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12 December 2018
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The heat is on

Demand for environmentally responsible and resource-efficient building materials and products is increasing. Elisabeth Jeffries looks at recent innovations that have been picked out by awards judges for their potential.

the heat is on


1 July 2014

It was one of the earliest domesticated plants, and now hemp could be mass-produced as a building material.


Hemcrete Projects, an ecologically minded enterprise owned by the company Lime Technology, claims to effectively produce blocks from hemp offsite, thus opening the door to greater commercialisation. 

For developing this procedure, the company recently won a respected 2014 Ashden award, a prize aimed at sustainable energy companies. 

“Until now, hempcrete has always been cast onsite, giving it limited commercial appeal. ‘Hembuild’ panels are made-to-measure offsite, then arrive at building sites ready to be slotted together like a jigsaw puzzle to form the building’s walls,” said the award judges.

Retailer Marks and Spencer has used Hembuild cassettes in its flagship Cheshire Oaks eco-store to cut energy consumption. 

Hemcrete is just one example in a cluster of emerging low-carbon businesses in the buildings sector. Many of the companies concerned are producing pioneering technologies and equipment that could help FMs make a major contribution to energy savings.  Ashden, an organisation that champions practical, low-carbon and local energy solutions, rewards these efforts.

Paul Watson, a spokesman for Hemcrete, outlines the project achievements. 

“Hemcrete has developed faster track, more predictable build times, where it was previously quite time-consuming and a bit of a messy [onsite] process.”

The building bricks, made of chopped fibres from the hemp stem mixed with a lime-based binder, could also be a suitable option for building extensions. 

According to Dr Julie Gwilliam, senior lecturer at the Welsh School of Architecture at Cardiff University, they are likely to work well in this context.

“This could be a perfectly good new material to build next to existing solid wall constructions during retrofits.

“It could be a niche market for this purpose and fit in very well. Sometimes the use of new materials next to traditionally built solid wall constructions can set up problems, due to different traditions in construction,” she points out.

M&S energy centre

Good u-values
Gwilliam, an expert in sustainable buildings, speaks warmly of the material’s characteristics, suggesting offsite production was “the step needed.”

“It’s a jolly good material which offers good U-values [a measure  of the effectiveness of a material as an insulator] and has good thermal mass properties which balance temperatures well. 

“Heat is stored in the material and only slowly re-emitted, so that the temperature falls slowly,” she says. 

Lime Technology is one of only a few alternative materials suppliers to go beyond the eco-warrior market. However, it is only a matter of time before questions are asked about the source. Like biofuels, the crop could have limitations if it replaced land used for food farming.


Energy savings
Demand Logic, an ICT company, was an Ashden runner-up. The company claims to have produced £390,000 in annual savings for Kings College, University of London. It makes an electronic box that monitors Building Management Systems (BMS), allowing more sophisticated understanding of a building’s energy use and defects as well as the identification of energy-saving opportunities. 

The kit is a web-based system that provides a real-time dashboard and regular performance reports. Users can log in any time and access live and historic data. That alone could be an improvement on the BMS, given that significant historic data is often lacking. 

Demand Logic also provides a single point of contact where those engaged on improving the building’s performance can share data and schedule improvements. The company’s expertise is based on a combination of buildings control engineering and web development.

“The BMS helps you draw conclusions on total energy use, but we’re saying rather than just do that, we want to know what is working, or not, and why. Demand Logic allows you to hunt around the system and find the specifics,” says Joe Short, the company’s communications manager.

Thus, users could identify the exact location of, for example, a heater that was working at the wrong time of day and therefore consuming too much energy.

“With a BMS, you can go back and look at the past week and say why something happened. There’s limited logging but you have to decide in advance what to log. You have to pay someone to decide whether to change the energy strategy. It’s designed to be used all day and every day and quite rightly is inflexible,” says Short.


However, he suggests analytics are vastly improved once complemented by the Demand Logic product.

Dr Julie Gwilliam, however, has some doubts about the usefulness of the product. As she points out, many BMS are wrongly set up. 

“The BMS testing process is often really hurried. The building may not have been tested properly across all the seasons,” she says. 

That means the monitoring kit’s operations might be founded on data about the building that is faulty in the first place.

