Time for change

It would be fair to say that the technology incorporated into the design of fire pump sets is not subject to rapid change. The focus on safety of building occupants and the protection of building fabric, understandably, involves an extensive process of product assessment and certification of fire pumps, to meet national standards and to satisfy the requirements of insurers.

In many cases, it would be difficult to justify entering into these lengthy and costly procedures to introduce a new product feature or a minor improvement in performance. There would be insufficient demand from customers to make these incremental upgrades desirable or commercially feasible. As a result, not all of the advances in technology incorporated into pumps for other non-safety related applications have been introduced into the design of fire pumps. This can be seen, I would argue, across all world markets, and in the product lines of all manufacturers.

In this article, however, I will be focusing on one key aspect of technology which is about to revolutionise the way in which fire pumps operate, representing a major step change in the way that these sorts of pumps are controlled. I refer to the introduction of variable speed pumping into the design of fire pump sets as an alternative to fixed speed. Over the last decade, variable speed pumping has largely replaced constant speed in pumps for HVAC applications.

The technology is well-established, with proven advantages and is widely available from all major manufacturers of HVAC pumps. For some time it has not been considered feasible to redesign fire pumps to operate on variable speed principles. The typical advantages relate to energy efficiency during operation and this, of course, is not the key priority for pumps that are only employed in the event of a fire. With the earlier variable speed pump models this was certainly the case, and manufacturers such as ourselves have continued to base our designs for fire applications on fixed speed capability.

With the latest generation of variable speed pumps, however, the cost justifications have changed significantly. This is because today’s pump models have a wider operating envelope than their predecessors, and the reductions in lifetime costs made possible by variable speed fire pump sets now provide compelling financial and technical arguments for migrating across to a more advanced technology. For fire pump installations involving high-rise buildings, and particularly those subject to pressure variations due to connection to the city main, these new variable speed pump sets bring advantages in terms of simplification of systems, lower installed costs, and reductions in the time and cost of routine maintenance. These all contribute to lower overall life cycle costs.