Channel Measurement of sealing

Channel Measurement of sealing​

• Duct leakage test SMACNA "HVAC Air Duct Leakage Test Manual (1985)," made according to the principles. Channel sealing measured by a special device. The connecting duct system metering devices in case of positive pressure within the channel is shown in FIG. The taper of the air fan, reversible binding to the desired side. Thus, pressure or vacuum can be created in the duct system. Fan speed is adjustable. Flow rate can be adjusted to the desired value with the aid of a rheostat. measuring pipe and the second number is shown.
• precise flow measurement can be performed in all flow range of the fan with two pipes of different diameters. 4 Pressure drop is read on the differential manometer measuring pipe shown in numbers. This flow of calibration curves associated with the pressure drop is read. 5 numbers show the connection hose. The hose end must be sealed with tape. and still another is expressed by 4 numbers showing the test pressure gauge has more. This pressure in the channel is read from the manometer.
• When channel pressure today and sealing system of the class specified channel allowable air leakage can be calculated. This seepage or leakage of surface channel units (L / s.m2) can be expressed as a percentage of total air flow. ASHRAE and seal duct leakage classes and classification according to CL = 720 SMACNA standards. Q / (δps) is based on the expression 0.65.
• liters per second in the unit square surface channels. leakage terms

LOW PRESSURE - CLASS A 0027 x p0.65
CENTRAL PRESSURE - CLASS B 0.009 x p0.65
HIGH PRESSURE - CLASS C 0.003 x p0.65
HIGH PRESSURE - CLASS D 0.001 x p0.65

Q = amount of leakage or leakage, L / s. m2 (surface area)

CL = Sealing class (750 Pa leakage flow pressure)
δps = pressure difference between the outer and inner channel (static pressure in the duct)