www.heatingandventilating.net
calculation methodology and filtration technology could also enable reduced flow rates – and therefore enhance energy efficiency – while still achieving the required cleanroom standard.
Energy consumption is also increased by the assumed need to ensure an operational environment at all times, despite the disparity in particles entering the space when it is unoccupied. By altering the temperature, humidity and air change parameters for non-operational hours, energy consumption can be reduced by up to two thirds, without de-validating the cleanroom’s classification status. If a wider temperature and relative humidity band is set for non-operational hours during initial validation, and pressure regimes are maintained during these periods, much less cooling (for humidity control) and re-heat energy (for temperature balancing) is required. This approach calls upon the knowledge of the cleanroom specialist to calculate the operational and non-operational temperature and relative humidity bands required to balance optimum energy efficiency with the required cleanroom environment, including the use of computational fluid dynamics (CFD) modelling data to analyse air flow and suggest possible layout or workflo w modific ations.
Designing into the spec esigning into the spec
It’s commonly assumed that cleanrooms do not need to comply with Part L but, in reality, all cleanrooms can comply with Part L. It’s often possible for them to exceed regulatory standards for energy efficiency too and meet the requirements for a RICS’ SKA rating for sustainable fit out.
As the cleanroom requires more cooling energy than heating, a clear emphasis should be placed on maximising the efficiency of the cooling system and selecting the correct HVAC arrangement for the installation. Where possible latent (moisture) and sensible (heat) cooling systems should be separated to enable the use of high efficiency chillers and free cooling. For higher ISO classes (with lower cleanliness standards), where the clean air requirement is similar to the cooling demand, a traditional air conditioning system may be sufficient, with heat recovery contributing to the re-heat requirements of humidity control. For facilities with a lower ISO classification (higher cleanliness standards), where air change rates exceed those required for cooling, partial conditioning with separate latent and sensible cooling units will reduce the fan, cooling and re-heat energy load.
Outdoor air conditioning is the most appropriate option for larger or multi- cleanroom high standard facilities, where air change rates exceed those required for cooling. Here, sensible cooling is provided by a separate, primary air handling unit (AHU), removing the need for re-heat and enabling the use of high temperature chilled water from very efficient chillers, combined with free cooling, to serve the primary AHU.
In cleanrooms requiring very low space relative humidity, desiccant dehumidification may be specified for use in combination with the most appropriate HVA C.
Bespok Bespoke design
Ultimately, it’s the detail of the HVAC design that provides the most substantial and sustainable energy reduction gains possible in a technically- advanced facility. Innovative design methodologies for reducing air moisture content before the air reaches the cooling system can significantly cut the cooling energy load, for example, and a more complex, multi-layered HVAC system will use substantially less energy over all.
Dedicated humidifier spares department Nationwide humidifier service team
Humidifying the UK for over 30 years
World leading humidifiers
Specialist advice and system design
Contactusfor Te
el
fo free expert advice Tel: +44 (0)1903 850 200
Email:
uk.sales@
condair.com Web:
www.condair.co.uk
Humidification and Evaporative Cooling
www.heatingandventilating.net
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64
