Positive and negative weight this two term you may discover in heaps of building applications in mechanical and electrical designing. Like a transformer room, switchgear room, gas preparing unit should have been kept up in either negative or positive weight as it requires.

For both the negative and positive weight, the room must be hermetically sealed. 

What is sure weight 

In basic word a room will be in positive weight if the pneumatic force in the room is higher than that of the environment gaseous tension. So no air will go into in to the room. In the event that any spillage exist, air will departure (stream outward).

Positive weight is utilized where external air isn't required in the room. Like in activity theater of healing facility environment air may convey air-borne germs. Or on the other hand in some generation territories where external air may veer off the nature of item like in pharmaceutical ventures.

What is Negative weight 

In basic word a room will be in negative weight if the gaseous tension in the room is lower than that of the environment pneumatic stress. So no wind stream from the room under negative weight. On the off chance that any spillage exist, air will entrance (stream internal).

Negative weight has some uncommon utilize like in Generator room, engine compartment, transformer room. The unsafe vapor or smell is kept inside the room and control debilitate framework is done securely.