residential heating load minimum requirements

[drp8888]

I am trying to find the code requirements pertaining to residential electric heat per square foot. I was taught to use 6-10 watts per square foot according to insulation factors and window sizes. Now I want the code minimums for competitive reasons.

 

[Jljohnson]

To my knowledge, NEC does not give a minimum. This is a design issue. The heat maunufacturer should have some design guidelines to go by. I was taught years ago to figure 10 watts per square foot. Nothing to back that up, just what I was taght growing up in the trade in cold Nebraska winters.

 

[mdshunk]

I'm in Zone 12 on the IRC Table N1101.2, and I use 1 watt per cubic foot of heated space. Again, this is not an NEC issue.

 

[ASK_EDDIE]

exact cals would have to be figured with a manual j with great experience, however most electric air handlers are figured with the tonnage of air, 1 1/2- 2 tons will be 10 kw, 2 1/2 - 3 tons 15 kw , 4-5 tons 20 kw ... and *rule of thumb* in texas is 1 ton per 500 sq feet. im also a licensed hvac contractor

 

[Jim W in Tampa]

A lot will depend on where your at and type of building.Here in Tampa a typical home of 1300 to 1500 sq feet will do fine with 10 kw.Actually my unit has 15 kw and i backed one of the 5 kw strips off of it because it was too much and would cause short cycles.Conditions in Pa would likely make me lean towards 10 per foot.

 

[suemarkp]

Is this place already heated by a different means that is being removed, or are there similar structures adjacent that already have a heating source? If you can get an HVAC person to tell you how many BTU's are required to heat the place (or do your own ACCA Manual J calculation), there are approximately 3,412 BTU's in one kilowatt.