The use of multiple modulating boilers is a good method for saving energy on larger loads –apartment buildings, for example. The scale of turndown allows for the “right-sizing” of heat to load as it changes during the day and year. Having more than one unit also provides security of service even during routine maintenance.
IBC’s VFC 15-150 and 45-225 modulating models are set up for staging without any extra controls – all that is needed is a 2-wire (twisted pair) connection between controllers and simple control settings using the keypads. During installation, a “master” boiler is selected, and the system can then be set up through that boiler to take advantage of the built-in outdoor reset function that will help optimize condensing operation and gain extra energy efficiency. IBC innovations such as domestic hot water “opt-out” and deep modulation squeeze even more out of your energy dollar.
Ease of venting IBC boilers allow for installation in difficult locations, and although the roof is always a good place for vent termination, doubly so with multiple units – where the steam plume can be that much bigger, sidewall options are popular provided a “sterile” wall is readily available (no windows, close neighbours). IBC has the longest vent allowance in the industry – up to 480′ with 3″ plastic pipe – so you can run wherever you need to go.
Use of a Primary/ Secondary piping configuration, with separate boiler pumps under the control of each unit is required. All of the components required in a typical installation can normally be picked up at a local supply house as off-the-shelf items, and as a bonus, repair work in the future can be performed more quickly and for less money due to these readily available components. For optimum efficiency, multiple condensing boilers should be placed in a parallel piping arrangement, so all units receive the same (cool) return water temperature. These are simple to install systems, readily understood by any competent installation team. The ability to move multiple boilers into position easily, allows for a complete boiler room replacement in commercial boiler rooms that have limited access for larger boilers. It is not uncommon for an IBC installation to arrive at the site through elevators or stairwells without the use of special moving equipment and crews.