The Church of Our Lady of the Assumption and the English Martyrs, Cambridge
Sector: Listed building refurbishment
Products: Varmax floor standing boiler
Application: Space heating
A need for change
Heating is an essential aspect of churches, as it helps to keep congregants warm and comfortable during services, especially during the colder months. With a large vibrant community with various parish groups and activities running at The Church of Our Lady of the Assumption and the English Martyrs Church, it was clear that the building would benefit from an efficient heating system when it came to replacing the existing failed gas fired cast iron boilers with pressure jet on/off boilers that were at the end of their operational life.
Heating a church can be challenging, especially if it is an old or large building. To evaluate the needs of the building, Bunton M&E was contacted to advise on updating the system. Robin Bunton, Bunton M&E commented,
“The client needed an affordable and reliable system that could be installed but there were
also various practical issues to consider as a result of the building’s age and Grade 2 listing status at the time of the refurb”.
Following a site visit, Bunton M&E identified the challenges as two-fold: as with many church buildings which are often centuries old, the church had an old existing heating system. The system comprised of cast iron radiators and fin coiled gas fired cast iron boilers with pipe trench heaters which were required to be kept at a high flow temperature with a conventional 11ºC delta T - this ensured that the mean water temperature was retained at over 76ºC to adequately heat the building. As the building was currently Grade 2 listed at the time of the project, the restricted flue size could not be enlarged.
Following discussions with various manufacturers, Bunton M&E turned to its local Hamworthy representative, who proposed a Hamworthy system using two 275kW high-efficiency floor-standing condensing Varmax boilers, cascaded in unison.
This decision was largely based on the large water capacity of the stainless steel heat exchanger of the Varmax. The stainless steel heat exchanger with 5-year warranty also has the added benefit of corrosion resistance which is an advantage for buildings or areas where the water is soft or has been artificially softened.
In addition to efficiently meeting the existing design parameters of the church, the simplified flue arrangement also provided a fitting solution to overcome the existing issues surrounding the restricted diameter of the chimney. Furthermore, as a separate plate heat exchanger did not have to be installed, this meant that, together with ensuring the original design flow temperature was unchanged, the church was able to benefit from valuable capital cost savings.
Going forward, the church can also expect to achieve savings on future servicing and maintenance intervals of the new system. Featuring wide opened hinged doors, larger Varmax models, such as those used in this project, include a fold out step and an LED light for easy access to the burner and electrical components for quick and simple access to the boiler. Featuring a lightweight design and a compact footprint, the new boilers also free up valuable floor space within the plant room. Straight forward to install, the new Hamworthy system was built offsite at Bunton M&E workshop and dissembled for transportation to the church, where it was installed and commissioned in three weeks. Robin Bunton commented,
"We have been installing Hamworthy products for over 35 years. Offering an excellent sales team, Hamworthy also provides a professional commissioning team with reliable technical support and a large catalogue of spares, all of which guarantee a trustworthy and efficient service".
The new installation now provides the church with an efficient heating system that will help to reduce overall gas consumption and subsequent running costs. Furthermore, as the church and the rectory now have separate heating zones which are remotely controlled on-site via a BMS system, the church can fully optimise its heating system and enhance the comfort of its parishioners for many years to come.