Tom Murray, Specification Director at Baxi Heating, looks at the benefits of using off-site manufactured technology for multiple boiler replacement.

With commercial building energy efficiency set to be prioritised in 2020, ensuring that the heating system operates at its most efficient is more important than ever. Replacing any old or inefficient boilers with high efficiency condensing boilers and adding the appropriate controls remains one of the most cost-effective means of transforming a building’s energy performance. 

But, as installers know only too well, shrinking available space in plant rooms, restricted access, and tight project schedules frequently present hurdles to quality boiler installation. All of which explains the growing use of off-site fabricated solutions to simplify boiler replacement programmes.

Rapid bespoke solutions

Off-site manufacturing is well established as a technique that can deliver quality, customisation, and cost benefits with reduced waste. Certainly, when it comes to heating, it’s an approach that can deliver huge advantages to contractors and installers, from time savings to increased ease of scheduling.

Take the bespoke rig system. Using site-assembled manufacturer cascade options will simplify and speed up installation. However, with the off-site rig system, all individual project and site requirements can be addressed and resolved from the outset. This ability to design ahead means that best use can be made of the available space. It also reduces on-site time, making it easier to meet restricted deadlines or, in the case of school heating refurbishments for example, to complete more projects within a fixed timeframe.

Maxing efficiency

So, where to start? When it comes to ensuring long-term reliable heating provision, selecting boilers with a reputation for quality performance and an extended manufacturer warranty is the first step. The arrangement of the boilers on the bespoke rig will then help maximise long-term heating efficiency. 

Matching the heat load with multiple condensing boilers, rather than with larger boiler units, improves the modulation capability of the boilers and increases the turndown ratio. This way, the boilers are able to match fluctuating loads more accurately, resulting in more efficient use of energy and lower bills. It also makes for easier maintenance, servicing, and replacement, all of which reduce lifetime operational costs.

Design flexibility

The bespoke rig is based on individual boilers from 30-300kW output, with no limit to the number that can be incorporated. The maximum and minimum output is defined at the design stage, together with the number of boilers and whether to use a back-to-back or an in-line layout. 

Physical site restrictions can be addressed through a choice of header extensions and connections. A further option is to design the bespoke rig so that it can be split into smaller modules, with simple re-connection into a single frame in the plant room.

The rig can additionally integrate project-specific controls such as weather compensation, sequencing, or building management system direct operation to maximise seasonal efficiency and lower running costs.

These can be pre-wired to enable faster, more straightforward connections. Hydraulic separation can be achieved by integrating a plate heat exchanger into the rig design.

Only once the design is clearly defined and approved does production take place. This is carried out in a factory environment with quality-controlled end-of-line testing providing added quality assurance. 

The boilers are then delivered to site on a wheeled rig unit. As even the position and size of the system connections on the rig can be produced to match the existing system pipework in the plant room, installers will find connection to the system both easy and rapid. 

On time/budget

With the bespoke rig, the design and costs of the rig and boilers are defined and agreed in advance. As a result, it’s easier to keep the project on budget.

What’s more, with the equipment coming from one supplier, only one delivery slot needs to be scheduled. So there’s less chance of a delay due to late delivery, which helps keep the project on track. 

Benefits for all

Importantly, with a solution like the off-site fabricated rig, everyone is a winner. The building occupant benefits from more reliable heating and improved comfort levels with minimal on-site disruption. The building owner benefits from reduced heating costs due to the more efficient heating provision. As for contractors and installers, in the rig they have a flexible, rapid, high quality solution that enables them to achieve long-term high heating efficiency for their customers while maximising their own site productivity.

As organisations look to reduce energy waste at every opportunity, the business case for cost-effective boiler replacement is abundantly clear. And, with off-site manufactured heating solutions like the bespoke rig designed to overcome common refurbishment challenges, improving heating efficiency has arguably never been easier.