Refrigerated Storage Design Guide
VESDA
®
The procedure for integrating VESDA with pre-action sprinklers is outlined below:
1. Use ASPIRE2 to design the pipe network and determine Maximum permissible Transport
Time . For FM approved, refrigerated storage, VESDA installations, sample hole spacing
should be the same as heat detector spacing as per the latest edition of the FM8-29
Datasheet and Memorandum 08-05
[1, 15]
.
2. Install the VESDA pipe network on the ceiling as shown below (Figure 16).
Figure 16 – Arrangement of the VESDA pipe network and
sprinkler heads on the ceiling.
3. Set the VESDA Alert alarm threshold for early detection and intervention.
4. Set the VESDA Fire 1 alarm threshold for pre-action sprinkler activation as indicated in
Table 4.
Note: Delays can be configured for both of these alarms.
The smoke thresholds in Table 4 are absolute values, hence the environmental background level
must be taken into account. All values are recommendations only, actual values being dependent
on individual site conditions such as air change rate, storage rack height etc. Before using any
values, the system performance MUST be verified by the commissioning test (refer to section 6.2).
Any VESDA Fire 1 alarm shall put all sprinkler valves, in that particular fire zone, into armed mode.
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