Ducts Application Note
VESDA-E
35424_02
2
Table 1: Sampling hole requirements for a VESDA-E VEP-1P detector with 5 m (16.4 ft.)
inlet pipe and 2 m (6.56 ft.) exhaust pipe in small ducts.
Duct width (m) {ft}
Number of Holes
Hole Ø (mm) {in}
Nominal Pipe Flow
Rate (L/min) {cfm}
0.3 {1.0}
2
6
{
15
/
64
}
40.8 {1.43}
0.5 {1.7}
3
5
{
13
/
64
}
44.2 {1.56}
0.7 {2.3}
4
4
{
5
/
32
}
38.6 {1.36}
0.9 {3.0}
5
4
{
5
/
32
}
46.4 {1.64}
Note!
Nominal sampling hole spacing is 0.2 m (0.66 ft.).
1.1.2 VESDA-E VEA
Return air sampling is achieved with microbore tubes for VEA system inserted in the return air duct behind the
exhaust grill. it is recommended the tubes are installed facing perpendicular to the duct airflow (Figure 3). A
specific sampling point, VSP-980-ST (No. 35295), must be used for VEA’s duct sampling. It can be mounted
on the duct by VEA Sampling Point Duct Bracket, part number VSP-1008.
Figure 3: Side view of the inlet tube position for a small ventilation duct
The detector inlet tube should be installed in the middle of the duct at height H, where H is half of the duct
diameter.
