Dormitory Load Calculation

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derwood14

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In performing a load calculation for a student dormitory, would NEC consider a dorm room to be a dwelling unit? Each dorm room will have A/C- heating unit and provisions for a microwave (cooking?). Each of the units will have a bathroom, living area and sleeping area. I believe the only thing missing is the permanent provision for cooking.
Can I use the demand factor table in 220.32 to determine the size of required service? How should I approach this calculation?
Thanks
 
Re: Dormitory Load Calculation

Article 100 defines a ?Dwelling Unit? as follows, ?One or more rooms for the use of one or more persons as a housekeeping unit with space for eating, living, and sleeping, and permanent provisions for cooking and sanitation.? The fact that a microwave can be plugged into a receptacle outlet does not constitute a ?permanent provision for cooking.? I conclude that a single dorm room is not a dwelling unit, and that Article 220.32, ?Optional Calculation ? Multifamily Dwelling,? would not apply.

But the dormitory building might be a dwelling unit. It is a bit of a tricky situation. The dorm I lived in my first three years in college had nothing that resembled a kitchen. So it would not have been called a dwelling unit, in the context of todays NEC. If your dorm building has a common kitchen, then you could use Article 220.30 ?Optional Calculation ?Dwelling Unit.?
 
Re: Dormitory Load Calculation

So in this case use 2 VA per square for lighting (since total is not known), add up all recp at 180Va per and derate by 220.13, and take 100% of the A/c load with no derating allowed. Plus motor loads, speacial loads, etc for commons. Am i on the right track?
 
Re: Dormitory Load Calculation

You are mixing apples and oranges. Decide first if you are calling the building, as a whole, a ?dwelling unit.? If you are, then 220.13 would not apply. The receptacles are part of the 2 VA/ft2 ? per 220.3(B)(10) ? and the demand factors are given in Table 220.11. As an alternative, you could use Article 220.30. I suggest doing it both ways, and using the smaller of the two answers.
 
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