VESDA
®
LaserFOCUS VLF-500 Product Guide
21
Installation considerations
Note:
For code-specific information, see
Codes and Standards Information for Air
Sampling Smoke Detection
on page iv.
The VESDA LaserFOCUS VLF-500 smoke detector provides very early warning smoke
detection specifically for small environments.
The pre-engineered pipe network designs can support up to 8 sampling holes for single pipes
and 12 sampling holes for branched pipe arrangements. The number of sampling holes used can
be increased to 24
1
, however, ASPIRE2 will need to verify that the additional sampling holes can
be supported. Sampling holes are positioned according to the standards relating to conventional
point detector placement.
The pre-engineered pipe network solutions described in sections
Single pipe network
on page 10
and
Branched pipe network
on page 11 achieved transport times of less than 60 seconds for
open hole sampling and less than 90 seconds for capillary sampling.
Where the VESDA LaserFOCUS is located outside the protected area (e.g. in a corridor outside
the room), consideration must be given to returning the detector exhaust air to the protected
environment to balance the pressure differences that may exist. In the majority of applications,
this is not necessary as pressure differences are minimal. The exhaust should also be returned
to the protected area in cases where there are hazardous substances inside the protected area,
eg hospital operating theatres. Where practical considerations fall outside pre-engineered
designs or where pressure differences exceed 50 Pa, in situations where the detector is located
outside the protected area, the solutions presented in this manual may not be suitable and it is
recommended that alternate designs are verified by a suitably qualified installer using ASPIRE2.
The following points should be considered when installing the sampling pipe:
•
minimize flexing in sampling pipes by supporting the pipe every 1.5 m (5 ft) or less, or at a
distance described in local codes and standards.
•
evenly arrange the sampling pipe network over return air grilles
•
sampling pipes fit firmly into the tapered detector ports,
DO NOT
glue
this connection
•
allow sufficient movement at the detector to permit pipe removal for maintenance
•
keep the exhaust deflector fitted to prevent foreign objects falling into the detector
•
keep the return air pipe as short as possible to minimize airflow resistance in the pipe
•
pipe ends must be made smooth for bonding
•
sampling holes must be drilled in line and perpendicular to the pipe.
•
sample holes must be clear of rough edges and debris
•
pipes are free of debris
•
all joints must be bonded except the endcaps and pipes entering the detector
Note:
In protected areas sampling holes should face into the direction of airflow, or point
downwards in static airflow situations.
Note:
You should try to keep the sampling holes evenly spaced.
Note:
For code-specific information, see
Codes and Standards Information for Air
Sampling Smoke Detection
on page iv.
Air sampling in a duct
For air sampling in a duct please refer to the VESDA System Design Manual for duct probe
design. For code-specific information, see
Codes and Standards Information for Air Sampling
Smoke Detection
on page iv.
1. For code-specific information, see
Codes and Standards Information for Air Sampling Smoke De-
tection
on page iv
