Dialogue and Presentation of Standardisation of OTTV Methodology of Complex Building and U-value of Reflective Insulation
Sustainable Built Environment through green building design
Green Building Index
Ar. Michael Ching
Friday, 4 August 2017
11:00 a.m. to 1.00 p.m.
PAM Centre, Bangsar, Kuala Lumpur
Ir. Leong Siew Meng
MASHRAE, GBI, MGBC, PAM, UKM Solar Energy Research Institute, RIMA (Reflective Insulation Manufacturers Association)
GBI (Green Building Index) is Malaysia’s green rating system for buildings and township, which was created to promote sustainability in the built environment and to raise awareness of environmental issues among the industry practitioners and the public.
In support of the continuous advancement of the green building industry, GBI has collaborated with the Solar Energy Research Institute(SERI) of UKM (The National University of Malaysia) to conduct a research on relective insulation and radiant barrier using heat flow meter (based on ASTM C-518 / ISO8301: MS2095).
The dialogue was to deliberate on the standardisation of OTTV methodology of complex buildings and U-value of reflective insulation in hot and humid conditions.
In the dialogue, SERI presented their findings in the research on relective insulation with field measurements and provided the following conclusions:
1) Radiant barrier incorporated into the roof assembly increased RSI from 0.37 m2K/W up to 2.93 m2K/W.
2) When the enclosed air space was increased from 25mm to 75mm, the RSI changed from 2.15 m2K/W to 3.08 m2K/W correspondingly.
3) Concrete tile (R=2.26) and clay tile (2.40) with radiant do not have significant difference in RSI.
4) The addition of a layer of radiant barrier (woven foil) on mass insulation material (mineral wool) had increased its RSI from 1.61 m2K/W to 2.77 m2K/W.
MASHRAE presented a tabulation of Thermal Resistance of Plane Air Spaces extracted from the Table 3 in Chapter 26 of the ASHRAE Handbook – Fundamentals for comparison and deliberation. Table 3 provides thermal resistance values for enclosed cavities for various conditions, depending on the combined or effective emittance of the cavity’s hot and cold surfaces.
It was pointed out that the research results obtained from field test measurements (dynamic conditions) differ from the lab tests under controlled / steady-state conditions).
SERI and GBI would conduct further reviews and explore means of converging their test results with the steady-state conditions as well as for practical applications.
Reported by Ir. Leong Siew Meng
Date: 4 August 2017 -
Time: 11:00 AM - 1:00 PM
Location: PAM Centre, Bangsar, Kuala Lumpur