BEAM Plus Existing Buildings

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BEAM PLUS FOR EXISTING BUILDINGS INDOOR ENVIRONMENTAL QUALITY (IEQ)
V ERSION 1.2 IEQ 12 L OCALISED V ENTILATION
Copyright © 2012 BEAM Society Limited. All rights reserved.
Page 129
COMMERCIAL KITCHENS In commercial kitchens a mechanical ventilation rate of 20 Ach may be
appropriate [3] for the cooking styles found in Hong Kong.
BATHROOMS AND
TOILETS
Where mechanical ventilation in the form of an extractor fan is provided
in bathrooms and lavatories, care should be taken to ensure that
plumbing seals are intact and operate according to the design intent [4].
In addition, consideration should be given to the quality and quantity of
air intake, air-flow path and fan capacity. The Environmental Health
Team of the World Health Organization (WHO) has advised that the
optimum flow rate for bathroom ventilation is 2 cfm/sq ft (10.2 l s-1 m-2 ).
WHO is of the view that a larger flow rate does not add much on the
comfort side and has the hidden risk of building up negative pressure in
the room. It is recommended to provide an opening to bathrooms and
lavatories for air relief, such as an undercut to the door or an opening
with louvre at the door or wall, in order to minimize the build-up of
negative pressure if an extractor fan is provided for ventilation.
REFUSE AREAS Exhaust from refuse storage areas and material recovery centres (RS &
MRC) should follow the principles of PNAP No. APP-35 [5]. In the cases
where a centralised ventilation system is adopted, a single air purifier
may be installed prior to the air being exhausted to the atmosphere. If
there are no odour problems then a mechanical fan and filter can be
used. The main exhaust outlet for a centralised system should be located
at roof level away from other buildings. If the building is surrounded by
taller buildings then the air may be exhausted at the main RS & RMC
location.
The noise level of the system should conform with the Technical
Memorandum published under the Noise Control Ordinance (Cap 400).
Fire dampers should be provided if the system has exhaust grilles and
ducting at each floor.
CHIMNEYS AND FLUES The siting and height of chimneys and flues should follow PNAP No.
APP-8 [6]. In particular, chimneys and flues should be situated so that
products of combustion cannot enter windows, ventilation openings,
supply air intakes.
3 Singapore Standard SS CP13. Code of Practice for Mechanical Ventilation and Air Conditioning in Buildings.
4 Buildings Department. Practice Note for Authorized Persons, Registered Structural Engineers and Registered
Geotechnical Engineers, PNAP No. ADV-25. Extractor Fans in Bathrooms and Lavatories in Domestic Buildings.
5 Buildings Department. Practice Note for Authorized Persons, Registered Structural Engineers and Registered
Geotechnical Engineers, PNAP No. APP-35 Refuse Storage and Collection Building (Refuse Storage and Material
Recovery Chambers and Refuse Chutes) Regulations.
6 Buildings Department. Practice Note for Authorized Persons, Registered Structural Engineers and Registered
Geotechnical Engineers, PNAP No. APP-8 Chimneys and Flues.