How many circuits do I need?
One 20 amp circuit for laundry area receptacles only (mandatory), one 20 amp circuit for bathroom only (mandatory), two 20 amp circuits for all other receptacles and lights, one circuit for furnace, as a reasonable bare minimum. Starting with the single existing basement circuit and six empty slots you have two slots remaining for air conditioners and will need both for one AC circuit for one and possibley two 240 volt AC units.
Depending on whether your panel will accept them in terms of fit and total number of breaker handles, you can use a few tandem breakers (single wide double breakers) so the dishwasher and receptacles in unfinished parts of the basement for the dehumidifier don't have to share the two general purpose basement circuits and/or furnace circuit. Also nothing keeps you from plugging the dehumidifier into the laundry circuit if you don't trip that breaker.
You will need to do a load calculation (refer to National Electric Code) for the entire house for a project this big. It is possible you may need to upgrade the 100 amp service to 150 amps or 200 amps.
You will not need to replace all the upstairs original wiring with grounded cables in order to do this project.
The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.
Last edited by AllanJ; 09-25-2012 at 08:21 AM.