Solar water heating, Legionella and heating daily to the store base

Solar water heating systems using comnventional hot water stores are reported by a UK government water safety agency WRAS as being highly likely to be creating a Legionella safety risk. Legionnnaire's disease risk can be minimised by improved design. One safer solar storage solution used by Solartwin is called dedicated solar volume in time. This safer design involves heating to the base of a solar hot water store every day in the evening to 60C. This solar hot water storage method fullly complies with regulation UK HSE Legionella L8 guidance para 158. Another safer solution is a thermal store. The safety principles also apply to heat pumps. Includes a suggested way to calculate the statistical number of people infected with Legionella per year from solar cylinders in UK.