Learning to think by sensors
A breakthrough, caused in no small part by energy saving legislation, has hit the normally sedate world of fan technology. Now the talk is less about the fans, and more about the way the fan systems are controlled.
Fan performance has reached a relative plateau and simply improving component performance does progressively less to raise whole building performance. What fan manufacturers have realised is needed is to focus on the total aspect of ventilation control, if whole building performance is to be significantly improved as directed in the new Building Regulations.
And for independent control ventilation within different areas of a buildings to happen, intelligent mechanical ventilation solutions is probably the only clear way forward. Therefore an ever increasing reliance on these new control-on-demand fans is inevitable to comply with the regulations.
Now innovative manufacturers have created a range of fans that ‘think for themselves’, continuously making miniscule changes to the fan speed in response to the ever changing conditions throughout the system. This obviously leads to reduced energy consumption, and also offers building owners major savings in running costs and reduced down time.
The technology behind many of today’s Intelligent Fans was pioneered for automotive applications and more recently has been designed to meet the continuously increasing demands of factory automation.
For fan manufacturers, a logical step was to build intelligent fan processors which react to input signals from a range of sensors. These can consist of motion detectors, air quality sensors, thermostat, humidistat, CO2 or a range of other detection measures. The result is they increase the extract, or supply rate of the fan to match the demand.
The sensors are all pre-wired and terminated with a plug; this is connected to the appropriate socket on the fan processor making it an easy process for installers. This simple process, with reduced wiring and labour costs, makes these systems a very economical option when compared to conventional fans.
When the appropriate sensor is activated an internal motorised valve or damper will open, bringing about a drop in pressure in the ductwork system. A duct-mounted pressure sensor reacts to the drop, notifying the fan, triggering the air extract to increase until the system returns to the preset pressure (set at the commissioning stage).
The benefit associated with moving to the use of intelligent mechanical ventilation systems will not be enough to enable a building to comply with the new requirements on its own.
It will, however, make an important contribution towards doing so. In combination with a systemic approach to whole building specification, design and construction, the inclusion of intelligent mechanical ventilation will enable those involved within the industry to make the transition to designing buildings to comply with 2006 requirements.