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Helping businesses make the switch

Technical Director Andy Green comments on updates to Approved Document L of Building Regulations

As updates to Approved Document L of Building Regulations ruling out non-condensing direct-fired water heaters come into force today, the hot water industry will be instrumental in ensuring a seamless switch to higher efficiency condensing water heaters.

Under the revised regulations, all direct-fired water heaters must now achieve a minimum heat generator seasonal efficiency of 91% (GCV) for natural gas and 92% (GCV) for liquefied petroleum gas (LPG). For indirect-fired water heaters, the minimum heat generator seasonal efficiency is set at 91% (GCV) for both natural gas and LPG. The new requirements apply to both existing and new non-domestic building stock.

Effectively, the uplift ends the option to carry out like-for-like non-condensing water heater replacements in the vast majority of non-domestic buildings in favour of higher efficiency condensing units.

The changes are part of the government’s roadmap to help the UK move towards its net zero target by 2050 by improving the energy efficiency of existing non-domestic buildings.

The valuable energy-saving benefits to end users from upgrading to condensing water heaters, which are on average up to 20% more efficient than non-condensing models, are clear. The move will help mitigate soaring energy bills while reducing carbon and NOx emissions for a more sustainable installation – particularly when combined with heat pumps to deliver more economical heat without compromising on peak hot water demands.

However, given that factors like and condensate arrangements will need to be taken into consideration and assessed on a project-by-project basis, it’s important to encourage businesses to plan ahead. Taking action now will help protect their operations in the future and avoid potentially costly, extended downtime and disruption.

Even on the few and far between projects where exemptions to the stricter efficiency standards apply, forward planning is essential. Early engagement will be critical if contractors are to ensure that the Building Control Body is satisfied with the recommendation and avoid any risk of censure.

Putting in place proactive asset management, regular condition surveys and robust upgrade programmes will all help facilitate this, efficiently optimising plant performance while allowing businesses to budget ahead.

Energy savings aside, the transition to condensing water heaters also brings an opportunity to reassess current hot water requirements, especially in buildings where occupancy and energy usage has changed in recent years. Ultimately, the revised calculations could point to a smaller water heater now being required, which would reduce both initial capital expenditure and longer-term running costs.

There may even be the option to relocate the plant – to the rooftop or outside – to make better use of space, perhaps creating new offices or hotel rooms.

The many carrots to be gained from this latest governmental stick are evident. But across the industry – from designers and specifiers to facilities managers, contractors and manufacturers – we must actively encourage increased forward planning to avoid buildings being left in an emergency situation with no hot water supply.

Experienced manufacturers have prepared for the changes, with many expanding their high efficiency condensing water heater ranges as well as offering customer awareness training and free site visits to assist with sizing and recommend the most appropriate solutions. Working together, we can help ensure a smooth transition to a more sustainable and future-proof hot water system that meets all project and legislative requirements.

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