M&E services Airport case study
Engineers faced the challenge of working on a section of Terminal 4 while the building services for the whole building were kept fully operational throughout
>
M&E team spent a great deal of time in the early days of the design reviewing the most energy efficient way to achieve internal environmental conditions consistent with the client’s technical standards and aspirations. Achieving an internal temperature of 20C to 24C
for the terminal in an energy efficient manner proved a challenge for the team. It investigated an extensive range of natural ventilation techniques and options before concluding that the unique combination of ambient, acoustic and security circumstances surrounding an existing airport terminal building effectively dictated a mechanically cooled and ventilated resolution of some description. The team settled on a solution where the concourse
extension is served by four new roof-mounted air handling units (AHUs), supplying air via a bank of jet nozzles located on a bulkhead at high level. The air handling units are enthalpy-controlled, and the rate of fresh air supply is controlled using CO2 sensors in the return air ductwork. The 12 metre-high ceilings of the extension mean
that the concourse is capable of handling relatively large fluctuations in internal heat gains, and the controls are configured to run the AHUs at low speed wherever possible in order to save energy. In the existing check-in areas, the solution was altogether simpler and relies on the re-use of existing systems. During early surveys, it had been noted by the team that the existing ventilation system was not performing as would have been expected. Upon further review, the issue was identified as being a combination
34 CIBSE Journal October 2010
of air distribution and BMS controls. By re-selecting supply and extract diffusers to suit the new ceilings, and re-commissioning the existing AHUs, significant improvements in conditions were achieved at the expense of minimal additional energy consumption. The construction sequence for the extension further
complicated matters, as the new AHUs were to be roof mounted and shielded from view by the new extension structure. This dictated that the units were selected, procured and installed far earlier in the project
The accuracy of our early environmental modelling and calculation took on a huge significance, given the procurement constraints
programme than anyone was ideally comfortable with. The accuracy of our early environmental modelling and calculation took on a huge significance on this project given the procurement constraints. The AHUs were selected to take account of the
specification of high-performance glazing (U-value of 1.3W/sq m.K) and a building fabric designed to achieve an air permeability of 5 cu m/hr at 50Pa. Combined with the consequential reduction in load on the existing gas-fired boilers and water cooled chillers, this resulted in the completed building performing even better than the calculation model suggested. Once the building
www.cibsejournal.com
>
Morgan Sindall
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 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84