180 VA is used for load calculation purposes. The rating of the device will determine what rated appliances you can plugged in it. So another words a 15A duplex receptacle is not limited to 180VA it is limited to 1800VA.
If that is what you are asking.
If a single load is going to exceed 180va you could simply reduce the number of receptacles on the circuit but, in reality the PC may be the only load on the circuit so it wouldn't matter anyways.I'm thinking if a duplex for a PC is considered 180 VA for calculations and the maximum of 13 outlets are connected to a 20A circuit, then the circuit would overload if the actual load per outlet is more than 180 VA, which I think it is for PC's. I wouldn't circuit 13 duplexes serving PC's, but I'm saying something seems wrong using 180 VA for PC's.