The Prefect Atlantic panel heaters are manufactured with our patented Energy Lock system which means this no-controls heater is Lot20 compliant. They are available with heat outputs of 0.5, 0.75, 1.0, 1.25, 1.5, 2.0 and 2.5kW. Irus can also operate ‘wet’ heating systems using our Valve Actuator.

The Power Unit switches the electrical supply to the heater and is controlled by the Irus room node

The key switched fused spur isolates the power supply to the heating equipment and control unit in the room.

The existing electrical wiring circuit is used to send and receive information from the room to the Master Interface Unit (MIFU), which in turn connects to the portal, from where Irus is controlled.

6 core low voltage cable connects the control unit to the power unit.

The Control Unit maintains the room’s temperature and energy use. It also monitors light, humidity and decibels. A CO2 sensor is also available. When used to control hot water, Irus can detect leaks and monitor water temperature to ensure compliance with Legionella water safety plans.

The dimmable screen displays the current temperature setting, as a number or any format such as ‘Max’, ‘comfort’, etc. Other operational messages i.e ‘Window open’ are displayed here.

Simple to use, up and down buttons with LED indicator lights mean operation of Irus is easy.

The PIR sensor ensures that energy is only used for heating when the room is being occupied.

Irus logo in purple

Prefect Irus is an award-winning building energy management system specifically developed for multiple occupancy properties such as university student accommodation and hotels.

All providers of rooms want to maintain a comfortable environment for their tenants and guests. But, understandably, they don’t want to pay more than they have to for energy use.

We are all familiar with thermostats being adjusted to maximum – rooms left unoccupied while the heating is on and windows being opened to cool a room – occupants are generally not too concerned about the cost of the energy they use – as they don’t pay the bill!

With Irus, energy use and therefore energy costs are completely controllable with recording and analysis of use making it easy to predict consumption for the future.

Irus can be classified as a BEMS inasmuch as the functions under control represent the vital building services. However, it offers the benefit of being very easy to use and, because of Mains Borne Signalling (MBS) operation, it is very cost-effective to install. Furthermore, it enables management to set and monitor boost and setback temperatures while controlling time profiles in each bedroom separately.

As well as heating control, the individual room sensors can also monitor humidity, CO2, light and decibel levels to ensure environmental conditions conducive to safe, comfortable living and study. When used to control water heating, greater savings can be made with the observation and action against DUoS and TNUoS charges. Leak detection is another feature that can employed to avoid expensive and disruptive water damage.

This level of localised control over individual rooms is not possible with other building management systems despite their obvious capabilities in more complex situations.

Put simply, PrefectIrus makes sure energy isn’t used when it isn’t needed. View our latest case study here.

Irus monitors and manages rooms and hot water systems

What does Irus do?

Room temperature control - and more...

Irus controls individual rooms from a central controller (located in the comms room/reception). On and off times can be set, along with minimum and maximum temperatures. Occupants can boost the temperature by pressing a button on the room node (CU3), but only to the maximum set parameter, the length of time the boost is maintained is pre-determined to revert to set-back. The PIR on the CU3 detects presence or absence, so, when a room is empty the heat input is reduced, after a set length of time with no activity the temperature reduces to Frost mode.

The back-lit LCD dimmable screen can provide the guest with recognisable ’21°C’ style layout or a custom display can be deployed such as the words Low, Normal, High or Max. It is our experience that the choice of words and or numbers can be psychologically useful to infer a warm comfortable environment that the guest has control of.

For student accommodation the system allows the onsite management team to tailor the time/temperature profile to achieve the maximum energy saving possible while providing a comfortable living environment. Where individual guests require warmer conditions, managers are able to temporarily increase the thermostats temperature and or timing range to that specific room, with a single click of the mouse. The system will then automatically return the room heating to the normal setting after a period of time. This feature is particularly useful when servicing guests from warmer climates.

All options for the room thermostat can be enabled or disabled remotely from the portal.

