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BEAM P
LUS FOR
E
XISTING
B
UILDINGS
I
NDOOR
E
NVIRONMENTAL
Q
UALITY
(I
EQ
)
V
ERSION
1.2
I
EQ
15 T
HERMAL
C
OMFORT IN
N
ATURALLY
V
ENTILATED
P
REMISES
Copyright © 2012 BEAM Society Limited. All rights reserved.
Page 133
6
IEQ
6.5
T
HERMAL
C
OMFORT
I
EQ
15 T
HERMAL
C
OMFORT IN
N
ATURALLY
V
ENTILATED
P
REMISES
E
XCLUSIONS
Buildings that are not designed to utilize natural ventilation.
O
BJECTIVE
Promote the application of measures that reduce elevated temperatures
caused by external heat gains, and ensure installed air-conditioning units
can provide adequate control of indoor temperature.
C
REDITS ATTAINABLE
2
P
REREQUISITES
None
C
REDIT REQUIREMENT
a) Performance with natural ventilation
1 credit for demonstrating indoor operative temperatures in
occupied/habitable rooms meet the 80% acceptability limits.
Alternatively,
1 credit for demonstrating the Predicted Mean Vote (PMV) in
occupied/habitable rooms is between –1 and +1.
b) Performance with air-conditioning
1 credit for sustaining the air temperature at the design value within
±1.5
C when the air-conditioning unit is operating at steady state under
normal occupied periods.
A
SSESSMENT
a) Performance with natural ventilation
The assessment will seek to establish the extent to which the building
envelope mitigates the effects of external heat gains. The indoor
operative temperature shall be compared with the criteria given in
ASHRAE 55 [1] under the ‘Optional Method for Determining Acceptable
Thermal Conditions in Naturally Conditioned Spaces’.
Assessment may be confined to the scenarios with the highest, monthly,
mean temperature or highest solar gain, whichever is highest i.e., for
those normally occupied areas of the building most susceptible to
external heat gains and/or which do not benefit from the prevailing
climatic conditions. The spaces in question must be equipped with
operable windows that can be readily opened and adjusted by the
occupants. Mechanical cooling for the space shall not be provided,
although mechanical ventilation with unconditioned air may be utilised.
Compliance may be demonstrated under appropriate summer conditions
through the measurement of temperature in suitable locations in a
sample of premises most exposed to external heat gains.
The Client shall provide evidence in the form of a report prepared by a
suitably qualified person detailing any means used to control the external
(solar) heat gains, the details of measuring equipment, sampling
locations, sampling time, time of measurements, external temperature
and prevailing weather conditions.
Where it can be demonstrated that the indoor temperature lies within the
80% acceptability limits given in ASHRAE 55-2004 a credit shall be
awarded.
Alternately, where it can be demonstrated that the Predicted Mean Vote
(PMV) in occupied/ habitable rooms is between –1 and +1, a credit shall
be awarded.
1
American Society of Heating, Refrigeration and Air-conditioning Engineers. ASHRAE 55-2004: Thermal Environmental
Conditions for Human Occupancy. Atlanta 2004.