Boiler cascades made simple: 5 things that make selection & installation easier
By
Charlie Mowbray, Senior Product Manager, Ideal Commercial Heating
Boiler cascade systems can offer significant advantages on refurbishment projects, particularly where heating demand varies and plant room access or space is restricted. A well-designed cascade should also be straightforward to specify, install and control. Here are five areas that can make the process easier.
- Start with the load, not the number of boilers
The starting point should always be the building’s heating requirement. A commercial building rarely needs its full design output all of the time, with demand changing according to outside temperature, occupancy and how different areas are used.
Several smaller boilers operating in cascade can be brought online or taken offline as demand changes, providing a greater overall modulation range and allowing the system to match the load more closely, particularly under part-load conditions.
- Use configuration tools to simplify design
Refurbishment projects often bring added constraints, including limited plant room space, difficult access and existing hydraulic arrangements.
Online configuration tools can simplify system design by guiding users through the available boiler combinations, hydraulic options and accessories. Ideal Commercial Heating, for example, offers separate Cascade Configurators for its Evomax 2 wall-mounted and Imax Xtra 2 floor-standing boiler ranges. These generate a complete cascade package, including a schedule of required components.
Configuration should also take account of the available space, with low-height or back-to-back arrangements potentially useful where plant room dimensions are restricted.
- Make use of prefabrication
Good quality prefabricated frame and header kits reduce the amount of measuring, cutting and fabrication required on site. This can save valuable installation time. Using Ideal Commercial Heating’s prefabricated frame and header kits, for example, a three-boiler Evomax 2 cascade can be assembled in under 90 minutes.
Smaller individual boilers may also be easier to manoeuvre through restricted access routes than a single large appliance.
- Don’t assume you need a complex BMS upgrade
Good cascade control is essential, but that does not necessarily mean installing or substantially upgrading a Building Management System (BMS).
With Evomax 2, Ideal’s Varican plug-in control card enables boilers to be linked and sequenced without requiring a complex BMS purely for cascade control. Where a BMS already exists, it can continue to provide the heating-system demand signal while Varican manages boiler sequencing.
That can be particularly valuable on refurbishment projects where altering an existing BMS would add cost and complexity.
- Design for servicing and resilience
One of the strongest arguments for a cascade is resilience. If one boiler is isolated for servicing or repair, the remaining appliances can continue operating.
But resilience should be designed into the installation. Ease of access, boiler isolation, rotation, reliability and manufacturer support should therefore all be considered from the outset.
Get these five elements right and a cascade can provide a flexible, efficient and dependable solution that is particularly well suited to the challenges of commercial refurbishment projects.
