The Lumen conservation rooflight has recently
undergone testing at the British Research
Establishment to achieve the weather performance
test BS6375: Part 1: 2004.
The rooflight performed exceptionally well under
extreme weather conditions and achieved the
following results:
Air Permeability +/- Class 4 up to 600 Pa
Watertightness 600 Pa Class 9A (no leakage)
Wind Resistance Class E2500 P1
Overall Class CE2500
P1 2500 Pa
P2 1250 Pa
P3 3750 Pa
So what does all this mean?
The mounted into a test rig and the
testing is carried out in three parts in the
sequence shown above.
The air permeability test involves the application
of a series of test air pressure differentials
across the rooflight with the measurement of air
passing through the casement measured at each
pressure step. This test involves both positive and
negative airflow. The maximum positive and negative
pressure differential was 600 Pascals (approx 70mph)
in pressure steps of 50, 100, 150, 200, 250, 300,
450 and 600 Pascals.
The results are measured into 4 categories; class 4
is applicable to the most airtight specimens while
class 1 describes those with most air leakage.
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The watertightness test is carried out by applying
specified amounts of water spray (6 litres per
minute) to the outside face of the rooflight while
steadily increasing the air pressure. The test
pressure, time and position of any water penetration
are then recorded. The maximum air pressure
differential used was 600 Pascals (approx 70mph).
Initially the water is applied without the air
pressure for 15 minutes. Then the air pressure is
increased at increments of 50, 100, 150, 200, 250,
300, 450 and 600 Pascals. To achieve the required
standard the rooflight must remain watertight for 5
minutes up to and at each test pressure. So the
Lumen rooflight endured water application at the
rate of 6 litres per minute in pressures up to 70mph
for 55 minutes without a single drop of water
passing through the opening casement. This means
that the rooflight not only met the requirements but
exceeded them.
The wind resistance test involves a series of both
positive and negative air pressures. Measurements
and inspections are made to assess relative frontal
deflection and resistance to damage from wind loads.
The first part of the test took the air pressure to
2500 rox 150mph). The second part of the
test involved 50 cycles of pulsating pressure to
assess the performance under repeated wind loads.
The particular part of the test was carried out at
1250 Pascals (approx 100mph).
The air permeability tests are then repeated to
measure whether the wind resistance test has had any
effect on the structure of the rooflight. Once again
the test confirmed the Class 4 rating meaning that
the pressures had little or no effect on the
rooflight.
The final part of the wind resistance test is
designed to assess the safety of the test specimen
under extreme conditions. The air pressure was
increased to 3750 Pascal (in excess of 200mph and
78lb/ft2). During the wind resistance test, the
rooflight is measured for deflection, which is how
much movement occurs in the glass and the framework.
We were delighted that even during such an extreme
test our deflection rate was less than 1mm and that
no damage or functional defects were recorded.
The Lumen has the highest performance rating of any
of the conservation rooflights available on the UK
market, what's more we are pround of a product
manufactured in great Britain to the very highest
standards.
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