Air Handling Unit Mechanical Performance
Casing air leakage measures the amount of air leakage when the unit is operating under pressure. For units with energy recovery devices the test is based on 400 Pa (1.6 inches w.c negative pressure. The GOLD unit is rated at L1(M) which is a maximum leakage rate of 0.15 l/(s-m²) (2.95 cfm/100ft²). L1(M) is the lowest leakage category.
EN 1886 also measures the air leakage around the filter rack. Leakage here means ventilation air is not being cleaned by the filters. The test measures the leakage rate at 400 Pa (1.6 inches w.c.). The GOLD filter leakage class is F9, the highest class, which is less than 0.5% of nominal airflow rate.
Thermal bridging a measure of “short circuits” in the cabinet where heat pass through such as metal hinges. The GOLD unit is rated at TB2.
Thermal transmission measures how well the cabinet is insulated. The GOLD thermal transmittance is T2 which is a U factor between 0.5 and 1.0 W/(m² -C) (0.088 to 0.176 Btu/h-ft²-F)
Mechanical strength is the measure of casing deflection measured in mm/m. The GOLD is rated at D1, the highest class with deflection of less than 4 mm/m (0.004 in./in.).