AMBRIDGEPORT
RT
PAGE 17 - CRAH - GUARDIAN SERIES
WHERE THE BEST ARE BUILT
TESTED, NOT ASSUMED
Casing performance and factory proof testing — what build quality means when the hall is 
counting on it.
<1%
LEAKAGE @ +1.5x DESIGN TSP 
POSITIVE-PRESSURE PROOF
<0.5%
LEAKAGE @ -12” W.G. TSP 
VALIDATED ON 725 kW CUSTOM
25+ YRS
LEAKAGE & STATIC METHODS PROVEN
IN PRODUCTION
100%
OF UNITS FACTORY 
RUN-TESTED
THE SPEC EVERYONE WRITES, ALMOST NOBODY PROVES
Every AHU spec says "low leakage." Few say at what pressure, by what method, on which unit. Brochure 
leakage classes come from lab panels, other unit sizes, or nothing at all — and the first manometer many 
casings meet is at commissioning, on the owner's schedule. On a 90,000 CFM unit, 1% leakage is nearly a 
thousand CFM you bought and can't use: bypass air, wasted fan energy, and containment undermined at the 
source. At negative pressure it's worse — unfiltered gallery air pulled straight into the supply stream.
Guardian casings are proof-tested on production units, to ASHRAE-aligned methods: 1% at 
+1.5× design static, <0.5% at −12″ w.g. — validated on the delivered 725 kW custom CRAH.
TEST PRESSURES VS TYPICAL DUTY
INSIDE THE CASING WALL
3.5”
+1.5x
-12”
Max design ESP — 
typical operating envelope
Positive-pressure proof test — 
1% leakage
Negative proof test — <0.5% leakage.
Most catalog casings can't take this
test, let alone pass it.
OUTER SKIN - formed on automated Prima Power fabrication
FOAM INSULATION - R7, full fill, no voids
TRUE THERMAL BREAK - no through-metal path, no gallery 
condensation
INNER SKIN - double-wall, washdown-capable
SST Drain Pans | Galvanized Filter Tracks | Removable Plug Panels

View this content as a flipbook by clicking here.