Absence makes the smart not squander!

How a simple setting can yield greater energy savings in student accommodation.

The levels of automation we enjoy through technology undoubtedly make’s our lives easier and in most cases more efficient. In the context of heating control for student accommodation, it can also make a significant difference to the energy budget.

For Energy and Accommodation Managers, a building occupied by students that have control over their room temperature but are not directly responsible for paying the utility bill, must be irksome to say the least.

If all students were diligent and turned their heating off when they left their room, unnecessary use of energy wouldn’t be a problem! Passive Infrared (PIR) sensors are used for this very purpose. However, they are often set for the convenience of the occupant, by activating the heating when the room is entered, rather than being set to maximise energy savings.

Irus is an automated energy management system with integrated PIR – and is designed specifically for student accommodation. A node in each room silently monitors temperature, humidity, light, and decibel levels. Managers access data on the web-based portal and set maximum temperature and time profiles for Boost, Setback and Frost modes in individual rooms. Irus is then left to get on with saving energy. All this without ever having to set foot in a bedroom.

Ecostat2 is a locally programmed control system that operates the same 3-stage student profile as Irus. Of the 5 control units in the range, two of them have integrated PIR sensors.

The PIRs can be set to detect either presence or absence. When set to Presence mode the programme will be activated to raise the room temperature when the resident returns. This automation is a benefit for the room’s occupant – but not so great for those paying the energy bill! If the room is entered for a short time only, for example, if a book has been forgotten, or for a quick change of clothes, the programme will run, and energy will be wasted when the room is vacated.

Switching the PIR to absence detection makes a lot more sense. This way, on entering the room the student is required to press a button to activate the heating programme. Perhaps less convenient for the occupant but it does provoke an awareness of their energy use and emphasise a policy of energy efficiency. At any time, they can increase the temperature with a press of the button taking the system into Boost mode, which will run for a pre-determined time, often 45 minutes, before reverting to the Setback mode.

The greatest energy savings are recorded when a student leaves their room shortly after activating the Boost mode, the PIR will notice the room is empty and cut short the Boost programme and revert to Setback, thus not heating an empty room.

If we conservatively estimate that 20 minutes of unnecessary heating is avoided in this scenario, and then multiply that for a 1000-bedroom facility, the numbers become eye watering – equating to almost a fortnight of heating that could be prevented! Consider that in terms of annual use and it becomes clear how automating your heating system, using control units with integrated PIR sensors set to absence detection, can make enormous savings. www.prefectcontrols.com