New energy-saving products, some enforced by recent legislation, are key drivers in the HVAC controls field. And, as Jerry Hamilton, national development manager of WF Electrical, explains, energy-efficient equipment is fast becoming the norm
THE heating controls marketplace divides into domestic and commercial; covering new installations together with refurbishment, facilities management, maintenance and repair requirements.

In every case there are fundamental issues that drive the selection of equipment, the chosen equipment provider and the timeliness of
delivery and installation.

In new build, the HVAC systems and their controls tend to be specified as a package and delivered by larger systems houses - either installed directly or by m&e contractors. Here, the trend has been to address energy efficiency either at the behest of the project owner or to comply with legislative
requirements.

Responsible companies meet both regulatory needs and project specifications.

Similarly, in new build for domestic residences, most heating timers and controllers can be sourced from a variety of distributors, wholesalers and retailers. Some specialised equipment - such as wireless controls - are trickier to source, and this is where distributors and specialists are more likely suppliers. While this sophisticated end of the domestic market is showing growth, it remains a niche area.

Similarly, projects occasionally throw up demand for solar heating or wind turbine generators. These remain few and far between and evidence suggests they are installed more as a demonstration of the user's commitment to ecological power than actually to benefit the HVAC system's efficiency.

The biggest single issue in HVAC is energy efficiency - or more particularly, energy wastage. Some years ago, Julian Miller, of energy consultancy AEC, said in the press that 90% of HVAC controls were inefficient or deficient in their operation; accounting for a bill to British industry of more than £500M in lost or wasted energy alone.

At the same time, beleaguered facilities managers could hardly be blamed for overriding motorised valves (fixing them permanently open) when replacement parts take days to arrive and the building goes cold while they're waiting.

Anything that compromises the timely repair to a system can be costly in terms of energy efficiency. In fact, in an application such as a damper motor control, the replacement of a faulty control can pay for itself within a day.

Again, the key is being able to get the best advice on products and the fastest possible delivery - it is unacceptable now to wait a week or more for an AC inverter to control a fan or pump drive.

In new-build properties, any fan or pump of more than 1.1kW used in HVAC installations must be fitted with a variable-speed control (AC inverter). This part of the market will therefore grow significantly over the coming years. The reason for this is clear when you consider that, depending on the motor efficiency and fan/impeller type, the power savings are generally as a cube of the speed reduction.

Consider that millions of HVAC electric motors are in daily continuous use in the UK. In Britain, only about 15% of the motors have any form of control. In continuous-duty applications such as powering HVAC fans, pumps and compressors, it is possible to effect substantial savings by reducing the motor speed by just a small amount.

This is because in such applications, the fundamental physical laws governing centrifugal fans and pumps also preside over the potential savings that can be achieved. Such fans and pumps consume power as a cube of output. Indeed, affinity laws dictate that while motor torque varies with the speed squared, power varies with the speed cubed. Hence, the cube law impacts greatly the energy efficiency.
On loads of this type, any speed reduction will save large amounts of energy (that is, a 20% speed reduction will result in a 50% power saving). And variable torque loads, such as fans and pumps, offer the greatest potential for energy saving.

In other words, tweaking a fan speed down by a few hertz can
pay for the drive through its energy savings in less than a year without perceptibly altering system performance.

Naturally, while legislation applies to new build, there are compelling reasons to fit inverter technology to any new or refurbished HVAC system. Building management systems cannot work properly without vital sensors and actuators. With energy so firmly on the agenda, it can be expected that facilities managers and building managers will demand that energy efficiency is maintained.

Where heating and ventilation controls are concerned, it seems so far that it is a combination of legislation, new applications of technology and the will to be seen to be green that is influencing the market.

WF Electrical says it has positioned itself to provide for the changing needs of the heating and ventilation controls market. It stocks products from all the major brands, has 80 branches nationwide and can deliver by the next day or sooner.