New research confirms the conventional wisdom about green roofs: Vegetative roofs can help reduce heat gain and heat losses, resulting in significant energy savings in mixed climates.
New research confirms the conventional wisdom about green
roofs: A recent study conducted by Oak Ridge National Laboratory (ORNL) and
SPRI shows that vegetative roofs can help reduce heat gain and heat losses,
resulting in significant energy savings in mixed climates.
According to SPRI, the association representing sheet
membrane and component suppliers to the commercial roofing industry, the
reduction in heat gain in cooling dominated periods - and heat losses in
heating dominated periods - translates into lower heating and cooling demands
for the conditioned space. However, the study notes that the energy savings
offered by are dependent on the local climate and are affected by the
efficiencies of HVAC equipment.
The results of the ORNL study also show that lower membrane
temperatures and temperature fluctuations were experienced by the vegetative
roofing system than the control black-EPDM and white-TPO roofing systems.
“As part of the effort to reduce energy use in commercial
buildings, energy codes are greatly increasing the required thermal efficiency
of roofing systems,” said SPRI Technical Director Mike Ennis. “It is important
to understand the energy savings associated with vegetative roofs so that they
can be properly credited in these codes.”
A summary of the ORNL/SPRI study written by Andre
Desjarlais, Abdi Zaltash and Jerald Atchley of ORNL and Mike Ennis of SPRI was
released earlier this year at the RCI Annual Convention.
We’ll publish SPRI’s in-depth analysis of the findings in a
future issue of the magazine.