Dormitory Load Calculations

[isurf]

Hi all,

I'm working on a load calc for a dormitory style building and looking for a little clarification on the NEC.

The building is as follows..
100 dorm units that are single occupancy (no fixed appliances or cooking appliances). Two dorm units share one bathroom (so 50 bathrooms for the 100 dorm units)
Corridor access from dorm units to common spaces
Laundry rooms in building
Common Lounge space with a kitchen

The dorm units here almost seem more like a hotel with the exception of the shared bathroom.

Table 220.12 says to use 1.5VA/ft.sq. for dorm units but does that include general receptacle loads like what would be included for dwelling units using 3VA/ft.sq.?
If it does not include general receptacle loads is there a rule of thumb for this or would we use 180VA and demand over 10kVA?

Would the dormitory 1.5VA/sq.ft. apply to the other spaces (laundry, common, corridor)? I do not see occupancy types that seem to match those spaces in Table 220.12.

Thanks for the input!!

 

[tortuga]

Table 220.12 says to use 1.5VA/ft.sq. for dorm units but does that include general receptacle loads ?

No, 220.12 is just your minimum lighting load.

If it does not include general receptacle loads is there a rule of thumb for this or would we use 180VA and demand over 10kVA?

See 220.14 (A), (H) and (I)

Would the dormitory 1.5VA/sq.ft. apply to the other spaces (laundry, common, corridor)?

I would think so 220.11 says to use the outside dimensions of the building.

[Answer based on 2020 NEC]

 

[isurf]

No, 220.12 is just your minimum lighting load.

See 220.14 (A), (H) and (I)

I would think so 220.11 says to use the outside dimensions of the building.

[Answer based on 2020 NEC]

Thank you for the reply!

My issue is the dormitory section was just added to the 2020 NEC and I feel like there is something lacking with not being able to apply a demand factor like you would with dwellings or hotels/motels.

When I calculate load for just the dorm units with the above method I get 361kVA after demanding the receptacle per table 220.44 (447kVA receptacles (demanded to 229kVA), 60kVA HVAC, 72kVA lighting).

From the digging I've been doing it looks like prior to 2020 NEC most considered dorms to be similar to a hotel/motel type occupancy. I feel like the project I am working on also is more in line with a hotel/motel type of building due to the single occupancy rooms (but do share bathroom between two rooms)

If I calculate like a hotel/motel @ 1.7VA/sq.ft. and use table 220.42 I end up with 43.5kVA for general lighting and receptacles + 60kVA for HVAC and a total of 104kVA.

I do have a microwave that is tripping me up with the hotel/motel calc. Each dorm unit will have a microwave that is not fixed per say but they will have a shelf built in dedicated to a microwave which I feel I need to count as a specific load in the calc. I am including that load (1.2kW) in the first calc and demanding with the receptacles but I am not sure how it would be included in the hotel/motel calc as far as demand goes.

Thanks for the input!