Xtralis VESDA VLC-505, Manual

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VESDA by Xtralis VESDA Pipe Network Design Guide
www.xtralis.com 41
9 Testing Design Performance
You can test the design performance with the ASPIRE2 software provided by Xtralis. The software is used to
evaluate the performance differences that occur by making changes to the pipe design. For the latest version
of the software see www.xtralis.com or contact your local Xtralis office.
The efficient performance of a pipe network design is dependent upon the ASPIRE2 software generating
acceptable values for:
l
Hole % balance
l
Maximum transport time
l
Hole sensitivity
Factors influencing these values are:
l
Pipe length
l
Number of sampling holes
l
Size of the endcap hole
l
Number and radius of bends
l
Number of pipes
l
Length of capillary tubes
l
Size of sampling holes
l
Aspirator speed
9.1 Hole Balance
Hole % balance is the amount of air being drawn from the sampling hole with the least amount of air flow,
divided by, the average air flow through the other sampling holes.
Subject to local codes and standards, a minimum hole balance of 70% or greater is recommended
The aim of an optimum pipe design is to have a relatively equal air flow through all sampling holes. To achieve
this, the Hole % Balance should be as close to 100% as possible. Pipe length, number of sampling holes, hole
size, and endcap hole size all effect the Hole % Balance.
Reducing the number of holes per pipe, and using multiple pipes, will increase the balance.
Figure 9-1: Hole balance
The mathematical formula is:
Balance = x 100
Min Flow
Max Flow
Balance = x 100 = 72.3%
4.7 %
6.5 %