The automated worksheets accompanying this page are based on only five of the permitted methods of calculation found in NEC 220. These worksheets are provided to help you comply with the requirements of the Residential Code of Ohio when preparing your load calculations.
- Worksheet 1 (heating load larger than A/C load) and Worksheet 2 (A/C load larger than heating load) use the optional calculation found in NEC 220.82 for a new single-family dwelling.
- Worksheet 3 uses the optional calculation found in NEC 220.83 to compute the adequacy of the existing service when a room addition is built or other loads are added to an existing single-family dwelling.
- Worksheet 4 uses the “standard” method of calculation (NEC 220.1 through 220.61) and can be used for two-family dwelling calculations.
- Worksheet 5 uses the optional calculation found in NEC 220.84 and can be used for 3-family dwelling calculations (when the 3-family dwelling meets the qualifications of NEC 220.84).
You are welcome to use these worksheets with your square footage measurements, your additional loads, and your HVAC loads to quickly and accurately determine your service requirements.
The NEC provides many methods of computing loads for residential occupancies. In addition to the sections found in NEC Art.220, there is additional information about load calculations in NEC “Annex D Examples”.
Feel free to contact us with questions about residential load calculations. We will be happy to assist you.
Download Residential Load Calculator Worksheets
Note: You will need to enable Macros when you open this file in Excel to have it work properly