Two clicks and you’re out
Too many building services control systems are not ‘intuitive’ and ask too much of the end user. The commercial heating sector must take on board the lessons learned by the IT industry and deliver easy to operate solutions, says Ron Barker.
Question: What type of building services system is the most energy efficient? Answer: One that is switched off.
A heating system should not run or cycle when heat is not needed, but many do, and this has a significant impact on their energy efficiency. Sorting this problem out is essential if we are to deliver the energy-efficiency improvements expected by clients and demanded by legislators — and the key is in the control strategy.
It does need restating to system designers and end users that if they really want to minimise the carbon impact of any commercial heating system they must ensure that it is idle for as long as possible. This simple fact can often be forgotten in the rush to provide the latest, most innovative solution.
The one exception to that rule is combined heat and power (CHP), which needs to run almost continuously, generating ‘free’ electricity while meeting a high heating and hot water demand. But, in the main, we have an increasing responsibility to make sure that the default condition of our systems is ‘off’. Unfortunately, the opposite is more often the case.
The increasing use of ‘smart meters’ means that energy consumption is becoming far more visible to end users, but the potential downside of is that they will become increasingly frustrated if they are limited in what they can do to manage consumption better. However, there is a balance to be struck so that end users are not able to completely undermine a perfectly good control strategy by ‘fiddling’ in the wrong places.
Many systems designed with the best of intentions are undermined by poor controls. The heating industry could learn a lot from the IT sector. Google and Microsoft will not design anything that requires the user to go on a training course to work out how to operate it. The golden 2-click rule is paramount. If it takes more than two clicks to find what you need or make something work, then it is back to the drawing board for their design engineers.
Too many building-services control systems are not intuitive and expect the user to follow a relatively complex procedure to set the system up as they want it. In many cases, this leads to the system operator simply over-riding the controls and setting the system to being continuously ‘on’.
The secret is to give the expert user — the facilities manager, for example — a measure of control so they can intervene where it is clear that energy is being wasted but to automate most of the complex and underlying elements.
The system should also automate everything, except the most basic adjustments, for the ultimate user — the individual building occupant.
For example, optimum start/stop control and time switches that ensure the building reaches its desired temperature when the occupant wants it to, but at the absolute minimum energy penalty, can deliver the required result with minimum input from the building operator.
However, this requires that the system is properly set up in the first place — and that means expert commissioning. The system needs to be designed with commissioning in mind from the outset, and there must be enough time in the project process to allow the commissioning engineers to weave their magic.
The Building Regulations are driving innovations to improve efficiency. For example, this has led to the widespread use of zone controls to minimise boiler running time so that the system is not attempting to heat the whole building when only parts are in use. Similarly, control systems need to be integrated to avoid the all-too-common scenario of heating and air conditioning systems battling each other. Ideally, the building-management system (BMS) will tackle this problem. However, the settings are often changed, perhaps during routine maintenance, and never reset.
Avoiding this type of situation requires clear explanation to the facilities manager, who must be discouraged from resetting the system unless absolutely necessary. To deliver long-term savings, we will need to establish a culture of regular evaluation so that engineers are able to go back into buildings and check that the controls are still at their optimum settings.
Hopefully, the greater use of Display Energy Certificates (DECs) which are due to be applied in more buildings with the forthcoming recasting of the Energy Performance of Buildings Directive (EPBD), will encourage users to invest in this kind of ongoing intervention as they will be able to see exactly how and why their building is failing.
The greater availability of wireless control systems integrated via broadband Internet connections will also give more users access to the latest controls technology at relatively low cost, as well as the ability to retrofit them to buildings without disrupting day-to-day operations.
This capability allied to smart metering gives unprecedented access to understandable energy information and the ability to act on it. Also, the involvement of the IT industry in this way also means that our industry will become used to the 2-click approach of simplifying controls.
Amid the push for technical innovation and growing appetite for emerging renewable technologies, there is a danger that controls could be forgotten. However, unless the design team has a clear idea how those technologies are going to be controlled from the outset there is very little chance of delivering the energy and carbon savings possible.
We need a new ‘controls culture’.
Ron Barker is group product manager at Ideal Commercial Heating.