M1 MMC Sept '16 cc

More documents

Recommendations

Info

Industry catching on to the importance of reducing return temperatures The heating and plumbing industry is becoming increasingly aware of the importance of lowering return temperatures to improve the efficiency and performance of central plant and heat network systems. For a number of years Altecnic, the UK’s leading supplier of heat interface units (HIUs) has been promoting this approach, lowering the return temperature will increase the delta-T so long as the temperature stays the same. There are two reasons why this is important, it increases the proportion of energy that can be supplied by the renewable energy source out of the total energy demand, and reduces the flow rate around the primary system. It’s therefore crucially important and it is becoming the overriding starting point in central plant and heat network design, according to Neil Parry, the company’s National Specification Manager. “Renewable heat sources, including heat pumps and solar thermal, can only really generate constant temperatures of around 50oC and if the system return is above this figure then the renewables can’t support the system,” he explained. “When we look at Combined Heat and Power (CHP)-led systems, high return temperatures restrict the CHP’s ability to cool the engine. As a result the engine switches off, stopping both electricity production and heat output, leaving an expensive, non-functioning box taking up space in the plant-room.” However, lowering the primary flow rate by increasing the delta-T is even more important as it affects both capital expenditure and operating expenditure. “Meeting the building’s energy demand with a lower flow rate allows the primary pipe-work to be reduced in diameter,” Neil continued. “The lower flow rate also reduces buffer vessel size and pump size. Clearly smaller pumps, vessels and pipework save on capital spend, but the operating costs are also dramatically reduced. As a result it’s not uncommon to see pipe diameters being reduced by two sizes or more when the calculations are recalculated with the correct delta-T in combination with the installation of an Altecnic SmartSat electronic HIU which assists in providing a very wide delta-T.” to see that something that Altecnic has been promoting for many years is finally getting the focus from the industry that it so readily deserves!” Top Tips ‘The Golden Rules of efficient heat networks’ • Select a HIU that has been designed specifically for low return temperatures. • Select a HIU with fast acting control valves suitable for the maximum differential pressure the system will produce. • Ensure that the sizing of the system (pump, pipe-work, buffer vessel) has been done to take advantage of these low return temperatures. • Utilise the correct hot water diversity factors. Our recommendation is the Danish Standard DS439 (also preferred by CIBSE and BSRIA). • Keep the primary system free of other flow restrictions and control valves that may take the valve authority away from the HIU’s control valve. • Switch off the HIU’s preheat wherever possible. • Minimise the number and correctly control the system bypasses. • Ensure that the pump is controlled correctly, from the index(s) apartment(s). • Integrate a plant-room thermal store to cover for the peak demands on the network. • Heavily insulate the primary pipework, at least to the relevant British Standard preferably more. Neil added: “As an added bonus, this approach also reduces the risk of one of the most common complaints associated with district heating systems – overheating in corridors caused by oversized pipes, high pump flow rates and high return temperatures. It’s great For more information contact Neil Parry, National Specification Manager 07800 865567 neil.parry@altecnic.co.uk www.altecnic.co.uk 30 MMC Sep/Oct 2016 MI
LED is the Jewel in Lighting’s Crown By Stephen Hurrell, Divisional Managing Director - UK Projects, Aurora Group There are several misconceptions about LED lighting, principally that LED lighting prices will go down so it pays to wait; LEDs are so efficient that controls are unnecessary; and that LEDs don’t work well in high-temperature environments. According to the Energy Savings Trust, LED offers best value for money in lighting today; the price of fittings has come down and, at the same time, performance has improved significantly. The Carbon Trust advocates LED as its number one efficiency recommendation. Leading website www.environmentalleader.com reports that while switching to LEDs creates a one-time savings event – typically