Reducing costs with effective control

Operating an air conditioning system without effective controls can be wasteful for any business. In the world of hotel and leisure though, where sporadic room occupancy has to compete with the need for the highest levels of comfort, the scope for wasted energy is even greater. Fortunately there are now an advanced range of air conditioning controls available that can be tailored to suit almost any establishment, whether large or small. Sebastien Desmottes from Mitsubishi Electric explains more.

For any hotel, guest comfort is a priority and air conditioning is now an essential way of ensuring the highest levels of internal comfort. Historically, the up-front costs of equipment and installation have been the main drivers of the purchasing decision for air conditioning. Today though, this approach is no longer a viable option with a raft of legislation, such as Parts L and F of the Building Regulations, demanding energy efficiency and evidence of a reduction in carbon emissions.

Coupled with this is the rising price of energy, year-on-year and the need for all businesses to minimise cost and maximise profit in what is still a constrained economic climate. The pressure is therefore on all business, especially hotels, to find new ways of delivering internal comfort levels and this is where effective controls can really make a difference.

Maximum efficiency

All hotels require systems that not only operate efficiently and can be seen to operate to maximum efficiency, but also do not compromise guest comfort.

A simple to use room controller is also now a necessity, as well as one that can be locked according to the individual needs of the hotel. These may well also need to fit into the décor of the room accordingly, so different options are required here, and there are now room controllers that have been specifically designed with hotel applications in mind. Very simple to use, with a super-slim design, these make installation flexible and easy and they also include a backlight function for easier use by guests at night.

Whether for a small hotel or a large establishment, the primary focus should be putting in place a programme that delivers effective control based on the initial brief, coupled with a monitoring and reporting system so that the performance of the heating and cooling equipment can be assessed properly and continuously.

In the case of the hotel sector, variables such as user habits, energy consumption patterns and outside temperature can now be used to inform system management and control. With modern controls using predictive algorithms, these interventions can now be made automatically to ensure optimum performance is maintained at all times.

Smaller establishments

For smaller hotels, having the air conditioning integrated with the room key card system or window sensors is often an essential requirement, again to maximise efficiency and reduce running costs.

An advanced controller, such as our AG150 will allow a hotel to monitor rooms centrally from its 9’’ touch screen controller, as well as over the internet if linked to the reception PC. Each individual air conditioning unit can be assigned to a different room and off times can be set to make sure that the air conditioning switches off when the room is very unlikely to be occupied, such as during the day.

When using a key card system, the card can be connected locally to the indoor unit. When the room is occupied, the unit switches on and when the room is unoccupied, the unit goes into night setback using the controller’s interlock function.

A good example of effective control is a recent installation at Kingsmills Hotel, a luxury 4 star hotel in the heart of the Highlands. The highly regarded hotel, just minutes from the centre of Inverness, is set in four acres of carefully kept gardens and has 83 rooms.

The team behind The Kingsclub and Spa development have developed a chic and contemporary hotel choice for discerning travellers to Inverness, focusing on relaxation, revitalisation and calm.

Due to the small number of bedrooms the AG150 controller ‘interlock function’ offered the best solution, as this allows the air conditioning to switch on at a predetermined setpoint and operating mode while the room key card is in and revert automatically to night set back when the key card is taken out. By doing this the controller allows the hotel to offer its guests exceptional comfort while ensuring the owners maintain low running costs.

Larger establishments

For larger hotels, it is essential that they have highly efficient systems which optimise energy efficiency and customer comfort. An integrated air conditioning system with key card or window sensors is often a requirement. Simple to use room controllers are a necessity and help to maximise efficiency and reduce running costs. Stylish room controllers may well also be required to fit in with the décor of the room.

We have packaged our large hotel solution under the Melcotel name to offer an interface that allows a hotel to have more accurate control over its air conditioning. It can be used to control and monitor up to 250 bedrooms and offers two different options to work with or without a key card system.

An excellent example of the way this works is the Premier Inn Hotel, Leicester, which occupies the first nine floors of a 20 floor building. The hotel is located in the heart of the city close to the main railway station and Premier Inn needed an advanced controller following the installation of a high efficiency heat recovery VRF (variable refrigerant flow) air conditioning system to provide heating and cooling to the 135 bedrooms as well as the bar, restaurant and back offices.

Premier Inn wanted to use this site to test the control interface and determine if they could reduce energy consumption, CO2 emissions and running costs.

At the Leicester site various control strategies were implemented over the 24 months that the system was monitored and analysed. This resulted in a 30% decrease in average monthly system running costs and CO2 emissions.

The monitoring and analysis of the data for this report clearly showed that by introducing an effective controls strategy, Premier Inn Leicester was able to benefit from reduced energy consumption and therefore reduced system running costs and CO2 emissions.

Complete flexibility of scale

Good controls will benefit any application, large or small but with a huge choice of systems available, the ability to identify the correct control for each individual situation is paramount.

The secret is in understanding the potential and being able to explain to customers what can be achieved with ‘off-the-shelf’ systems or knowing when a bespoke solution is more appropriate.

Understanding the true value of controls in gaining better control of air conditioning systems now has the real potential to increase performance and deliver dramatic reductions in running costs. Key to all of this is putting in place a programme that delivers effective control based on the initial brief, coupled with a monitoring and reporting system so that the performance of the heating and cooling equipment can be assessed properly and continuously.

With today’s increasingly predictive systems, this is more straightforward than ever before.

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