Xtralis VESDA VLC-505, Manual

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VESDA Pipe Network Design Guide VESDA by Xtralis
14 www.xtralis.com
4.4.5 Hot Aisle Containment Sampling
In Hot aisle containment systems, racks are positioned in rows (back to back). The hot aisle in between racks
will be covered on the top and at the end of the rows and ducted back to the air conditioning unit (Figure 4-10).
The result is a full separation between supply and return air.
Figure 4-10: Hot Aisle Containment Sampling
4.4.6 Cold Aisle Containment Sampling
In cold aisle containment, racks are positioned in rows (front to front). The cold aisle in between racks will be
covered on the top and at the end of the rows. The result of this is a full separation between supply and return
air. Cold air will be supplied through a raised floor into the contained cold aisle; hot return air is exhausted from
the racks into the room.
Figure 4-11: Cold Aisle Containment Sampling
4.4.7 Hole Orientation
Industry experience shows that the pipework can be fine tuned by locating the sampling holes 30 degrees
away from the airflow path. Sampling can be improved by avoiding the high and low velocity areas. One
common problem with this model is that the detector needs to work in all possible situations. If you are
installing pipework into a high airflow area keep in mind what will happen if/when the AHUs are turned off.