IRUS can be installed with a ‘wet’ heating system, to control radiators as per electric heaters. The radiators TRV (thermostatic radiator valve) is removed and replaced by a silent thermal drive valve, so there is no need to drain down the system. The valve is simply wired to the IRUS room control in the same way as an electric heater.

Water heating control and TRIAD warnings

The IRUS system is capable of controlling hot water either electrically heated and stored, or gas central plant. The system provides live data of water temperature and triggers alerts when over-heat or under-heat is detected.

Probes on each of the elements of a water tank feed data to the CU3 which shows element activity, temperature etc. By interpreting this data a failing element can soon be noticed and replaced ensuring efficient use of energy.

Each year, National Grid and its Scottish equivalents are paid a Transmission Network Use of System (TNUoS) fee in order to finance the cost of maintaining and updating the UK’s electricity grid.

This fee is divided between consumers and generators of electricity. Consumers, receiving charges from their Distribution Network Operator (DNO), pay their share based on consumption during the TRIAD, which are the three highest half-hour periods of demand between November and February each year, they typically occur during cold weather between 4-6pm, when industrial demand and the domestic tea-time periods coincide.

However, with prior warning, you can reduce this charge by reducing consumption when a TRIAD is forecast. In practice Irus heats water to the desired temperature as close to the period as is practical and then shuts off power input until the high tariff subsides.

Use our Tariff Calculator to estimate the savings you could be making.

PIR movement detection

The PIR can be set to detect presence or absence. If set for presence, when someone enters the room the programme will begin.

In most cases, and to guarantee greater savings, the PIR is set for absence detection. When a student enters the room and activates Boost by pressing the button, the unit will monitor the space, and when no further movement is detected, the programme will stop and revert to Setback mode.

Window-open technology

It is common sense not to send heat into a room that has an open window, as the heat along with the energy budget will simply disappear into thin air.

Irus learns how long a room takes to heat up to maximum levels along with dissipation rates. If the room cools more quickly or the temperature drops by a given amount over a certain time, the only explanation is that a window or door have been opened and as a result heat is being lost and energy wasted.

Should this happen, the CU3 will display ‘Close Window’ and the heat input will be reduced by 50% until the window has been closed.

Humidity level sensor

Sensors within the CU3 monitor humidity levels and report back to the Master Interface Unit. Levels are usually fairly constant changing marginally depending on occupancy and whether food is being cooked in the room.

If damp becomes an issue in a room Irus will detect rising levels of humidity and alert managers to the problem. Likewise, if kitchen facilities are not provided and the room isn’t damp, if occupants are using illicit cooking equipment such as steamers or portable hobs, Irus will detect a sharp rise in humidity and send alerts.

Light level sensor

Light sensors within the Irus CU3 monitor lux levels. Typical positioning of a CU3 is in a water tank room, kitchens, corridors and living spaces.

Recommended lux levels for these areas are between 100lux (for tank rooms) and 500lux (for study areas). The Irus light sensor will report light levels in individual areas to prove compliance with these recommendations and alert managers to levels that dip below. Lower levels could indicate failing lamps or lighting panels. In less frequented areas such as water tank rooms, the light display on the Irus portal will indicate if a light has been left on in a room that is usually dark.

The light sensor also manages the back-light on the display to optimise legibility or to dim during hours of darkness

Decibel level sensor

A decibel level sensor can be set to activate alerts should noise exceed desired levels for a set period of time. The sensor hears but does not listen, a subtle difference but suffice to say, it monitors decibel levels but cannot interpret or record identifiable sounds.

Normal conversation or background music is usually around 60dB while heavy traffic, lawnmowers or underground railways can exceed 80dB.

To maintain conducive environments for study, good sleep and wellbeing, Irus can be set to collect data on sounds that exceed an acceptable level over a given period of time for defined periods of the day or night. For example, if a fellow resident is making noise above 70dB for more than 5 minutes at 11 pm – this will be logged and could be used as evidence for a case of antisocial behaviour. Any criteria can be input to reference against and an alert set accordingly.

