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TABLE A1
Average Reductions In Ceiling Heat Flow Due To Addition of Radiant Barrier to R-19
Attic Floor Insulation
SUMMER COOLING CONDITIONS
| Radiant
Barrier
Location |
Whole House
Tests |
Test Cell Tests |
| MIMA |
ORNL |
FSEC* |
TVA |
| Roof: attached
to roof deck |
---- |
---- |
36 - 42% |
16% |
| Roof: draped
over rafters |
20%** |
---- |
---- |
---- |
| Roof: stapled
between rafters |
---- |
---- |
38 - 43% |
---- |
| Roof: stapled
under rafters |
24% |
25 - 30% |
---- |
23 - 30% |
| Attic Floor*** |
35% |
32 - 35% |
38 - 44% |
40 -42% |
*Tested at attic air space ventilation rate of five air changes per hour. Typical average ventilation
rates are somewhat lower.
**Test was a simulation of draped configuration. The radiant barrier did not extend over the
rafters, but was stapled near the joints between the rafters and the roof deck.
***Values are for new and undusted radiant barrier installations; percentages will be lower for
aged radiant barriers.
TABLE A2
Average Reductions in Ceiling Heat Flow Due to Addition of Radiant Barrier to R-19
Insulation
WINTER HEATING CONDITIONS
| Radiant Barrier
Location |
Whole House
Tests (ORNL) |
Test Cell Tests
(TVA) |
| Roof: attached
to roof deck |
---- |
4% |
| Roof: draped
over rafters |
---- |
---- |
| Roof: stapled
between rafters |
---- |
---- |
| Roof: stapled
under rafters |
5% to 8% |
8% |
| Attic Floor |
1% to 19% |
15% |
Notes for Tables A1 and A2:
Caution: These % values do not represent utility bill savings and cannot be represented as
such.
NOTE: All measurements represent average heat flows through the insulation path, and do not
include effects of heat flow through framing.
Key to Abbreviations:
FSEC: Florida Solar Energy Center
ORNL: Oak Ridge National Laboratory
MIMA: Mineral Insulation Manufacturers Association
TVA: Tennessee Valley Authority
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