AC in commercial buildings is often an out of tune orchestra

Commercial buildings may have the latest air conditioning units, but the expected savings often do not materialise. Why? The problem is to do with their control.

Just look at buildings ‘festooned’ with outdoor air conditioning units that are stand-alone, not multi-split. The building has several units on a floor, each with a controller (either wall-mounted or ‘handheld’), but this separate control leads to inefficient operation. Often the controls are in a row in one location, so they cannot reflect the temperature of the room they control. One can only dream of them taking into account the usage of a given room. When something needs to be changed, the same action needs to be performed several times on each box. The system simply cannot be centrally controlled and optimised, and so therefore costs rise rapidly.

… but the facility manager doesn’t see it and therefore lots of energy is wasted. This issue can be solved by linking the cooling to the window opening – when this happens, the air conditioner has a ‘hard’ switch off via the contactor. But that doesn’t do the device any good and shortens its service life.

The same inefficiency is implied by zero follow-up on the presence of people in the room. Most of the time everyone is concerned about making the office cool, but it is easy to forget to turn it off when you leave.

Another common pain of cooling controls in commercial buildings is that they clash with other systems – heating, air curtains… it’s hard to get the technologies to work together.

Unnecessarily inflated reserved power

Imagine a sunny day in a hotel resort. Guests have a nice lunch and usually go to cool off in their room for an hour, perhaps have a nap. During the morning, the sun has made the room quite warm, so they turn on the air conditioning. During this time the surge electricity consumption of the building is very high. To avoid an overload and so that the hotel is able to cover these peaks, the reserved power charged must be greatly overestimated at a flat rate.

The key to efficiency and comfort: intelligent air conditioning with Loxone

Intelligent control systems can solve these and many other operational problems. There is no need to imagine buildings of the future under the term ‘intelligent building’. These intelligent buildings can be new builds, but can also be your current 30-year-old offices or a historic townhall building. An intelligent building is simply modern management of existing technologies – including active cooling systems, eliminating operational difficulties. Ensures better energy management and saves the business money.

These may seem only small features and benefits in relation to the existing air conditioning system, but they have a great positive impact on operators, administrators and facility managers:

• Central visualisation and control over all units in a single mobile or desktop App (real-time monitoring).
• Maximum and minimum adjustable temperature limits for users. Instead of 16 to 28 degrees, staff for example, will only be able to choose on a scale of 21 to 24.
• The cooling is only switched off when the window is open for longer than, for example, five minutes – thanks to the intelligent Loxone BMS coordinating the connection to the window sensor. Vent yes, waste no.
• If there is a long absence from a room, the cooling is turned off.
• Single wall panel (tablet) to control multiple air conditioning units, even though they are not multisplit. There is no need for multiple boxes on the wall creating wall acne.
• Air conditioning operation responds to switching on the heater or air curtain.
• Stress manager function regulates the power and surges, and thus there is no need for a giant transformer and an overestimated lump sum of reserved power. Instead, it automatically temporarily disconnects unnecessary draws at the time, such as wallbox charging or water tank heating.
• Warning in the App, if the desired temperature cannot be reached, for example by an open door to the corridor. The facility manager knows exactly where to go to close the door or who to ask to do it.
• Connection to electric roller blinds saves even more costs – if possible, the system will prioritise passive over active cooling and triggers the shielding technique. The air conditioning will only start itself when the blinds or shutters are not enough to keep the room cool.
• Forecasts prevent the cooling from starting when it is unecessary as the weather is expected to be comfortable.
• Thanks to connection with PV or SPOT the system can pre-cool rooms at convenient, cost-effective times.
• In the App, you can set service intervals and have notifications sent to you when maintenance is due.
• Reporting error states.
• Air conditioning start-up dependency on the calendar including public holidays and vacations.
• Possibility of linking control and data from multiple sites into a single App.

How does this work in practice?

In practice, these ideas are often met with limitations on the control side supplied by the manufacturers, yet they are not unrealistic. Modern air conditioners usually have open interfaces, which allows them to be controlled by a higher-level system.

There are two ways to implement this integration. The first is to develop a custom solution, which is expensive, difficult to maintain and difficult to extend. The second option is to use a universal system, such as Loxone BMS. This system offers a ready-made software solution with regular updates, ensuring minimal commissioning and maintenance costs.

In addition, Loxone also enables interconnection of all technologies in the building into one App and multi-purpose use of sensors (for lighting automation, alarm or presence-based cooling). It integrates both multisplit systems including zone control using Modbus, as well as separate air conditioning units through the AC Control Air.

Satisfied users, easier to obtain sustainability certifications and meet ESG goals

Will users be bothered by these restrictions? Maybe at first, out of spite, but after a few days they will understand that it pays to leave cooling to automation. Throughout the workplace, in any room, they will have a comfortable temperature throughout the working day. And if they do really want to change the temperature, they can based on user permissions through the Loxone App, it’s much easier than having to tweak programs on complicated wall switches and dials.

Last but not least, the energy management of a building is a key evaluation criteria for sustainability certifications and ESG (Environment, Social, Governance). Automating the AC is an easy win that will yield great results on energy usage, contributing to saving the environment (and saving money with a quick ROI).

In short, intelligent air conditioning is a key element for the efficient management of commercial buildings. The Loxone system offers a modern approach to temperature control that ensures optimal conditions for users and contributes to energy sustainability of buildings. When deployed correctly, it brings not only savings, but also increased comfort and helps meet ESG targets.