Learn about strategies to reduce heat gain and peak air temperatures for the USGBC LEED Green Associate certification exam, including using high reflectance roofing materials.
Table of Contents
Question
Use of which of the following can help reduce the heat gain and peak air temperatures?
A. A drip irrigation system
B. Pervious paving materials
C. Low albedo paving materials
D. High reflectance roofing materials
Answer
D. High reflectance roofing materials
Explanation
High reflectance roofing materials can help reduce heat gain and peak air temperatures by reflecting more sunlight away from the building, thereby reducing the amount of heat absorbed by the roof. This can lead to lower cooling loads and energy use for air conditioning.
High reflectance (high albedo) roofing materials help reduce heat gain and peak air temperatures by reflecting more of the sun’s energy back into the atmosphere rather than absorbing it. This keeps the roof surface cooler, which in turn reduces the amount of heat transferred into the building.
Some key points about high reflectance roofing:
- High reflectance roofs have a high solar reflectance index (SRI), usually 0.65 or higher for low-slope roofs and 0.25 or higher for steep-slope roofs
- Common high reflectance roofing materials include white thermoplastic membranes (TPO, PVC), coated metal, and special reflective asphalt shingles
- High reflectance roofs can reduce peak roof surface temperature by up to 30%, cutting cooling costs by 10-20%
- In addition to energy savings, cooler roofs last longer as the materials degrade less from heat and UV
The other options would not significantly reduce heat gain or air temperatures:
- Drip irrigation delivers water directly to plants’ root zones but doesn’t cool surfaces
- Pervious paving allows stormwater to drain through but has minimal effect on surface temperatures
- Low albedo (low reflectance) paving absorbs more heat, increasing surface and air temperatures
So in summary, high reflectance roofing materials are the most effective option presented for reducing heat gain and peak air temperatures in and around a building. Using a high SRI roof is a key strategy for mitigating urban heat island effect and improving building energy efficiency.
USGBC LEED Green Associate certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the USGBC LEED Green Associate exam and earn USGBC LEED Green Associate certification.