Space Heating

Lots of energy is consumed heating spaces.  Generally, the least efficient, but cheapest way to heat a space is to use electric resistance heating (e.g. baseboards connected to household wiring).  Burning natural gas / propane is generally considered more efficient.  However, in moderate to warm climates, using an electric heat pump to move heat in and out of a space can be most efficient.  Using electricity also opens up the possibility of tapping local or centralized sources of non-fossil-fuel-generated energy.

Misc

• on Flexible Ducts: get a good contractor
• Split-Ductless systems can be good where heating and cooling are needed only in certain rooms
  • I think the units in hotel rooms are often connected to central heat/chillers
  • we assume "Mr. Slim" pumps heat in as well as out