CO2 level sensor

As an addition to the standard CU3, a CO2 detection module can be fitted. Measuring CO2 is used to monitor air quality.

Indoor air quality is known to affect the health, comfort and wellbeing of a room’s occupants. It has been proven that poor air quality reduces productivity and the ability to learn.

CO2 is one of the gasses that can contribute to poor air quality, high levels can cause drowsiness and headaches, causing occupants to function at lower activity rates. Outdoor levels of CO2 are usually 350-450 parts per million (PPM) whereas the indoor level considered acceptable is 1000ppm. Irus will monitor levels and bring to the attention of managers any rooms that could benefit from better ventilation.

By measuring CO2 in sleeping hours Irus will detect presence which will maintain programmes when the PIR is not activated.


Water safety monitoring

As part of compliance with Water Safety Plans, Irus will raise the temperature above necessary levels and maintain them for the requisite time over set periods to avoid the risk of Legionella contamination.

The use of Sentinels will measure the temperature across the water system from the water inlet, bottom and top elements of the tank, outlet, and the first and last tap in the pipe run, logging the data to provide evidence reports of compliance.

Leak detection

With the addition of moisture detection pads or tapes, Irus will alert managers to any leaks within pipework or on the floors within water tank housing.

Coupled with automated valves, Irus can turn the water supply off to the inlet of a tank or the riser of a block, restricting potential water damage.

This leak detection solution is accepted and in some cases required by insurance companies.

Email/SMS alerts

All data collected by the room nodes and transmitted to the portal can trigger alerts to an email address and or telephone number to communicate unusual levels or that any criteria warranting an alert has been met.

Third-party application integration

Irus can be integrated with “front-of-house” management software allowing for automated control of a room’s heating. Connections to management tools such as the hotel booking system can be configured to provide the room node with a trigger to boost temperature when the guest arrives and to lower the temperature when the guest checks out.

As with the hotel booking system, IRUS is capable of exchanging data with other systems such as building management, metering and door entry etc.

IRUS is designed to evolve as new techniques and systems become available. An example of this is the way IRUS tracks peak electricity charging periods and automatically reacts to enable greater efficiencies when purchasing power.

IRUS also stores data, allowing the tracking of a room’s performance over a time period. This data is used to display a visual record of your screen, but can also be linked to systems such as EMMS to track performance and faults within a building.

3-stage student profile

Typical temperature and time settings


Irus enables Energy Managers to set temperatures/times for the 3-stage student profile. Setback mode is the default setting (typically 18°C), but if the student requires more heat, they simply tap the ‘up’ button triggering Boost mode (commonly 23°C). Boost runs for a pre-set time (45 minutes) before reverting to Setback. If the student leaves the room during Boost, the PIR detects their absence and reverts to Setback, likewise if windows are opened heat input is reduced by a programmed percentage. If rooms are vacant for longer periods (typically 12 hours), Frost mode is activated which cuts energy input until the room reaches the pre-set protection against frost temperature which should not be lower than 5°C.

These examples of temperatures and times are common settings. Location and condition of building can affect performance, but our system is infinitely variable and can be set to what is required in each situation and, more importantly, specific to each room.

Any number of profiles can be created easily, setting distinct time and temperatures. Once set they can be adjusted to ensure a balance between the comfort of the room’s occupant and energy saving.
Examples of useful profiles

  • Standard room
  • Warmer room
  • Enhanced room
  • Corridor heating
  • Warmer overnight etc.

How Irus components connect

Irus is a control system comprising a room node or control unit (CU3) which connects to a power unit (PU3) which in turn powers a panel heater (or thermal drive valve on a wet radiator) within each room. The CU3 has a built-in PIR which ensures rooms are only heated when occupied.

The system uses the earth and neutral cables in the buildings existing wiring circuit (Mains Borne Signalling) to send data to and from the Master Interface Unit (MIFU) via the Secondary Interface Unit (SIFU) which boost the signals from individual room nodes.

