It is not critical to seal up all the small leaks like under doors etc. and you don’t need to make the area gas or air tight.
But you do need to seal all unnecessary penetrations including cable, telco & piping access etc.
The rule is simple the more or the quicker the suppression gas (FM200) can escape the less effective it is.
Most fire engineers will calculate the amount of gas required allowing for minor leakage so the site needs to be managed with in this criteria.
Fire suppression works by several factors.
– the time taken to bring the gas density to the required level.
– The gas density or concentration for a period of time.
Thus if you have gas escaping too quickly the gas concentration will not occur in sufficient time or not reach the required level. The other problem with smaller holes or to many smaller holes the gas concentration can not be maintained for sufficient time thus the fire can re flare.
Another way of overcoming gas loss is to increase the amount of gas, it’s discharge rate or a longer discharge time, depending on the rate of gas loss and the type of area or equipment you are trying to protect.
But remember the more gas used the higher the cost of both installation and gas.
PS. make certain any fire dampers operate on the gas firing and they seal tight, this is also essential for retaining fire spread. Test all system regularly as I have often found sites with good inferstructure but the fire dampers are working or the cable penetration are not resealed at the completion or every days work.
Please let me know if you want any more info.