Heaters, part of Baxi Commercial Division, announces additions to the components of the SOLARflo solar thermal water heating system, including an extended choice of flat plate collector, the introduction of a new heat pipe evacuated tube option and added protection for the pump station.
The new SOL25OH flat plate solar thermal collector, manufactured within the BDR Thermea group, measures 2.35m2 and is suitable for installation in landscape or portrait orientation. New design places the absorber in a fabricated frame and the glass finish of the collector has been adapted to improve the efficacy of UV light, thereby increasing its efficiency for UK installations. Marketed under the Andrews Water Heaters brand, SOL25OH is MCS approved and ready for immediate specification.
The new heat pipe evacuated tubes, a high specification version of evacuated tubes, further extend the choice of solar thermal collectors. Designed to prevent solar fluid overheat and stagnation, they are particularly intended for buildings that have periods of low demand and/or non-occupation, especially when solar gain is high, such as schools.
Visually similar to direct flow evacuated tubes, the heat pipe collector uses a dry pocket connection and condenser bulb principle. Each pipe contains a small volume of evaporator fluid. As the pipe warms up, the fluid changes to a vapour and rises up the pipe to the condenser bulb. Within the manifold, the solar transfer fluid is passed across the dry pocket that houses the condenser. The condenser releases the latent heat of evaporation to the solar transfer fluid and condenses, the condensate returns to the heat pipe and the cycle is repeated.
The heat pipes contain a temperature limiting device which operates at 95oC, in the event of low hot water demand and continued collector heat gain, a bi-metallic valve prevents the condensed content of the pipe from leaving the condenser bulb, thereby protecting the glycol based solar transfer fluid from stagnation damage and eliminating unwanted heat transfer. This dry pocket design also allows for individual tubes to be replaced without draining down the solar system, offering lifetime repair and maintenance savings.
The Pump Station is now encased in a unit that incorporates a 15 litre cooling vessel to protect the rubber diaphragm within the expansion vessel from damage that can be caused when the solar fluid heats up and expands.
Baxi Commercial Division is the only supplier packaging all these components in one system.