The MIFU connects to the internet. At the centre of the system is the IRUS secure control portal. Managers log in and interact with the system viewing all their accommodation on a user friendly, comprehensive portal accessed from anywhere with any online device.

Within the system, access levels can be assigned to restrict the interaction within individual rooms. For example, reception staff can have a basic view – stage one, service managers – stage two, senior management – stage three and energy managers stage four. Each stage and its level of access within the system is decided and agreed before the site goes live. All access is logged and any changes can be seen immediately.


Data on savings

We have collated data from a number of installations to collate evidence of energy savings. Individual site specifications; the building’s condition; and the profiles/settings used; will all affect the efficiency of the system. However, when data for the consumption of energy is compared with before and after installation, we can demonstrate that Irus repeatedly performs at levels where annual energy savings are between 30%-40%.

Saving on tariff

Energy Savings

Return on Investment

Case Studies

Click on the images below to download our case studies

Bath Spa University

Green Park House

Cambridge University

Pembroke College

Sandman Signature Hotel




What do people say about Irus?

Chris Jones
Energy Manager – University of Bristol

Chris has been using Irus for many years across the University of Bristol
accommodation estate and probably knows the system as well as anyone.
Here he talks about his experiences with Prefect Controls and Irus.

“When we saw the Prefect offering, we thought Fab! This is what we need, more control, shorter running times, reduced energy consumption…”

Kirsti Norris
Energy Manager UWE
(see case study)

“We looked at other systems, but we couldn’t quite find one that did what we wanted it to do as well as Prefect did, they can be a lot more complex and a lot of what they can do is unnecessary. Prefect seems to give the best user control and the most visibility for me. I can sit at my desk and see what is happening in various rooms.”

 Robert Griggs – Building Manager
Pembrooke College, Cambridge University
(see case study)

“It’s a piece of cake [to use] actually. Surprisingly so. The best feature is that rooms are not being heated when they are unoccupied and obviously the remote control helps to save time while being energy efficient.”

Murray Todd
General Manager
The Sandman Signature Hotel, Aberdeen
(see case study)

“Prefect installed the system, and only when they were satisfied did they hand the job back to us. They installed it, they commissioned it and then they warrantied it. They also provide the annual cover on the system. They were brilliant, really easy to deal with.”

 Mark Pragnell
McCarthy Bainbridge Limited
M&E consultants
(see case study)

“The ability to increase the temperature in a student’s room, when they ask for it, and then for it to automatically return back to the original settings after a period of time, is very useful. Irus is so simple to use, we haven’t had any complaints from students on the operation of the system or the comfort levels, so that says something!”

Dr Julian Greaves
Sustainability Manager – Bath Spa University
(see case study)

“When I call Prefect I find them really helpful. Although I wasn’t here when the system was installed, it is very easy to use and it seems to do exactly what it is supposed to do.”

Simon Hall
IT administrator – Headlands Hotel

(see case study)

“No one else offers the full range of controlling services as with Prefect Irus. Prefect Irus is more bespoke and sits in this market-place better than traditional BEMS companies. Prefect focus on heating and ventilation and offer all the functions that they require. Their solution went quite a way to reducing the running costs.”

Mark Comerford
Mechanical and Electrical Consultant
MEP Engineering Solutions Ltd.,

(see case study)

“Guests seem happy, we make sure their rooms are warm, which is what they want and they can turn it up and down as they wish. I think we recovered the cost of the whole system within about two years.”

Jitesh Patel
Owner – Best Western Buckingham Hotel

(see case study)

“The quicker we make the projects happen, the quicker we make the financial savings. We are conservatively estimating saving 20-30% – that’s over £75K per year!”

Melissa Clarke
Energy Projects Officer – UWE
(see case study)

“the Prefect Irus system is fantastic and it’s amazing to have a view of everything that’s going on in a room in terms of the temperature, the lighting and the decibel levels. Now, if we have a complaint, we’re able to see a live representation of what’s going on in that room on the system – we have data to hand without ever setting foot in the room!”

Lee Williams
Halls Operation Manager – Bangor University
(see case study)

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