Project
HOTEL AND RESIDENTIAL APARTMENTS TERTIARY SYSTEMS
• Hotel and retail areas : These areas are served by constant and variable air volume chilled water air handling units all installed in enclosed masonry plantrooms and ceiling voids . Air distribution is through P3 ducting with a mixture of ceiling diffusers and side wall outlets .
• Hotel bedrooms : Each bedroom is served by an inceiling chilled water fan coil unit . Air distribution is via P3 ducting and single deflection side wall grille . Fresh air is preconditioned via an energy recovery wheel and is distributed to each in-ceiling fan coil unit position via externally insulated galvanised ducting and volume control dampers . Return air back to the fan coil units is via a single deflection return air grille complete with volume control damper and sound baffles mounted in the ceiling . The showers and ablutions in the Hotel bedrooms are serviced via the heat recovery wheel . Disk valves are installed in the flush plaster ceilings and used to extract the steam from the showers and odours from the ablutions . This air is then returned via insulated ducting back to the heat recovery wheel . The heat recovery wheel has a cooling coil and hot water coil for pre-treating of fresh air . During winter months , when the temperature drops below 20 ° C ambient , a dedicated heat pump will supply hot water and the ambient air will be heated and delivered to the in-ceiling fan coil units in the bedrooms .
• Back of house offices and ancillary : Back of house offices , conference venues and server rooms are served by variable air and constant air volume chilled water air handling units installed in enclosed plantrooms and within ceiling voids all as shown on the drawings . Air distribution to each area is through P3 and ceiling mounted diffusers . Storerooms and refuse rooms are ventilated via extract ducting , inline axial fans and discharge weather louvres complete with vermin proofing .
• Kitchens : Fresh air into the kitchen areas are via externally positioned vermin-proofed weather louvres connected in line with a primary filter bank , axial flow fan , sound attenuators and discharge grilles . Kitchen canopy extract air is via associated axial flow fans and 1mm thick galvanised ducting , with 300 ° C duct sealer which discharges to atmosphere .
• Public ablutions : All toilets are mechanically ventilated through axial flow fans and associated ducting systems , which are discharged to atmosphere . chilled water system via the retail tertiary pumping system . Conditioned air from each unit is supplied through systems P3 ducting and distributed to the areas through ceiling type diffusers . Re-circulated air is returned through grilles positioned at the rear of the store and the ceiling void is used as return air plenums back to the AHUs . The required quantity of fresh air is introduced through external louvres mounted in each plant room . The plant is automatically controlled to provide the required temperature conditions in summer and is switched on and off automatically at the plant control . A manual override control , which allows each plant to operate for a maximum of two hours when actuated , is positioned at a remote-control point in each store .
• Majors and line shops : The line shops are divided into a number of zones , each served by chilled water airconditioning units positioned in closed plant rooms . Conditioned air from each unit is supplied through systems of P3 ducting and distributed to the areas through ceiling diffusers . Re-circulated air from the line shops pass into the Mall areas from whence the air is ducted back to the plant areas . The required quantity of fresh air is introduced through external louvres mounted in each plant room .
RETAIL TERTIARY SYSTEMS
• Major and mini-major stores : These areas are each served by chilled water air handling units ( AHUs ) situated in closed plant rooms . Chilled water is supplied from the main central
Siemens intelligent valves .
www . refrigerationandaircon . co . za RACA Journal I April 2023 39