BEAM Plus Existing Buildings

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BEAM PLUS FOR EXISTING BUILDINGS APPENDICES
V ERSION 1.2 8.2 BASELINE BUILDING MODEL
Copyright © 2012 BEAM Society Limited. All rights reserved.
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8.2 BASELINE BUILDING
MODEL
8.2.1
8.2.2
8.2.3
8.2.4 AIR-CONDITIONING SYSTEM DESIGN AND EQUIPMENT PERFORMANCE
8.2.1 ENVELOPE
CHARACTERISTICS
Since the building facade design is considered as difficult to change for
an existing building, the envelope characteristics of the baseline building
model for assessing an existing building will be basically same as the
“as-built” characteristics of the assessed building, except that features
like overhangs and side-fins will be ignored for two reasons: i) for
simplicity in establishing the zero-credit benchmark; and ii) to be
consistent with the basis upon which the simplified models were
established.
8.2.2 INDOOR DESIGN
CONDITIONS,
OCCUPANCY DENSITIES ,
AND VENTILATION AND
INFILTRATION RATES
For building operation parameters, including Occupancy Density,
minimum Outdoor Air, Operating Schedule, Service Water Heating
Power and Equipment Power Density, the designer should prepare a
table summarizing the design value of these operation parameters for all
the different spaces in the building. For simplification purpose, spaces
with similar functions and operational characteristics, as represented by
the operation parameters, may be grouped together as a space type. For
details including table format, Section A3.5.2 (a) of BEC 2012 [1] may be
considered as a reference.
An operating schedule for each type of space should be prepared
summarizing for different times of a day the operation densities of
occupants, equipment, lighting, AHU/fan, cooling, heating hot water etc.
The operating schedule should reflect the time profiles which establish
the extent of operation, such as the percentage of the equipment load
that ON by hour of day. For details regarding time profile and occupant
density, Section A3.5.2 (b) & (c) of BEC 2012 can be referred to. For
residential building type, it needs to note that the air-conditioner
operation pattern applies to all days in April to October inclusive. The
assumption is made that Air-conditioners will not be used in other
months in the year.
8.2.3 INTERNAL LOADS The lighting power intensities to be used for various types of premises in
the Baseline Building model for an existing building shall be the
threshold compliance values as stipulated in the Building Energy Code
(BEC 2012) applicable to the types of premises. For those types of
premises that the Building Energy Code (BEC 2012) does not cover, the
values in Table 8.3 are used.
The equipment power density shall be modelled as existing condition.
The equipment power reduction in Assessed Building model must be
documented by an exceptional calculation methods: the applicants must
provide justification for assumptions used in both the Baseline Building
model and the Assessed Building model, supported by following:
• Side-by-side comparison of local industry standard equipment and
new proposed equipment, with energy efficiency metric for each
piece of equipment (e.g., kWh/ pound of material processed);
• List of modifications that make new equipment more efficient;
• Operation schedules for facility and equipment.
1 Electrical and Mechanical Services Department - Code of Practice for Energy Efficiency of Building Services Installation 2012