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HPM September 2017

66 H E AT I N G & C L IMAT E C O N T R O L S Taking control of the indoor environment Darren Trivett, managing director of Omnie, considers the best strategies for For anyone who has had a maintaining a comfortable and healthy living environment bout of the flu over the winter, such viruses are an unpleasant reminder that we can feel very unwell when our body temperature deviates by just the smallest amount. Of course, when we are in robust normal health, our blood circulatory system and processes such as perspiration are very good at regulating our core temperature to 37ºC and this means we can cope with both frosty mornings and sweltering summer days without the need of intervention, except our choice of clothing. It is also the case, that our perception of being ‘comfortable’ can be affected by relatively small changes in ambient temperature or humidity, and phenomena such as draughts, but factors we remain unaware of can still affect medium and long-term health issues. It is for this reason that construction consultants, as well as other professionals, are paying increasing attention to the control of the indoor living environment with Building Regulations, BREEAM and other construction standards all striving to address the issues. Shelter and warmth can be considered as basic physiological needs, but ever since central heating became the norm, people have craved far greater control over their comfort levels. Thermostats were the first step in a series of technical advancements, which have progressed to such a level that it would have seemed like science fiction a decade or ago. Conversely, it should also be borne in mind that continued emphasis from the government on cutting energy losses, has brought their own problems in the form of creating potentially stuffy, moisture laden or even harmful indoor atmospheres. Improved air tightness For not only do we have increased insulation standards, but these have been coupled with measures to improve airtightness. As a result natural air changes have been reduced to the point where heightened levels of water vapour or even carbon dioxide can make us feel uncomfortable or drowsy. Humid air also creates more favourable breeding conditions for germs, mould and dust mites. The UK’s Building Regulations and the Building Standards in Scotland of course include sections on ventilation but we can look to the German PassivHaus standard or the Canadian Super E approach to construction as guidance taking a more proactive approach through the adoption of mechanical ventilation with heat recovery (MVHR). The challenge for architects and their mechanical services engineers is to quite literally balance the requirement for achieving adequate air changes, without compromising the efforts made to reduce energy usage and to do so in a manner which does not over-complicate everyday life for the building owner or occupant. The best answer, then, is to specify heating and ventilation systems, which can operate in harmony, ideally utilising controls which are both intelligent and user-friendly. Many consultants now recognise that underfloor heating systems (UFH) can offer a solution that is both economic to run and comfortable to live with. Firstly, by operating at lower flow temperatures than wall radiators, they assist both condensing boilers and ground or air source heat pumps deliver optimum efficiency. They also help create a very even temperature within the occupied space, which is pleasant for people whether they are relaxing or involved in some activity. It is vital, of course, that the MVHR chosen not only operates quietly, but consumes the minimum amount of electricity in extracting the stale moist air which we inevitably produce, replacing it with sufficient pre-warmed, filtered fresh air to keep occupants comfortable, alert and healthy. Comfort cooling It may be the case, in higher spec residential or non-domestic properties, that the designer may also want to incorporate some level of comfort cooling, which can be effectively achieved by using the borehole or ground array providing energy to the heat pump. In the summer, the ground temperature can be 150ºC at just two metres below the surface, so the brine in the system can be circulated through the UFH to provide free cooling. To make all of these systems run efficiently and make the best use of the fuel or electricity supplied to any property, these systems must be linked not just to sensors, thermostats and timers, but to an integrated control network that will properly monitor and optimise the entire internal space. + + = TOTAL CONTROL The ESi range of WiFi products including the Centro app lets you take control of the heating and appliances in your home from anywhere in the world. For more information about the 5 series range of programmable room thermostats or our other WiFi products call 01280 816 868 or visit www.esicontrols.co.uk www.hpmmag.com September 2017 enquiry number 138 enquiry number 345


HPM September 2017
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