reducing lighting energy use by up to 50% – integrated sensing and controls can nearly double those energy savings, making controls essential for maximum savings and project economics. And did you know that by using LED in construction, it significantly contributes to the BREEAM rating of a building as it typically halves energy consumption of traditional light sources. Miniaturisation has also led to a significant reduction in raw materials utilised in manufacture. Artificial lighting in buildings is usually categorised in three ways. The ‘Ambient’ lighting function provides light to the space to an accepted level. ‘Accent’ lighting highlights certain features and/or attributes. ‘Task’ lighting illuminates specific working areas to aid visibility. Lighting Performance The four key criteria governing LED performance are thermal management, optical control, efficacy of light and reliability of power. So, what are the guiding principles of best practice in quality manufacturing? Heat has a negative impact on any LED light source’s performance. The next generation in thermal management dissipates heat away from the LED chip, providing higher quality, brighter light for longer. There’s also been continuous improvement in efficacies of LED chips so the higher the lumens per watt, the better. Look for products warranted to L70 to a stated number of hours. This means you can expect a light output of 70% of the lumen performance stated at that period of time e.g., a 1000 lumen LED luminaire will deliver at least 700 lumens after six years, based on burning 4000 hours per year. An emerging trend in construction is to insulate the ceiling void by ‘blowing in’ loose fill insulation as an alternative to loose-laid products. Loose fill completely encloses the fitting which could affect LED performance in inferior downlights. Biodynamic lighting Light controls our biological or body clock and this is known as the circadian rhythm. New to the market, biodynamic LED lighting allows people to control their environment according to need, mood and task, which can improve performance and motivation. Changing the colour temperature of the artificial lightsource (e.g. from extra warm to warm through to cool) can have a dramatic effect. Biodynamics is particularly suitable for dynamic interior projects, retail applications, and in healthcare and homes for the elderly. Enlite LED Lighting Essentials The Aurora Group has responded to increased demand for LED by engineering the Enlite range of 250+ “Lighting Essentials”. Enlite offers Offsite’s varied modular business model big performance, high quality and the best in value to meet specifications and budgets. Firm Enlite LED favourites in the MMC sector are the E8 TM 8W integrated fire rated downlights with halogen like appearance, the ultra-slim E6060 TM 600mm 2 flat panels for commercial applications, the UniPac TM and LinearPac TM IP65 linear anti-corrosives which replace traditional T8 TM s and the vandal resistant Orbital TM IP66 bulkhead. Regulatory compliance Lighting design is a complex issue and part of a quality manufacturer’s role is to develop bespoke schemes which will comply with regulations. A revised version of the Building Regulations, Part L (2013), came into force in April 2014. BIM LEVEL 2 was introduced as a requirement for all government construction projects this April 2016. Call: +44 (0) 1727 83 66 11 or visit enlitelighting.com Sep/Oct 2016 M1 MMC 31
Page 1 and 2: MMC MODERN METHODS OF CONSTRUCTION
Page 3 and 4: MMC Sep/Oct 2016 issue M1 Here at M
Page 5 and 6: Bringing stress to work can be fata
Page 7 and 8: The Outstanding Joist System The Po
Page 9 and 10: Right to buy abolishment & Offsite
Page 11 and 12: The entire SureClad ® façade syst
Page 13 and 14: A W A R D W I N N I N G L E D L I G
Page 15 and 16: MMC Sep/Oct 2016 M1 15
Page 17 and 18: AN AIR TIGHT OSB SYSTEM YOU CAN DEP
Page 19 and 20: SPECIFY JJI-JOISTS AND WE’LL GIVE
Page 21 and 22: Pasquill supplies glulam and i-jois
Page 23 and 24: The CONCRETE Times www.
Page 26: Are we fishing from a small pool th
Page 29: The flexible choice in advanced Ren
Page 33 and 34: Sep/Oct 2016 M1 MMC 33
Page 35 and 36: commonly requires the design to be
Page 37 and 38: New Façadeshield UV protects build
Page 39 and 40: FLAT ROOF MANUFACTURER BAUDER EXTEN
Page 41 and 42: Fermacell set to debut at Education
Page 43 and 44: Building a better future for over 8
Page 45 and 46: See us at The Offsite Construction
Page 47 and 48: INNOVATION FOR CONSTRUCTION Modern

M1 MMC Sept '16 cc

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?