Concrete is one of the oldest building materials known to man. It’s application in construction is boundless and hails at least as far back as the time that the Egyptian pyramids were built. Despite the development and use over time of alternative resources – i.e., rammed earth, bamboo, recycled plastic, wood, mycelium (made out of the root structure of fungi and mushrooms) – the dominance of concrete is globally set into stone.
The Most Widely Used Substance on Earth, Apart From Water
With new and next generational technologies at the fore – i.e., 3D printing and PCM – a disruption in industry building materials may one day occur. But 70% of the world’s population lives in concrete structures and that number is growing. Concrete isn’t going anywhere, although, owing to innovation in technologies, concrete, both in application and composition, is headed along a more sustainable path. Initiatives such as the Concrete Sustainability Council are helping to mitigate the carbon footprint of this omnipresent material.
Sustainable Thinking Calls For A Growth Mindset
The construction industry is plagued with a fixed mindset. It’s an older, established club full of reticence despite emerging technologies. New and modified concrete materials are rebuffed in this fixed-mindset industry. Market penetration for industry innovators is often difficult, often delayed and sometimes altogether stymied.
“It’s the change in mindset that’s always proven to be the biggest challenge,” says Tim Chapman, director at Arup. “There are still many practitioners who want to protect the established ways of doing things, but the evidence from other industries where technology has taken hold is that soon it will be too big a draw to ignore.”
Technology Can Help Make Concrete Green
Where materials and processes become cemented in practice, a heightened duty arises to ensure their sustainability. Concrete must today become a green solution to the CO2 problem it has itself helped to create.
The sustainable construction movement in the Middle East is an impressive and ideal space to make change happen. Standing at the fore of climate change action, and with unfettered access to a global workforce and accompanying innovations, opportunities to incorporate technology into projects are promising. Using technology to build sustainable concrete structures can help us reach our net zero and nearly net zero building (nZEB) targets.
Thermal Energy Storage (TES) Solutions
Innovation in long and short-term thermal energy storage solutions is gaining traction worldwide. In the UAE, this week’s press release from Emirates Central Cooling Systems Corporation (Empower) underscores the contribution that TES systems provide toward reducing carbon emissions and attaining energy efficiency goals for district cooling.
Ahmad Bin Shafar, CEO, Empower, said: “Given the huge energy demand of both heating and cooling in buildings, which takes up as much as 60 per cent of a facility’s total energy consumption, advancing our interests in energy-efficient solutions will keep the UAE closer to its sustainability goals… Thermal energy storage tanks, which have already been positively contributing to district cooling’s energy efficiency goals, offer huge potentials for the district cooling sector. They act like batteries, which makes it easier to address the fluctuations in energy demand,” said Ahmad Bin Shafar, CEO, Empower.
Using Concrete Slabs For Airborne Thermal Energy Store
We have today a technology available that allows the concrete slabs of a building to act as the battery that stores the energy for cooling (or heating) a structure. Cool air is channelled into concrete slabs that are chilled with airborne thermal energy collected and stored during the night.
During the day, air is cooled mechanically and stored in the slabs, keeping the structure consistently cooled. The differential between the air in the rooms of a building and the air in its surrounding structure is reduced, and less energy is needed to keep occupants cool. The concrete structure becomes part of the energy store and part of the mechanics of cooling a building. TermoDeck is this type of TES system that stores air in the fabric of a building, (also referred to as a Thermo Active Building System or TABS). It is a simple, revolutionary, and affordable innovation.
Steps Forward Need Not Be In Isolation
Mathew Riley, managing director of Ramboll UK. “Construction earns its money on a series of individual, mostly unrelated, projects with no incentive to invest in new ways of working.” The TermoDeck TES or TABS system has been successfully applied in 20+ projects in the GCC and over 400 projects worldwide. It is ready and posited to become a mainstay of the HVAC construction industry.
Science Supports A Paradigm Shift
As explained, in the 2012 ASHRAE Journal, “Thermo active building systems (TABS) [or TES] exploit the high thermal inertia of the [concrete] slab to perform peak shaving, which consists of reducing the peak-required cooling power so that it is possible to cool the structures of the building during a period in which the occupants are absent (during nighttime as in offices. This way, the energy costs can be reduced using the lower nighttime electricity rate. At the same time, a reduction in the size of heating/cooling system components (including the chiller) is possible.”
As the majority of cooling occurs during the nighttime, the cooling efficiency of chillers (COP) increase and energy consumption is reduced.
“TABS [or TES] may be used with natural and mechanical day and night ventilation, with or without dehumidification, depending on external climate and indoor humidity production. In the example in the image, the peak cooling power needed to dehumidify the ventilation air during daytime is sufficient for cooling the slab during nighttime.” – Bjarne W. Olesen, Ph.D., of the International Centre for Indoor Environment and Energy, Denmark.
In addition to recognition in ASHRAE, buildings using the TermoDeck system have been awarded green certification from multiple ratings organizations worldwide, including outstanding and excellence in LEED, BREEAM and Passive House.
The Time For Concrete TES Is Now
Radiant heating and cooling has been applied in pipes embedded in concrete slabs (in-situ slabs) since the 1930s in Europe. Thanks to improvements in the composite materials in concrete, and to innovations in technology, this low energy HVAC solution can be applied today in a variety of projects and designs: in-situ, precast hollow core, and even as a retrofit.
TermoDeck has the added advantage of using air (not water) to cool the slabs, and provides ventilation without the need to provide a secondary ventilation system. It can also complement solar PV power by storing surplus energy in the slabs. The technology has been perfected after decades of operation. There is simply no reason not to incorporate it into contemporary HVAC designs.
In the United States today, a more onerous, costly and revolutionary concept of seasonal thermal energy storage is under development. The intention is similar to TermoDeck: to balance the variations in renewable electricity and production and provide a more sustainable source of energy.
In the not so far off future, seasonal thermal energy storage, if fully developed, could very well allow us to cool our homes in summer time with crisp autumn or winter breezes, stored under house, and circulated naturally and freely inside of structures made of organic and recycled materials.
In the meantime, cleaner, greener more efficient buildings that themselves act as a radiant cooler and thermal energy store should become the standard. The technology is ready and waiting, available at a low capital and operational cost. All it needs is a shift in mindset. Are you ready?
“Building Smart Buildings Smartly – The New Technology of Construction (21 June 2017) Memoori Research
“Using Building Mass to Heat and Cool Thermo Active Building Systems,” ASHRAE Journal, vol. 54, no. 2 (February 2012)
“Thermal Energy Storage Solutions Boost Empower’s Efficiency Targets: CEO,” Press Release (17 December 2017)
“William Smith Building, Keyworth, Nottinghamshire, by Pick Everard,” The Architect’s Journal (8 June 2009)