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How to estimate KWH consumption per sqft

How to estimate KWH consumption per sqft

How to estimate KWH consumption per sqft


I am trying to find a rule of thumb (KWH/sqft) to estimate domestic electrical (KWH) consumption in a standard, residential, apartment unit, in a multi-unit residential building. The space heating and domestic hot water are not considered in this calculation because they are provided by the building.

I'd appreciate your help in estimating KWH consumption of such apartment units based on a rule of thumb KWH/sqft factor.

Thank you.

RE: How to estimate KWH consumption per sqft

What country?
What culture in that country?
What city in that country? (What latitude, what environment, what seasons of the year?)
What economic level in that city in that culture in that country?

Your question CANNOT be answered by "averaging" a family in India in a ghetto with a single woman living in Vienna with an extended family living in New York with a small family living in Lima Peru. You cannot "average" a single lawyer living in Vienna and London and New York and Washington DC and San Francisco and then throw in Atlanta or Miami.

You cannot "average" Quebec and Madrid - even though they are at comparable latitudes. You cannot "average" Miami or Key West with central Australia outback - even though are at equal latitudes.

RE: How to estimate KWH consumption per sqft

I understand the problem. I should have provided a more specific case.

I'm trying to estimate non-heating/cooling related domestic electrical consumption for a senior's one-bedroom apartment unit in an average N. American city. I suspect the usual loads would be fridge, electric range/oven, lighting, and receptacle loads.

RE: How to estimate KWH consumption per sqft

Look in the NEC or CEC under demand factors.
Example only from the CEC.
This rule may not be used without consideration of a number of other rules.
This rule may be amended by other rules in the code.
Example only.
You may have to buy the code for a complete answer.

Quote (Canadian Electrical Code)

Services and feeders
8-200 Single dwellings (see Appendices B and I)
(1) The minimum ampacity of service or feeder conductors supplying a single dwelling shall be based on the
greater of Item (a) or (b):
(a) (i) a basic load of 5000 W for the first 90 m2 of living area (see Rule 8-110); plus
(ii) an additional 1000 W for each 90 m2 or portion thereof in excess of 90 m2; plus
(iii) any electric space-heating loads provided for with demand factors as permitted in Section 62
plus any air-conditioning loads with a demand factor of 100%, subject to Rule 8-106(4); plus
(iv) any electric range load provided for as follows: 6000 W for a single range plus 40% of any
amount by which the rating of the range exceeds 12 kW; plus
(v) any electric tankless water heaters or electric water heaters for steamers, swimming pools, hot
tubs, or spas with a demand factor of 100%; plus
(vi) any electric vehicle supply equipment loads with a demand factor of 100%; plus
(vii) any loads provided for in addition to those outlined in Items (i) to (vi) at 25% of the rating of
each load with a rating in excess of 1500 W if an electric range has been provided for, or 100%
of the rating of each load with a rating in excess of 1500 W up to a total of 6000 W, plus 25%
of the load in excess of 6000 W if an electric range has not been provided for; or
(b) (i) 100 A where the floor area, exclusive of basement floor area, is 80 m2 or more; or
(ii) 60 A where the floor area, exclusive of basement floor area, is less than 80 m2.

"Why not the best?"
Jimmy Carter

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