The smart world of apps, broadband and WiFi has alighted on our utility rooms. With a number of compelling options now available, offering to take the nerdishness out of home automation, we are able to more easily control our heating systems, which can run themselves intelligently — all with the aim of reducing our energy usage.
At the heart of all this is an understanding of the limitations of the existing control systems we have. Most home equipment is simply controlled by on/off switches: lighting, cookers and security alarms, for example. Some equipment, such as TVs and computers, have sleep or standby modes which are designed to match energy and convenience.
The one area, however, where there is a much higher level of sophistication is heating, where we have both time clocks and thermostatic controls. The time clocks are used purely to save energy, while the thermostatic or temperature controls are in place both to save energy and to enhance comfort. As central heating and hot water provision accounts for 75 per cent of a home’s typical energy bill, the ability to reduce consumption has tangible benefits.
What’s Wrong With Our Existing Systems?
The problem with existing systems is that they are inflexible. They tend to suit people with predictable lifestyles who know when they will be at home and who know when they go to bed and when they get up. The standard time clock arrangement will work fine for them.
However, a great number of households don’t keep regular hours. People that work shifts or travel a great deal tend not to fit into time clock profile and while, in theory, time clocks are adjustable, tinkering with them has never been easy or straightforward.
Furthermore, designers have found that the more complexity they build into timers, the less easy they are to understand. It’s all very well having three or more on/off periods every 24 hours, plus weekend modes and holiday modes, but the evidence is that most people tend to end up using them on factory settings.
In smart systems, the potential is there to get the house warm as and when you need it, rather than just dumbly following the settings on your time clock. This in turn has the potential to save you a lot of money — especially if you live an irregular-hours lifestyle.
How Effective Are Smart Systems?
Nest have produced a comprehensive and, it has to be said, very impressive modelling analysis of the energy savings they predict by using the various features on their thermostats. The results vary depending on:
- the location (different parts of the UK have different heating requirements);
- the size of the house itself;
- the amount of heat the house uses as a ‘baseline.’
The estimates suggest that with use of the various setbacks and ‘away’ settings that Nest provides, the smart thermostat could reduce energy consumption by around:
- 5-6,000kWh (£225-270) per year for a detached home
- 3-5,000kWh per year (£135-225) for a semi-detached home
- 2,500-4,000kWh per year (£112-180) for a terraced home.
Nest thermostats cost around £180, giving them a rather impressive payback time of between nine months and two years.
All the new smart heating systems are based around replacing your existing controls with a new box of tricks which can be controlled by an app from anywhere in the world, and which is either wired up to your boiler and heating system, or uses a wireless system to do the same thing. As your existing controls are already wired together, it’s easy to replace them with something new without having to run extra cabling.
Price wise, the various offerings all seem to come in between £200 and £250, though note that some prices include installation and some don’t.
British Gas’ Hive Active Heating™ is one of the simpler systems. It essentially replaces your existing heating controls with its own versions which you can then either control remotely or conventionally. In this respect, it’s one of the least smart of the applications.
Nest offer a facility to switch your heating on and off automatically by linking it to your mobile, which knows where you are — a feature referred to as occupancy detection. US-based Nest hit the headlines at the beginning of 2014 when Google paid $3.2billion to purchase the company, which is barely out of start-up phase, and its product has just been launched in the UK.
Tado is a German business that does everything that Nest does but without the Apple-like style, and is compatible with other manufacturers’ products. It costs £250 plus installation.
Honeywell too have long been established in heating controls and have recently launched evohome, which is a proprietary system for controlling all the different elements of your heating system, including individual rooms and radiators.
Worcester’s Wave Smart Thermostat (around £250 or so installed) allows manual (remote) and automatic (learned) programming. It includes weather compensation by postcode monitoring rather than external sensors. It also takes into account the current room temperature and only fires the boiler at the necessary level; making for a much more efficient system.
Z-Wave is a wireless communication protocol now widely used in the field of home automation. Sitting somewhere between WiFi (which uses much more energy) and Bluetooth (which has a very limited range), it is particularly well suited to home control systems because each device acts as a repeater so that they mesh with one another and don’t need to be boosted or wired together.
It’s been adopted by a number of established manufacturers like Danfoss and Horstmann who have chosen to use it for wireless control rather than make their own proprietary control systems as Honeywell have done.
Z-Wave extends far beyond just heating control: lighting, audio visuals, security, and smoke alarms can all be incorporated into a Z-Wave control system too, providing the equipment is Z-Wave compliant. Search online for Z-Wave controls and you’ll find a number of manufacturers working in this field.
nCube is a British start-up dedicated to exploiting Z-Wave as the medium for home control. It too offers a remote heating solution, but it also offers home lighting and security as options, controlled from an app on your phone, putting it someway in advance of most of the competition.
nCube’s basic offering, the heating starter package, is built around a Z-Wave hub, based on the ubiquitous Raspberry Pi computer card, and a Horstmann wireless heating control. By using Z-Wave, the system can also control individual radiators using Danfoss radiator valves.
The beauty of the nCube system is that it is not tied to any particular manufacturer, nor does it need to be supported by nCube in the future.