Overcoming heritage refurb challenges

An exciting and challenging heritage project is underway at one of England’s greatest stately homes. And a newly upgraded heating system involving our Potterton Commercial Sirius three boilers is playing a vital role in protecting this historic building and its contents for future generations.

Replacing ageing boilers in historic, listed buildings can be challenging at the best of times, and never more so than in the middle of a global pandemic. However, it’s vital that the heating system operates efficiently, both to protect a building and its contents as well as to optimise thermal comfort. So, when the dated old boilers serving Wentworth Woodhouse began to show signs of failing, the estates team needed to find a rapid and affordable replacement – fast.

Wentworth Woodhouse is a hidden architectural gem set in the heart of South Yorkshire. With its iconic façade, vast gardens and wide, open grounds, it will be familiar to many as the backdrop for numerous television and film period dramas including Darkest Hour and Gentleman Jack. 

Once the seat of the Earls Fitzwilliam, today the 18th century, Grade-I listed stately home is owned by the Wentworth Woodhouse Preservation Trust, who bought it in 2017 to save it from decline.

The Trust’s 20-year restoration masterplan to repair and regenerate Wentworth Woodhouse is well underway to ensure that the house will flourish for centuries to come. Protecting the buildings and the stunning architectural features was a natural priority, and a huge amount of essential repair work, including tackling dry and wet rot, has now been completed. 

Rapid solution

So, when faced with a boiler emergency at the start of the heating season, the estates team immediately evaluated the options open to them.

“We had to act fast to improve humidity levels in the house, especially in the state rooms,” explained Julie Readman, head of the Wentworth Woodhouse estates team. “And, of course, we also want our visitors to be warm once the pandemic restrictions are lifted and we are able to welcome them back to Wentworth Woodhouse!” 

Heating buildings with energy from a renewable source is the ultimate goal for the building services industry. However, in older, poorly insulated buildings with high temperature heating systems, the economically and technically viable options can be limited when replacing ageing boilers – especially when the building is listed. 

“Our future aim is to introduce green heating technologies,” continued Julie. “But at the time, the complexities of heritage refurbishment and the inability to plan ahead meant that installing replacement boilers was the only feasible option.”

Upgrading any dated or inefficient boilers to high efficiency condensing boilers remains one of the most cost-effective solutions to improved efficiency. It might not take us all the way to net zero, but it will make important strides towards our target if the focus is on using the energy as efficiently and effectively as possible.

Optimising efficiency

At Wentworth Woodhouse, durability, reliability and efficiency were the major requirements when selecting replacement boilers to optimise operational cost savings.

The Potterton Commercial Sirius 3 Floor Standing boilers with integrated plate heat exchangers and boiler shunt pump kits met all the criteria. The Sirius three range offers high gross seasonal efficiencies of up to 97.5%, a wide 9:1 modulation ratio for improved efficiency and boiler longevity, weather compensation functionality for reduced operational costs and stainless-steel heat exchangers for reliable and energy-efficient heat transfer. 

The boilers are also supplied with the latest Siemens controls with state-of-the-art PCB for improved control options. The plate heat exchangers and additional filtration will protect the new boilers from any system contaminants for increased longevity, while ensuring optimal system performance and efficiency.

The estates team specified two Sirius three FS 150 boilers with a third boiler to be installed at a later date, when funds allow, to ensure optimum reliability of the service.

Plant room_Sirius three_600x450

Space constraints

NRC Services Ltd were appointed the project contractors.

Nathan Briddock, Mechanical Divisional Director at NRC said: “Given the nature of the building, the project involved the typical refurbishment challenges, all of which we were able to successfully overcome.

“The space within the basement plant room is limited, so it was tight to fit in the new equipment, flues and ventilation and allow space for the third boiler. But thanks to careful planning and the compact dimensions of the Sirius three boilers, we managed to position everything within the available space and ensure good access for future maintenance.”

Flueing considerations

The flueing arrangements for the new condensing boilers were also more complex due to the listed nature of the building. 

“We explored lots of options,” said Julie, “but the only solution that met the exacting legislative and heritage considerations was to use the existing flue void.”

Flue specialist Jeremias Chimney Systems installed a new flue in the same service riser with new ventilation ducts routed to courtyard for aesthetic purposes.

Efficient, 21st century heating

The project was completed within the two-month schedule.

“Both Baxi Heating and NRC did a great job with the installation and in ensuring that we achieved the most appropriate and cost-effective solution,” confirmed Julie. 

Due to COVID restrictions, Wentworth Woodhouse is temporarily closed to the public. The Trust received grants from the UK government’s Culture Recovery Fund to help it through the winter, awarded by Historic England and the National Lottery Heritage Fund on behalf of the Department for Digital, Culture, Media and Sport. This funding has enabled it to install and run the refurbished heating system and so protect the building fabric.

The estates team has fitted a gas meter to monitor fuel consumption moving forward and is anticipating considerable carbon and energy savings from the new boilers. 

“The new Sirius three boilers are up and running and providing an impressive amount of heat in our state rooms,” Julie added. “Even with just two boilers (300kW), we are getting more heat than we did with our old boilers, which had a total output of 420kW. They are so much more efficient – we’re delighted!”