Surface level improvements

Surface heating and cooling technologies can be the perfect answer for lower energy consumption in many projects. Building Products reports.

Given that the heat used in our buildings is responsible for around half of all energy consumed in the UK, and accounts for almost 50% of the UK’s carbon emissions [1],  the way in which an internal space is heated is a key factor in the delivery of these targets and requirements.

In comparison to Europe, traditional heat sources such as radiators and air conditioning units remain the status quo in the UK, in spite of the availability of alternatives that can deliver a more consistent level of comfort, cut energy consumption and reduce running costs. Surface heating and cooling is one such alternative. Whilst conventional heat sources push hot air upwards via convection currents, surface heating systems radiate warmth from a larger surface area, creating a more homogeneous temperature with the heat most concentrated in the bottom two metres of the room, where it is needed most. This heating method allows energy savings of 30-50% in high ceiling buildings and 10-20% in their low ceiling equivalents. It also requires less energy to heat up, as radiant energy exchange means that the temperature in the room can be up to 2°C lower whilst maintaining the same physical comfort levels.

Whilst the UK has a long way to go before surface heating and cooling becomes the norm, progress is being made. Shopping centres for example, with large open plan areas and high ceilings, are notoriously difficult to heat. As a result, surface heating and cooling is increasingly becoming the standard. The recently opened £1.5bn Westfield Shopping Centre in Stratford, London (pictured) installed a Warmafloor underfloor heating system as part of a "low cost and low energy" design, says Warmafloor. Featuring a wire grid system of 20 mm pipe embedded in an enhanced screed, the system uses 230 V electric actuators on the pump mixing manifolds, enabling an enhanced level of control and optimum comfort. Negligible maintenance, low dust circulation and the "design freedom that comes from having no room equipment" were also key factors in the specification.

Surface heating and cooling systems are natural partners for new low-energy heat sources, such as biomass boilers, heat pumps and solar panels, allowing them to work at their most efficient. With Chris Huhne announcing a target of cutting 50% of CO2 emissions from 2023 to 2027, compared with 1990 levels [2], there is no surprise that more and more projects are including such technologies. The Weymouth and Portland National Sailing Academy in Dorset, which will host 2012 sailing events, employs both solar and wind turbine technology.An SEN School at the Avenue Centre in Kent, the Genesis Centre in Taunton and Swindon’s new Central Library all combined surface heating and cooling with geothermal ground source heat pumps, resulting in a reduction in energy consumption of as much as 30%, says Warmafloor.

Surface heating and cooling can be flexibly designed around the building type and function. Large or multifunctional floor spaces can be zoned to accommodate the differing heating requirements in each area, and managed by a central control system that can co-ordinate multiple energy sources to ensure they deliver maximum benefit and reduce whole-life costs. The underfloor system at Portsmouth University’s Frewen Library, for example (pictured), was divided into 28 separate zones, with the IT area of the library installed with underfloor cooling to offset the higher heat gains. Sophisticated controls monitor and adjust temperatures to ensure maximum comfort and maximum productivity. This also helps with the preservation of library books and archival collections as temperature and relative humidity contribute significantly to the breakdown of materials.Maximum use of wall space was also important to house many thousands of books.

Surface heating and cooling, widely used in Europe, can playa part in taking the government’s sustainable construction agenda forward, especially in terms of resource efficiency and reducing carbon footprint.With rising energy costs and ambitious government pledges, we can no longer ignore the issue of energy efficiency. The industry needs to re-consider the value of some of its sacred cows or future legislation will simply force them to make changes.

Published Date: November 14th, 2011