Who has the S Factor?
Five intrepid representatives of the building services industry managed to survive a grilling by the S Factor judges at the recent HEVAR exhibition in London.
This unusual event was based on the format of the TV show 'X Factor 'that puts showbiz wannabes through their paces. In this version, ‘S’ stands for ‘sustainability’ and each contestant had to convince the judges and the large audience that their chosen technology was sustainable.
The judging panel, consisting of leading consulting engineer Ant Wilson, former M&E Sustainability chairman David Frise (left), and HVCA vice-president Graham Manly, debated the various merits of CHP (combined heat and power), heat pumps, air conditioning, controls and dynamic demand management.
CHP
David Shaw, business development manager at Baxi SenerTec UK, was chosen to put the case for CHP. He pointed out that central power generation is only 35 per cent efficient due to transmission losses and rejected heat from the generation process, whereas on-site CHP produces useful heat and cheap electricity at a combined efficiency between 80 and 85 per cent.
“We must stop polluting the air with waste heat,” he told the panel. “All that wasted heat from power stations is enough to provide every home in the UK with free heating and hot water.”
David added that recent Carbon Trust field trials had proved that wider adoption of onsite mini and micro CHP that generates power and heat at the point of use would cut carbon emissions by 20 per cent.
“Reliability is also a big issue,” he added. “CHP generates power when the sun is not shining and the wind not blowing. CHP is tried and tested, proven and reliable. It is easy to install and does not need any big holes dug in the ground or roofs reinforced – it can go into existing plant rooms or where boilers used to be.”
The judges asked a number of searching questions, but in the end they accepted that CHP would play a vital role in the country’s future energy strategy. They added that it was a sensible way to improve the poor efficiency of our national energy generation.
Heat pumps
Graham Hazell from Colt International was next up and put a persuasive case for wider adoption of ground and air source heat pumps because he believed the industry was not exploiting as much energy from the sun as it should.
“The combination of ground source heat pumps and solar thermal technology means we can exploit solar energy all year round,” said Graham. “The ground acts as a massive thermal store – it can even be used for cooling in the summer.”
He said heat pumps were reliable, discreet, secure, low noise, low maintenance, safe and non-polluting. However, the judging panel argued they were too expensive adding that there were not many applications in the UK where ground source versions actually work.
“In most applications, designers are adding a back-up system for the ground source heat pump,” commented David Frise. “Why are they doing that if they have confidence in the system?”
However, the judges did think there was a place for heat pumps in refurbished buildings where nothing more could be done to improve the thermal performance of the building fabric, but argued it should be primarily air source as the ground works for ground source are too disruptive, too expensive and unrealistic for many projects.
Ant Wilson also condemned those members of the industry who make unrealistic claims for heat pumps.
“I worry when I hear claims for them delivering COPs of between 4 and 6,” he said. “Let’s keep this simple and realistic and make sure they are applied properly and only where appropriate.”
Air Conditioning
The heat pump argument was also applied to show that air conditioning could be sustainable.
Martin Fahey of Mitsubishi Electric demonstrated that ac technology had advanced significantly in recent years to the point that it now can make use of the waste heat it was previously designed to “throw away” as part of the cooling process.
He said that heat could now be transferred to places where it would be useful and that ac manufacturers now offered domestic heat pumps that could provide hot water at COPs of between 3 and 4.5.
“We also expect to improve that efficiency by a further 20 per cent next year,” added Martin.
However, to be sustainable a solution has to be much more than just energy efficient and the role of indoor air quality was another area tackled in this discussion. Each building occupant is supposed to receive 10 litres of fresh air per hour under the requirements of the Building Regulations and Martin argued that modern air conditioning systems are best placed to meet that demand thus improving health and productivity.
He also claimed that 88 per cent of ac components are now recyclable – another key sustainable criterion.
The judges still needed considerable convincing with Graham Manly asserting that building services designers should start from the position of trying to do without air conditioning completely. However, Ant Wilson felt the need for occupant comfort and productivity was often overlooked in discussions about sustainability.
“I expect the air conditioning industry to pioneer many of the renewable solutions in their efforts to deliver a more closely controlled environment in a more sustainable way.”
Controls
This led neatly into the debate about the role of controls with Doug Robins, President of the Building Controls Industry Association (BCIA), in the spotlight.
He argued that controls were the link between all the other solutions and the only way of ensuring they were truly sustainable.
“Controls can monitor and control every kilowatt of energy being used in a building at any time,” said Doug. “They also limit the wear and tear on plant and equipment, which can only be as efficient as they are designed to be if they are properly controlled.
“A proper controls strategy is absolutely essential for any building that uses renewables and passive design features. Mixed mode buildings will not function without intelligent controls that make use of aspects such as weather compensation.”
The judges accepted this argument, but pointed out that the controls industry was sometimes guilty of not listening to clients. They said that a better understanding of how buildings operate could lead to systems being designed more appropriately.
“We must be able to let temperatures ‘float’ with the seasons and get people to dress more appropriately,” said David Frise. “Sticking rigidly to temperature setpoints all year round drives up energy consumption.”
The judges also felt controls had much to offer in the area of lighting, but agreed there was a big debate to be had about whether all lighting systems should be automatically controlled via occupant sensors and the like, or whether occupants should still be allowed an element of control.
Overall, they accepted that controls had a critical role to play in delivering sustainable buildings.
Dynamic Demand
M&E Sustainability’s own technical consultant Mike Malina was next up to fight the corner for Dynamic Demand – often referred to as Demand Management. This proved to be a highly popular session and a logical extension from the arguments about the role of controls.
Many delegates were unfamiliar with the technology itself – click here for Mike’s 60 Second Guide to Dynamic Demand for an overview of what it is and how it works.
Mike argued that by going to the root of the problem by smoothing out the peaks and troughs in the demand drawn from the National Grid, Dynamic Demand was the nearest thing the industry could get to a ‘silver bullet’.
“All the technologies we have heard about today are great and each has their place, but we are running out of time and need something that can be quickly and cheaply adopted that can make a massive difference.
“We must take control of how we use our energy,” said Mike. “We have a total electricity capacity of 62GW in the UK – 3GW of that is spinning continuously just to keep up with possible surges in demand i.e. when people put their kettles on at the end of Eastenders. We are effectively running the Grid flat out and wasting electricity all the time.
“By installing a match box sized device that costs £5 in every home we could save the equivalent of one and a half power stations by reducing the demand on the Grid.”
He added that this technology was now being widely adopted in California because of that state’s highly publicised problems with power shortages.
“We will run short of energy very soon – then people will be clamouring for this,” said Mike.
The judges felt this subject deserved greater publicity and wider explanation to the general public and politicians. They unanimously agreed that Dynamic Demand had the S Factor.