Climate management with brains
Climate-control systems are becoming increasingly energy-efficient due to more stringent legislation, standards and regulations. However, energy consumption can be reduced even further by installing intelligent building controls explains Martin Passingham of Daikin UK.
Offices, shops, hotels, hospitals and schools are typically areas of intensive energy consumption — with multiple systems for internal climate control, refrigeration, lighting and alarms.
Intelligent controls use smart technology to deliver more energy-efficient climate control, allowing system operations to be adjusted in line with usage patterns. Using this kind of technology can significantly reduce energy consumption in all types of buildings.
The best of today’s intelligent climate control systems can be integrated seamlessly with building-management systems for easier commissioning and maintenance.
Daikin’s Intelligent Touch Manager, for example, has an interface much like a tablet computer, with a touch screen that enables new and experienced users alike to operate and monitor a building’s energy-management systems. Users can view their system via a simple menu or via an interactive floor plan.
|The depth of information that is available via climate-controls systems is well illustrated here.|
Both options allow control and monitoring of one or more air-conditioning units, as well as other building systems such as lighting and security. Users can also view a comprehensive history of the system, to help them optimise settings and operational parameters to maximise energy savings, improve comfort and enable preventative maintenance.
System functions are often directly accessible over the Internet, enabling users to control one or multiple building systems remotely. They also give users the ability to set system schedules on a weekly, monthly or annual basis — taking into account holidays and seasonal variations in demand throughout the year, ensuring the system is being operated in the most energy-efficient way.
Daily and monthly data and energy consumption projections can also be provided so that performance can be monitored both against targets and against previous years.
By pinpointing equipment that is not performing in the most efficient way, the Intelligent Touch Manager can assist building managers by adjusting how a system operates, resulting in smarter energy management and more energy-efficient climate control (such as switching off air conditioning in unoccupied rooms or at certain times of the day).
Some control systems also allow building managers to calculate energy usage on a room-by-room basis, so individual billing in buildings with multiple tenants is made simple.
High-street bank proves the benefits of effective control
A well-known High Street retail bank in North Wales installed an RTD-20 Intelligent Retail Economiser for a 12-month trial, with the energy data analysed and compared with operation for the previous year.
The data from the period before the RTD-20 was installed showed a consistent daily consumption, even during periods where HVAC use could be expected to be low. Conversely, when the metric predicted high use, a boost was not seen. This was due to the fact that the system was operating constantly, which suggests a significant amount of unnecessary HVAC operation.
By comparison, the data from the period when the RDT-20 was in place shows that HVAC use increased in proportion to the expected seasonal loading.
This meant that the temperature at the site was being controlled in a much more energy-efficient manner, so that energy use matched the actual conditions of the locale to maintain comfort levels while preventing unnecessary operation.
When compared alongside the seasonal loading metric, the energy use for the two periods shows that the RTD-20 controlled HVAC used less energy for most of the time compared to the period before it was installed.
During the trial, the staff at the bank were aware that some changes had been made as they no longer had free control over HVAC units; informal questioning was used to determine if any perceived changes in comfort had occurred. No complaints were received that could be attributed to changes in the system. In fact, as there was less heavy cycling of units producing either very hot or cold air, which can be a source of discomfort to occupants, it could be argued that comfort levels even increased.
On completion, the trial found that energy use was 35% lower with the intelligent control system in place. This reduction translates to an annual saving of £1683. The cost of the control hardware, including retrofitting the equipment, was about £2600. This means that, at this site, the intelligent control system would have paid for itself in around 18 months and would deliver net running cost savings after this.
Energy savings can be increased further when RTD controls are used. These devices are pre-programmed to manage operating modes, fresh air ventilation and room temperature, at the same time maintaining comfort levels. The technology enables HVAC to be integrated into a building-management system, helping maximise efficiencies for any application. If there is no building management system available, the RTD can operate on a stand-alone basis.
Designed for a wide range of applications, including hotels and offices, an RTD control system can help building managers and operators reduce their energy consumption (and bills), as well as lowering carbon emissions.
For example, hotel air-conditioning systems can be interlocked with keycards and window contacts to change the operating mode or switch them off. In retail environments, interlocking with presence detectors allows the temperature setpoint to be adjusted automatically according to occupancy.
Interlocking also allows the deadband to be adjusted to turn off units and stop them switching continually between cooling and heating modes. RTD controls can also communicate with the building-management system to reveal when equipment is working correctly or where there is a fault.
Today’s intelligent control systems have a host of new features to help engineers service or commission equipment, make life easier for those living or working in a building and also to simplify energy management and maximise energy efficiency.
For those striving to meet increasingly exacting regulations and standards while maintaining high levels of comfort, a complete building and energy-management package with a reasonable outlay initially should prove a highly intelligent investment — saving both time, energy and money in the long run.
Martin Passingham is product manager DX at Daikin UK.