For example, sensors communicating via a BMS may indicate they are in a particular place in the building, but actually be located elsewhere, so that the system is heating or cooling in the wrong place.

“If the BMS is working as it was designed to do then this kit could be useful. But I’m not convinced it will fix a system that’s fundamentally broken,” she says.

Further automation, she suggests, may not be the answer. “As a human being, you’re a good centre yourself... you find out more by talking and engaging,” she says.


Natural ventilation
Breathing Buildings is another innovative company that has won an accolade for being a new energy pioneer, this time from prolific market intelligence company Bloomberg New Energy Finance.

It has developed a new way of naturally ventilating buildings by exploiting the heat gains from people, lights, IT and solar in a building. This can avoid the use of radiators – often the only solution to cold draughts. The technology, based on a Cambridge University patent, could halve a building’s energy consumption.

“People fail to recognise that in most modern buildings such as schools and retail outlets, for example, the amount of heat gain is phenomenal. 

“Why use a radiator? We don’t bring in the air through a low-level window. Instead, it comes through at a high level and is mixed with ceiling fans. That means you don’t need the heating on until the outside temperature falls to zero degrees Centigrade,” explains Shaun Fitzgerald, chief executive officer.

The main product consists of a stack natural ventilation system. It is designed to ensure a minimum rate of air change between a building and the exterior in winter to comply with Part F building regulations, while minimising the heating energy required. This is achieved by mixing the incoming cold fresh air in winter with hot interior air it before it reaches the occupants. 

the heat is on 2


Air quality
According to Fitzgerald, the system ensures that the air quality remains very high, but also that the building is totally comfortable, avoiding the risk of cold draughts often associated with natural ventilation.

The alternative is mechanically or manually opening windows accompanied by the use of fans. Using windows alone may mean the space gets too hot, however, if temperatures rise outside. Roof stacks give higher rates of natural ventilation, but when it gets cold outside, uncomfortable cold draughts may come through the window or down the stack. Heaters are often required to remove these draughts. However, that may use a great deal of energy. 

Breathing Buildings’ E-stacks – typically placed in the ceiling above the window level – remove cold draughts by mixing incoming air with warm room air. 

According to Fitzgerald, this strategy uses significantly less energy than heating incoming air. A number of additional options are available, but the basic system comes with full controls such as temperature and CO2 sensors and traffic-light indicators for window opening. It also includes fan-boosted flow on the hottest days and automated secure night cooling. 

Fitzgerald says the components last 15 to 20 years. The static parts, he suggests, last “for decades.” 

Upfront investment should be rewarded by lower energy bills.

Dr Julie Gwilliam applauds the idea, which could also be suitable for refurbishments. 

“It’s theoretically possible, but perhaps only in certain buildings,” she says. 

“The amount of air needed to make a building comfortable is dependent on the number of people – and that’s driven by the oxygen required. 

“It may make sense where there’s a high air change rate, but I don’t know where the line is drawn... I’d like to see some monitoring data.” 

Breathing Buildings’ initial focus on school buildings might make sense. 

“Schools often have high ceilings, so there’s a lot of wasted space. This may only be useful where there is a substantial amount of ceiling height,” says Gwilliam.


Healthier, more breathable air
An attempt to avoid sickness while retaining efficiency may be one of the motivations behind another new energy pioneer, Coolerado.

Based in Denver, Colorado, the company produces an air conditioning system based on indirect evaporative cooling. 

According to public relations manager Jamie Diamond, its technology can cool buildings using 90 per cent less energy than traditional cooling equipment while introducing 100 per cent fresh air and without the use of chemical refrigerants. 

The standalone coolers use a unique process that cleans and filters the outdoor air they pull in before it is cooled, leading to healthier and more breathable air. 

“Coolerado’s equipment carries a premium price versus traditional, compressor-based air conditioners, however, its price is very competitive compared with other high-efficiency cooling alternatives,” says Diamond.

According to Dr Julie Gwilliam, the principle is sound.

“Indirect evaporative cooling makes sense. The company appears to have tried to benefit from the concept of evaporative cooling, which is very efficient, without incurring the risk of Legionnaire’s disease.

According to 2014 figures from the government’s Department of Energy & Climate Change, British households are now using about a fifth less energy than they were in 2004.

Innovative companies such as these could help ensure similar success in other sectors.