Solar News 25 August 2009. Following an inquiry from Barry Johnston, Managing Director of Solar Twin Ltd, to the UK’s Health and Safety Executive, a three hour meeting took place this week to consider the contentious issue of Legionella safety in solar water heating systems.

For background, Solar Twin Ltd have recently been told by some senior players in the solar hot water heating industry to stop expressing our legitimate concerns on our websites that most of UK’s twin coil solar water heating hot water cylinder installations clearly do not comply with the safety guidance in the HSE document L8 (Legionella Approved Code of Practice and Guidance para 158) which states that hot water cylinders should be heated to the base to 60 C for an hour every day. Most solar cylinders do not do this.

“After making a phone call, we wrote a short email to HSE asking certain questions about an apparent inconsistency between the England and Wales building regulations and HSE guidance. We were pleased that HSE promptly responded with an offer to meet myself and colleagues at our premises.” Commented Mr Johnston. The main inquiry was as follows:

“There are possibly inaccurate references to HSE Legionella ACOP&G L8 in DCLG document called Building Regulations part G.

“What is the correct scope of L8? The HSE interpretation document called Legionella Residential 2003 includes: “A wide range of organisations, groups or self-employed individuals providing residential accommodation who are responsible for the water system(s) in their premises, including:   local authorities;   universities;   housing associations, including housing companies; charities; hostels;   landlords in the private renting sector;   managing agents;   hoteliers, B&B, guest house and holiday camp owners;and caravan and camping site owners, including fixed caravan sites.”

“But in the new Building regs Part G3 on water, in section 3.6 there appears to be a paragraph which draws attention to L8 only in relation to workplaces and not to the above large list. This seems to be anomalous. Perhaps some relaxation or reduction of HSE’s scope is taking place and I hope you can clarify this.

“Question. If someone contracts Legionellosis in a social home and if a solar hot water installation which clearly does not comply with L8 is found to be the cause, will the installer of it be open to prosecution under the 2003 document? Or will they be protected from prosecution by what is written in the more recent part G document? I would grateful for a written response.”

Solar Twin Staff met with HSE and raised this interesting question along with some other areas including safety of a variety of types of solar hot water stores, external solar loops in direct systems, and ways that some thermostatic blender valves are installed.

Besides the Building Regulations, UK Documents relating to Legionella and L8 guidance compliance linked to the British Plumbing Education Council (BPEC), the Energy Saving Trust (EST), The Microgeneration Certification Scheme (MCS), The Building Research Establishment (BRE), and the Chartered Institute of Building Services Engineers (CIBSE), were also mentioned at the meeting.

In addition a short but perhaps rather influential European technical paper from Europe’s CEN Technical Committee 312 on Solar Thermal was discussed. CEN TC 312 are Europe’s most powerful solar industry people. They write the standards for solar heating in Europe. This paper conflicts with the CEN water safety standards committee on Legionella because it appears to conclude that unless the solar water heating industry can quietly impose a little bit of extra Legionella risk on to solar thermal users then their solar thermal system will under-perform by about 50%. It then asks for this position (ie that an environment imperative should trump safety) to become part of be European and national policy.

But is this 50% claim accurate? We think not. We presented to the HSE solar simulation data to show that this 50% energy loss claim is a huge exaggeration. In fact, for a given size of panel, the energy performance hit you get by using an L8 guidance compliant hot water cylinder is no more than 11%. Usually under 10%. Indeed, because this often that you can reuse existing cylinders instead of replacing them, that the costs-benefits of solar hot water systems which comply with L8 can actually be the same or even better.

“I am particularly concerned that Dr Chris Laughton, FIDHEE, who in UK is the Chair of BSI’s solar thermal technical committee RHE 25, besides being a technical contributor to many of UK’s solar regulatory committees and documents, has actually co-authored this inaccurate paper.” commented Mr Johnston. Concerned about where this 50% figure comes from, I have written to all four of the paper’s technical authors across Europe, including to Dr Laughton, asking them to justify their 50% assertion with real data. So far, over six weeks later, none has yet responded in any way at all, not even with a holding response. I am becoming concerned that their lack of response to our pointing out what seems to be an unjustified exaggeration aimed at dropping safety standards may eventually bring some sections of Europe’s solar thermal industry regulatory system into disrepute.

Towards the end of the meeting Solar Twin Ltd discussed the UK government’s aim to have 7 million homes with solar thermal fitted by 2020. This represents a 50-100 fold increase on today’s installed figures and means a massive installation rate of over half a million homes a year.

“I want to make sure that our industry starts growing in the right direction. Solar Twin Ltd are committed to delivering safe, sustainable, energy efficient and cost efficient solar water heating systems. All of the solar hot water systems supplied by Solar Twin today have zero carbon operation.

“As for Legionella, there remains a real problem because L8 compliant installations are still currently excluded from government grants in UK. This anomaly has affected about a thousand of Solartwin’s retail customers at £400 or more a time. We still have to give rebates in lieu of grants in order to gain retail business. We have foregone millions of pounds of business in the social housing arena because we cannot deliver 50% grants in the way that our competitors can. We are astonished that the Office of Fair Trading have not properly looked into our concerns.   All of the cylinders we fit into comply with HSE L8 guidance on Legionella safety. Our precautionary approach to safety is the challenge that the rest of the industry does not want to face up to.” explained Barry Johnston.

POSTSCRIPT. 26 Feb 2010 Sadly, Solar Twin Ltd have today been denied corporate membership from the IDHEE because we have criticised Dr Laughton “heavily”. Is this not a case of “shoot the messenger”? If you want a ball, feel free to lodge your complaint with IDHEE about either (a) Dr Laughton’s antics or (b) us irresponsibly and recklessly reporting his conduct to the public and thereby bringing our precious industry into disrepute. Let’s see how it squares with a rather stony code of conduct which is linked to the preceding words which are particularly black.