Peter Lowther, md of fan coil manufacturer Ability Projects, suggests that the BACnet open controls protocol could break the free-issued controls stranglehold
LONG gone are the days when fan coil manufacturers would supply and fit analogue controls to their units, most contracts now requiring the fitting of programmable DDC controls that have been free issued. But are things about to change?

In the seventies, eighties and early nineties, probably 80% of fan coils were supplied with simple analogue controls purchased by the fan coil manufacturer. Since then however, the tide has turned to a point where free-issued controls rule the day and nowadays constitute nearly 80% of a fan coil manufacturer’s workload. The reason, as everyone knows, was the need for the more recent communicating terminal control devices to be matched to the rest of the site-wide building management system. Fan coil unit controls therefore, became the provision of the BMS control system specialist.

Inefficient

Speaking as a fan coil manufacturer that has had to suffer the terrible manufacturing inefficiencies and vagaries often associated with fitting free-issued controls, even I can understand the ultimate logic behind why this shift happened.

But more recently there has been a significant move, led by the US, towards open protocol BMS control systems. BACnet, the Building Automation Control network developed by ASHRAE, has for some time been the USA’s chosen open protocol. And when it gained ISO recognition in 2003, the rest of the world also took notice.

BACnet is a language, designed and structured specifically to allow translation-free intercommunication between all manner of building services equipment. It is already commonly used in many areas of building management systems but as yet, not greatly used in the UK and continental Europe at the terminal level.

BACnet cannot be purchased. BACnet is literally a reference book that defines methods which BMS manufacturers can use, if they choose, to make their systems interoperate with other BACnet systems.

Using BACnet offers ‘plug and play’ flexibility. Control items can be dropped into or changed on a BMS system at any time.

Using BACnet breaks the dependency on control items from a single controls manufacturer. As BACnet is universal and free, any manufacturer can program his devices in BACnet and once approved, its products will effectively ‘listen’ and ‘talk’ to any other BACnet approved device from any other source.

Using BACnet opens up manufacturers’ choice when purchasing controls. For example, if the best controller is made by X and the best sensors by Y then BACnet allows the fan coil manufacturer to mix the two without compromise.

Being universal, BACnet BMS systems can be installed and subsequently maintained by anyone with a qualified understanding of the language. Gone are the days when a BMS system was so complex only one company could be trusted with its ongoing upkeep. A BACnet system allows the installation and more importantly, the maintenance to be quoted by a much wider group of companies.

Best of all, BACnet will be cheaper. Because it is universal, BACnet will promote far more competition for the supply and installation of products, as well as for the ongoing upgrading and maintenance of any system.

Added benefits

So why does this interest a fan coil manufacturer? The reason is that using open protocol terminal BACnet controllers will allow fan coil manufacturers once again to both supply and fit the control devices to their products. An open protocol controller supplied and fitted by my own company, Ability Projects to an FCU, will function and communicate every bit as well as one supplied by any of today’s conventional controls manufacturers but with added benefits. Firstly, being familiar with a single control system and possibly two, allows a fan coil manufacturer to fit these controls in the way best suited to its product. The current free-issued system means that almost every day yet another wheel is invented as yet another new controls package arrives on the doorstep.

Secondly, with the controls once again being ordered by the fan coil manufacturer, details such as the delivery dates and the on-time performance of the control manufacturer are back under the control of the fan coil manufacturer and his supplier. This means that the manufacturing efficiency of every fan coil company will improve and in turn its own performance to its client will also improve.

Last but by no means least, the price of the fan coil/control package will be less. If the effects of the manufacturing efficiency improvements and the fact that the controls will be purchased from controls manufacturers who themselves will be in a far more competitive situation are added together then clearly, the price of the fan coil and controls package can only go one way.

It may all sound too good to be true but I can confirm that Ability Projects could supply fan coil terminal controllers, every bit as able as the existing well known makes purchased today, but showing a substantial price reduction. Also, it is often the case that part of the cost of many controllers purchased today may be at a premium commanded by the particularly prominent but closed protocol BMS control system involved. BACnet avoids this. Being a totally open protocol means anybody, providing they follow the BACnet guidelines, can produce a product without commitment, financial or otherwise to the rest of the BMS system. All that is needed is for the product to be BACnet-tested and approved.

The arguments for BACnet open protocol terminal controllers seem compelling at every level. The comparative simplicity of the system, the ability for the BMS to adapt if required as time passes and the fact that prices will inevitably be keener for both the devices and the services companies that install and maintain them are there for all to see. As far as fan the coil manufacturer is concerned, it will not be too long perhaps, before the fan coil controls package can be, and consequently should be, back as part of its supply.